TUFFAK polycarbonate sheet Fabrication guide Technical manual Table of Contents Page Introduction . 3 Typical Properties 4 TUFFAK Product Selection Guide 5-6 Chemical Environmental Resistance 7-13 Cleaning Recommendations . 14-15 Fabrication Machining 16-21 Fabrication Laminate Heavy Gauge Sheet 22-25 Thermoforming . 26-31 Troubleshooting Guide . 32-40 Brake Bending Cold Forming Annealing .41-42 Bonding Applications . 43-45 Mechanical Fastening . 46-49 Finishing . 50-52 Glazing Guidelines . 53-58 2 Contact Technical Service Group with additional questions 800.628.5084 plaskoliteplaskolite.com 3 TUFFAK Sheet Typical Properties Property Test Method Units Values ASTM D 792 1.2 PHYSICAL Specific Gravity Refractive Index ASTM D 542 1.586 Light Transmission Clear 0.118 ASTM D 1003 86 Light Transmission I30 Gray 0.118 ASTM D 1003 50 Light Transmission K09 Bronze 0.118 ASTM D 1003 50 Light Transmission I35 Dark Gray 0.118 ASTM D 1003 18 Water Absorption 24 hours ASTM D 570 0.15 Poissons Ratio ASTM E 132 0.38 ASTM D 638 psi 9500 MECHANICAL Tensile Strength Ultimate Tensile Strength Yield ASTM D 638 psi 9000 Tensile Modulus ASTM D 638 psi 340000 Elongation ASTM D 638 110 Flexural Strength ASTM D 790 psi 13500 Flexural Modulus ASTM D 790 psi 345000 Compressive Strength ASTM D 695 psi 12500 Compressive Modulus ASTM D 695 psi 345000 Izod Impact Strength Notched 0.125 ASTM D 256 ftlbsin 18 Izod Impact Strength Unnotched 0.125 ASTM D 256 ftlbsin 60 no break Instrumented Impact 0.125 ASTM D 3763 ftlbs 47 Shear Strength Ultimate ASTM D 732 psi 10000 Shear Strength Yield ASTM D 732 psi 6000 Shear Modulus ASTM D 732 psi 114000 Rockwell Hardness ASTM D 785 M70 R118 Coefficient of Thermal Expansion ASTM D 696 ininF Coefficient of Thermal Conductivity ASTM C 177 BTUinhrft F 1.35 Heat Deflection Temperature 264 psi ASTM D 648 F 270 Heat Deflection Temperature 66 psi ASTM D 648 F 280 ASTM D 7
46 F -40 - -200 NFRC 100-2010 0.97 THERMAL Brittleness Temperature from ductile to brittle Shading Coefficient clear 0.236 3.75 x 10-5 2 Shading Coefficient Gray or Bronze 0.236 NFRC 100-2010 0.77 U factor 0.236 summer winter NFRC 100-2010 BTUhrft2F 0.85 0.92 U factor 0.375 summer winter NFRC 100-2010 BTUhrft2F 0.78 0.85 Dielectric Constant 10 Hz ASTM D 150 2.96 Dielectric Constant 60 Hz ASTM D 150 3.17 Volume Resistivity ASTM D 257 Ohmcm 8.2 x 1016 Dissipation Factor 60 Hz ASTM D 150 0.0009 ELECTRICAL Arc Resistance Stainless Steel Strip electrode ASTM D 495 Seconds 10 Tungsten Electrodes ASTM D 495 Seconds 120 ASTM D 149 Vmil 380 Dielectric Strength in air 0.125 4 Typical properties are not intended for specification purposes. TUFFAK Product Selection Guide TUFFAK Grade Key Product Features Typical Applications GP High impact clarity and temperature resistant Industrial glazing machine guards structural parts thermoformed and fabricated components GP Patterns Pebble matte and prismatic surface finishes Industrial glazing privacy glazing signs displays and lighting covers OP Optical Quality Face shields laminates FI UL 94 V-0 5VA FAA rated not UV stabilized Electrical devices equipment housings switchgear covers and interior aircraft components LF UL 94 V-0 FAA rated has UV stabilizer Electrical devices equipment housings switchgear covers light fixtures aerospace components FD FDA compliant for food contact Machine guards bulk food bins candy molds sneeze guards hospital trays bassinets incubators and medical device storage containers SL Enhanced outdoor weathering performance Flat and formed sign faces and channel letters SL Matte Enhanced outdoor weathering performance with matte texture Flat and formed sign faces channel letters and digital displays LD LED light diffusion enhanced outdoor weathering performance Flat and formed sign faces and channel letters using LEDs NR Non-reflective UV resistant proprietary matte surface impact strength Displa
y and screen protection signage lenses and menu boards NR-C Non-reflective UV resistant one side hardcoated textured surface Display and screen protection fuel dispensing systems signage lenses and menu boards with improved chemical resistance UV High optical quality enhanced outdoor weathering performance and can be cold formed on site Covered pedestrian walkways entryway canopies awnings skylights barrel vaults glazed archways and sloped vertical and curved glazing SK Designed as inner light of a dual domed skylight Awning skylights entryway canopies barrel vaults sloped vertical and curved glazing SK1 Smooth and prismatic optimized to diffuse and distribute light with high light transmission UV resistant Awning skylights entryway canopies barrel vaults sloped vertical and curved glazing multi UV Light weight high structural strength multiple geometries for different structural and insulating properties Greenhouses solariums and atriums covered walkways insulative privacy glazing AR Long lasting abrasion and chemical resistance and outdoor weathering performance Replacement glazing industrial guarding safety components 15 Long lasting abrasion and chemical resistance and outdoor weathering performance Fifteen 15 year limited product warranty Architectural glazing for residential retail transportation centers psychiatric facilities FC Cold formable and drape formable meets ANSI Z26 .1 AS-6 Motorcycle and recreational vehicle windscreens face shields and formed applications CG375 CG500 CG750 Meets ASTM F 1915 ASTM F 1233 H.P. White TP 0500 Jails prisons detention and psychiatric containment glazing BR750 Meets UL 752 Ballistic resistant glazing for government institutional and commercial installations 5 6 TUFFAK Grade Key Product Features Typical Applications BR1000 Meets UL 752 Level 2 ASTM F 1233 ASTM F 1915 H.P. White TP 0500 Ballistic resistant glazing for government institutional banks and commercial installations BR1250 Meets UL 752 Level 3 NIJ Level II ASTM
F 1233 ASTM F 1915 H.P. White TP 0500 Ballistic resistant glazing for government institutional banks and and commercial installations MS1250 Meets UL 752 Level 6 Ballistic resistant glazing for severe threat Lumen XT Superior LED and conventional light diffusion wide range of diffusion levels Interior LED and conventional lighting fixtures Lumen XT-V Meets UL 94 V-0 5VA Interior LED and conventional lighting fixtures DX-NR Specifically formulated for superior LED light diffusion with enhanced weathering performance Exterior LED and conventional lighting fixtures IR Meets welding shades 3 and 5 complies with ANSI Z87.1 EN 169 CSA Z94.3 Face shields for flame welding and cutting general IR protection welding curtain MG 0.750 2.0 thick for machining textured surface Machined parts such as manifolds insulators diaphragms electrical semiconductor military applications WG 0.750 2.0 thick transparent Sight windows for tanksvessels viewports medical parts military applications AU UV and abrasion resistant ultra clear high visible light transmission Specialty laminates UC High light transmission and high optical quality Military aircraft canopies specialty laminates SQ High optical quality High optical quality with specifications tailored to end-use application HV UV and abrasion resistant high optical quality thick gauge sheet meets ANSI Z26.1 AS-4 Forestry equipment agricultural and industrial vehicle glazing TX Extended UV and abrasion resistant glazing for windows meets ANSI Z26.1 AS-4 and FMVSS 302 RV construction and commercial truck rear windows BG UV and abrasion resistant optical performance meets ANSI Z26.1 AS-4 and FMVSS 302 Bus window glazing TG High optical performance with enhanced UV and abrasion resistance meets FRA 49 CFR 233 49 CFR 238 for flammability smoke ballistics and impact Passenger rail car glazing Marine 5 High optical clarity low optical distortion UV abrasion and chemical resistant Marine flexible enclosures tent and awning enclosures VR High
optical quality low optical distortion high clarity Marine flexible enclosures tent and awning enclosures Bayblend MTR Opaque sheet for mass transit interiors. Meets FRA 49 CFR 238 standards for flame and smoke meets SMP-800C toxic gas generation Thermoformed rail interior parts such as structural seating components wall cladding window reveals ceiling panels Bayblend MTR AG Opaque sheet with anti-graffiti scratch and stain resistance meets FRA 49 CFR 238 standards for flame and smoke meets SMP-800C toxic gas generation Thermoformed rail interior parts such as structural seating components wall cladding window reveals ceiling panels Bayblend MTR AG Deco Opaque sheet with anti-graffiti scratch and stain resistance customizable first service print. Meets FRA 49 CFR 238 standards for flame and smoke meets SMP-800C toxic gas generation Thermoformed rail interior parts such as structural seating components wall cladding window reveals ceiling panels FP Long lasting abrasion chemical and outdoor weathering performance customizable edge fritting Heavy equipment cab safety glazing marine and mass transit glazing AL High optical quality abrasion chemical and UV resistant Automotive laminates Chemical Environmental Resistance 7 The chemical and environmental resistance of TUFFAK depends on the unique combination of factors and variables it encounters in its application. Outlined below is an overview of its primary outside influencers and common types of potential damage. A summary of laboratory tests designed to meet its practical requirements as well as its resistance to a wide range of chemicals and substances is also provided. Your Plaskolite Representative with the support of our Technical Service Group is available to work with you to evaluate your specific application. Influencing parameters TUFFAK properties are influenced chiefly by The composition of chemical ingredients Chemical Environmental Resistance Molecular degradation Many of TUFFAK properties are det
ermined by the size of its molecules. If an incompatible chemical causes a reduction in molecular weight mechanical property degradation can occur. The molecular weight has virtually no influence on electrical properties and only a slight influence on thermal properties. Solutions with a high pH bases can act to lower the molecular weight of polycarbonate. Low pH acids solutions typically do not degrade the molecular weight. Ammonia and amines are aggressive towards polycarbonate. Plaskolite laboratories have tested a series of chemicals and commercial products to determine their compatibility with polycarbonate. The results of TUFFAK resistance to substances are included in the following table pages 10-13. Duration of exposure Laboratory tests supply information on the formulation tested. The composition of many commercial products can change over time. The level of internal or applied stress and strain Oxidative damage Types of damage TUFFAK is relatively stable toward oxidizing agents such as oxygen nitric acid and hydrogen peroxide. Temperature TUFFAK can sustain several distinct types of damage including swelling dissolution stress cracking and molecular degradation. Circumstances under which these potential types of damage can occur are detailed below. Different chemicals may act simultaneously on TUFFAK sheet causing one or more types of damage. Swelling or dissolution When low-molecular aromatic halogenated and polar components migrate into the polycarbonate the damage can range from a tacky surface to swelling to complete dissolution. Stress cracking Even in small quantities a number of chemicals can penetrate the surface of TUFFAK. This may result in stress cracks that affect the formed or fabricated parts appearance or mechanical properties. With transparent grades of TUFFAK stress cracks are generally easy to detect. In opaque grades it may be difficult to detect them. Stress cracks can act like a notch leading to significant deterioration in several
