The molecular structure of PET plastic is highly symmetrical and has a certain crystal orientation ability, so it has high film-forming properties and properties. PET plastic has good optical properties and weather resistance, and amorphous PET plastic has good optical transparency.
In addition, PET plastic has excellent abrasion resistance, dimensional stability and electrical insulation. PET bottles have high strength, good transparency, harmlessness, anti-permeation, light weight, high production efficiency, etc., so they have been widely used.
PBT and PET molecular chain structure is similar, most of the properties are also the same, but the main molecular chain has changed from two methylene groups to four, so the molecule is more flexible and the processing performance is better.
PET is a milky white or light-colored highly crystalline polymer with a smooth and shiny surface. Creep resistance, soothing fatigue, good friction resistance, low abrasion and high hardness, with the toughness of thermoplastic plastics; good electrical insulation performance, less affected by temperature, but poor corona resistance.
Harmless, weather resistance, chemical resistance, good stability, high moisture absorption, drying before molding is necessary. Resistant to weak acids and solvents in agricultural production systems, but not immersed in hot water or alkali.
PET resin has high glass transition temperature, slow crystallization speed, long molding cycle, long molding cycle, large molding shrinkage, poor dimensional stability, brittleness of crystallization molding, low heat resistance, etc.
Through the improvement of nucleating agent, crystallization agent and glass fiber reinforcement, PET has the following characteristics in addition to the properties of PBT:
The heat distortion temperature and long-term use temperature are very high in thermoplastic general engineering plastics;
2. Because of the high heat resistance, the reinforced PET is immersed in a solder bath at 250°C for 10s, and it hardly deforms or discolors. It is especially suitable for the preparation of soldered electronic and electrical parts;
3. The bending strength is 200MPa, the modulus of elasticity is 4000MPa, the creep and fatigue resistance are also very good, the surface hardness is high, and the mechanical properties are similar to thermoset plastics;
4. Since the ethylene glycol used in the production of PET is almost half cheaper than the butylene glycol used in the production of PBT, the price of PET resin and reinforced PET is low among engineering plastics and has a high cost performance.
5. Adhesion of PET resin: sili-1706 one-component room temperature vulcaniz Specially used for bonding engineering plastics.