PAINTING AND COATING OF PLASTICS JAIME CYPHER RYAN SEYLER DANIEL WILSON

Introduction Purpose of coating and painting Purpose of coating and painting DecorativeDecorative For consumersFor consumers ProtectionProtection From unwanted environmental effectsFrom unwanted environmental effects Helps overall performanceHelps overall performance Methods: Painting, Powder Coating Methods: Painting, Powder Coating

Introduction Background on Painting Background on Painting More aesthetically pleasingMore aesthetically pleasing Most common method of coatingMost common method of coating Paint applied to surface as liquidsPaint applied to surface as liquids Higher surface energy = BetterHigher surface energy = Better

Introduction Background on Powder Coating Background on Powder Coating Used on metals, ceramics, & plasticUsed on metals, ceramics, & plastic Powdered solid coating appliedPowdered solid coating applied

Preparation of Plastic Prevent foreign substances Prevent foreign substances Detergent cleaningDetergent cleaning Salts and OilsSalts and Oils GlovesGloves Fingerprint soilsFingerprint soils Destaticizing air blow-offDestaticizing air blow-off Operate in “clean room”Operate in “clean room”

Paint Adhesion Overcoming surface smoothness Overcoming surface smoothness Micro-etch with chemical agentMicro-etch with chemical agent Avoid over and under etchingAvoid over and under etching Solvent choice is criticalSolvent choice is critical De-glazing with abrasive media De-glazing with abrasive media Areas of frictional heatingAreas of frictional heating Cross-linked skin formsCross-linked skin forms

Paint Adhesion Oxidative surface treatingOxidative surface treating For non-polar plastic surfacesFor non-polar plastic surfaces Polarity from chemical reactionPolarity from chemical reaction Polypropylene and PolyethylenePolypropylene and Polyethylene Open flame exposureOpen flame exposure Photosensitizers and UV lightPhotosensitizers and UV light

Painting Advantages of Painting Advantages of Painting Protective coatingProtective coating Richer color than internal colorantsRicher color than internal colorants Thin coatings possibleThin coatings possible Same color parts in assemblySame color parts in assembly

Painting Disadvantages of Painting Disadvantages of Painting Poor adhesion to certain plasticsPoor adhesion to certain plastics Air pollutionAir pollution Disposal of wasteDisposal of waste Paintability varies among plasticsPaintability varies among plastics

Types of Painting Processes Spray Spray Silk-Screening Silk-Screening Dip-Coating Dip-Coating Rolling Rolling Brushing Brushing Wiping Wiping

Spray Most common and versatile method Most common and versatile method Easily automated Easily automated Air pressure & liquid stream mixed Air pressure & liquid stream mixed Distance from part & speed important Distance from part & speed important Overspray unimportant, booths used Overspray unimportant, booths used

Spray Advantages Advantages Excellent surface qualityExcellent surface quality Uniform thicknessUniform thickness Few runsFew runs Few imperfectionsFew imperfections

Silk-Screening Series of screens prepared Series of screens prepared Multi-color imagesMulti-color images One screen per colorOne screen per color One screen per portionOne screen per portion Drying time necessary Drying time necessary

Silk-Screening Advantages Advantages Flat & cylindrical partsFlat & cylindrical parts High volume productionHigh volume production Disadvantages Disadvantages Adhesion problemsAdhesion problems Due to bad preparationDue to bad preparation Presence of mold releasePresence of mold release

Others Dip-Coating Dip-Coating Immersion in paint & rotatingImmersion in paint & rotating Brushing, Rolling, & Wiping Brushing, Rolling, & Wiping Used less frequentlyUsed less frequently AdvantagesAdvantages Special effectsSpecial effects Small lotsSmall lots

Powder Coating Process Process Immersion in plastic particles or sprayedImmersion in plastic particles or sprayed Baked at high temperaturesBaked at high temperatures Caution of degradation from fusionCaution of degradation from fusion

Powder Coating Types Types EpoxyEpoxy HybridHybrid Aromatic UrethaneAromatic Urethane TGIC PolyesterTGIC Polyester

Powder Coating Advantages of Powder Coating Advantages of Powder Coating Many types of finishesMany types of finishes Better performanceBetter performance Better for environmentBetter for environment Low costLow cost

Powder Coating Disadvantages of Powder Coating Disadvantages of Powder Coating Degradation or softening possibleDegradation or softening possible Causes part deformationCauses part deformation Long color change timeLong color change time

New Technology In-Mold Painting In-Mold Painting Automotive usesAutomotive uses Insert-molding techniqueInsert-molding technique Eliminates paint-facility expensesEliminates paint-facility expenses Better design flexibilityBetter design flexibility Recycling easierRecycling easier

New Technology 2K Polyurethane Coating 2K Polyurethane Coating Automotive usesAutomotive uses Excellent appearanceExcellent appearance Excellent performanceExcellent performance Curing at low temperaturesCuring at low temperatures Wide variety of plasticsWide variety of plastics

Materials Not to be considered Not to be considered PE, PP, and low polarity plasticsPE, PP, and low polarity plastics Low surface energyLow surface energy Cautionary materials Cautionary materials PC & PSPC & PS Exposure to sensitive solventsExposure to sensitive solvents

Design Requirements Material Selection Material Selection Adding raised part details Adding raised part details Ink applied using rollerInk applied using roller Flat surfaces if possible Flat surfaces if possible Uniform thicknessUniform thickness CheaperCheaper

Examples Painting Painting

Examples Powder Coating Powder Coating

Conclusion Coating & Painting valuable Coating & Painting valuable DecorativeDecorative ProtectiveProtective Preparation is crucial Preparation is crucial Many different processes Many different processes Becoming more popular today Becoming more popular today