Homopolymer co-extrusion process high transparent PET plastic sheet rolls

Specification of Homopolymer co-extrusion process high transparent PET plastic sheet rolls

Parameters of Homopolymer co-extrusion process high transparent PET plastic sheet rolls

PET is a milky white or light yellow highly crystalline polymer with a smooth and shiny surface. Creep resistance, fatigue resistance, abrasion resistance, good dimensional stability, low abrasion and high hardness, with the greatest toughness among thermoplastics: good electrical insulation, low temperature influence, but poor corona resistance. Non-toxic, weather resistance, good chemical resistance stability, low water absorption, resistance to weak acids and organic solvents, but not immersed in hot water and alkali. PET resin has high glass transition temperature, slow crystallization speed, long molding cycle, long molding cycle, large molding shrinkage, poor dimensional stability, crystallization molding is brittle, low heat resistance, etc. Through the improvement of nucleating agent and crystallization agent and glass fiber reinforcement,
In addition to the properties of PBT, PET has the following characteristics:
1. The heat distortion temperature and long-term use temperature are the highest among thermoplastic general engineering plastics;
2. The bending strength is 200MPa, the elastic modulus reaches 4000MPa, the creep and fatigue resistance are also very good, the surface hardness is high, and the mechanical properties are similar to those of thermosetting plastics;
3. Since the price of ethylene glycol used in the production of PET is almost half the price of butylene glycol used in the production of PBT, PET resin and reinforced PET are the lowest price among engineering plastics and have a high cost performance.

The molding process of PET can be injection molding, extrusion, blow molding, coating, bonding, machining, electroplating, vacuum metal plating, and printing. The following mainly introduces two kinds.
1. Injection molding level ① Temperature setting: Nozzle: 280~295℃, front section 270~275℃, middle forging section 265~275℃, rear section 250-270℃; screw speed 50~100rpm, mold temperature 30~85℃ , Amorphous mold is below 70℃, back pressure is 5-15KG. ②Try the desiccant dryer, the barrel temperature is 240~280℃, the injection pressure is 500~1400℃, the injection molding temperature is 260~280℃, the drying temperature is 120~140℃, and it takes 2~5 hours.
2. For the film level, the PET resin chips are pre-dried to prevent hydrolysis, and then the amorphous thick flakes are extruded through a T-die in an extruder at 280°C, and then quenched by a cooling drum or coolant to keep them Amorphous shape for stretching orientation. The thick film is then biaxially stretched by the tenter to form a PET film. Longitudinal stretching is to preheat the thick sheet to 86~87℃, and stretch it about 3 times along the plane extension direction of the thick sheet at this temperature, so that its orientation can increase the crystallinity and reach a higher temperature: transverse stretching preheating temperature 98~100℃, stretching temperature 100~120℃, stretching ratio 2.5~4.0, heat setting temperature 230~240℃. The film after stretching in the vertical and horizontal directions needs to be heat-set to eliminate the film deformation caused by stretching and make a film with better thermal stability.