mechanical properties particularly impact flexural and tensile performance. Laboratory tests such as impact or flexural strength can be used as indicators for mechanical property degradation. Temperature and the duration of exposure are key influencers in the potential cracking of TUFFAK. As temperature rises the time that elapses before damage occurs shortens. The exposure time required for initial damage ranges from a few seconds to more than 1000 hours due to the chemical involved temperature and stress level. For example when formed or fabricated parts with pronounced stresses are immersed in aggressive solvents stress cracks will occur in less than one minute. It is possible for a component within a solid to migrate to polycarbonate through long-term contact and cause damage. One example is the contact between polycarbonate and plasticized PVC. Plasticizers within PVC such as phthalates can trigger stress cracking and result in damage to the 8 polycarbonate. Resistance TUFFAKs resistance to chemicals common industrial cleaners pharmaceuticals household and cosmetic substances is dependent on the ingredients in the product as well as the temperature and duration of exposure. The following section provides a general overview of resistance to these commonly used materials. If you require additional information please contact your Plaskolite representative. Resistance to sealing compounds adhesives and plastics TUFFAKs resistance to sealants adhesives and plastics is largely dependent on the presence of aggressive components such as plasticizers e.g. phthalates or solvents which can migrate into polycarbonate. Resistance to paints Solvents in paints may cause stress cracking or swelling depending upon the solvent and the flash-off and drying conditions. It is possible to formulate paints with solvents that do not cause damage. In some applications painting can increase the chemical resistance of the finished part. Two component paints are resistant if the individ
ual components do not cause damage to TUFFAK in the short period between the application and curing. The SDS can be used to identify the chemical composition of the paint. Resistance to cleaning and washing agents TUFFAK is resistant to most household soaps but not those containing amines ammonia and sodium hydroxide. Resistance to disinfectants drugs and cosmetics TUFFAK may be damaged by disinfectants drugs and cosmetics which contain solvents or active ingredients that are incompatible with polycarbonate. For example nail polish and nail polish remover will cause damage to the material. If the product ingredients are known it is possible to estimate the compatibility with TUFFAK. However it is recommended to put the finished part through a practical test if no data is available. Refer to the compatibility table pages 10-13 for resistance levels. Chemical Environmental Resistance Testing to meet practical requirements The compatibility information presented in this section should be used as a starting point for determining the integrity and durability of your application. Testing is essential if finished TUFFAK components are likely to encounter aggressive chemicals during use. The internal and applied stress in a formed or fabricated part as well as duration of chemical exposure can lead to very different results. Compatibility assessment methods The data shown in the compatibility table pages 10-13 was generated using DIN 53449-3. This method uses test pieces of 80 x 10 x 4 mm TUFFAK sheet clamped to a curved fixture. The fixture applies a graduated strain ranging from 0 to 2. Assessment criteria The information in the compatibility table is based on exposure to chemicals at 23C and a range from 0-2 strain. Components that lead to damage with a strain of 1.0 are classified as incompatible. The results shown in the following tables are based on a one-time test. Change in the composition by the producers of these substances can change the results. Please c
ontact your Plaskolite representative or the Technical Service Group at 800.628.5084 with any questions or if you require additional information. 9 Legend Explanation of the symbols O - Resistant Partially resistant Not Resistant Chemicals Acetaldehyde Acetic acid up to 10 solution Acetone Acetylene Acrylonitrile Allylalcohol Alum Aluminum chloride saturated aqueous solution Aluminum oxalate Aluminum sulphate saturated aqueous solution Ammonia Ammoniacal liquor Ammonium chloride saturated aqueous solution Ammonium nitrate saturated aqueous solution Ammonium sulphatesaturated aqueous solution Ammonium sulphide saturated aqueous solution Amylo acetate Aniline Antimony chloride saturated aqueous solution Arsenic acid 20 solution Benzaldehyde Benzene Benzoic acid Benzyl alcohol Borax saturated aqueous solution Boric acid Bromic benzene Bromine Butane liquid or gaseous Butyl acetate Butanol Butylene glycol Butyric acid Calcium chloride saturated aqueous solution Calcium hypochloride Calcium nitrate saturated aqueous solution Calcium-soap fatpure Carbon acid wet Carbon monoxide Chlorine benzene Chlorine gas dry Chlorine gas wet Chlorine lime slurry 10 O O Chlorine lime 2 in water Chloroform Chrom alum saturated aqueous solution Chromic acid 20 in water Citric acid Copper sulphate saturated aqueous solution Cresol Cupric chloride saturated aqueous solution Cuprous chloride saturated aqueous solution Cyclo hexane Cyclo hexanol Cyclo hexanone Dekaline Diamyl phthalate Dibutyl phthalate plasticizer Diethylene glykol Diethylether Diglycolic acid saturated aqueous solution Dimethyl formamide Dinonyl phthalate plasticizer Dioctyl phthalate plasticizer Dioxane Diphyl 5 3 Ether Ethyl alcohol 96 pure Ethyl amine Ethyl bromide Ethylene chlorohydrine Ethylene chloride Ethylene glykol Ferritrichloride saturated aqueous solution Ferro bisulphate Formaline 10ig Formic acid 30 Gasoline Glycerine Glycol Heptane Hexane Hydrochloric acid 20 Hydrochloric acid conc. H
ydrofluoric acid 5 Hydrofluoric acid conc. Hydrofluorosilicic acid 30 Hydrogen peroxide 30 Iodine Isoamyl alcohol Isopropyl alcohol Lactic acid 10 in water Lead tetraethylene 10 in gasoline Lighting gas Chemical Environmental Resistance O O O O O O O O Chemical Environmental Resistance Ligroin hydrocarbon compound Lime milk 30 in water O Magnesium chloride saturated aqueous solution Magnesium sulphate saturated aqueous solution Manganous sulphate saturated aqueous solution Mercuro chloride saturated aqueous solution Mercury Methacrylic acid-methyester MMA Methane Methanol Methyl amine Methyl ethyl ketone MEK Methylene chloride Nitric acid 10 Nitric acid 10-20 O Nitric acid 20 Nitric Gas dry Nitrobenzene Oxalic acid 10 in water Oxygen Ozone Pentane Perchloric acid 10 in water Perchloric acid concentrated O Perchloro ethylene Perhydrol 30 Petroleum O Petroleum ether O Petroleum spirit Phenol Phenyl ethyl alcohol Phosphor trichloride Phosphoric acid conc. Phosphoric oxichloride Potassium aluminum sulpate saturated aqueous solution Potassium bichromate saturated aqueous solution Potassium bromide saturated aqueous solution Potassium carbonate saturated aqueous solution Potassium chloride saturated aqueous solution Potassium cyanide Potassium hydroxide Potassium metabisulphide 4 in water Potassium nitrate saturated aqueous solution Potassium perchlorate 10 in water Potassium permanganate 10 in water Potassium persulphate 10 in water Potassium rhodanide saturated aqueous solution Potassium sulphate saturated aqueous solution Propane gas Propargyl alcohol Propionic acid 20 O O O O O Propionic acid conc. Propyl alcohol Pyridine Resorcin oil solution 1 Carbon disulphide Hydrogen sulphide Soda Sodium bicarbonate saturated aqueous solution Sodium bisulphate saturated aqueous solution Sodium bisulphide saturated aqueous solution Sodium carbonate saturated aqueous solution Sodium chlorate saturate
d aqueous solution Sodium chloride saturated aqueous solution Sodium hydroxide Sodium hypochloride 5 in water Sodium sulphate saturated aqueous solution Sodium sulphide saturated aqueous solution Styrene Sublimate saturated aqueous solution Sulphur Sulphur dioxide Sulphuric acid 50 Sulphuric acid 70 Sulphuric acid conc. Sulphurous acid 10 Sulphuryl chloride Tartaric acid 10 Tetrachlorocarbon Tetrachloroethane Tetrahydrofurane Tetraline Thiophene Toluene Trichloro acetic acid 10 Trichloroethyl amine Trichloroethyl phosphate plasticizer Trichloroethylene Tricresyl phosphate plasticizer Urea saturated aqueous solution Water Xylene Zinc chloride saturated aqueous solution Zinc oxide Zinc sulphate saturated aqueous solution 11 Disinfectants Accel TB Baktol 5 Carbolic acid Chloroamine Clorox BROAD SPECTRUM Quaternary Disinfectant Cleaner Clorox Healthcare FUZION Cleaner Disinfectant Clorox Healthcare Bleach Germicidal Cleaner Delegol 5 Dimamin T 5 Hydrogen peroxide Iodine tincture Lysoform 2 Lysol Brand III Disinfectant Spray original Maktol Merfen 2 Oktozon 1 PDI Super Sani-Cloth Disposable Wipes Perhydrol PeridoxRTU Sporicidal Disinfectant Resorcinol solutions 1 Safetec Surface Safe Wipes Sagrotan 5 Spirit pure Steriplex SD Sublimate TB-Lysoform Trosilin G extra 1 5 ZEP 40 Non-Streaking Cleaner ZEP SPIRIT II Zephirol Nutrition O O O O Pharmaceutics and cosmetics Blood plasma Delial-Sunmilk Botanicare Hydroplex Iodine tincture Klosterbalsam Lanoline Menthol 90 in Alcohol Nail polish Nail polish remover Odol-mouthwash Periston blood substitute Vaseline Vicks VapoRub 12 Chemical Environmental Resistance O O Allspice Apple juice Beef sebum Beer Beets syrup Brandy 38 Butter Chocolate Cinnamon Clove Cod-liver oil Coffee Common salt Fish Fruit juice Fruit syrup Raspberry Gherkins Grape sugar Grapefruit juice Juniper berry Lard Linseed oil Liquor Margarine Meat Milk Mineral water Mustard Nutmeg Onion Orange juice Paprika Pepper Rum Salad oil Syrup Sugar
solution saturated aqueous solution Tea Tobacco Tomato juice Tomato puree Vanilla Vegetable juice Vegetable oils Vinegar Vodka Water Wine Worcestershire sauce O Chemical Environmental Resistance Washing and cleaning agents Household soap Top Job Joy Palmolive Liquid Technical oils and fats Camphor oil Castor oil Cod-liver oil Drilling oil Fish oil Fuel oil Lubricant based on paraffin Paraffin oil O Sodium soap fat Miscellaneous Battery acid Blood Castor oil Cement Freon 113 Gasoline Natural rubber Oleic acid conc. Polishing wax Polyethylene Polyvinylchloride containing plasticizer Sea water Starch Weak acid 4.7 pH Weak base 9.5 pH Tannic acid O O O - 13 Cleaning Recommendations 14 Cleaning Recommendations TUFFAK cleaning instructions Removing adhesive-backed labels Periodic cleaning of TUFFAK is recommended to prolong the service life of your material. To minimize the risk of damage use only compatible household cleaners and correct cleaning procedures as outlined below. Isopropyl Alcohol Naphtha VMP grade or Kerosene will help lift stickers and adhesives. TUFFAK GP polycarbonate mars easily with wiping action. TUFFAK 15 TUFFAK AR and Hygard laminate sheets are hard coated abrasion and mar resistant polycarbonate products that offer a high degree of surface hardness and abrasion resistance. These products provide superior protection against unintentional chemical attack. However the use of abrasive gritty cleaners or hard cleaning implements e.g. hard brushes scrapers squeegees should be avoided to eliminate the possibility of scratching the coating. Compatible cleaners The following cleaning agents are compatible with TUFFAK polycarbonate sheet products when used according to the manufacturers recommendations Top Job Joy Palmolive Liquid Windex Ammonia free Top Job and Joy are registered trademarks of Proctor Gamble Palmolive is a registered trademark of Colgate Palmolive Windex is a r
egistered trademark of Drackett Products. General cleaning instructions Thoroughly pre-rinse with warm water to loosen and wash away surface residue grit and grime. Using a soft microfiber cloth or moist non-abrasive sponge gently wash with a mild diluted soap or detergent. Rinse thoroughly with lukewarm clean water. To prevent water spots thoroughly dry the glazing with a dry soft cloth. Removing heavy oils and tars Thoroughly pre-rinse with warm water to loosen and wash away surface residue grit and grime. With a 5050 isopropyl alcohol-water mixture gently rub the area with a soft non-abrasive cloth. Immediately rinse thoroughly with lukewarm clean water. To prevent water spots thoroughly dry the glazing with a dry soft cloth. Removing graffiti paint marker inks and glazing compounds Immediately rinse thoroughly with lukewarm clean water. To prevent water spots thoroughly dry the glazing with a dry soft cloth. Important reminders Do not clean TUFFAK with any cleaners other than those on the approved compatible list included in this guide or those tested and found compatible. Do not use abrasive cleaners. Do not use high alkaline cleaners high pH or ammoniated. Do not leave cleaners sitting on TUFFAK for periods of time rinse off immediately. Do not apply cleaners under direct sunlight or at elevated temperatures. Do not use scrapers squeegees razors or other sharp instruments as they may permanently scratch TUFFAK. Do not dry rub or dry clean TUFFAK as sand and dust particles clinging to the exterior of the glazing may scratch its surface. An Anti-Static Canned-Air Ionizer can reduce electro static charge buildup on TUFFAK and aids in reducing dirt and dust buildup that can hinder cleaning. Contact the Plaskolite Technical Service Group at 800.628.5084 with any questions. TECH TIP The edges of coated polycarbonate sheet are not protected with an abrasion and chemical resistant hard coating. Do not allow cleaning solutions and solvents to pool along t
