Introduction of flame-retardant coated silicone
By adding flame retardants (such as aluminum hydroxide, magnesium hydroxide, halogen-containing compounds, phosphorus-based flame retardants, etc.), coated silicone can have different levels of flame retardant properties. The specific features are as follows:
Flame retardant mechanism:
Inorganic flame retardants (such as aluminum hydroxide) absorb heat when decomposed by heat, while releasing water to dilute oxygen, forming a silica flame retardant layer to isolate the flame;
Halogen-containing flame retardants inhibit combustion reactions by releasing hydrogen halide gas (but may produce toxic gases, and are gradually replaced by environmentally friendly formulas).
Common flame retardant grades:
UL94 V-0 grade: the highest level of vertical combustion test, the sample burning time is extremely short (no more than 10 seconds per time), no dripping ignites the cotton pad below, which is a common standard in the electronic and electrical fields;
UL94 V-1/V-2 grade: the burning time is slightly longer (V-1 no more than 30 seconds per time, V-2 allows dripping to ignite the cotton pad);
UL94 HB grade: horizontal combustion test, suitable for materials with a thickness of ≤3mm, and a slower burning speed.
Application scenarios:
Electronic and electrical fields (such as circuit boards, cable connectors): need to pass UL94 V-0 grade flame retardant to prevent short circuit fire from spreading;
Automobile, aerospace: flame retardant coated silicone can be used to protect components in the engine compartment and cabin to reduce the risk of fire;
Public facilities: such as wires and pipeline coatings in buildings, must meet fire retardant standards.
