Plastic Injection Molding Materials


Common Thermoplastic Polymers

The base materials used for plastic injection molding generally are referred to as thermoplastic polymers. There are many different types of these plastics, and each family of resin has its own characteristics, advantages and disadvantages. Further, every family has different grades, which have their own unique qualities. Although there are multiple properties of plastic, the most frequently referenced ones include heat resistance, chemical resistance, impact resistance, weather resistance, UV resistance, moisture resistance, flame retardant, toughness, hardness, flexibility, stability, elasticity, strength, weight, mass density (or specific gravity), and clarity.

 

With so many types, grades and properties of plastic, it can be difficult to know where to begin the search for the right material for a part, component or requirement. As such, the table below lists the most common plastic injection molding materials and their main properties and frequent applications. Although this certainly is not a complete and definitive listing, it should serve as a helpful guide to start researching the right thermoplastic polymer for your project. If you have any questions or would like some assistance, please do not hesitate to contact us. We are happy to help.


Plastic Injection Molding Materials Chart


MATERIAL
HIGHLIGHTS
COMMON
APPLICATIONS
MASS DENSITY
(g/cm)
SHRINKAGE
(in/in)
CLARITY
TONNAGE PER
SQUARE INCH

(Estimated)
COST
ABS
Acrylonitrile Butadiene Styrene
Flame retardant; impact resistant
Automotive; medical; electrical; appliances; toys
1.02-1.05
0.005
Translucent
2.5-3.5
$
ASA
Acrylonitrile Styrene Acrylate
Toughness; chemical, heat and weather/UV resistant
Automotive; outdoor applications; electrical
1.07
0.004-0.007
Opaque
2.5-3.5
$$
EVA
Ethylene-Vinyl Acetate
Softness; flexibility; clarity; gloss
Sporting goods; medical; foam; rubber replacement
0.92-0.97
0.007-0.020
Transparent
2.0-3.0
$
HDPE
High Density Polyethylene
Rigidity; moisture resistant; food contact
Packaging; food; industrial
0.935-0.96
0.025-0.035
Opaque
2.5-3.5
$
HIPS
High Impact Polystyrene
Impact resistant; flame retardant; food contact
Food; packaging
1.04
0.003-0.007
Transparent
2.0-2.5
$
LDPE
Low Density Polyethylene
Chemical resistant; flexibility; toughness; gloss
Packaging; food; industrial
0.91-0.925
0.015-0.026
Transparent
or Opaque
2.0-3.0
$
LLDPE
Linear Low Density Polyethylene
High tensile strength; high impact resistance; flexibility
Bags; packaging; toys; covers; lids; containers
0.918-0.94 0
0.015-0.035
Translucent
2.0-3.0
$
PA6
Polyamide 6 (Nylon 6)
Heat and chemical resistant; impact modified
Automotive; electrical; industrial; consumer; engineering
1.13
0.009-0.012
Opaque
3.0-4.0
$$
PA66
Polyamide 66 (Nylon 66)
Heat and chemical resistant; impact modified
Automotive; electrical; industrial; consumer; engineering
1.14
0.015-0.020
Opaque
3.0-4.0
$$
PA66 30%GF
30% Glass Filled Polyamide (Nylon 66)
High rigidity, hardness and strength; high stability
Automotive; engineering; gears; cams; bearings; electrical; metal substitute
1.22-1.49
0.003-0.008
Opaque
4.0-5.0
$$
PBT
Polybutylene Terephthalate (Polyester) [Valox]
Chemical and heat resistant; mechanical strength
Electrical; automotive; showerheads; irons
1.31
0.012-0.023
Opaque
3.0-4.0
$$
PC
Polycarbonate
[Lexan]
High impact strength; clarity; flame retardant
Electrical; lighting; automotive; appliances; medical
1.20
0.005-0.007
Transparent
4.0-5.0
$$
PC+ABS
