PET is a milky white or former yellow highly crystalline polymer with a smooth and glossy surface. Resistance to creep, fatigue resistance, friction and dimension stability, low abrasion and high hardness, maximum toughness in thermoplastic plastics; Good electrical insulation performance, low temperature effect, but low resistance to corona. Non - toxic, weather resistant, anti - chemical stability, low water absorption rate, weak acid and organic solvent, but not heat - resistant water immersion, non - alkali.
1. The advantages of PET
1.1 with good mechanical properties, the impact strength is 3~5 times of other films and good folding resistance.
1.2 oil resistance, fat resistance, dilute acid, dilute alkali and most solvents.
1.3 low permeability of gas and water vapor, with excellent resistance to gas, water, oil and odor.
1.4 transparency is high, can block ultraviolet ray, luster is good.
1.5 non-toxic, tasteless, hygienic safety, can be used directly in food packaging.
2. PET injection molding process.
2.1 tube embryos
Preparation of blow molding bottle, the first will be PET chip for bottle preform injection molding, it requires that the secondary recovery ratio cannot be too high (below 5%), the recycling number cannot exceed twice, and low molecular weight and viscosity cannot (31000-50000, the molecular weight of 0.78 21.25 px3 characteristic viscosity/g).
2.2 blow molding
This stage is to place the preheated flask (embryo) into the blown mold that has been done, and then inflate the inside of it. Blow the billet into the desired bottle. The full-automatic bottle blowing machine combines the two operations of the bottle with the operation of the manipulator, eliminating the process of putting the preheated flask into the blow molding. The rate of production has been greatly speeded up.