he edges for any length of time. Always rinse edges thoroughly with generous amounts of lukewarm clean water. Removing scratches Deep scratches and gouges made by sharp objects such as keys screwdrivers and knives cannot be repaired. Fine scratches may be reduced in severity or cosmetically hidden by using a buffing compound such as NOVUS 2 Plastic Fine Scratch Remover followed by a cleaning and polishing agent like NOVUS 1. However for abrasion resistant coated products buffing the surface is not recommended. Buffing these scratched sites worsen the condition and further damage the coating. Once the coating is removed it cannot be repaired and buffing may optically distort the window. Thoroughly pre-rinse with warm water to loosen and wash away surface residue grit and grime. Using Naphtha VMP grade Isopropyl Alcohol or Butyl Cellosolve gently rub the area with a soft non-abrasive cloth. Do not apply solvent cleaners under direct sunlight or during high temperatures. Immediately rinse thoroughly with lukewarm clean water. To prevent water spots thoroughly dry the glazing with a dry soft cloth. Butyl Cellosolve is a trademark of DOW. Novus 1 and Novus 2 are registered trademarks of Novus Plastic Polish. 15 Fabrication 16 Fabrication Introduction Cutters Dimensional accuracy TUFFAK sheet products easily fabricate using standard cutting tools. Carbide-tipped cutters are recommended. Always use properly sized sharp cutting tools. The rate at which TUFFAK sheet expands is higher than materials such as glass and metal. It has a movement rate of 0.060 per 12 inches of linear dimensions over a 70F temperature change. As a result the dimensions should always be checked at room temperature. Cooling Cooling TUFFAK sheet while fabricating is not typically required. In the event of localized overheating when fabricating only use compressed air or water mist. Avoid cutting fluids of any type. The additives in these products are largely incompatible and can cause chemical
stress cracking. TECH TIP Wear eye protection and ensure equipment has safety guarding. Stock feed rates must be carefully controlled as an excessive rate causes vibration and may crack the part. Protective masking TUFFAK sheet comes with protective masking. This film guards against surface damage during shipmenthandling as well as fabrication. This masking should be left on during fabrication. Masking cannot withstand direct outdoor exposure for prolonged periods and must be removed soon after installation. If not removed the film will eventually degrade and may be difficult or impossible to remove. Storing sheet outdoors is not recommended for this reason. Remove the masking prior to doing any type of heat processing for further guidance on this subject please contact Plaskolite Technical Service Group for more information. SAWING SHEARING DRILLING MILLING ROUTING DIE CUTTINGPUNCHING CIRCULAR SAWING As shown in the accompanying illustration use a carbide-tipped circular saw blade with triple-chip tooth design which cuts clean and lasts longer than high strength steel. Blade is hollowground and slotted for expansion and cooling. The blade cutting speed should be 5000-6000 ftmin and the table saw setup gap between saw blade and bed must be kept to a minimum for clean cuts. Circular saw blade and cutting Circular saw troubleshooting Cutting speed ftmin 5000 - 6000 4 Blade 8 - 10 teethinch 8 - 10 Blades 6 - 8 teethinch PROBLEM Melting or Gummed Edges SUGGESTED SOLUTIONS 1. Increase blade tooth size 2. Reduce saw speed Triple-chip grind 3. Increase feed rate 4. Use compressed air to cool blade 5. Inspect blade for sharpness 6. Check blade-fence alignment 7. Reduce number of sheets in stack PROBLEM Chipping SUGGESTED SOLUTIONS 1. Decrease blade tooth size 2. Increase saw size 3. Provide better clampingsupport for sheet stack 4. Reduce feed rate Blade 5. Check blade and arbor for wobble 6. Inspect blade for sharpness Circular saw blade suppliers Dino Saw Company 340 Pow
er Ave. Hudson NY 12534 518 828-9942 www.dinosaw.com General Saw Corp. 2518 Andalusia Blvd. Cape Coral FL 33909 800 772-3691 www.generalsaw.com FTM Inc. 327 Industrial Drive Placerville CA 95667 530 626-1986 www.thefabricatorssource.com 17 Fabrication BAND SAWING Band saw troubleshooting Band sawing is preferred for cutting contour and irregular shapes. PROBLEM Melting or Gummed Edges SUGGESTED SOLUTIONS General guidelines 1. Increase blade tooth size Use precision or standard blades for sheet and parts made from thin gauge 2. Reduce saw speed 3. Use compressed air to cool blade Use buttress or skip-tooth blades for sheets thicker than 18 inch 4. Check blade sharpness PROBLEM Chipping SUGGESTED SOLUTIONS Choose band-saw blades with generous set to reduce friction and heat buildup Cool the cut junction with air or a water mist 1. Decrease blade tooth size Control the feed rate carefully to prevent binding and gumming 2. Slow down stock feed rate 3. Provide better clampingsupport to eliminate vibration Use saw guides whenever possible 4. Check blade sharpness Band saw blade design Part thickness inch 8 - 12 teeth 1 per inch Tooth type Pitch teethinch Band speed ftmin 18 Precision or Standard 8 - 12 2000 18 - 14 Buttress or Skip Tooth 5-6 1500 14 Buttress or Skip Tooth 3-4 1000 SHEARING TUFFAK sheet up to 14 inch thick can be sheared. Sheared edges have a burred and rolled cut that is highly stressed and should be saw trimmed to prevent future cracking. Important considerations for shearing A guillotine blade on a fixed bed cuts a cleaner edge than a two blade shear Top Blade 45-degree rake angle blade recommended Clearance between the blade and bed should be no more than 0.001-0.002 inch If cracks develop upon shearing consider warming the material first inspect blade TUFFAK Sheet 45 Rake Angle Shearing flame retardant product is not recommended as the additives in the sheet reduce its ductility. Warming material may help prevent cracking but does not g
uarantee success 18 Bed 0.001-0.002 Max. Clearance Fabrication DRILLING Drill bit design While standard drills and bits can be used with TUFFAK sheet those specifically designed for plastics perform with greatest precision. They have wide polished flutes to reduce friction as well as spiral or helix designs to remove chips quickly. 90 includes cutting-lip angle Drill-point angles typically range between 60 and 90 degrees Smaller angles for smaller holes and larger angles for larger holes .15 Drilling speeds range between 100 and 200 feet per minute however feed rates can be increased under ideal conditions of proper cooling sharp drills and efficient chip removal Clearance Angle 0- 5 Negative Rake General guidelines for drilling TUFFAK sheet Use carbide-tipped drills they resist gumming and maintain edge sharpness longer than standard drills Drill holes slightly oversized Allow distance between sheet edge and drilled hole to be at least two times the diameter of hole Do not use cutting fluids use cool forced air Drill inch Feed inchrev Drill speed RPM Up to 18 0.001 - 0.002 1750 18 to 14 0.002 - 0.004 1750 - 1500 14 to 12 0.004 - 0.006 1500 - 500 12 to 1 0.006 - 0.008 500 - 350 Countersink is not recommended counter-bore is acceptable a 2 x drilled hole a a Common drilling problems and remedies Problem Hole too large Rough or burred hole Breaking of drill Chipping of high-speed drill Probable cause Remedy 1. Unequal angle on length of cutting edge 1. Properly regrind drill 2. Burr on drill 2. Properly regrind drill 1. Dull drill 1. Regrind properly 2. Improperly ground drill 2. Regrind properly 3. Too fast feed 3. Reduce feed 1. Feed too fast in relation to spindle speed 1. Reduce feed or increase speed 2. Dull drill-grabs in work 2. Regrind drill 3. Inadequate chip cleaning 3. Check application setup 1. Improper heat treatment after regrinding 1. Follow manufacturers recommendations 2. Too coarse feed 2. Reduce feed Specialty drill bit suppliers Onsrud
Cutter 1081 S. Northpoint Blvd. Waukegan IL 60085 800 234.1560 www.onsrud.com Craftics Inc. 2804 Richmond Dr. Albuquerque NM 87107 505 338.0005 www.craftics.net FTM Inc. 327 Industrial Drive Placerville CA 95667 530 626-1986 www.thefabricatorssource.com 19 Fabrication MILLING 20 Milling is used to remove large volumes of plastic with relatively high accuracy and precision. Mounted in a drill press an end mill can plunge repeatedly to a preset depth to produce parts that are flush and smoothly trimmed. For best results use high-speed end mills with four cutting flutes and a 15-degree rake angle. Always keep mills sharp and well-polished to reduce friction. Consider the following when milling TUFFAK sheet Milling TUFFAK sheet typically works best at feed speeds of 510 inchesminute and cutting speeds of between 100 and 200 minute. Improper milling can induce high stress levels causing future problems Carbide cutters generally provide smoother finishes and allow for higher feed rates. Special cutters designed specifically for plastics produce the smoothest finishes at the fastest feed rates. Check with your cutter supplier for the latest designs for polycarbonate. TECH TIP Excessive feed rates can cause rough surfaces Insufficient feed rates can generate too much heat and cause part melting distortion or poor surface quality Compressed air stream or water mist helps to remove heat and prevent buildup Consider annealing milled parts in cases where the machining stresses are known to be high. Fabrication ROUTING Side View TUFFAK sheet Router cutting produces a smooth edge on TUFFAK sheet and easily cuts curved or irregular shapes. Use a recommended router speed of 20000-25000 rpm with straight 2- or 3-fluted carbide-tipped or high-speed bits with diameters 14 inch to 12 inch. Fence Table General guidelines for router cutting TUFFAK sheet Overhead View TUFFAK sheet Router bit design Clearance angle 5 - 10 Rake angle 0 - 10 Cutting speed rpm Feed Direction Fence 20
000 - 25000 Router Bit Table Top Important Feed the sheet against the router bit rotation and use a fence for sizing when making straight cuts. Specialty router bit suppliers Onsrud Cutter 1081 S. Northpoint Blvd. Waukegan IL 60085 800 234.1560 www.onsrud.com Boshco Inc. 2 Sterling Road North Billerica MA 01862 978 667.1911 www.boshco.com Dino Saw Company 340 Power Ave. Hudson NY 12534 518 828-9942 www.dinosaw.com DIE CUTTING PUNCHING Types of dies used in cutting TUFFAK sheet include steel-rule punch and clicker in gauges up to 0.080 inch. Steel-rule dies trim lighter-gauge parts and clicker dies perform heavier-gauge cuts and continuous cuts in sheet. To obtain a clean cut in most applications maintain a clearance between the punch and die of about 0.005 inches. General guidelines when die cutting punching or blanking TUFFAK sheet For best results consider warming the part first before die cutting punching or blanking Maintain sharp cutting edges for cleanest cut and to avoid creating notches and scratches that could later act as stress concentrators Avoid sharp radii in the corners of non-circular cut-outs Die cutting punching or blanking parts made of flame retardant grade sheet is not recommended Use 3 pt 0.042 thick steel to fabricate steel-rule die. Flush or center bevel-ground rule provides a clean cut. Facet-ground steel rule is used to cut 0.060 inch TUFFAK sheet. The center bevel rule is the most common and provides the longest life in terms of wear. Cleaner cuts can be attained by using a facet bevel rule. The longer bevel reduces material displacement especially with thick material while the broad tip remains sharp. The flush bevel rule also provides clean cuts but has a weak tip that is susceptible to roll-over. To maximize both cut quality and rule longevity the side bevel rule is recommended. Laser Laser cutting TUFFAK can lead to slight discoloration in the cut edge. Contact your laser equipment manufacturer for additional advice on laser setti
