Thermoplastics Triangle

Click the sections of the triangle to explore characteristics and application considerations for the materials in each grouping

HIGH PERFORMANCE
HIGH SERVICE TEMPERATURE
HIGH COST
IMIDIZED MATERIALS
  • Best physical properties above 400°F
  • Best temperature resistance
  • High temperature, high load bearing and wear capabilities (bearing grades)
  • Good chemical resistance
IMIDIZED
MATERIALS
500°F
approximate maximum*
  • Vespel®
  • PAI
IMIDIZED MATERIALS
500°F
approximate maximum*
IMIDIZED MATERIALS
  • Best physical properties above 400°F
  • Best temperature resistance
  • High temperature, high load
    bearing and wear capabilities (bearing grades)
  • Good chemical resistance
  • Vespel®
  • PAI
HIGH PERFORMANCE ENGINEERING PLASTICS
350°F
approximate maximum*
AMORPHOUS HIGH
PERFORMANCE MATERIALS
  • High service temperatures
  • High strength
  • Hot water and steam resistance
  • Thermoformability
  • Radel® R
  • Ultem®
  • Polysulfone
ENGINEERING PLASTICS
250°F
approximate maximum*
AMORPHOUS
ENGINEERING PLASTICS
  • General purpose structural parts
  • Moderate strength
  • Moderate temperature
  • Good dimensional stability
  • Good Izod impact
  • Easily fabricated
  • Polycarbonate
  • Noryl® PPO
COMMODITY PLASTICS
180°F
approximate maximum*
AMORPHOUS
COMMODITY PLASTICS
  • Low temperature
  • Low strength
  • Good bondability
  • Good machinability
  • Good formability
  • Low cost
  • Polystyrene
  • PVC
  • ABS
  • Acrylic
  • PETG
  • KYDEX®
GENERAL
CHARACTERISTICS
AMORPHOUS PLASTICS

Softens over a wide temperature range
Easy to thermoform
Transparent
Poor chemical resistance
Bonds well using adhesives or solvents
Prone to stress cracking
Poor fatigue resistance
Structural applications only
(not suitable for bearing and wear)
IMIDIZED MATERIALS
500°F
approximate maximum*
IMIDIZED MATERIALS
  • Best physical properties above 400°F
  • Best temperature resistance
  • High temperature, high load
    bearing and wear capabilities (bearing grades)
  • Good chemical resistance
  • Vespel®
  • PAI
TEMPERATURE RISES
350°F
approximate maximum*
SEMI-CRYSTALLINE
HIGH PERFORMANCE MATERIALS
  • High service temperature
  • Excellent chemical resistance
  • High purity
  • PEEK®
  • PPS
  • PTFE
  • PVDF (Kynar®)
TEMPERATURE RISES
250°F
approximate maximum*
SEMI-CRYSTALLINE
ENGINEERING PLASTICS
  • General purpose bearing and wear or structural parts
  • Moderate strength and stiffness
  • Good chemical resistance
  • Moderate temperature
  • PET
  • PBT
  • Nylon
  • Acetal
TEMPERATURE RISES
180°F
approximate maximum*
SEMI-CRYSTALLINE
COMMODITY PLASTICS
  • Low temperature
  • Low strength
  • Good chemical resistance
  • Low moisture absorption
  • Low cost
  • Polypropylene
  • Polyethylene
  • (HDPE, LDPE, UHMW-PE)
GENERAL
CHARACTERISTICS
SEMI-CRYSTALLINE PLASTICS

Sharp melting point
Difficult to thermoform
Opaque
Good chemical resistance
Difficult to bond using adhesives or solvents
Resistant to stress cracking
Good fatigue resistance
Good for bearing and wear
(as well as structural applications)