What is HCR?

Question: What is HCR?

Answer: This heat cure rubber or high consistency rubber is an old technology. Its physical form appears to be a solid block of rubber as pre-cure material. As a result of thixotropic untreated silica and a very high viscosity polymer, HCR is a very high consistency material. Since untreated silica is very thixotropic, it requires high shear to break the hydrogen bond. This leads to a reduction in viscosity and flows into molds. High pressure presses are typically used to mold HCR. The properties of HCR in comparison with other silicone materials are illustrated in the table below.

Type of Silicone Rubber Tensile Strength Tear Strength Elongation

Units: Mpa Units: kN/m Range

HCR – High Consistency Rubber 4 to 13 9 to 55 90 to 1120%

FSR – Fluorosilicone Rubber 9 to 12 18 to 46 160 to 700%

LSR – Liquid Silicone Rubber 4 to 12 11 to 52 220 to 900%

RTV – Room Temperature Vulcanize 6 9 370%


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About Veasna

After interning for more than a year at Albright Technologies, Veasna gained experience in many aspects of silicone manufacturing including understanding of materials, mold making, and silicone molding. Veasna received a Bachelors of Science in Plastics Engineering from University of Massachusetts in Lowell in 2010, shortly after he accepted a full time position at Albright Technologies. In the spring of 2011, he received a Graduate Certificate in Plastics Design from UML. Veasna is mainly responsible for managing customer’s projects which begin from signed purchase orders to accepted and on-time part deliveries, he is also actively involved in research work on silicone bonding.