ngs for cutting or marking of polycarbonate. Adhere to proper safety procedures when laser cutting. The work should be performed in a space with exhaust hoods and good ventilation. TECH TIP TUFFAK sheet should be stored in a well-protected ventilated area with no direct exposure to sunlight or harsh weather conditions. If temporarily stored outdoors sheets should be covered with a heat reflecting opaque covering. Center Facet Flush Side 21 Fabrication Laminate Heavy Gauge Sheet 22 Hygard laminates and TUFFAK WG and MG plate products are designed for heavy fabrication. It is possible to fabricate parts with tight tolerance design using standard cutting tools. Use carbide-tipped cutters for greater duability and a cleaner cut edge. Leave the masking on the product while fabricating to protect against surface damage. Remove masking soon after installation as prolonged outdoor exposure degrades the film making it difficult or impossible to remove. Fabrication Laminate Heavy Gauge Sheet TECH TIP The edges of Hygard laminates are not protected with abrasion and chemical resistant hard coating. Do not allow cleaning solutions and solvents to pool along the edges for any length of time. Always rinse edges thoroughly with generous amounts of lukewarm clean water. Proper fabricating practices are especially important when cutting parts intended for security applications. This ensures product integrity with respect to strength properties and performance ratings. Sharp cutting tools are important as is feed rate control. To avoid material overheating decrease cutting speed and feed rate. CIRCULAR SAWING Use a carbide-tipped circular saw blade with triple chip tooth design. It allows for cleaner cuts and greater durability than high- strength steel. Blade is hollow-ground and slotted for expansion and cooling. Recommended blade cutting speed is 5000-6000 ftmin. Circular saw blade and cutting Cutting speed ftmin 5000 - 6000 Blade 3 teethinch Circular saw troubleshooting PR
OBLEM Melting or Gummed Edges SUGGESTED SOLUTIONS 1. Increase blade tooth size 2. Reduce saw speed Triple-chip grind 3. Increase feed rate 4. Use compressed air to cool blade 5. Inspect blade for sharpness 6. Check blade-fence alignment 7. Reduce number of sheets in stack PROBLEM Chipping SUGGESTED SOLUTIONS 1. Decrease blade tooth size 2. Increase saw size 3. Provide better clampingsupport for sheet stack 4. Reduce feed rate Blade 5. Check blade and arbor for wobble 6. Inspect blade for sharpness 23 Fabrication Laminate Heavy Gauge Sheet BAND SAWING DRILLING Hygard laminates TUFFAK WG and MG products can be band saw cut with blades having 8-12 teeth per inch. Carefully choose feed rates and blade speed to avoid gumming or melting the plastic edge. While standard drills and bits can be used when fabricating Hygard laminates TUFFAK WG and MG products those specifically designed for use with plastics perform with greater precision. Drills for plastics generally have wide polished flutes to reduce friction as well as spiral or helix designs to remove chips quickly. Pitch teethinch Band speed ftmin. Blade set inch 8 - 12 2500 - 3000 0.020 - 0.030 Use drill-point angles larger than 90 degrees Drill bit design 90 includes cutting-lip angle Band saw blade design .15 8 - 12 teeth Clearance Angle 1 per inch 0- 5 Negative Rake General guidelines for drilling Hygard laminates TUFFAK WG and MG Use carbide-tipped drills they resist gumming and maintain edge sharpness longer than standard drills Avoid cutting fluids most are not compatible with polycarbonate Cool work if necessary by forced-air stream TECH TIP Solvent polishing edges of a laminated sheet is not recommended due to the possibility of the TPU bonding layer absorbing the solvent and swelling resulting in the potential delamination of the product. Microcracking may also occur along solvent polished edges. TECH TIP Laser cutting of Hygard laminates is not recommended due to increased stress level and higher ri
sk for discolored edges. Water jet cutting of laminates is not recommended due to the potential for delamination. Avoid drilling into the edge of laminated sheets due to possible loss of interlayer adhesion Use sharp drills for cleanest cut and frequently clear the hole of chips. Avoid overheating as stress buildup in the material may have an adverse effect on mechanical properties compromising product performance and reliability. If drilling holes place them no closer than 2 times the diameter of the hole from the edge. Avoid holes in parts intended for ballistic rated applications. Hole diameter 18 1750 14 1050 - 1500 12 350 - 500 RESOURCE ON DRILLING AND ROUTER CUTTING httpswww.onsrud.complusdocsDoclist.htmlpg0sfcodesddmodel.categoryTECH 24 Drill speed rpm MILLINGROUTING Summary on cutting To cut clean edges on Hygard laminates and TUFFAK WG and MG use straight 2-3 fluted carbide tipped or high-speed bits and router speeds of 20000- 25000 rpm. Feed sheet against the router bit rotation at a controlled rate to avoid overheating minimize vibration and produce a smooth part edge. Use a fence for sizing when making straight cuts. Use only sharp cutters Fabrication Laminate Heavy Gauge Sheet Drill holes slightly oversized Drill holes off sheet edge by distance at least 2 times diameter of hole Countersink is not recommended counter-bore is acceptable in heavy gauge sheet Countersink and counter-bore is not recommended for Hygard laminates As cooling medium use forced air not cutting fluids Do not allow material to overheat Cut edges must be smooth sand coarse surfaces and chatter marks Leave masking on product during fabrication remove soon after installation Use cleaners compatible with polycarbonate. If unsure consult with manufacturer before use FRAME DESIGN Select a metal frame that matches the same level of security-rated protection as the specified Hygard laminate. Corner design Mitered corners require added bracing. Attach metal angle bracing at
the corners to strengthen the overall frame. Product performance relies heavily on the method of attachment the assembly and the potential for thermal expansion. Contraction Expansion For optimal frame design use a continuous metal extrusion. Metal Angle Bracing NO Rabbet Depth Edge Engagement YES Hygard laminate Glazing recommendations Frame system must meet or exceed Hygard laminate ballistic rating Hygard laminate dimension must allow for at least 1 inch edge engagement Use only gaskets tapes and sealants compatible with polycarbonate Use setting block strips of polycarbonate EPDM neoprene or Santoprene synthetic rubber Remove protective masking soon after completing the installation as prolonged exposure to the outdoors will degrade the film making it difficult or impossible to remove Santoprene is a registered trademark of Exxon Mobil Corporation 25 Thermoforming 26 Thermoforming Thermoforming is a cost-effective and practical processing method for producing three-dimensional shapes from a flat thermoplastic sheet using heat and pressure. Thermoformed parts can be found across transportation signage architectural specialty and industrial markets. Known for its low tooling cost and moderate equipment investment thermoforming is most economical where production volumes are 10000 parts per year or less. It allows for great design flexibility and serves as a practical means for prototyping and pre-production trialing of injection molded applications. PRODUCT GUIDE FORMABILITY TUFFAK product Vacuum forming Drape forming Line bending GP DX-NR FC FI LF LD Lumen XT OP NR SL SK UV Pre-drying TUFFAK sheet Drying timeshours Prior to thermoforming TUFFAK sheet must be pre-dried to prevent its physical properties from being compromised. Without pre-drying the high processing temperatures may vaporize the small amount of moisture absorbed in the polycarbonate causing air bubbles or voids in the thermoformed part. Gauge 250F 180F 0
.093 4 8 0.118 4 14 0.177 12 30 Pre-dry TUFFAK at 250F in an air circulating oven equipped with a vent to properly discharge any moisture removed from the sheet. Drying at lower temperatures requires a longer time to thoroughly dry the sheet. 0.236 24 50 Registration or distortion thermoforming Registration forming also referred to as distortion thermoforming is the process of taking a distorted printed plastic sheet and vacuum forming the image or picture over the thermoformed mold. This allows the initial distorted image to appear in corresponding areas of mold resulting in a non-distorted three-dimensional image. 180F 40 250F Hours Remove the protective masking from the sheet prior to pre-drying and hang or rack in the oven with a 1-inch separation to allow for adequate air exposure. Note sheets stacked without air spacing will not dry. While properly dried TUFFAK sheets will remain dry for approximately eight hours or less in humid climates and conditions Plaskolite recommends that sheets be processed as soon as possible upon removal from the oven. 50 30 20 10 0 0.093 0.118 Gauge 0.177 0.236 27 Thermoforming Forming equipment Pressure forming When setting up the thermoformer ensure there is adequate clearance between the clamping frame and mold to allow for deep sheet sag. Optimize the platen speed and clamp frame to maximize the processing rate. Pressure forming uses compressed air up to 100 psi to force the sheet into the mold. It allows for greater part definition and dimensional control. It also achieves more mold surface detail than other methods for applications that require texturing or lettering etc. Recommended heater elements include ceramic quartz and halogen. Calrods and nichrome elements can also be used but typically do not perform as well for heating control. The most efficient thermoforming machines have both top and bottom heater banks for heating polycarbonate sheet. One-sided heating limits forming method options and tends to overheat the sh
eet surface and lengthen cycle times. Zone heating allows different banks of heating coils to be controlled separately to produce even heating. Unbalanced heating can lead to a non-uniform temperature profile in the sheet and is evident by uneven sag of the sheet. Pressure Plate Mold The thermoformers reserve vacuum tank must be of sufficient size with a pump capable of generating and maintaining a vacuum of 20-inches Hg pressure throughout the thermoforming cycle. Forming techniques Vacuum forming Selection of a female tool versus a male tool depends on the application and is most often determined by the parts appearance or the importance of its fit or assembly. Female tooling is used where the outside part geometry is more important than the surface finish. Male tools are for applications needing inside geometry detail and a blemish-free part surface. Make note that any blemish on the tool male or female will result in an imperfection on the part. Female Tool Male Tool Heating and sag of sheet Dropping sagged sheet on mold Air Pressure Vacuum Plug-assisted forming Plug-assisted forming prevents excessive thinning of material in deep-mold cavities. A plug-assisted formed part has more uniform thickness in the walls than a part produced by typical single-stage vacuum forming. Vacuum Plug Assist Vacuum applied Plug Assist Finished part 28 Vacuum Thermoforming Twin sheet forming Twin sheet forming uses two sheets of plastic and two female molds in a single clamp frame setup. A blow pin is inserted between the sheets and pumps hot air between them to prevent sticking as they soften and sag. This process requires a two-side heater bank. Twin sheet forming is ideally suited to hollow parts with sealed edges and parts made of two different materials. Female mold upper half Air pressure applied through needle Vacuum Air pressure applied through needle Formed hollow part Sheets formed against mold interior with air pressure Female mold lower half Vacuum Molded halves seal
ing sheets together 0.360 Vacuum forming heating cycle 0.280 Characteristics of thermoforming polycarbonate The target sheet temperature for vacuum forming TUFFAK is between 340F to 415F depending on gauge. The temperature profile of the sheet will define the resulting sag in the sheet. Maintaining the sag depth and shape provides a visual indicator for forming consistency. Thickness in. 0.320 0.240 While TUFFAK sheet forming characteristics are different than other thermoplastic sheet materials it outperforms them in 0.200 production efficiency due to its short heating times and rapid 0.160 and cooling cycles. forming TECH TIP Thermoforming temperature is relatively narrow 340F - 415F 0.080 0.040 Polycarbonate has a glass transition temperature of 298F. Above0 311F it begins to soften rapidly. Heating from top and bottom shortens cycle time. Forming guidelines Sheet temperature Typical Optimum Metal mold temperature 0.360 0.120 Important reminders for thermoforming TUFFAK 0 40 80 120 160 200 240 280 If TUFFAK is not pre-dried vaporizing moisture absorbed in Heating Time sec. the sheet can cause air bubbles 340F - 415F 350F - 375F 210F - 250F Polycarbonate cools rapidly. Platen movement and clamp frame travel must operate at appropriate rates without delay. Typical heating times for TUFFAK polycarbonate sheet Sheet sag at forming temperature 0.320 8 0.240 Sag in. Thickness in. 0.280 0.200 0.160 0.120 0.080 4 2 0.040 0 0 6 40 80 120 160 Heating Time sec. 200 240 280 1 2 Sheet Short Dimension ft. 3 4 29 Thermoforming Molds Free forming Extremely durable and higher quality than their lower cost counterparts aluminum molds are ideal for high volume and recurring production programs. However for limited or small run volumes less expensive mold materials like epoxy fiberglass and wood may be more economical choices. Free blown billow forming as shown below is a process used for making dome shapes. Apart from the mold the procedures and equipment are the same as vacu
