Amorphous And Semi Crystalline

The IAPD Plastics Primer, Module 3The IAPD Plastics Primer, Module 3

The International Association of Plastics DistributorsThe International Association of Plastics Distributors

Amorphous and Semi-CrystallineCommodity Thermoplastics

Materials, properties and applications.

Prepared by the IAPD Education Committee (Module 3)

Presented courtesy of Modern Plastics, Inc.



IMIDE MATERIALS Key Characteristics: Very High Cost Per Pound Excellent Properties Above 400°F Excellent Electrical Properties Excellent Dimensional Stability Low Coefficient of Friction

Materials: PI

PAI PBI

IAPD THERMOPLASTICS RECTANGLE

AMORPHOUS HIGH PERFORMANCE PLASTICS

Key Characteristics High Cost

High Temperature High Strength & Good Stiffness

Good Chemical Resistance Transparency

Hot Water & Steam Resistance

Materials: Polysulfone

Polyetherimide Polyethersulfone Polyarylsulfone

SEMI-CRYSTALLINE HIGH PERFORMACE PLASTICS

Key Characteristics: High Cost

High Temperature High Strength

Good Electrical Properties Outstanding Chemical Resistance

Low Coefficient of Friction Good Toughness

Materials: PVDF PTFE

ECTFE FEP PFA PPS

PEEK

AMORPHOUS ENGINEERING PLASTICS

Key Characteristics: Moderate Cost

Moderate Temperature Resistance Moderate Strength

Good Impact Resistance Translucency

Good Dimensional Stability Good Optical Qualities

Materials: Polycarbonate Modified PPO Modified PPE

Thermoplastic Urethane

SEMI-CRYSTALLINE ENGINEERING PLASTICS



Good Chemical Resistance Good Bearing and Wear Properties

Low Coefficient of Friction Difficult to Bond

Materials: Nylon Acetal PET PBT

UHMW-PE

SEMI-CRYSTALLINE COMMODITY PLASTICS

Key Characteristics: Low Cost

Low Temperature Resistance Low Strength

Excellent Chemical Resistance Low Coefficient of Friction

Near Zero Moisture Absorption Very Good Electrical Properties

Good Toughness

Materials: Polyethylene

Polypropylene Polymetnylpentene(TPX)

AMORPHOUS COMMODITY PLASTICS


Low Temperature Resistance] Low Strength

Good Dimensional Stability Bond Well

Typically Transparent

Materials: Acrylic

Polystyrene ABS PVC

PETG CAB

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AMORPHOUS PLASTICS KEY CHARACTERISTICS: Soften Over a Broad Range Of Temperatures

Easy to Thermoform Tend to Be Transparent

Bond Well Using Adhesives and Solvents Prone To Stress Cracking Poor Fatigue Resistance

Stuctural Applications Only (Not for Bearing & Wear)

SEMI-CRYSTALLINE PLASTICS KEY CHARACTERISTICS: Sharp Melting Point

Difficult to Thermoform Tend to Be Opaque

Difficult To Bond Using Adhesives and Solvents Good Resistance To Stress Cracking

Good Fatigue Resistance Good For Bearing and Wear, As Well As Structural Applications



Amorphous Commodity ThermoplasticsKey Characteristics

• Low cost• Low temperature resistance• Low strength• Good dimensional stability• Bonds well• Typically transparent



Amorphous Commodity ThermoplasticsMaterials

• Polymethyl methacrylate (PMMA) • Polystyrene (PS)• Acrylonitrile butadiene styrene (ABS)• Polyvinyl chloride (PVC)• Polyethylene terephthalate glycol (PETG)• Cellulous acetate butyrate (CAB)



Acrylic (PMMA) Strengths

• Availability of all ranges of optical transparency, including opacity

• Rigidity• Surface hardness• Half the weight of glass• Heat resistance



Acrylic (PMMA) Limitations

• Grain effect • Discolor with high UV exposure• Attacked by organic solvents• Limited chemical resistance• Poor wear and abrasion resistance• Low impact strength



