Poly­styrene (PS)


  • Ther­mo­plas­tic that is trans­par­ent and also avail­able in colors
  • Usu­ally processed by injec­tion mold­ing, but blow and vac­uum mold­ing, ther­mo­form­ing, extru­sion or com­pres­sion mold­ing, and machin­ing work equally well
  • Resis­tant to alka­lis, salts, lower alco­hols and weak acids
  • FDA-compliant
  • General-purpose poly­styrene (GPPS) has excel­lent trans­parency, water resis­tant and dielec­tric strength
  • High-impact poly­styrene (HIPS) has excel­lent dimen­sional strength and impact– and heat-resistant

Com­mon uses

  • Elec­tronic circuits
  • Elec­tri­cal components
  • High-frequency insu­la­tion sheeting
  • Home appli­ances
  • Toys


Mate­r­ial Specifications

ASTM or UL test Prop­erty GPPS
D792 Den­sity (lb/in3)/(g/cm3) 0.043 (1.05)
D570 Water absorp­tion, 24 hrs (%) 0.06
D638 Ten­sile strength (psi) 7,500
D638 Ten­sile mod­u­lus (psi) -
D638 Ten­sile elon­ga­tion at break (%) 47
D790 Flex­ural strength (psi) 6,100
D790 Flex­ural mod­u­lus (psi) 475,000
D785 Hard­ness, Rockwell 75
D256 Izod notched impact (ft-lb/in) 0.8
D696 Coef­fi­cient of lin­ear ther­mal
expan­sion (x 10–5 in./in./°F)
D648 Heat deflec­tion temp (F°) at 264 psi 144.60
D3418 Melt­ing temp (F°/C°) -
D3418 Vicat soft­en­ing temp (F°/C°) 224/107
- Max oper­at­ing temp (F°/C°) 150/65
C177 Ther­mal con­duc­tiv­ity
UL94 Flam­ma­bil­ity rating H-B
D150 Dielec­tric con­stant at 1 MHz 2.5
D150 Dis­si­pa­tion fac­tor at 1 KHz 0.0005–0.00690
D150 Dielec­tric strength at 1KHz 305–14,000
D495 Arc resis­tance (sec) 70
D257 Vol­ume resis­tiv­ity (ohm/cm) at 50% RH >1016

These are typ­i­cal val­ues for ref­er­ence and com­par­i­son only. They should not be used as a basis for design spec­i­fi­ca­tions or qual­ity con­trol. Con­tact us for the man­u­fac­tur­ers’ com­plete mate­r­ial prop­erty datasheets. All val­ues were taken at 73°F (23°C) unless oth­er­wise noted.

Don’t see what you’re look­ing for? Call us at 800–423-2769 or email us at tom@crownplasticsinc.com.