um forming. Billow forming can be done with compressed air or vacuum. Procedure Note Aluminum tools require internal heating to maintain a surface temperature of 210F - 250F. 1. Pre-dry TUFFAK sheet following recommendations Mold design 3. Place sheet in clamping frame of thermoformer Mold shrinkage Molds require oversizing in their design to compensate for part shrinkage due to cooling. TUFFAK sheet shrinkage is 0.005 0.007 per inch. 4. Heat sheet until uniform sag forms 340-375F 2. Preheat clamps and tooling to 240-250F 5. Remove heat source 6. Lower pressure box to seal air supply pressure 7. Apply high air pressure initially. As dome takes shape reduce air pressure 3.021 Mold 8. When overall height is achieved maintain positive air pressure until part cools 9. Be sure air source is properly filtered and uniformly dispersed for even formation of dome 10. Utilize electric eye designs or micro switches for height control and consistency 11. Remove and trim part 3.00 Part Draft Angles Draft angles greater than 5 allow for easier removal of the part from the mold. Blown dome forming Heater Heater Radii and Fillets Use generous radii wherever possible. The radius minimum should be equal to or greater than the starting material thickness as this minimizes the thinning of the sheet improves part rigidity and avoids creating a stress riser point. On female tooling use corner fillets. Vacuum Holes To form sheet rapidly and allow for fast air evacuation make several holes with small diameters. A 0.030-inch diameter hole is usually small enough unless the parts wall thickness is less than 0.030. In female molds use air evacuation holes at all deep draw areas especially around the mold perimeter where the sheet draws last. Drawn dome forming Air Airbox box Heater Heater Clamp Clamp frame frame Vacuum Vacuum box box Clamp Clamp frame frame Vacuum Vacuumline line Air Airinlet inlet TUFFAK TUFFAK polycarbonate polycarbonatesheet sheet Tips on mold design In both male and fema
le tooling keep the diameter of the drilled holes no larger than the thinnest wall section to avoid marking the sheet. Additionally in female tooling design long thin slots forair evacuation. Vapor hone or sand blast metal tools for a uniform surface finish. Sag Sag Electric Electriceye eye sensor sensor A highly-polished mold surface is not recommended as it causes sticking and air pockets. Sag Sag Electric Electriceye eye sensor sensor The radius minimum should be equal to the sheets original thickness to relieve stress riser points. Preheat mold. Cold molds can cause surface defects warping and elevate internal stress in parts. If mold temperature becomes too high during thermoforming TUFFAK sheet can stick to the mold. Control mold temperature between 210F and 250F. 30 Air Airpressure pressure Vacuum Vacuumapplied applied TECH TIP Utilize an electronic eye to control height consistency. Thermoforming Drape forming Line bending or strip heating Drape forming requires a felt covered wood tool for making a single radius of curvature parts or designs of slight contours. Face shields and recreational vehicle windscreens are examples of parts made by this method. The sheet is typically heated on an oven shelf or other means of supporting sheet. Line bending also referred to as strip heating is a technique for producing linear bends. Generally pre-drying is not required for line bending TUFFAK sheet gauges up to 0.177. For thicker sheets back routing or V-grooving along the bend line is recommended. Procedure Procedure 1. Pre-drying TUFFAK sheet is not typically required in drape forming 1. Remove protective masking in bend area 2. High quality reproducible forming requires consistent orientation in handling and cutting top versus bottom as well as extrusion direction. Do not flip or rotate sheets. 3. Place sheet over heating element at bend area 3. Heat oven at 320F-325F 4. Locate the oven shelf at the midpoint of the oven for optimum heat balance. Place a felt
covered piece of plywood or other flat rigid heat-resistant sheet on the oven rack or on a portable oven dolly. Be sure to use a fabric cover to protect the sheet from scratches. 5. Bring TUFFAK sheet to forming temperature in the oven at 320-325F. Depending on gauge this may take several minutes. For example 0.118gauge sheet takes approximately 3-5 minutes. 6. Manually remove the heated sheet from the oven and immediately position it over the felt covered mold. 2. Regulate heating element to 340F - 365F 4. Allow heat to soften material. The amount of time depends on gauge 5. Remove sheet and make desired bend on a felt covered fixture 6. Bend immediately as polycarbonate cools quickly 7. Allow part to cool on the fixture until set up - about 30 seconds Note Some bends may require a degree of over-bend to achieve desired angle. TECH TIPS Line bending works best for lengths of 24 or shorter. Longer dimensions require preheating the entire piece to 200F first to prevent warping. For best results with gauges greater than 0.177 use two-side 7. Apply pressure at the edges of the sheet to help the sheet take the form of the mold or use matched molds clamshell molds. Cooling takes about 30-60 seconds. heating or turn the part frequently when using a one-side heater. This helps with even heat penetration preventing moisture bubbling. 8. Always wear thermal gloves when handling hot sheet holding the material by its edges. Additionally for gauges greater than 0.177 back route or Force Heat bending device V-groove with a 116-inch radius to heat cross section. Again this will help avoid moisture bubbling while still creating a sharp angle. Male Mold Female Mold Nichrome resistance wire or Calrod type heater V-grooving radius 116 Back routing radius 116 Typical representation of thermoformed part Milled groove to accept Nichrome wire approximately 116 - 18 below surface of TUFFAK sheet. Do not allow wire to contact sheet directly. 31 Troubleshooting Guide 32 Troubleshooti
ng guide Society of Plastics Engineers Description of Problem Bubbles in formed parts Possible Causes Excessive moisture Possible Corrective Action Pre-dry sheet as recommended Preheat sheet Heat sheet on both sides Protect sheet from moisture until ready to use Heating sheet too rapidly Lower heater temperature Increase distance between heaters and sheet Blow air across the sheets surface during heating Uneven sheet heating Check heater output andor power consumption Use pattern heating Screen by attaching baffles masks or screening Crazed or brittle parts Warped parts Mold too cold Increase mold temperature Incompatible mold lubricant Change mold lubricant Mold too cold Preheat mold Clamp frames too cold Preheat clamp frames Removing part too soon Increase cooling cycle time Overheated part Use fans to help cool part Decrease mold temperature Uneven part cooling Add more coolant channels or tubing to mold Check for plugged water flow Poor material distribution For deep drawing use pre-stretching or plug assist Check for uneven sheet heating Poor mold design Add vacuum holes Add moat to mold at trim line Check for plugged vacuum holes Poor part design Break up large flat surfaces with ribs where practical Re-design with tapers or fillets Texture washout and gloss increase Forming temperature too high Reduce heater temperature Decrease heater cycle time Improper heating technique Heat sheets from smooth side keep texture side cool Pre-coat texture with strippable mask 33 Troubleshooting guide Non-uniform drape Description of Problem Possible Causes Uneven sheet heating Possible Corrective Action Check heater output and adjust Use selective screening or shading to control heating Check for cold air drafts in heating station Incomplete forming of part poor detail Sheet too cold Increase heating time Increase heater temperature Increase watt density Check for heating uniformity Cold clamping frame Preheat clamp
ing frame Insufficient vacuum Check for clogged vacuum holes Check for proper location of vacuum holes Increase number of vacuum holes Increase size of vacuum holes Check vacuum pump Check vacuum system for leaks Vacuum not drawn fast enough Where possible use vacuum slots instead of holes Increase size of vacuum holes Increase vacuum surge andor pump capacity Increase size of vacuum line and valves avoid bends and tee-elbow connections Part draw ratio too large Check for vacuum system for leaks Insufficient pressure Increase vacuum capacity Add plug pressure or frame assist Increase air pressure on side of part opposite mold surface if mold can withstand this force Use frame assist Use plug silicone slab rubber or other pressure assist Increase pump capacity Poor mold design Add vacuum holes Check for good seal between clamp frame and vacuum box Scorched sheet Top or bottom surface too hot Decrease heating cycle time Decrease heater temperature 34 Troubleshooting guide Poor surface finish Description of Problem Possible Causes Possible Corrective Action Mold surface too rough Draw-polish mold or use mold material better suited to mold service requirements Mold mark-off Use powdered mold lubricant sparingly Draft angle too shallow Increase draft angle Air entrapment over smooth mold surface Grit-blast mold surface Add vacuum holes in affected area Insufficient vacuum Add vacuum holes Check for proper location of vacuum holes Check vacuum system for leaks Check for plugged vacuum holes Mold too hot Decrease mold temperature Mold too cold Increase mold temperature Dirty sheet Clean sheet with deionizing airgun Dirty mold Clean mold with deionizing airgun Dust in atmosphere Clean thermoforming area Isolate thermoforming area and filter air Loss of color Scratched sheet Polish sheet Overdrawn sheet Part too thin Increase sheet gauge Increase sheet temperature Use pre-draw Use plug assist for deep-draw parts 35
Troubleshooting guide Chill marks or mark-off Description of Problem Possible Causes Possible Corrective Action Mold temperature too low stretching stops when sheet meets cold mold or plug Increase mold temperature Insufficient draft angle and radii Increase draft angles and mold radii Plug temperature too low Increase plug temperature Use wood plug assist Cover plug with cotton flannel or felt Sheet too hot Reduce heater temperature Heat more slowly Use fans to reduce the surface of hot sheet slightly before forming Nipples on mold side of formed part Vacuum holes too large Decrease hole size Dust on mold or sheet Clean mold and sheet with deionizing air gun Mold too cold Increase mold temperature Mold surface too smooth Draw-sand mold surface with medium-grit paper Vacuum rate too high Place small orifice over main vacuum hole Sheet too hot Decrease heating cycle time Decrease heater temperature Webbing bridging or wrinkling Sheet too hot in center Screen center of sheet allowing edges to heat first use taller vacuum box to provide more pull in area Decrease heating cycle time Decrease heater temperature Sheet too cold in webbing area Use pattern heating Increase billow height Mold too cold Increase mold temperature Vacuum rate too fast Slow down vacuum rate Use smaller vacuum holes Restrict main vacuum line Insufficient vacuum Check vacuum system for leaks Increase number of vacuum holes or slots Check for clogged vacuum holes Check for proper location of vacuum holes Increase size of vacuum holes 36 Troubleshooting guide Description of Problem Possible Causes Webbing bridging or wrinkling Cont. Draw ratio too great in area of mold or poor mold design or layout Possible Corrective Action Redesign mold Use plug or ring mechanical assist Use female mold instead of male mold Add take-up blocks to pull out wrinkles Increase draft and radii where possible Increase space between multiple articles Speed up assist
