HTV silicone - combination of the properties of rubber and silicone

What is HTV silicone?

HTV silicone stands for high-temperature vulcanising silicone rubber or solid silicone. It is usually produced on the basis of VMQ (vinyl methyl silicone) or FVMQ (fluoro-vinyl methyl silicone). In contrast to liquid silicone (LSR), HTV is available as a solid, kneadable mass that is processed in a pressing, transfer or injection moulding process and then vulcanised using heat. This processing method makes HTV silicone the preferred choice for precise Molded Silicone such as seals, profiles or membrane elements - and due to its adhesive properties is also suitable for Metal Composite Parts, where the material is permanently bonded to metallic substrates.

 

What are the properties of HTV silicone?

The properties of HTV silicone lie somewhere between the soft RTV silicones and the flowable LSR-types. It combines the resilience of classic rubber with the durability of silicone:

  • Mechanical strength: Higher than with LSR and RTV. Due to the higher filler content (mostly silica), HTV has greater tear resistance, abrasion resistance and dimensional stability
  • Elasticity in the temperature range from -50 °C to +200 °C
  • Temperature resistance: Comparable with LSR, significantly better than RTV. HTV withstands long-term temperature changes without losing hardness or structure
  • Chemical resistance: Excellent against Oils, greases, fuels and many solvents, especially in the case of FVMQ-types
  • Ageing- and UV resistance: Identically high as with LSR; no embrittlement or cracking even after years outdoors
  • Electrical properties: Good insulation values, but slightly weaker than LSR, which offers advantages for thin-walled parts due to its purity
  • Surface quality: HTV produces a slightly rougher, more matt surface than LSR, which enables very smooth and transparent parts
  • Purity: HTV contains low residues of peroxides or additives, depending on the type of cross-linking

HTV is mechanically stronger and more robust, LSR more precise and cleaner, RTV easier to process, but less resilient.

 

What are the possible applications for HTV silicone?

  • Automotive industry: HTV silicone is used for Seals, hoses, plugs and Vibration dampers used
  • Electronics: Due to its electrical insulation properties, HTV is suitable for high-voltage insulators, cable sheathing and connectors
  • Medical technology: HTV is used for tubes in medical components, Seals or membranes. It is biocompatible, odourless and can be sterilised without losing its elasticity
  • Mechanical and plant engineering: HTV is recognised as a Gasket- and moulding material used in machines that are exposed to temperature, pressure or chemicals
  • Composite parts: HTV can be easily combined with appropriately surface-treated metal or plastic inserts