Choosing the right plastic material for your product is one of the most important decisions in manufacturing. The wrong material can lead to premature failure, high production costs, or processing difficulties. This guide covers the most common engineering plastics — their properties, advantages, limitations, and typical applications.
| Material | Strength | Heat resistance | Chemical resistance | Cost | Processing ease |
|---|---|---|---|---|---|
| ABS | Good | Fair (80°C) | Fair | Low | Excellent |
| PC (Polycarbonate) | Excellent | Good (130°C) | Fair | Moderate | Good |
| PA (Nylon) | Excellent | Good (120-180°C) | Excellent | Low-Moderate | Good |
| POM (Acetal) | Good | Fair (100°C) | Good | Moderate | Excellent |
| PEEK | Excellent | Excellent (260°C) | Excellent | Very High | Moderate |
| PP | Fair | Fair (100°C) | Excellent | Very Low | Excellent |
| PMMA (Acrylic) | Good | Fair (80°C) | Poor | Low-Moderate | Good |
| PVC | Good | Fair (70°C) | Good | Low | Good |
Properties: ABS is a tough, impact-resistant thermoplastic with good dimensional stability and a high-gloss surface finish. It combines the strength and rigidity of acrylonitrile and styrene with the toughness of butadiene rubber.
Key specs: Tensile strength 40-50 MPa, Flexural modulus 2.0-2.5 GPa, HDT 80-100°C, Shrinkage 0.4-0.9%
Pros: Excellent impact resistance, easy to process, good surface finish, low cost, easily painted and bonded
Cons: Poor UV resistance (degrades in sunlight), limited heat resistance, attacked by solvents and hydrocarbons
Typical applications: Consumer electronics housings, automotive interior trim, toys (LEGO bricks are ABS), luggage shells, power tool housings, appliance casings
Properties: Polycarbonate is an amorphous thermoplastic known for exceptional impact strength (250x stronger than glass), optical clarity, and heat resistance. It can be transparent or colored.
Key specs: Tensile strength 60-70 MPa, Flexural modulus 2.3-2.4 GPa, HDT 125-135°C, Shrinkage 0.5-0.7%, Light transmission 88-90%
Pros: Extremely high impact strength, excellent optical clarity, good heat resistance, flame retardant grades available
Cons: Susceptible to stress cracking (especially with hydrocarbons), requires thorough drying before processing, scratches easily (hard coating can help), high processing temperature
Typical applications: Safety glasses and goggles, bulletproof glass, medical devices, light covers and lenses, automotive headlight lenses, electronic display windows
Properties: Nylon is a semi-crystalline engineering thermoplastic with excellent mechanical strength, wear resistance, and low friction coefficient. Common grades: PA6, PA66, PA12, and glass-reinforced variants.
Key specs (PA6): Tensile strength 65-85 MPa, Flexural modulus 2.4-3.2 GPa (unfilled), HDT 80-100°C, Shrinkage 0.5-1.5%
Pros: Excellent strength and toughness, very good wear and abrasion resistance, low coefficient of friction, good chemical resistance (oils, fuels, solvents)
Cons: Highly hygroscopic (absorbs moisture — must be dried before processing), dimensional changes with moisture absorption, poor UV resistance, notch-sensitive
Typical applications: Gears and bearings, under-hood automotive parts, power tool housings, cable ties, electrical connectors, textile machinery components
Properties: POM is a semi-crystalline engineering thermoplastic known for its high stiffness, excellent dimensional stability, and very low friction. It machines beautifully and holds tight tolerances.
Key specs: Tensile strength 60-70 MPa, Flexural modulus 2.6-3.0 GPa, HDT 95-110°C, Shrinkage 1.8-2.5%
Pros: Excellent dimensional stability, very low friction (self-lubricating), good wear resistance, excellent machinability, good creep resistance
Cons: Difficult to bond (requires special adhesives or mechanical fastening), limited heat resistance compared to other engineering plastics, degrades in acidic environments
Typical applications: Precision gears, zippers, pump impellers, valve components, conveyor belt links, food processing equipment, automotive door lock components
Properties: PEEK is a high-performance semi-crystalline thermoplastic with exceptional mechanical properties, chemical resistance, and continuous service temperature of 260°C. It is the gold standard for demanding applications.