Acrylic (PMMA) Applications

• Protective glazing• Windows• Toys• Point of purchase (POP) displays



Polystyrene (PS) Strengths

• Inexpensive• Easy to bond• Quick to bond • Easy to decorate



Polystyrene (PS) Limitations

• Low impact resistance

• Brittle after UV exposure

• Cannot be used at elevated temperatures

• Mechanical stress



Polystyrene (PS) Applications

• Refrigeration

• Disposable beverage glasses

• Medical devices

• Disposable laboratory products

• Wood replacement products



Acrylonitrile Butadiene Styrene (ABS)Strengths

• Good impact resistance

• Easily formable

• Many different formulations



Acrylonitrile Butadiene Styrene (ABS)Limitations

• Grain effect • Will discolor with high UV exposure• Attacked by organic solvents• Hygroscopic (absorbs moisture)



Acrylonitrile Butadiene Styrene (ABS)Applications

• Aircraft interiors• Computer housings• Cassette holders• Mass transit components• Wall coverings• Consumer electronics• Appliances• Automotive



Polyvinyl Chloride (PVC)Strengths

• Low cost• Good chemical resistance• Versatile• Naturally UV resistant• Good strength



Polyvinyl Chloride (PVC)Limitations

• Heat sensitive• Low impact strength• Poor wear resistance



Polyvinyl Chloride (PVC)Applications

• Pipe, valves and fittings • Thermoformed parts for transportation, exhibits and

machinery parts• Point of purchase displays• Pollution control equipment parts• Packaging



Modified Polyethylene Terephthalate Glycol (PETG)Strengths

• Optical transparency

• Good toughness

• Easy to fabricate

• Easy to form

• Ability to be sterilized



Modified Polyethylene Terephthalate Glycol (PETG)Limitations

• Limited UV resistance• Cannot be used above 60°-66°C/140°-150°F

range• Low softening point precludes sterilization



Modified Polyethylene Terephthalate Glycol (PETG)Applications

• Packaging

• Graphic arts

• Point of purchase (POP) displays



Cellulose Acetate Butyrate (CAB)Strengths

• Tough at low temperatures

• Compounded easily for unique applications



Cellulose Acetate Butyrate (CAB)Limitations

• Not compatible with other materials• Not self-extinguishing



Cellulose Acetate Butyrate (CAB)Applications

• Cash register keys• Tool handles• Windshields• Thermoformed signs• Trim stripping• Window well covers



Semi-Crystalline Commodity PlasticsKey Characteristics

• Low cost, strength and temperature resistance• Excellent chemical resistance• Low COF• Near zero moisture absorption• Very good electrical properties• Good toughness



Semi-Crystalline Commodity PlasticsMaterials

• Polyethylene (PE)– High density polyethylene (HDPE)

– Low density polyethylene (LDPE), (LLDPE)

• Polypropylene (PP)

• Polymethylpentene (PMP)



Polyethylene (PE), Polypropylene (PP) Polymethylpentene (PMP)Key Characteristics

• Partially crystalline, partially amorphous

• Largest family are the polyolefins

• Cost, benefits and limitations are different for each



Polyethylenes (PE)Key Characteristics

• Classified by density and molecular weight• Excellent chemical resistance• Zero moisture absorption• Light weight (1/8 weight of steel)• Excellent insulator• Low COF• High impact strength



Polyethylenes (PE)Applications

• Packaging• Wire and cable • Industrial



Low Density Polyethylene (LDPE)Key Characteristics

• Good chemical resistance• Very flexible• High impact strength• Low heat resistance (60-79°C/140-175°F)• Used extensively in packaging industry and for

prosthetic devices



High Density Polyethylene (HDPE)Key Characteristics

• Higher rigidity and tensile strength than low and medium density polyethylenes

• Good formability

• Slightly lower impact strength than LDPE

• Virgin grades are FDA and USDA approved



Low Density Polyethylene (LDPE)High Density Polyethylene (HDPE)Applications

• Films• Industrial trash bags• Liners• Shipping bags• Marine industry• Playgrounds• Bathrooms• Pipe• Automotive