Polycarbonate + ABS
[Cycoloy]
Toughness; dimensional stability; low moisture absorption
Appliances; automotive; electrical; consumer; medical
1.08-1.22
0.005-0.007
Opaque
3.0-4.0
$$
PEEK
Polyether Ether Ketone
Mechanical and chemical resistance
Bearings; piston parts; aerospace; automotive; medical; chemical processing
1.30-1.50
0.010-0.020
Opaque
5.0
$$$
PEI
Polyetherimide
[Ultem]
High tensile strength; flame retardant; chemical resistant
Electrical; aerospace; medical; lighting; appliances
1.27
0.006
Translucent
4.0-6.0
$$$
PET
Polyethylene Terephthalate
[Dacron]
Lightweight; moisture barrier; strength; impact resistant
Bottles; food packaging
1.44-1.73
0.002
Transparent
4.0-5.0
$$
PMMA
Polymethyl Methacrylate (Acrylic)
High clarity; weather, heat and chemical resistant
Glass substitute; automotive; lighting; medical; lenses; optics
1.19
0.002-0.006
Transparent
3.0-4.0
$
POM
Polyoxymethylene (Acetal)
[Celcon; Delrin]
Lubricated; wear and chemical resistant; stiffness
Automotive; industrial; mechanical; electrica
1.41-1.42
0.018-0.035
Opaque
3.0-4.0
$$
PP (Copolymer)
Polypropylene Copolymer
Impact resistant; lightness; food contact
Automotive; household; electrical; packaging
0.90
0.010-0.025
Opaque
2.5-3.5
$
PP (Homopolymer)
Polypropylene Homopolymer
Impact resistant; lightness; food contact
Automotive; household; electrical; packaging
0.902
0.010-0.025
Translucent
2.5-3.5
$
PPE
Polyphenylene Ether
Electrical properties; flame retardant; chemical resistant; low moisture absorption
Electrical; appliances; construction; automotive
1.13
0.006
Translucent
3.0-4.0
$$
PPS
Polyphenylene Sulfide
[Ryton]
Chemical and fire resistance; thermal and dimensional stability
Automotive; electrical; industrial; appliances
1.40-2.00
0.003-0.010
Opaque
3.5-4.5
$$
PS
Polystyrene (GPPS)
Impact resistant; flame retardant; food contact
Packaging; electrical; toys; appliances
1.05
0.003-0.007
Transparent
2.0-2.5
$
PVC
Polyvinyl Chloride
Flame retardant; high impact resistance
Industrial; electronic
1.22
0.002
Opaque
2.0-3.0
$
SAN
Styrene Acrylonitrile
Chemical and heat resistance; clarity
Electrical; appliances; automotive
1.06
0.002-0.005
Transparent
2.5-3.5
$$
TPE
Thermoplastic Elastomer
Elasticity; chemical and weather resistant
Rubber substitute; automotive; seals; overmolding
0.87-1.20
0.017-0.047
Translucent
2.5-3.5
$$
TPU
Thermoplastic Polyurethane
Range of hardness grades; abrasion and chemical resistant
Footwear; sporting goods; wheels; seals
1.01-1.23
0.012-0.017
Transparent
2.5-3.5
$$
TPV
Thermoplastic Vulcanizate
[Santoprene]
Strength; flexibility; lightweight
Automotive; appliances; electrical; construction; healthcare; industrial
0.92-0.97
0.010-0.050
Transparent
2.5-3.5
$$

Clarity: Opaque = No light passes through; Transparent = Some light passes through; Translucent = Light passes through

Disclaimers: The information provided herein is general in nature and is based upon averages, nominal ranges, estimates, non-specified grades of materials in their natural form, and readily available public information. Accordingly, this guide should be used only as a handy comparison of materials and as a starting point for conducting research, and users must perform their own studies and testing of materials. ALL WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE OR USE, ARE EXCLUDED AND DISCLAIMED. Without limiting the generality of the foregoing, Precision Molded Plastics, Inc. assumes no responsibility or liability of any kind for this guide or for the information contained herein.