The characteristics of PET plastic crystallization machine of packing belt production line: PET is a hygroscopic material. If the water content is too high, it will produce hydrolysis under high temperature processing, which will cause the breakage and thermal decomposition of PET molecular chain to produce acetaldehyde. The physical and mechanical properties will decrease, and the crystallization rate Accelerated, when the preforms are ejected, the preforms will be partially crystallized and the quality of the product will be affected. Packing belt production line manufacturers
PET pellets must be dried to a moisture content of 0.005% (50ppm) or less before the preforms are injection molded so as to produce good amorphous transparent preforms. The proportion of recycled materials should not exceed 25%, and the recycled materials should also be thoroughly dried.
Material : pet broken material
Crystallization Drying Temperature: 160-170°C
Crystal Drying Time: 5h
Raw material moisture content: ≤2000ppm
After drying, water content: 100-120ppm
Dry Air Dew Point : -40°C---45°C
Second, pet crystal machine features
1. The constant-speed stirring design makes the plastic not crystallize in the crystallizing process temperature, and the crystallizing efficiency is high and uniform.
2. It can simplify and improve the efficiency of raw materials drying;
3, the raw material can be dried at high temperature, and the drying process can directly use the existing standard drying bucket;
4. Double overheat protection device to reduce accidents caused by human or machine failure;
5, the process temperature can be accurately controlled through the thermostat;
6, increase the use of recycled materials in the new PET material;
7, standard equipped with a tripod, can be used with a dehumidifier, direct dehumidification operations;
8, optional vacuum hopper, suction machine, magnetic base, suction box for transportation;
9, optional screw feed device quantitative output crystal material
The working principle of PET crystallization machine:
The feed is started and the electric fan starts and the raw material starts heating. When the raw material fills above the level switch position, the main control box stops outputting signals to the auxiliary feeder, the raw material is heated for a period of time, and when the temperature probe of the bucket reaches the set crystallization temperature value, the raw material is fed by the feeding device. At this time, as the material level in the material head gradually decreases, the feeding device starts to supplement the uncrystallized material to achieve continuous crystallization operation.
When the temperature probe reaches the set stop discharge temperature value, the feed device stops working. When the temperature rises to the set crystallization temperature value, the discharge device works again, so that continuous crystallization is achieved by continuous circulation.