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How Does PET Restore Strength?

Apr 27, 2019

The physical recycling process of PET plastic bottles is relatively simple, mainly to dry and granulate the cleaned PET plastic bottle waste. The physical handling of PET plastic bottles is closely related to the sorting process. There are two main physical recycling methods: one is to cut a waste plastic PET plastic bottle into pieces, separate HDPE, aluminum, paper and adhesive from PET, then wash, dry and granulate the PET chip; waste PET Non-PET caps, binders, labels and other impurities on plastic bottles are mechanically separated, washed, comminuted and granulated. Recycled PET must not contain PVC impurities, otherwise it will affect the color of PET. When the amount of mixed PVC is small, it can be manually separated on a conveyor belt. That is, when torque is applied, the PVC and PET plastic bottles produce different melting points in the stressed portion, and the broken PET and PVC chips pass through the heater and temperature. The controlled conveyor belt PVC melts and adheres to the conveyor belt, allowing it to be separated from the PET. After the bottle is broken and combined with the blower and cyclone, the label on the beverage bottle can be removed. It can also be separated by a suction column separation device. The broken PET chips are added vertically from the top of the separation column, and the debris forms a countercurrent with the updraft. Using the difference in specific gravity between the PET and the label, remove the label and remove the PET from the bottom of the separator. In order to ensure label separation efficiency, more than two sets of separation devices can be used in production. Cleaning of the PET chip is very important. Washing typically uses 80-100 ° C hot water to soften or dissolve the EVA adhesive or other types of adhesive attached to the label and substrate. To prevent the peeling adhesive from sticking to the PET chip, add additives such as water, emuls, emulsifiers or other special chemicals. The cleaning fluid is usually determined by the factory based on the source and adhesion characteristics of the waste bottle. The cleaning solution can be filtered and reheated and recirculated. Washing can be carried out in a special washing tank equipped with a stirrer. For the cleaning effect, a washing can be carried out using a secondary washing process. The PET chips were reduced to 2% by using a centrifugal dehydrator and then dried by a belt or tube dryer to reduce the moisture content to 0.5%. The high-quality PET plastic bottle recycling system successfully developed by Krones Germany has an annual processing capacity of 15,000 tons of PET beverage bottles. The processed PET material can be directly made into other PET containers, which greatly reduces the production cost. PET plastic bottle recycling system uses chemical coating elimination technology, using caustic soda as a chemical coating remover to remove contaminants attached to the surface of PET plastic bottles, which can realize the recycling of various PET plastic bottles. Recycled products treated with this technology can not only directly mix prefabricated parts, but also because of the low content of acetaldehyde and yellow pigments, the recycled products can meet the purity and quality requirements, especially for the food and beverage industry. Packaging, the cost is 20%-30% lower than ordinary new materials.