andor mold travel Blanks too large for mold Redesign grid plug or ring assists Leave minimum of material around mold Insufficient draw-down Poor wall thickness distribution and excessive thinning in some areas Uneven cooling due to slow drape speed Drape at higher speed Improper sheet heating Increase heating time and temperature Insufficient vacuum Check vacuum system for leaks Uneven heating Check uniformity of heater output Use screening or shading to control heating Check for drafts or air current in heating station Improper forming technique Use billow or snap-back forming method Reduce time delay between pre-stretch and mold drawing Control height Excessive sag Reduce sheet temperature Use pattern heating Cold mold Increase mold temperature Check for uniform mold heating Check temperature control system for scale or plugging Sheet pulls from rails Air-cool rails prior to heating Move rails in to grasp more sheet Use drag bands at rail edge Sheet slips from frame Adjust frame alignment Increase frame clamp pressure If retainer springs are used change to high-temper springs Pre-heat frames prior to inserting sheet Check heaters around clamp area for proper operation Screen or shade center of sheet to allow more heat at perimeter 37 Troubleshooting guide Shiny streaks on part Description of Problem Possible Causes Sheet too hot in spots Possible Corrective Action Lower heater temperature in overheated area Use screening or shading to control heating Decrease heating cycle time Increase distance between heater and sheet Excessive shrinkage or distortion of part after removing from mold Part not adequately cooled Increase cooling cycle time Use cooling fixtures Increase capacity of cooling system Use fan or vapor spray mist to cool part faster on mold Mold too hot Reduce mold temperature Increase mold coolant flow rate Corners too thin in deep draw Uncontrolled material distribution Consider other techniques such
as billow-up plug assist etc. Sheet too thin Use heavier-gauge sheet Sheet temperature too high at corners Use screening or shading to control heating pattern Mold temperature not uniform Adjust temperature control system for uniformity Check operation of mold heating system Drape speed too fast 38 Reduce drape speed Troubleshooting guide Difficult part removal Description of Problem Possible Causes Part or female mold temperature too hot Possible Corrective Action Increase cooling cycle time Decrease mold temperature Male mold too cold part sticking Increase mold temperature Male mold too hot causing part distortion Decrease mold temperature Insufficient mold draft Increase taperdraft Use female mold Remove part from mold as soon as possible Ejection pressure too low Add air holes Increase injection pressure Use powdered mold release Mold undercuts Use stripping frame Increase air-eject air pressure Remove part from mold as soon as possible Wood Mold Spray mold surface with a compatible mold release agent Rough mold surface Polish corners or entire mold surface Use mold-release agant Use PTFE spray Loss of vacuum seal Sheet sticking to plug Cold clamp frames Preheat clamp frames Improper spacing between clamp frames and vacuum box Adjust space between clamps and vacuum box to between 0.50 and 0.750 in. 13 and 19 mm Plug temperature too hot Decrease plug temperature Use mold release agent on plug Apply a PTFE coating Cover plug with felt cloth or cotton flannel Wood plug assist Cover plug with felt cloth or cotton flannel Use mold release agent on plug Apply a permanent PTFE coating to surface of plug Tearing of sheet during forming Mold design Increase corner radius Sheet too hot Decrease heating cycle time Decrease heater temperature Check sheet for uniform heating Preheat sheet Sheet too cold usually thinner gauges Increase heating cycle time Increase heater temperature Check sheet for uniform heating
Preheat sheet 39 Troubleshooting guide Tearing of sheet during forming Cont. Description of Problem Possible Causes Poor material distribution Possible Corrective Action Check sheet for variations in gauge Check sheet for uneven heating Pre-stretch too large Reduce billow blowing time Reduce billow temperature Cracking of part during service Stress concentration Increase fillets Increase sheet temperature Be sure part is completely formed before removing from mold Use proper forming temperature and cooling rate for deep-draw parts Increase mold temperature Poor embossing detail Poor part or mold design Re-evaluate design Sheet gauge too thin for draw Increase sheet gauge Uneven sheet temperature Use screening or shading to control heating pattern Embossing depth too shallow Increase depth of embossing pattern Drawing not uniform Use screening or shading to control heating pattern Use plug assist andor billow to pre-stretch sheet Excessive sheet sag Sheet too hot Decrease heating cycle time Decrease heater temperature Sheet area too large Use screening or shading to control heating particularly in the center of the sheet. Varying sag levels among sheets Sheet-to-sheet temperature variation Check for cold air drafts in heating station Non-uniform billow Uncontrolled sheet heating Check heaters for proper operation Use screening or shading to control heating Check for cold air drafts in heating station Non-uniform die pressure within billow Check air pressure system for leaks Check seal between sheet and billow box Redirect incoming air to billow box 40 Brake Bending Cold Forming Annealing 41 Brake bending Cold forming Brake bending Cold forming TUFFAK polycarbonate sheet up to 0.177 thick can be brake bent up to 90 angles. For gauges thicker than 0.177 strip heat bending is recommended to prevent potential cracks or breakage. Strip heat bending should also be used for all flame-resistant sheet grades. TUFFAK sheet may be col
d-formed bent into place without heating to a radius based on the sheet thickness. As a guideline the minimum cold forming radius is equal to 100 times the thickness R T x 100. Sheet thickness Minimum radius Perform the bending operation quickly 0.118 12 To attain the desired angle some degree of over-bend 0.177 18 0.236 24 Do not brake bend flame retardant grades due to 0.370 37 is required TECH TIPS Cold forming radius guide inch possibility of cracking R 100 x sheet thickness For best results with gauges greater than 0.177 use two-side heating or turn the part frequently when using a one-side heater. This helps with even heat penetration preventing moisture bubbling. Additionally for gauges greater than 0.177 back route or V-groove with a 116-inch radius to heat cross section. Again this will help avoid moisture bubbling while still creating a sharp angle. TUFFAK cold forming product guide Cold formable Not cold formable GP 15 DX-NR AR FC Hygard FI NR-C LF LD Lumen XT NR OP SL SK UV Annealing Batch oven method Annealing procedure Annealing is a way of relieving internal stresses in thermoplastic parts caused by thermoforming or fabrication. The polycarbonate sheet is thermal conditioned at an elevated temperature over a specified time period and then cooled slowly. Through annealing potential dimensional instability of a part such as warp is also reduced. 1. Prior to heating support or fixture the part to the desired geometry using low thermal conductivity framing e.g. wood While annealing is effective for reducing stresses it is timeconsuming and may not be economical or practical for all situations. Also extended heat histories can affect the physical properties of plastics. If you have questions or concerns regarding annealing contact your Plaskolite representative or the Technical Service Group. 42 2. Slowly heat oven fixture and part at the same time to 250F 3. Hold at 250F for 15 minutes per 0.125 sheet thickness 4. Turn off heater blower remains on
starting the cool-down cycle 5. Remove part from oven remove the part from the fixture Bonding Applications 43 Bonding Applications Solvent bonding Avoid whitening of bond Solvent bonding joins one plastic to itself or another type of plastic that dissolves in the same solvent. Typically this process involves treating the bonding area with the minimum amount of solvent needed to soften the surfaces and then clamping the parts together until they bond. Use fresh solvent whenever possible. Once a container is opened the solvent can absorb moisture from the air over time. Wet solvent can cause a cloudy bond. Methylene chloride or ethylene dichloride bonds TUFFAK sheet to itself. Methylene chlorides fast evaporation rate helps to prevent solvent vapor entrapment for simple assemblies. For complex assemblies that require more curing time use ethylene dichloride. A 6040 mixture of methylene chloride and ethylene dichloride will allow for longer a time to assemble parts than pure methylene chloride. Expect brittleness and reduced impact strength at the bonded joints. Note Wear proper protective equipment when working with chemicals. Adequate ventilation is essential. Review Safety Data Sheet from product manufacturer and control exposure according to OSHA guidelines. Fabricate in a climate controlled area with low relative humidity. Add 10 glacial acetic acid to a container of previously opened solvent to help reduce whitening. Add 5-10 polycarbonate shavings to the solvent to help slow cure time and reduce whitening. Adhesive bonding Adhesive bonding systems are among the most robust for joining plastic parts to parts made of the same plastic different plastics or non-plastic materials. Generally adhesives produce more consistent and predictable results in joints requiring strength and durability than other joining methods. Consider the following when selecting an adhesive bonding material Chemical compatibility with TUFFAK sheet Flexibility or rigidity require
ments Load bearing force Environmental condition and temperature requirements Bonding procedure Aesthetics 1. For optimum bonding confirm the parts mate flush. This helps to ensure uniform pressure distribution across the entire bond area. General characterizations of different adhesive systems 2. Clean joint surfaces with isopropyl alcohol. UV-cured adhesives attractive for curing in seconds provide high bond strength. 3. Use fresh solvent. 4. For best results avoid using excessive solvent - it causes bubbling and squeeze-out which decreases bond strength. 5. Apply a thin bead of solvent using a needle applicator the capillary action will pull the solvent into the joint interface. 6. For large parts it may be easier to use a shallow pan containing enough solvent to cover the edge of the bonding part. In general urethane and epoxy adhesives impart excellent bond strength. Silicone adhesives have flexible strong bonds. Foamed adhesive tapes are known for strength and durable performance. Hot melts provide quick set times where high bond strength is not required. Use care in selecting adhesives as some can be aggressive toward TUFFAK sheet. 7. Dip part into pan wetting its edge. 8. Transfer onto mating part. 9. Apply pressure to the mating parts. 10. Hold fixture for a minimum of 60 seconds. 11. The bonded part is now safe to handle. TECH TIPS A fully cured joint requires 24-48 hours drying time Always cure parts in a well-ventilated area never in an enclosed space. Trapped methylene chloride vapors chemically attack polycarbonate reducing its physical properties. A 5-10 solution of polycarbonate shavings dissolved in methylene chloride helps to produce a smooth filled joint and improves strength. For critical applications requiring more durability consider an adhesive product. 44 Typical Butt-T Joint Design Bonding Applications Adhesion selection guide Product Description Bond type Methylene chloride Solvent High tensile strength low impact resistance U
