Physical properties requirements: When we understand the application environment requirements of silicone products, we need to convert into the corresponding physical properties requirements of silicone rubber raw materials in order to choose the appropriate silicone raw materials. Physical property requirements mainly consider the following aspects:
1, electrical performance requirements: some products have insulation, high voltage resistance, conductivity and other requirements, then you need to choose the corresponding silicone material.
2, color and light transmission requirements: some color products need to specify the color of silica gel, and some optical products need to use high transparent silica gel, then you need to choose the corresponding silica gel raw materials.
3, mechanical properties requirements:
  Hardness: hardness is the core factor in the mechanical properties of silica gel, characterizing the impact resistance of silica gel, must choose the appropriate hardness of silica gel raw materials in order to produce good silica gel products. The hardness of silica gel is generally between ShoreA0-90.
   Tensile strength: tensile strength refers to the maximum tensile stress until the break, silica gel with high tensile strength is what we often say is high-strength silica gel, tensile strength has a direct impact on the resilience and service life of silica gel, the selection of silica gel material tensile strength is an important factor to consider.
   Elongation at break: Elongation at break is the percentage of the length of the standard silica gel sample at the time of breaking to the original length. Some silicone rubber products need to be stretched more times when used, then the parameter of elongation at break must be considered.
   Tear strength: tear strength refers to the resistance of silicone under the action of tearing force, some silicone products damaged by tearing force (such as pacifiers and other baby products) must be selected with high tear resistance silicone raw materials to ensure a long service life.
   Compression permanent deformation rate: compression permanent deformation rate refers to the percentage of silicone under high temperature compression conditions under irreversible deformation, for some seals and rollers, low compression permanent deformation rate is the core requirement. For silicone rubber, the compression permanent deformation rate of less than 10% can be called low pressure silicone.
4, the temperature range of use requirements: some products need to be used at a higher temperature (such as hot stamping silicone parts), while other products need to be used in a low temperature environment (such as aerospace seals), which requires the corresponding selection of high temperature silicone, low temperature silicone raw materials.
5, fire retardant requirements: some silicone products have fire protection requirements (such as silicone cables), silicone parts can not ignite, then you must choose flame retardant silicone. Silicone flame retardant commonly certified as UL, fire rating from high to low in order of UL94-V0, UL94-V1, UL94-HB, generally speaking, ordinary silicone can pass the UL94-HB test.
6, chemical resistance requirements; Ordinary methylvinyl silicone rubber is resistant to weak acids, strong alkalis and inorganic salts, but it is generally resistant to organic solvents, and a specially formulated silicone rubber is required to meet the chemical requirements. Ordinary silicone is not resistant to lubricating oil.
7, radiation resistance requirements: ordinary silica gel raw materials are resistant to natural light and ozone, but can not withstand high-intensity ultraviolet radiation, then you need to choose the corresponding silica gel raw materials.