Thermoplastic Materials

THERMOPLASTIC MATERIALS

A THERMOPLASTIC IS A TYPE OF PLASTIC MADE UP OF POLYMER RESINS THAT BECOMES SOFT AS THE MATERIAL IS HEATED AND HARD AS IT IS COOLED. THESE MATERIALS DO NOT SHOW ANY CHEMICAL PROPERTY CHANGES WHEN HEATED OR COOLED MULTIPLE TIMES, MAKING THEM MORE SUITABLE FOR RECYCLING.

Thermoplastic materials can be homogenous and heterogeneous in their makeup. Unique properties can be achieved by blending thermoplastics, co-extruding, or including special property-enhancing additives.

Thermoplastics can be manufactured and fabricated using several standard methods. Most thermoplastic sheet and film is produced using an extrusion process. Cast methods can also produce some sheet materials. Nearly any sheet thermoplastic material can be formed by using thermoforming, vacuum forming, or cold forming methods. Thermoplastics with or without reinforcement can also be injection molded into complicated shapes with features not achievable through standard machining.

Thermoplastic materials are suitable for numerous applications – aerospace, defense, medical, satellite communications, food service, and electronics being just a few industries that utilize thermoplastics. Although thermoplastics are often processed similarly, performance characteristics, workability, and cost can vary greatly.

 

AMORPHOUS VS. SEMI-CRYSTALLINE

 

Thermoplastics can be broken into two groups by composition: Amorphous and Semi-Crystalline thermoplastics.

While the molecules in semi-crystalline polymers are clustered and structured in a region, the molecules in amorphous polymers are randomly arranged.

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AMORPHOUS:

  • Easy to thermoform
  • Typically translucent
  • Softens over a range of temperatures
  • Bonds well using adhesives
  • Good for structural applications
  • Poor fatigue resistance
  • Not ideal for wear applications
  • Subject to cracking from stress
 

SEMI-CRYSTALLINE:

  • Challenging to thermoform
  • Typically opaque
  • Sharp melting point
  • Difficult to bond
  • Good for structural applications
  • Good fatigue resistance
  • Good for wear & bearing applications
  • Good resistance to cracking from stress


AMORPHOUS THERMOPLASTICS:

Amorphous thermoplastics are more conducive to thermoforming. They soften over a range of temperatures and have better bonding ability when combined with adhesives.

Amorphous plastics often have better dimensional stability and impact resistance than semi-crystalline thermoplastics of a similar grade. However, stress makes amorphous plastics more prone to fatigue and cracking. 

 

SEMI-CRYSTALLINE THERMOPLASTICS:

Semi-Crystalline thermoplastics are excellent for wear and structural applications.

Compared to amorphous thermoplastics, these semi-crystallines tend to have better chemical resistance, electrical properties, and a lower coefficient of friction. However, semi-crystalline plastics are challenging to thermoform, difficult to bond, have a sharp melting point, and have lesser impact strength.

 

PLASTIC FAMILIES:

Thermoplastics can be further categorized into families by temperature rating.

Each family comprises amorphous and semi-crystalline plastics with distinct advantages and disadvantages, depending on what is trying to be achieved.,

 

 

Thermoplastic pyramid 01 resized

COMMODITY THERMOPLASTICS:

AT THE BOTTOM OF THE PYRAMID, COST-EFFECTIVE COMMODITY PLASTICS SUCH AS PP, PE, PVC, PS, AND PET POLYMERS ARE FOUND IN SEMI-CRYSTALLINE AND AMORPHOUS FORMS.

These plastics don’t require highly-engineered properties and are produced at larger volumes to support many everyday applications.

Although the operating temperature of these materials is lower and they are generally weaker than higher-performing plastics, they can offer good chemical resistance and machinability (although there is variability between commodity plastics). Commodity thermoplastics are by far the most common plastic and are widely used worldwide.

APPLICATIONS:

  • Textiles
  • Automotive
  • Toys
  • Containers
  • Electronics
  • Construction
  • Housewares
Commodity Thermoplastics
Description Test Method Units pp

PETG

HDPE

ABS

Specific Gravity

ASTM D792

0.905

1.27

0.95

1.04

Water Absorption

ASTM D570

%

<0.01

0.2

<0.01

1

Hardness, Rockwell

ASTM D785

92

115

69

105

Tensile Strength

ASTM D638

psi

4800

7700

4800

6000

Elongation at Break

ASTM D638

%

12

18

900

150

Flexural Modulus

ASTM D790

ksi

180

310

200

340

Flexural Yield Strength

ASTM D790

psi

7000

11200

10000

Compressive Modulus

ASTM D695

ksi

320

Impact Strength

ASTM D256

ft-Ib/in

1.9

1.7

3

2.5

Dielectric Constant

ASTM D150

2.25

2.6

2.3

2.7

Dielectric Strength

ASTM D149

kV/m

660

410

900

500

Dissipation Factor

D150

0.001

0.005

0.0002

0.01

Coefficient of Thermal Expansior

D696

x10^-5in./in/F*

6.2

3.8

6

5

Heat Deflection Temp

D648

F 

210

163

170

198

Glass Transition Temp

D3418

F 

327

180

260

221

Max Operating Temp

F 

180

150

180

176

Thermal Conductivity

AST F433

BTU-in/hr-ft^2-F

0.8

2

2.92

1.73

Other Commodity Thermoplastic Materials include
Transformer Table Icon 3.6.2 Thermoplastic Materials PolyPro FR® Formex®
Vivak®

Contact Us Today to learn more about commodity thermoplastic materials from The Gund Company or request a quote for your application!