rethane Polymer base Structural bond fatigue resistant limited flexibilty and UV resistance Epoxy Polymer 1 and 2 component Structural bond heat and chemical resistant limited flexibility absorbs moisture Silicone Silicone Flexible strong bond heat chemical environmentally resistant Adhesive tape Hot melts Acrylic adhesive Flexible structural bond foam-backed films for non-aesthetic uses Polymer Fast set versatile range of bond strengths Selected product web links Solvent hardware store chemical suppliers SOLVENT CEMENT httpes.ipscorp.compdfassemblyAssemblyAdhesive_Product_Selection20Guide_Jan08.pdf URETHANE httpes.ipscorp.comassemblypolycarbonate EPOXY httpwww.masterbond.comlpperformance-properties-and-common-applications SILICONE httpwww.tremcosealants.comproductsproglaze-ssg.aspx ADHESIVE TAPE httpsolutions.3m.comwpsportal3Men_USAdhesivesTapesBrands3M-VHB-Tape HOT MELT httpwww.bostik-us.comour-brandsthermogrip 45 Mechanical Fastening 46 Mechanical Fastening Mechanical fasteners Due to their low cost and reliability screws bolts and rivets are common joining methods. Common practices and selection criteria are discussed within this section. Common head styles of screws and bolts Fastening with self-tapping screws Pay special attention to the fasteners head. Use bolt and screw heads that have a flat underside called pan or round head. This bolt design imparts lower compressive stresses on the material. Conical heads called flat or oval heads produce undesirable tensile and hoop stresses and should be avoided. Use thread-cutting screws which cut away material from a pre-drilled hole to form a mating thread and result in better long-term performance. Note the radial and hoop stresses imparted to the part by thread-cutting screws are lower after installation vs. thread-forming screws. Typically thread-cutting screws are classified as ANSI BT Type 25 ANSI T Type 23. Thread-cutting screws may not be appropriate in all applications and environments. Cracks around the
screw hole may form under conditions where the polycarbonate expands and contracts due to temperature variations. Washer Flat Filister Hex and Square Truss Oval Pan Fastening with bolts nuts and washers Type 25 Thread-Cutting Screw Hi-Lo Thread-Cutting Screw Hi-Lo is a trademark of ITW Shakeproof Use Washers Fastening with rivets Use Standoffs Correct Correct Type 23 Thread-Cutting Screw Rivets offer a low-cost and simple hardware solution for static parts. Aluminum rivets are preferred over harder materials. Select rivets with large flat heads and three times the shank diameter. Use of washers on the flared end are helpful in distributing loads but be careful not to over-tighten as it can result in compressive stress and damage to the plastic. Four standard rivet heads Correct Correct Incorrect Incorrect Incorrect Incorrect Button Button Correct Incorrect Counter bore vs Countersunk Truss Truss Flat Flat Pan Pan Countersunk Countersunk Use flat aluminum or hard plastic washers under nuts and fastener heads to evenly distribute the applied force. Their ability to resist over-compression helps to prevent localized stressing of the joining part. Ensure there is sufficient distance between the edge of the fasteners hole and the parts edge at minimum two-times the diameter and twice the parts thickness. Note Slotted holes require more edge clearance. TECH TIP Avoid thread locker products. They are generally incompatible with TUFFAK polycarbonate sheet causing cracking and crazing. 47 Mechanical Fastening Joining dissimilar materials For assemblies constructed of a combination of TUFFAK sheet and metal two dissimilar materials it is important to design for thermal movement behavior. When heated the plastic may buckle due to its higher thermal expansion rate. Conversely when cooled the greater thermal shrinkage of plastic will cause strain-induced stress and may exceed the plastics working limit. This could lead to part failure. No allowance for expansion The figure to
the right shows a plastic part fastened to a metal component. As the ambient temperature rises the plastic will expand more than the metal because the plastics coefficient of linear thermal expansion is four times higher. For applications where wide temperature variations exist use slotted screw holes in the plastic part. When joining plastic and metal parts do not tighten fasteners to the point where joint friction and compressive loads prevent relative movement. If the fasteners are too tight it negates the effect of the slotted holes. Slotted hole allows for expansion Factors to consider when joining plastic and metal parts The size of the parts to be joined The magnitude of the temperature range The relative thermal expansion coefficients of the materials used in the part Restricted assembly design not recommended CORRECT INCORRECT Allow for relative movement in assemblies of dissimilar materials TUFFAK Part Metal Part TUFFAK Panel Metal Bracket Slotted Hole Soft Washer Slotted Holes The slotted hole could be in either piece as long as relative movement is allowed. Fastener Metal Bracket There are many J clips and fasteners that will allow relative movement in assemblies. Coefficient of Linear Thermal Expansion CLTE values for materials Material CTLE 105 ininF TUFFAK 3.8 Aluminum 1.3 Example 1 Calculate the change in length for a 96 inch part that is constructed at 70 F but will see operating temperatures up to 120 F L plastic CLTE metal CLTE temperature change length of part 0.000038 0.0000135096 . L 0.120 inches Therefore the design has to accommodate a growth of 0.12 inches. Example 2 How much shrinkage will the same part see at -20 F L plastic CLTE metal CLTE temperature change length of part 0.000038 0.0000139096 . L 0.216 inches 48 Therefore the design has to accommodate a contraction of 0.216 inches. Mechanical Fastening Ultrasonic welding Troubleshooting An ultrasonic welder has two primary parts a horn and a nest. The horn typically
presses down on the upper plastic part of the two to be welded clamping the two parts together. The nest supports the bottom plastic part to prevent it from moving. The horn is vibrated ultrasonically for a preset time. Friction from mechanical vibrations cause localized heating resulting in plastic melting at the interface of the two parts. Pressure is then maintained after the vibrations are stopped until the melted plastic cools. Once the plastic has solidified the clamping pressure is retracted and the two joined parts can be removed from the nest fixture. Clean the mating surfaces with isopropyl alcohol to remove dust fingerprints and grime prior to welding. Check to see if the horn is making proper contact to the welding surface. Non-uniform horn contact produces non-uniform weld lines. Carbon paper is useful to confirm uniform contact. Confirm sufficient energy is being supplied into the weld. Increase pressureclamping force on the parts being welded. Increase the weld time. The most important feature for a clean ultrasonically welded joint is for one of the parts to be welded be designed with a triangular-shaped energy director. This minimizes the initial contact between parts. During welding the ultrasonic energy is concentrated at the director tip melting it and ultimately joining the interface with molten resin. Design energy directors with an apex angle from 60 to 90. Generally the base width of the energy director should not be more than 20 to 25 of the wall thickness supporting it. Increase the amplitude to the horn. Consult equipment suppliers for recommended welding amplitude settings for polycarbonate. For ultrasonic welding machines the converter booster and a properly maintained weld horn are all key factors for delivering a welding amplitude that produces a repeatable and robust weld joint. Confirm that routine maintenance daily checks and calibration programs are in place. Set and document minimum energy output for the unit that ensures a
reproducible welding joint. For optimum welding The horn fixture and parts must be aligned properly 14 W The stationary part should fit snugly in the nest or fixture The height of the energy director should be approximately 0.020 inch Join parts made of the same resin 60 - 90 W For more information on ultrasonic joining techniques contact Branson Ultrasonics Corp. httpwww.emersonindustrial.comen-USbransonProductsplastic-joiningPagesdefault.aspx Dukane Corp. httpwww.dukane.comusPPL_upa.htm Forward Technology Industries Inc. httpwww.forwardtech.complastic-assembly Herrmann Ultrasonics Inc. httpwww.herrmannultrasonics.comproducts-plastics.html Ultra Sonic Seal Co. httpwww.ultrasonicseal.comupaupa_tooling.html 49 Finishing 50 Finishing Metallizing is an example of a process that adds functionality such as electromagnetic shielding. Before decorating with any material contact the manufacturer to confirm its suitability for use and compatibility with polycarbonate. The aesthetics or functionality of TUFFAK sheet can be enhanced through finishing or surface-decorating processes. Painting and screen-printing are typical decorating methods for enhancing a parts visual appeal. PRODUCT GUIDE DECORATION METHOD TUFFAK Products Digital Print Screen Print Paint Vinyl Hot Decorating AR14 GP DX-NR1 FC FI LF LD Lumen XT1 NR1 OP SL 2 NR-C 4 3 UV SK 1. Textured surface may interfere with decoration media requires testingverification 2. Hard coat surface interferes with adhesion requires testingverification 3. Painting prismatic surface will interfere with optical properties requires testingverification 4. AR1 and NR-C decorate the non-coated side of the sheet Screen printing TUFFAK sheet can be printed with standard silk screening equipment. Note that screen mesh affects both the amount of ink that is deposited as well as the resolution of the printed image. As with all thermoplastics TUFFAK sheet must be cle
an and free from surface contaminants prior to screening. Many screen printers use a 5050 washing solution of waterisopropyl alcohol to clean the surface prior to printing. Be sure to use soft nonabrasive cloths when cleaning to avoid scratching. Antistatic or ionized air guns also provide a good method for removing lint and dust as well as static. After printing keep sheets separate on a drying rack until ink is dry. DO NOT pack sheets for shipment until inks are completely dry. Digital printing UV cured inks are used in digital printing due to their quick cure times. Historically a UV Mercury arc lamp has been used as the light source but newer UV LED curing lamps are now preferred. These bulbs use less electricity produce less heat last much longer and do not require a warm-up period. Its important to note however that the market has reported intermittent adhesion issues when printing on plastic substrates when curing with UV LED systems. Pretreating the plastic substrate with corona discharge flame UV light solvent wipes or adhesion promoters has proven successful in overcoming adhesion issues. For advice on UV LED cure ink applications contact the Technical Service Group at 800.628.5084. Painting Many commercially available paints are available for TUFFAK sheet. Be sure to use only paints that have been tested by the supplier to be compatible with polycarbonate. As with screen printing it is important the surface of the TUFFAK sheet be clean and free from surface residuals prior to painting. Many painters use a pre-rinse of 5050 water isopropyl alcohol to clean the surface. Be sure to dry thoroughly prior to painting. Use a soft nonabrasive cloth or sponge to avoid scratching. Conventional spray spray masked roller coat and brush are common application methods. Vinyl decorating Application of colored vinyl film is a common decoration technique for TUFFAK sheet. Follow the vinyl film manufacturers directions for product use. Flash drying TUFFAK sheet for at lea
st one hour at 250F prior to the film application has been shown useful in helping to prevent bubbling or blistering of the film over time. 51 Finishing Hot stamping TUFFAK sheet is easily decorated with a single-color image by hot stamping a process widely used for its convenience versatility and performance. A heated die fuses the impression made by the stamp to transfer color from the foil carrier to the substrate. The temperature pressure and dwell time are adjusted based on the type of foil and substrate. Contact equipment and foil manufacturers about processing conditions and products for polycarbonate. Heat transfer Heat transfer decorating also uses a combination of heat pressure and dwell time to apply preprinted graphics onto a part. Unlike hot stamping the graphics are preprinted images that can be complex and multicolored. The major advantage of heat transfer decorating over printing or painting is that it is a dry process making it more environmentally friendly. There are no strong odors associated with the process from volatile chemicals. Printing and painting hard coated sheet products Adhesion of ink and paint to the abrasion resistant coated surface is unreliable and not recommended on TUFFAK 15 TUFFAK AR TUFFAK NR-C and TUFFAK FC. TUFFAK AR1 is a one-side hard coated sheet that can be printed on the side opposite of the coating thus allowing for decoration in combination with the weatherable abrasion resistant coating. Solvent polishing In order to improve the look of saw-cut edges begin by sanding the edges smooth. For smoother glossy edges consider solvent polishing with methylene dichloride. To prevent humidity blush after drying it may be necessary to add a small amount of glacial acetic acid. Keep in mind that polishing cannot be expected to totally eliminate sand marks from the sheet edge. Solvent polishing is not recommended on laminated products and should only be used on monolithic polycarbonate sheet. Note Use extreme caution when worki
