The International Association of Plastics Distributors The IAPD Plastics Primer, Module 6...

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The IAPD Plastics Primer, Module 6The IAPD Plastics Primer, Module 6

The International Association of Plastics DistributorsThe International Association of Plastics Distributors

Understanding Thermoset

Plastic Materials

Prepared by the IAPD Education Committee (Module 6)

Presented courtesy of Modern Plastics Inc.

Thermosets

• Resin

• Thermoset vs. thermoplastic

ThermosetsTypes

• Laminates• Composites• Polyurethanes

Thermoset Laminates

• Phenolics• Epoxies• Melamines• Silicones• Polyesters• Composites

Laminates Key Characteristics

• Corrosion resistant

• Good insulating characteristics at low temperatures

• Good machinability

LaminatesProcess

Heat and pressure applied to the top and bottom of the material.

Resin Binder

Reinforcing Substrate

Laminates Types

• Paper based• Cotton based• Glass based• Synthetic fabric based

Phenolic Laminates Strengths

• High degree of resistance to deforming under load

• Can withstand 149°C/300°F continuously• One of the hardest plastics available • Cross-linked phenolics are very resistant to

compressive loads

Phenolic Laminates Limitations

• Brittleness

• Impact resistance

• Moisture resistance is limited

• Resins darken when exposed to heat and ultra

violet light

Phenolic Laminates Types

• Paper based

– Grades X, XX, XXX, XP,

XXP, XXXP, XPC, XXPC

and XXXPC

• Cotton based– Grades C, CE, CYB, L, LE,

LYB, LM

Phenolic Laminates Applications

• Wiring devices• Switch gear• Circuit breakers• Insulators• Gears• Wear guides• Pulleys• Rollers

Epoxy Laminates Strengths

• Offer virtually no water absorption

• Good insulating and electrical properties

• Excellent dimensional stability

• Good temperature and chemical resistance

Epoxy Laminates Limitations

• Brittle

• Poor UV resistance

• Poor weathering resistance

Epoxy Laminates Types

• G-10• FR-4• G-11• FR-5

Epoxy Laminates Applications

• Electrical insulators

• Circuit board backing

• Construction

• Aviation/aerospace

Melamine LaminatesStrengths

• Made from melamine and formaldehyde resins• Usually used as a laminate with cloth• Easily produced in an unlimited range of colors• Good electrical properties under humid conditions• Excellent arc-tracking resistance• Excellent compressive strength• Good physical properties• Very good solvent resistance• Can withstand temperatures of 204°C/400°F • Good chemical and weather resistance• Strong mechanical properties

Melamine LaminatesLimitations

• Can be attacked by strong acids• Brittleness• Poor resistance to organic solvents• Difficult to bond• High cost

Melamine LaminatesTypes

• G-5• G-9

Melamine LaminatesApplications

• Welding rod holders

• Heavy duty switch gears

• High temperature switches

• Electrical insulators

Silicone LaminatesStrengths

• Retain properties over a wide temperature range

• Remain flexible down to negative 16ºC/60ºF• High degree of biocompatibility

Silicone LaminatesLimitations

• Tensile strength low• Abrasion resistance low• Swell in oils, fuels and other solvents

Silicone LaminatesType

• G-7 (glass cloth reinforced silicone)

Silicone LaminatesApplications

• Sealants• Gaskets• Medical

Polyester LaminatesStrengths

• Low cost• Good arc and track resistance

Polyester LaminatesLimitations

• Lower abrasion resistance • Brittle• Great change to electrical properties in humid

environments

Polyester LaminatesTypes

• GPO-1• GPO-2• GPO-3

Polyester LaminatesApplications

• Structural profiles• Sodering pallets

Composites - Thermosetting Matrix

• History• Definition

CompositesMaterials

• Polyester and vinyl esters• Epoxy• Bismaleimides (BMI)• Polyimides• Polyureas

– Cyanate ester and phenolic triazine (PT)

Polyurethane (PUR)Strengths

• Good abrasion resistance

• Good toughness

• Very high tear resistance

• High load bearing ability

• High impact resistance

• Good elastomeric memory

PolyurethaneLimitations

• Hot water limitation 82°C/180°F

• Poor chemical resistance to strong acids,

bases and certain solvents

Polyurethane and the Environment

• TDI

• MDI

• Processes

PolyurethaneHardness Chart

PolyurethaneApplications

• Automotive• Building and construction• Furniture and mattresses• Insulation for refrigerators, shipping

containers, tanks, pipes

Polyurethane Urethane Types

• Polyether

• Polyester

Polyether Urethane Strengths

• Better water resistance

• Better dynamic properties

• Better low temperature properties

Polyether Urethane Limitations

• Lower abrasion resistance than polyesters• Stiffer material than polyesters• More likely to tear

Polyether Urethane Applications

• Bushings• Idler rollers• Printing machine rolls• Hydraulic seals• Elevator wheels• Paper mill rolls

Polyester UrethaneStrengths

• Higher physical properties• Generally softer than polyether • Stronger cut and tear resistance• Better oil and heat aging resistance• Meets FDA requirements for wet food

applications

Polyester Urethane Limitations

• Poor resistance to hydrolysis (moisture absorption)

• Less resilient than polyethers • Poor low temperature performance

Polyester Urethane Applications

• Cutter bars on printing machines• Wear pads • Tumbler liners• Squeegees• Office equipment rollers

Polyurethane's Product Range Comparisons to Other Materials

The End

The International Association of Plastics Distributors The IAPD Plastics Primer, Module 6...

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