Physical Recycling Of PET Plastic Bottles

The physical recycling method of PET plastic bottle is relatively simple, mainly drying and granulating the cleaned PET plastic bottle waste. The physical treatment of PET plastic bottles is closely related to the sorting process. There are two main physical recovery methods: one is to cut waste PET plastic bottles into pieces, and separate HDPE, aluminum, paper and adhesive from PET, and then wash, dry and granulate the PET fragments; Second, the impurities on the waste PET plastic bottle, such as non PET bottle cap, base, label, etc., are separated mechanically, and then washed, crushed and granulated. The recycled PET shall not contain PVC impurities, otherwise the color of PET will be affected. When the amount of PVC mixed is small, it can be separated manually on the conveyor belt. That is, PVC and PET plastic bottles will have different melting points at the stressed part under the action of torque. Broken PET and PVC fragments will pass through the conveyor belt equipped with heater and temperature control. PVC will be melted and adhered to the conveyor belt, so that it can be separated from PET. The label on the beverage bottle can be removed by the combined separation device of blower and cyclone separator after the bottle is broken. The extraction tower separation device can also be used for separation. Broken PET fragments are added vertically from the top of the separation tower. The fragments form a countercurrent with the updraft. The labels are removed by taking advantage of the specific gravity difference between PET and label fragments. PET comes out from the bottom of the separator. In order to ensure the label separation efficiency, more than two sets of separation devices can be used in production. The washing of PET fragments is very important. The hot water at 80-100 ℃ is often used to soften or dissolve the EVA adhesive or other types of adhesives used to stick labels and bases. To prevent the adhesive from falling off from adhering to PET fragments, additives such as alkali, emulsifier or other special chemicals need to be added to the water. The composition and content of the cleaning solution are generally determined by the factory according to the source and bonding characteristics of the waste bottle. The cleaning solution can be recycled after filtering impurities and reheating. Washing can be carried out in a special cleaning tank equipped with an agitator. In order to ensure the cleaning effect, the two-stage washing process can be used. PET chips usually use a centrifugal dehydrator to reduce the moisture content of the chips to 2%, and then dry them in a belt or tube dryer to reduce the moisture content to 0.5%. The recycling system of high-quality PET plastic bottles successfully developed by Krones of Germany has an annual processing capacity of 15000 tons of PET beverage bottles. The processed PET raw materials can be directly made into other PET containers, greatly reducing the production cost. PET plastic bottle recycling system uses chemical coating elimination technology and caustic soda as the chemical coating remover to remove the pollutants attached to the surface of PET plastic bottle, which can realize recycling of any kind of PET plastic bottle. The recycled products treated by this technology can not only be directly mixed to make bottle preforms, but also can meet the requirements of purity and quality due to the low content of acetaldehyde and yellow pigment. It is especially suitable for packaging products in the food and beverage industry, and its cost is 20% - 30% lower than that of ordinary new materials.