Insulators are prone to static charge due to friction i […]
Insulators are prone to static charge due to friction in dry air, which causes great harm to processing and use. The method to prevent the harm of static electricity is essentially to reduce or prevent friction to reduce the generation of static charge, or to make the static charge leak quickly through various ways. At 20 ℃, if the ρs of the polymer sample is less than 1010Ω, the polymer can be considered to have good antistatic properties: if ρs = 1010-1012Ω, the polymer can be considered to have good resistance Static performance; when ρs = 1012-1014Ω, the polymer can be considered to have a moderate antistatic effect; when ρs = 1014-1015Ω, only a weak antistatic effect; when ρs is higher than 1015Ω, it is considered to have no antistatic effect . At present, the processing methods of antistatic polyolefin composite materials mainly include the method of adding conductive fillers, the method of adding antistatic agents and blending with structural conductive polymer materials.
This type of method incorporates an inorganic conductive filler into the matrix of polyolefin material. At present, carbon black filling is the most widely used, because carbon black raw materials are easily available, inexpensive, and have long-lasting and stable conductive properties, and can also greatly adjust the conductive properties. Carbon black itself has a volume resistance between 0.1 and 10.2 Ω and is a natural semiconductor. In the resin composite, when the carbon black particles are in contact with each other to form a mesh network or the gap between the carbon black particles is several 10-10m, a conductive path can be formed. Therefore, the composite antistatic polymer material made of carbon black is a kind of antistatic material with wide application and large amount. Metal fillers can also be used, mainly including metal powders (Ag, Cu, Al, Ni, etc.), metal fibers (copper fibers, aluminum fibers, stainless steel fibers, alloy fibers, etc.) and metal oxides.