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 present as a solid, kneadable mass, which in the Press-, Transfer- or Injection moulding process processed and then heated through vulcanised becomes.
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.
Application of 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