Key specs: Tensile strength 90-100 MPa, Flexural modulus 3.5-4.2 GPa, HDT 160°C, Continuous service 260°C, Shrinkage 0.5-1.0%
Pros: Exceptional high-temperature performance (260°C continuous), outstanding chemical resistance (resists all common solvents), excellent mechanical properties, inherently flame retardant, biocompatible (medical implant grades available)
Cons: Very expensive (5-20x cost of standard engineering plastics), high processing temperatures (350-400°C), limited color options, must be processed in clean environments
Typical applications: Medical implants (spinal cages, hip replacement components), aerospace components, oil & gas seals, semiconductor wafer handling, high-temperature electrical connectors
Properties: PP is a low-cost, semi-crystalline commodity thermoplastic with excellent chemical resistance, good fatigue resistance, and the unique ability to create living hinges.
Key specs: Tensile strength 25-35 MPa, Flexural modulus 1.2-1.6 GPa, HDT 90-110°C, Shrinkage 1.0-2.5%
Pros: Very low cost, excellent chemical resistance, outstanding fatigue resistance (living hinges can flex millions of cycles), lightweight (density 0.905 g/cm³), good moisture barrier
Cons: Low stiffness compared to engineering plastics, poor UV resistance, difficult to paint or bond, flammable (requires additives for flame retardancy)
Typical applications: Living hinges (one-piece bottle caps), automotive interior parts, battery cases, food containers, laboratory equipment, furniture, fibers and textiles
Properties: PE is the most widely produced plastic, available in multiple densities (HDPE, LDPE, LLDPE, UHMWPE). HDPE offers the best strength-to-cost ratio among commodity plastics.
Key specs (HDPE): Tensile strength 20-35 MPa, Flexural modulus 0.8-1.5 GPa, HDT 80-100°C, Shrinkage 1.5-4.0%
Pros: Very low cost, excellent chemical and moisture resistance, good impact resistance (especially LDPE), FDA-approved grades available, excellent electrical insulation
Cons: Low temperature resistance, poor UV resistance, difficult to bond, high shrinkage, low surface energy (hard to paint/print)
Typical applications: Bottles and containers, plastic bags and films, pipe systems, fuel tanks, cutting boards (UHMWPE), orthopedic implants (UHMWPE)
Properties: PVC is a versatile thermoplastic available in rigid (RPVC) and flexible forms (plasticized PVC). It is flame retardant due to chlorine content and offers good chemical resistance.
Key specs (Rigid): Tensile strength 40-60 MPa, Flexural modulus 2.0-3.2 GPa, HDT 60-70°C, Shrinkage 0.2-0.5%
Pros: Inherently flame retardant (self-extinguishing), excellent weatherability (uPVC), good chemical resistance, low cost, good electrical insulation, weldable and bondable
Cons: Limited heat resistance, releases HCl when burned (toxic), plasticizers can leach out of flexible grades, poor low-temperature impact resistance (rigid grades)
Typical applications: Window frames and piping (rigid), wire and cable insulation (flexible), flooring and wall coverings, medical tubing (flexible), credit cards, signage
Properties: PMMA is a transparent amorphous thermoplastic known as acrylic. It offers exceptional optical clarity (92% light transmission) and outstanding weather resistance.
Key specs: Tensile strength 55-75 MPa, Flexural modulus 2.4-3.3 GPa, HDT 80-100°C, Shrinkage 0.4-0.7%, Light transmission 92%
Pros: Excellent optical clarity and gloss, outstanding UV and weather resistance (unlike PC, does not yellow), good scratch resistance (better than PC), easily machined and polished
Cons: Brittle (low impact strength), attacked by solvents and chemicals, can craze under stress, higher coefficient of thermal expansion
Typical applications: Aquariums and display cases, automotive taillight lenses, signage and light guides, architectural glazing, skylights, sanitary ware (bathtubs)
Follow this decision framework when selecting a plastic material for your product:
| Application requirement | Recommended materials | Avoid |
|---|---|---|
| High impact / safety | PC, ABS, PC/ABS | PMMA, PS |
| High temperature (150°C+) | PEEK, PA6-GF, PPS | PP, PE, ABS |
| Wear / friction / gears | POM, PA, UHMWPE | PP, PS |
| Optical clarity | PMMA, PC, PS | PA, PP, POM |
| Chemical resistance | PP, PE, PEEK, PA | PC, PMMA, ABS |
| Food contact | PP, PE, PA, POM | PVC (unapproved additives) |
| Outdoor / UV exposure | PMMA, ASA, UV-stabilized ABS | Unstabilized PP, PE, ABS |
| Low cost / high volume | PP, PE, PS, ABS | PEEK, PC (for volume) |
→ Related: Materials Selection Overview Guide
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