There are two kinds of materials in plastic seals, PP and PE.
PE is a kind of thermoplastic resin made of ethylene, no stink and no poison and it feels like wax. It has good anti-low temperature performance. It can be used at -70～-100℃ with steady chemistry. And resist corrosion of most acid and alkali but it doesn’t resist corrosion of acid with oxygen. It does not solve in common solvents at common temperature, with small water absorption and good electricity insulating property. But the property of PE varies from different types. It has bad reaction to environment chemistry and mechanics and bad anti-heat and anti-aging performance. PE can be made of common thermoplastic. It has wide application, mainly is used to make film, vessel, pipeline, single wire, cable lines, daily goods, and also can be used as high frequency insulant materials of TV and radar. PP is a kind of thermoplastic resin made of propylene, without poison or flavor, small density, its strength, rigidness and hardness anti-thermal performance is lower than low pressure PP. it can be used at about 100degree. It has good electricity performance and high frequency insulant is not influenced by humidity. But it will become fragile, aging at low temperature. It is applied to make common mechanical parts, anti-corrosion parts and insulant parts. Common acid and alkali organic solvents does not influence its performance, and it can be used for tableware.
PP and PE are both wax polymers in milk white and half-transparent color. They have good consistency, no poison and good chemical stability, easy to shape. The difference of PP and PE is that PE is easy to be oxidized while PP has good strength and anti-heat and rigidity. PP is smaller than PE in density and the tenacity of PP is bad in low temperature.
Plastic seal is made of PP and PE, which increases seals hardness and softness, which is more suitable for various environments.
