As we all know, the packing material has plastic, ceramic, metal optional, then how to choose it when we buy packing? See below:
(1) Plastic Packing: material mainly includes polypropylene (PP), polyethylene (PE) and polyvinyl chloride (PVC), etc., general use of polypropylene material. Plastic packing has good corrosion resistance, can withstand the general inorganic acid, alkali and organic solvent corrosion. Its good temperature resistance allows long-term use under 100 ° C.
Plastic packing is of lightweight, cheap, with good toughness, impact resistance, breakage-proof, can be made into thin-walled structure. It has large flux, low pressure, usually use for absorption, desorption, extraction, dust and other devices. The drawback of plastic packing is poor surface wetting performance, but this can be improved by appropriate surface treatment.
(2) Ceramic Packing: good corrosion resistance and heat resistance, ceramic packing is cheap, with good surface wetting performance, its biggest drawback is crisp and fragile. Commonly use in gas absorption, gas washing, liquid extraction and other applications.
(3) Metal Packing: can be made of a variety of materials, the main consideration while choosing is corrosion ability. Carbon steel packing is of low cost, and has a good surface wetting performance, for non-corrosive or corrosive substances should be given priority to use; Stainless steel packing has high corrosion resistance, can resist common corrosion in addition to Cl -, but it needs high cost, and the surface wetting performance is poor, it needs surface treatment in some special occasions (such as vacuum distillation process under very low spray density), in order to achieve good results; Titanium, special alloy steel and other materials metal packing are high cost, generally only used in some highly corrosive system.
In general, the metal packing can be made into thin-walled structure, its large flux, small gas resistance, and high impact resistance, allow it to be used in high temperature, high pressure, high impact strength. Its application range is most widely.