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Home > Materials > Platinum Cure HCR Silicone Sheet - SSP4749 High Purity Series

Platinum Cure HCR Silicone Sheet


SSP4749 High Purity Series

Platinum Cure Silicone

SSP4749-XX high performance silicone rubber is a unique high consistency rubber (HCR) that is platinum catalyzed. This platinum cured silicone is an excellent choice for medical device (non-implant) applications meeting USP Class VI, food contact applications that need to meet FDA CFR 21 177.2600 and other applications that may have sensitivities to outgassing or leaching. Stockwell Elastomerics provides SSP4749-XX to customers that need this high performance silicone rubber for such applications.





Platinum vs. Peroxide Cured High Consistency Rubber (HCR)

SSP4749-XX is a unique high consistency rubber (HCR) that is platinum catalyzed. Platinum catalyzed silicones are often used in medical and food contact applications as a result of the "cleaner" curing process. Free radical curing, which typically uses peroxide as a catalyst, generates organic acids as a by-product that can leach or be extracted. For medical devices, food contact and other sensitive applications, peroxide cured silicones may not be allowed or may require post curing to drive off the volatiles. In general, platinum cured silicones like SSP4749-XX are the best choice for sensitive applications. In these industries, the terms "platinum cure" and "addition cure" are used interchangeably.




SSP4749-XX vs. Liquid Silicone Rubber (LSR)

Most liquid silicone rubber (LSR) materials are addition cured so they don't generate the organic acids that peroxides do. Stockwell Elastomerics injection molds LSR for 3D geometries. For applications that need to be die cut, require a wider temperature range or greater elongation and tear properties - SSP4749-XX is the better option. SSP4749-XX is made in continuous rolls vs. Stockwell’s LSR 12”x12”sheets. These continuous silicone rubber rolls offer better efficiency for die cut, waterjet cutting, and tool-less flashcutting.




Processing High Consistency Rubber (HCR) vs. Liquid Silicone Rubber (LSR)

High Consistency Rubber (HCR) silicone is sometimes called gum based silicone in contrast to liquid silicone rubber. Traditionally HCRs are peroxide cured and in raw form look like potters clay. LSRs are generally platinum cured and in raw form are Part A and Part B liquids. These liquids are mixed and either injection molded or cast and heat cured. SSP4749-XX is a cleaner platinum cured HCR or gum based silicone that can be compression molded or roto-cured into continuous sheets.




SSP4749-XX Benefits and Properties

SSP4749-XX combines the benefits of the "cleaner" platinum cure system, commonly associated with liquid silicone but with better physical properties associated with HCRs. These include a wide temperature range of -67°F (-55°C) to 392°F (200°C), high tear strength, and greater elongation. SSP4749-XX can also be post cured to further improve its excellent outgassing properties. Many silicone rubber products are not able to meet the total mass loss (TML) and/or Collected Volatile Condensable Materials (CVCM) limits for low outgassing. NASA defines the low outgassing thresholds of 1.0% TML and 0.10% CVCM.




FDA High Consistency Rubber (HCR), Silicone

Stockwell Elastomerics offers SSP4749-XX material in 7 different hardnesses, from 10 durometer to 70 durometer.

  • SSP4749-10 – 10 durometer High Consistency Rubber (HCR)
  • SSP4749-20 – 20 durometer High Consistency Rubber (HCR)
  • SSP4749-30 – 30 durometer High Consistency Rubber (HCR)
  • SSP4749-40 – 40 durometer High Consistency Rubber (HCR)
  • SSP4749-50 – 50 durometer High Consistency Rubber (HCR)
  • SSP4749-60 – 60 durometer High Consistency Rubber (HCR)
  • SSP4749-70 – 70 durometer High Consistency Rubber (HCR)



Contact Stockwell Elastomerics for SSP4749-XX

Contact Us for further assistance with SSP4749-XX High Consistency Rubber (HCR), a high performance silicone rubber for medical device (non-implant) and food contact applications.