In machining production, plastic is one of the commonly used raw materials. Because there are many kinds of plastics, operators need to have a comprehensive understanding of the materials when processing, so as to give better play to the properties of plastic raw materials. The commonly used plastics in production are ABS, PE, PP, etc., and the commonly used transparent plastics are PC, PS, PMMA, etc.
Characteristics of commonly used plastics
1. ABS acrylonitrile butadiene propylene ethylene
This kind of plastic has excellent impact resistance, heat resistance, low temperature resistance, chemical resistance and electrical properties. It also has the characteristics of easy processing, stable product size and surface gloss. It is easy to paint and color. It can also be sprayed with metal, electroplated and welded on the surface. It is widely used in machinery, automobile, electronic and electrical fields.
2. PE polyethylene
Polyethylene is odorless, non-toxic and feels like wax. It has excellent low temperature resistance, good chemical stability, can resist the erosion of most acids and bases, is insoluble in general solvents at room temperature, has small water absorption and excellent electrical insulation performance.
3. PP polypropylene
Non toxic, tasteless, low density, strength, stiffness, hardness and toughness are better than low-pressure polyethylene, which can be used at about 100 degrees. It has good electrical properties and high-frequency insulation, which is not affected by humidity, but becomes brittle at low temperature, is not wear-resistant, and is easy to age. It is suitable for making general mechanical parts, corrosion-resistant parts and insulating parts.
2、 Transparent plastic features
1. PC polycarbonate
This kind of plastic is colorless, transparent, high-temperature resistant, has strength similar to non-ferrous metals, and has both ductility and strong toughness. Its impact strength is extremely high. It can not be damaged by hammering, and can withstand the explosion of TV fluorescent screen. It can be used repeatedly and can be colored in any way.
2. PS polyhexene
This is a colorless and transparent thermoplastic, which is resistant to water, light, chemical erosion, insulation, high temperature, brittle and flammable. It has a glass transition temperature higher than 100 degrees Celsius, so it is often used to make all kinds of disposable containers that need to bear the boiling water temperature, as well as disposable foam lunch boxes.
3. PMMA polymethylmethacrylate
This kind of plastic, also known as acrylic or plexiglass, has good transparency, corrosion resistance and outstanding aging resistance. It is easy to dye and process, and has a beautiful appearance. There are many colors, including mirror gold and silver. Its proportion is less than that of ordinary glass, and its ability to resist fragmentation is very high. It is widely used in the construction industry.
Application of plastics
1. The shell of high-end electronic products usually adopts abs+pc.
2. The display screen is PC. if PMMA is used, it needs to be hardened.
3. Most of the electronic products in the midsole used in daily life use ABS as the shell.