Polypropylenes (PP)Key Characteristics

• Excellent chemical resistance

• Excellent fatigue strength — referred to as “living hinge”

• Lower impact strength than polyethylenes

• Available in homopolymer and co-polymer

• Co-polymer offers better impact, clarity and cold temperature properties



Polypropylenes (PP)Applications

• Packaging• Automotive• Consumer/durable goods• Vacuum formed parts• Fiber/carpet



Polymethylpentene (PMP)Key Characteristics

• High transparency, even in thick sections • Very light weight (.83 specific gravity)• Higher heat resistance than other grades in this group

—compares favorably to PTFE up to 148.89°C/300°F• Good electrical properties• Low-temperature impact strength• Very brittle• Poor UV resistance• USDA compliant



Polymethypentene (PMP)Applications

• Medical products• Food processing equipment• Microwavable packaging



IMIDE MATERIALS Key Characteristics: Very High Cost Per Pound Excellent Properties Above 400°F Excellent Electrical Properties Excellent Dimensional Stability Low Coefficient of Friction

Materials: PI

PAI PBI

IAPD THERMOPLASTICS RECTANGLE

AMORPHOUS HIGH PERFORMANCE PLASTICS

Key Characteristics High Cost

High Temperature High Strength & Good Stiffness

Good Chemical Resistance Transparency

Hot Water & Steam Resistance

Materials: Polysulfone

Polyetherimide Polyethersulfone Polyarylsulfone

SEMI-CRYSTALLINE HIGH PERFORMACE PLASTICS

Key Characteristics: High Cost

High Temperature High Strength

Good Electrical Properties Outstanding Chemical Resistance

Low Coefficient of Friction Good Toughness

Materials: PVDF PTFE

ECTFE FEP PFA PPS

PEEK

AMORPHOUS ENGINEERING PLASTICS



Good Impact Resistance Translucency

Good Dimensional Stability Good Optical Qualities

Materials: Polycarbonate Modified PPO Modified PPE

Thermoplastic Urethane

SEMI-CRYSTALLINE ENGINEERING PLASTICS



Good Chemical Resistance Good Bearing and Wear Properties

Low Coefficient of Friction Difficult to Bond

Materials: Nylon Acetal PET PBT

UHMW-PE

SEMI-CRYSTALLINE COMMODITY PLASTICS


Low Temperature Resistance Low Strength

Excellent Chemical Resistance Low Coefficient of Friction

Near Zero Moisture Absorption Very Good Electrical Properties

Good Toughness

Materials: Polyethylene

Polypropylene Polymetnylpentene(TPX)

AMORPHOUS COMMODITY PLASTICS


Low Temperature Resistance] Low Strength

Good Dimensional Stability Bond Well

Typically Transparent

Materials: Acrylic

Polystyrene ABS PVC

PETG CAB

SE

MI-C

RY

ST

AL

LIN

E P

LA

ST

ICS

AM

OR

PH

OU

S P

LA

ST

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AMORPHOUS PLASTICS KEY CHARACTERISTICS: Soften Over a Broad Range Of Temperatures

Easy to Thermoform Tend to Be Transparent

Bond Well Using Adhesives and Solvents Prone To Stress Cracking Poor Fatigue Resistance

Stuctural Applications Only (Not for Bearing & Wear)

SEMI-CRYSTALLINE PLASTICS KEY CHARACTERISTICS: Sharp Melting Point

Difficult to Thermoform Tend to Be Opaque

Difficult To Bond Using Adhesives and Solvents Good Resistance To Stress Cracking

Good Fatigue Resistance Good For Bearing and Wear, As Well As Structural Applications

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Amorphous And Semi Crystalline