ENGINEERING THERMOPLASTICS

ALTHOUGH THEY SHARE MANY SIMILARITIES WITH COMMODITY THERMOPLASTICS, ENGINEERING THERMOPLASTICS ARE DESIGNED FOR ENVIRONMENTS THAT REQUIRE HIGHER STRENGTH, TEMPERATURE RESISTANCE, AND DURABILITY, AMONG OTHERS.

Common engineering plastics include polycarbonate, nylon (PA), acetal (POM), and UHMW-PE.

Variation in characteristics between these materials does exist, but in general, they are all used in environments unsuitable for commodity thermoplastics. Engineering thermoplastics are generally more expensive than commodity thermoplastics, but both are relatively inexpensive. 

APPLICATIONS:

  • Bearings, Springs, Valves
  • Automotive
  • Medical/Healthcare 
  • Textiles
  • Electronics 
  • Cookware

Engineered Thermoplastic 

DescriptionTest MethodUnits

pC

Nylon

Acetal

UHMW

Specific Gravity

ASTM D792

1.2

1.15

1.41

0.93

Water Absorption

ASTM D570

%

0.15

0.3

0.2

<.01

Hardness, Rockwell

ASTM D785

118

115

120

66

Tensile Strength

ASTM D638

psi

9000

11500

9500

3100

Elongation at Break

ASTM D638

%

110

50

30

30

Flexural Modulus

ASTM D790

ksi

345

450

400

125

Flexural Yield Strength

ASTM D790

psi

13500

15000

12000

Compressive Modulus

ASTM D695

ksi

345

420

400

Impact Strength

ASTM D256

ft-Ib/in

18

0.6

1

N/A

Dielectric Constant

ASTM D150

2.96

3.6

3.8

2.3

Dielectric Strength

ASTM D149

kV/m

380

15.7

420

900

Dissipation Factor

D150

0.0009

0.02

0.005

0.00002

Coefficient of Thermal Expansior

D696

x10^-5in./in/F*

0.375

5.5

5.4

11

Heat Deflection Temp

D648

F 

280

200

220

95

Glass Transition Temp

D3418

F 

310

500

335

280

Max Operating Temp

F 

300

210

180

180

Thermal Conductivity

AST F433

BTU-in/hr-ft^2-F

1.35

1.7

1.6

2.92

Other Engineered Thermoplastic Materials include
Transformer Table Icon 3.6.2 Thermoplastic Materials Zytel® Lexan®
Valox® Mylar®
Statex® Delrin®

To learn more about engineering thermoplastic materials from The Gund Company or to request a quote for your application, Contact Us Today.

HIGH PERFORMANCE AND IMIDIZED 

HIGH-PERFORMANCE PLASTICS AND IMIDIZED PLASTICS MAY BE NECESSARY FOR MORE DEMANDING OR SPECIALIZED APPLICATIONS.

High-performance plastics such as PEEK, PTFE, and PSS can withstand very high temperatures and offer excellent chemical resistance.

Imidized plastics are often suited more for aerospace applications but can also be used for thermal insulators, high-performance bearings, and electrical connectors in extreme environments. Imidized plastics such as polyamide-imide (PAI), polybenzimidazole (PBI), and polyimide (PI) feature the highest temperature resistance and load-bearing capabilities, among other properties.

APPLICATIONS:

  • Aerospace
  • Insulation
  • Wear Components
  • Electronics 
  • Food Service 
  • Medical 
Imidized Plastics High Performance Plastics
Description Test Method Units

PI

PAI

PBI

PEEK

PTFE

Ultem

Specific Gravity

ASTM D792

1.43

1.41

1.3

1.31

2.16

1.28

Water Absorption

ASTM D570

%

0.24

0.4

0.4

0.1

<0.01

0.25

Hardness, Rockwell

ASTM D785

50

80

125

103

50

112

Tensile Strength

ASTM D638

psi

12500

18000

20000

16000

3900

16500

Elongation at Break

ASTM D638

%

7.5

10

3

20

300

80

Flexural Modulus

ASTM D790

ksi

450

600

950

600

72

500

Flexural Yield Strength

ASTM D790

psi

16000

24000

32000

25000

N/A

20000

Compressive Modulus

ASTM D695

ksi

350

700

900

500

3.5

480

Impact Strength

ASTM D256

ft-Ib/in

3.76

2

0.5

1

3.5

0.5

Dielectric Constant

ASTM D150

3.55

4.2

3.2

3.3

2.1

3.15

Dielectric Strength

ASTM D149

kV/m

559

580

550

480

285

830

Dissipation Factor

D150

0.026

0.003

0.003

<0.0002

0.0013

Coefficient of Thermal Expansior

D696

x10^-5in./in/F*

3

1.7

0.13

2.6

7.5

3.1

Heat Deflection Temp

D648

F 

532

800

320

132

392

Glass Transition Temp

D3418

F 

754

527

750

644

635

419

Max Operating Temp

F 

466

500

700

480

500

340

Thermal Conductivity

AST F433

BTU-in/hr-ft^2-F

3.7

2.8

1.75

1.7

0.9

 
Other Materials include
Transformer Table Icon 3.6.2 Thermoplastic Materials Torlon® Udel®
Teflon® Kynar®
Vespel®  Radel®
PEEK® Rulon®

Contact Us Today to learn more about high-performance or imidized thermoplastic materials from The Gund Company, or to request a quote for your application!


For an in-depth guide on selecting the right thermoplastic for your application, click here!