ng with solvents. Adequate ventilation is essential. Control exposure levels according to OSHA guidelines. Obtain Safety Data Sheets from the solvent manufacturer. Sanding The edges of TUFFAK sheet can be sanded using both wet and dry techniques. Of the two wet sanding produces a smoother finish and is less likely to gum the sandpaper. In both instances the part will require further finishing such as solvent polishing in order to yield a high gloss appearance. TUFFAK sheet can also be buffed using a 2-wheel system. The first wheel uses a buffing compound to remove shallow scratches. The second buffing wheel is used for restoring the gloss. Jointing-planing A standard woodworking jointer-planer can be used to finish TUFFAK sheet edges. Blades must be carbide or high-speed steel. Avoid removing too much material in each pass 164 or less normally yields the cleanest edge. Attempting to remove too much material in a single pass results in a rough edge or cracking of the sheet. If smoother edges are required wet sanding with fine grit sandpaper is recommended. SOURCES INK ASPA www.screenprinting-aspa.cominks-for-screen-printing.html Ink World www.inkworldmagazine.comtrade-associations NAPIM www.napim.orgprinting-inks PNEAC www.pneac.org SGIA www.sgia.orgprinting-imaging SignIndustry.com www.signindustry.comscreen DIGITAL PRINTING EFI httpscustomer.efi.comsupportccpIndex Radtech www.radtech.org ScreenWeb www.screenweb.combg SGIA www.sgia.orgprinting-imagingdigital-printing-and-imaging FOIL FSEA www.fsea.comquicklinks.aspcolumnpickhotstampingfoil PAINT ACA httppaintandcoatingsbuyersguide.com Akzo Nobel Coatings www.akzonobel.com Matthews Paints www.ppg.comcoatingsmatthewspaintpagesdefault.aspx 52 Naz-Dar Corporation www.nazdar.com SignIndustry.com www.signindustry.compainted Glazing Guidelines 53 Glazing TUFFAK polycarbonate sheet can be installed using wet caulking type sealant or dry gasket type glazing systems. TUFFAK sheet can be glazed as a single layer as two lay
ers for added thermal insulation or over-glazed for increased security to an existing window. General recommendations Comparative expansion rates Match the metal framing typically aluminum or steel to the application requirements such as the wind load or ballistics Engage all sheet edges in the frame Ensure the rabbet depth is sufficient for edge engagement as well as thermal expansion or contraction Material TUFFAK 0.0000375 Glass 0.0000050 Aluminum 0.0000129 Steel 0.0000063 Use gaskets sealants and tapes compatible with polycar bonate that have adequate elongation capability contact the manufacturer of the product if unsure Note that fastening with bolts through the glazing should only be used when unavoidable the design needs to be reviewed to ensure thermal movement will not be restricted Note that a sash intended for glass is unlikely to have enough rabbet depth particularly for windows larger than 36 inches in one dimension Use dry glazing with EPDM or neoprene gaskets for large windows greater than 24 inches sealants specifically designed with high elongation may also be a consideration Peel back the masking only around the perimeter of the sheet prior to installation to protect from damage. Remove the remaining masking once the installation is complete. Do not leave the masking on the sheet for an extended period. InchInchF Example calculation rabbet depth for a 48-inch sheet length and 70 temperature change Calculation of ExpansionContraction 0.0000375 x sheet dimension inches x temperature change 48 expansion 0.0000375 x 48 x 70 degrees 0.13 48 contraction 0.0000375 x 48 x 70 degrees 0.13 Rabbet depth Edge engagement Expansion Contraction 0.56 0.26 0.82 Contraction Expansion Use isopropyl alcohol or VMP naphtha and a soft cloth for cleaning during installation Refer to the TUFFAK sheet cleaning guideline for recommended practices and products Thermal expansion allowance The coefficient of linear thermal expansion of TUFFAK sheet is much gre
ater than framing materials such as aluminum and steel see table for comparisons. The window design needs to accommodate for adequate expansion room to allow for free movement of the sheet to avoid unsightly sheet bowing and optical distortion. A general guideline is to allow 116 inch expansioncontraction per foot of sheet in both the length and width directions. Rabbet Depth Edge Engagement TUFFAK laminate Sheet edge engagement thermal expansion and rabbet depth table Expansion 130F 54 Install 60F Contraction -10F Sheet size 24 36 48 60 Expansion Contraction 18 316 14 516 Edge engagement 38 12 916 34 Rabbet depth 12 1116 1316 1-116 Glazing Wind load The wind load charts cover a range of sheet sizes and aspect ratios consult the size closest to the design of interest. Within each chart the thickness of the sheet is represented in the horizontal axis and each color line represents a different wind load. The predicted deflection is for a given size window sheet thickness and wind load represented in the vertical axis. If a 3.5 Deflection x 96 sheet size Deflection - inch - inch 24 x 9624 sheet size 3.5 3 3 2.5 2.5 2 2 1.5 1.5 1 1 0.5 0.5 0 0.118 3.5 0 0.118 3 2.5 2.5 2 2 1.5 1.5 1 1 0.5 0.5 0 0.118 4.5 0 0.118 4 4 3.5 3 3 2.5 2.5 2 2 1.5 1 1.5 1 0.5 0.5 0 0.118 4.5 0 0.118 All edges of the sheet are engaged in the frame Dry glazing with 15 gasket compression clamping force allowing for sliding retention Deflection x 96 sheet size Deflection - inch - inch 72 x 96 72 sheet size 4.5 4 4 3.5 3.5 3 3 2.5 2.5 2 2 1.5 1.5 1 1 0.5 0.5 0 0.118 0.177 0.177 0.236 0.236 0.375 Thickness Thickness inches inches 0.375 0.5 5 0.177 0.236 0.236 0.375 Thickness Thickness inches inches 0.375 0.5 0.177 0.177 0.236 0.236 0.375 Thickness Thickness inches inches 4.5 4 4.5 4 3.5 3 3.5 3 2.5 2 2.5 2 1.5 1 0.5 1.5 1 0.5 0.5 0 0.118 0.177 0.5 5 0.375 0.177 0.5 0.177 0.236 0.236 0.375 Thickness Thickness inches inches 0.375 0.5 0.5 0.375 0.5 0.5 0.375 0.5 0.5 Deflection x 96 sheet size Def
lection - inch - inch 84 x 9684 sheet size 5 0 0.118 0.177 0 0.118 0.5 Deflection x 96 sheet size Deflection - inch - inch 48 x 9648 sheet size 4.5 3.5 Wind load deflection calculation assumptions 4.5 Deflection x 96 sheet size Deflection - inch - inch 36 x 9636 sheet size 3.5 3 deflection exceeds 2.5 inches consider thicker sheet for the application. 0.177 0.236 0.236 0.375 Thickness Thickness inches inches Deflection x 96 sheet size Deflection - inch - inch 96 x 9696 sheet size 5 4.5 4 4.5 4 3.5 3 3.5 3 2.5 2 2.5 2 1.5 1 0.5 1.5 1 0.5 0 0.118 0 0.118 0.177 0.177 0.236 0.236 0.375 Thickness Thickness inches inches Deflection x 96 sheet size Deflection - inch - inch 60 x 9660 sheet size 4.5 4 4 3.5 3.5 3 3 2.5 2.5 2 2 1.5 1 1.5 1 0.5 0.5 0 0.118 0 0.118 Design pressure 0.177 0.177 0.236 0.236 0.375 Thickness Thickness inches inches 0.375 0.5 0.5 Hurricane category MPH 10 PSF 63 MPH - 63 20 88 1 74-95 30 108 2 96-110 40 125 3 111-129 50 140 4 130-156 55 Glazing Basic glazing methods The following requirements apply for both wet and dry glazing Measure the rabbet depth of the frame Account for design wind load Confirm edge engagement Sealant cap bead Address potential expansion and contraction of the glazed dimension Check for compatibility and adhesion of gasket sealant or tape Wet glazing Wet-glazing is typically limited up to a 36x36 inch size window. Glazing shim tape is used to back the sealant cap bead as shown in the image. Dry glazing Optional setting block Shim tape EPDM or neoprene gasket Dense wedge gasket For dry glazing choose the extruded rubber gasket geometry that will prevent walk out due to sheet thermal movement and deflection. EPDM and neoprene are common gasket products for the interior glazing side of this application. Setting blocks help to allow for drainage via weep holes and also protect the sheet edge from contact with other liquids that might pool in the sill. Optional setting block with weep WetDry glazing Wetdry glazing combination
uses an extruded rubber and a sealant product. A soft open cell gasket type that breathes allows curing of the sealant cap bead. Basic glazing is shown in the illustration. Contact your gasket manufacturer for specific instructions for use as well as preferred tape and sealant products. 56 Dense wedge gasket Optional setting block Sealant cap bead Soft open cell gasket Glazing Over-glazing Over-glazing offers performance enhancements such as energy efficiency and soundproofing. It also offers a design solution where glass alone cannot meet the personal safety requirements or specific threat levels in high risk locations. Installation considerations Design a large enough air gap between the glass and TUFFAK sheet to accommodate sheet deflection due to wind or attack load. Wind load is not an issue for interior over-glazing so a thinner sheet may be an option. The framing must be designed to match the performance of the glazing and appropriate to the threat level of the application Clean sash to be certain it is free of manufacturing contaminants such as cutting oil Ensure sash is smooth and free of burrs Confirm size of sash opening and verify a proper design edge engagement and expansioncontraction allowances L angle Clean and inspect sheet edges for damage after cutting to size Glazing tape Stop with countersunk screw Use a glazing gasket tape or sealant recommended for polycarbonate with an adequate elongation TECH TIP To ensure a proper window seal follow the manufacturers recommendation for seal compression. As a general rule 15-40 impression is adequate for most applications. Over compressing a gasket applies unnecessary stress to the polycarbonate and can lead to product failure. For detailed information visit www.plaskolite.com Selected gaskets silicone and tape products GASKET Tremco EPDM Neoprene httpwww.tremcosealants.comcategory_detailglazing-solutionsglazing-restorationdesign-engineering-group.aspx SILICONE Dow-Corning 795995 httpwww.dowcorn
ing.comapplicationssearchdefault.aspxR501EN Momentive SCS 2700 SCS1200 SCS 1700 SCS 1800 SCS 2000 SCS 2350 SCS 2800 httpwww.siliconeforbuilding.com TAPE Saint-Gobain V2100 httpwww.foams.saint-gobain.comBondingTapeStructuralGlazingThermalBond.aspx Tremco Polyshim httpwww.tremcosealants.comproductspolyshim-ii-tape.aspx 57 Glazing TUFFAK sheet and Hygard laminate products Thickness inch Light Transmission Typical Shading Coefficient Solar Heat Gain Coefficient Total Solar Solar Absorption 0.118 86 0.99 0.87 83 11 Solar U-Factor Reflectance Summer Winter 6 0.91 1.00 0.177 85 0.99 0.86 82 12 6 0.88 0.96 0.236 84 0.97 0.85 80 14 6 0.85 0.92 0.370 80 0.95 0.83 77 17 6 0.78 0.85 0.480 77 0.93 0.81 75 16 9 0.73 0.79 Tint 70 0.86 0.75 66 27 7 Tint 50 0.77 0.67 55 38 7 Tint 18 0.62 0.54 34 60 6 BR750 89 0.95 0.83 75 19 6 0.64 0.68 BR1000 66 0.88 0.76 65 30 5 0.56 0.60 BR1250 72 0.91 0.79 68 27 5 0.51 0.54 CG375 82 0.94 0.82 76 18 6 0.77 0.84 CG500 79 0.93 0.81 73 21 6 0.72 0.78 CG750 72 0.90 0.79 69 25 6 0.63 0.68 WG 0.75 71 0.89 0.78 69 23 8 0.62 0.67 WG 1.0 64 0.86 0.75 64 29 7 0.56 0.60 WG 1.25 59 0.85 0.74 61 32 7 0.50 0.53 WG 2.0 48 0.82 0.71 55 39 6 0.39 0.41 Thickness dependent WG products have limited weathering properties for more information contact your Plaskolite representative or the Sheet Technical Services Group TUFFAK sheet light transmission curve Noise reduction The tables below show sound reduction levels in decibels for TUFFAK sheet single and dual glazed systems. SINGLE GLAZED DUAL GLAZED TUFFAK thickness inch Rw dB STC dB OITC dB Sheet thickness inch Air Space inch TUFFAK thickness inch STC dB OITC dB 0.118 24 24 19 0.236 PC 0.5 0.236 28 23 0.177 27 27 22 0.250 Glass 0.5 0.5 31 26 0.236 29 29 24 0.375 33 33 27 0.250 Glass 0.5 0.5 laminate 36 28 0.500 35 34 30 58 STC Sound Transmission Class Rw Weighted Sound Reduction Index OITC OutdoorIndoor transmission Class ASTM E 90 These suggestions and data are based on information we believe to be r
eliable. They are offered in good faith but without guarantee as conditions and methods of use are beyond our control. We recommend that the prospective user determine the suitability of our materials and suggestions before adopting them on a commercial scale. 2018 PLASKOLITE LLC 082018 TUFFAK and Hygard are registered trademarks of Plaskolite LLC Bayblend is a registered trademark of Covestro AG PLASKOLITE 400 Nationwide Blvd Suite 400 Columbus OH 43215 800.254.1707 Fax 800.457.3553 plaskoliteplaskolite.com www.plaskolite.com BRO002
