Six Kinds of Recycled Plastic Process

Process flow of recycled low-density polyethylene (LDPE)

LDPE, scientific name of high-pressure polyethylene, generally refers to plastic packaging film. Such as: woven bag lining film, food packaging film, daily necessities packaging film, greenhouse film. Most of these films are natural color, but there are also light blue and black. It is best to separate the color samples before recycling. Low-pressure film and PP film cannot be put together, and OPP and PVC film cannot be put in. The recycling and reuse of LDPE is the recycled LDPE process. The entire recycled LDPE process mainly has four processes.

1. Crushing process. The effect of washing with water is better. Since some good high-pressure films can be re-blown without adding new materials if they are kept clean enough. Therefore, attention should be paid to cleaning during the crushing process. When the crushed materials flow into the water tank, it is best to roll them again to further rinse the cleaning points.

2. Drying process. Generally, the remaining water is dried in the spin dryer. If conditions permit, they are dried in the sun. This can save electricity and improve quality. Of course, attention should be paid to prevent secondary contamination of the materials during drying.

3. Granulation process. The granules produced by the special extruder have two basic uses: re-blowing film and injection molding.

The materials coming out of the 80 to 120 mesh filter can be blown again; the materials coming out of the 40 to 60 mesh filter can meet the quality requirements of injection molding. Generally speaking, high-pressure materials are blown again, and the good ones are blown in the original color, and the ones that are slightly worse are blown in black film and garbage bags. The price after injection molding is lower.

4. Pelletizing process, usually cold water pelletizing. In this process, you must pay attention to the labeling when packaging. One is for blow molding and the other is for injection molding to avoid mistakes. In addition, the packaging bag for blow molding must have an outer bag and an inner liner bag to avoid secondary contamination.

Recycled Polypropylene (PP) Process

Most of PP comes from daily necessities, such as plastic boxes, foot basins, buckets, rice baskets, plastic chairs, stools, woven bags and other packaging woven cloths, strapping tapes, etc.

1. First, separate the colors of the various materials, because separation will make it convenient for users and the price can also be high.

2. Crush and rinse with water, put it in a spin dryer to dry the remaining water, then dry it in the sun and pack it in bags. Use a mixer to mix and add some color and additives.

3. Use a special plastic machine to granulate the plastic, but the granulation temperature should not be too high, otherwise it will become brittle, so you must pay attention to the temperature.

4. Water-cooled pelletizing should be of standard 3X4mm, otherwise even the best material will not look good and will not be standard.

Recycled polyethylene terephthalate (PET) process flow

PET, scientific name: polyethylene terephthalate, is a linear thermoplastic

PET is usually a crystalline plastic. PET bottles have replaced some traditional packaging materials due to their advantages such as light weight, not easy to break, and low energy consumption. They are widely used in food, beverages, cosmetics and other fields. The recycling and reuse of PET is the recycled PET process.

The recycling process of PET bottle flakes is to separate the PET bottle body from the cap, label, etc., and then crush, wash and dry them.

Its specific process is as follows:

1. The first step is the selection process: select and classify various PET bottle pieces. Tear off the outer labels, most of which are OPP, and some are polyvinyl chloride shrink films, which must be peeled off first.

2. Crushing process: rinse with water during the crushing process to remove dirt from various PET bottle pieces.

3. Put the fragments into the steam treatment device, add caustic soda, and remove grease and other stubborn impurities.

4. Wash with clean water, shake off the remaining water and bag. Then put it in a vacuum oven for drying.

5. Spinning, shaping, stretching with hot water steam, and shaping again.

ABS plastic process flow

ABS plastics mostly come from electrical products, various daily necessities and some small mechanical parts.

1. ABS is mostly used in computer cases, TV cases, instrument cases, car panels, and decorative materials. Pick out these materials, especially the electroplating and paint colors.

2. Chemical treatment, stripping, and paint stripping, but stripping must be done with caution, because the chemical solutions have a certain ratio and protective equipment and containers must be used, otherwise it will cause injuries and other incidents.

3. Go to the cleaning tank to clean, then go to dry, match colors or put auxiliary materials to improve quality.

4. Use a special extruder to granulate, but be sure to put a filter on it, but the filter should be placed according to product requirements.

Recycled Polycarbonate (PC) Process

Polycarbonate, non-crystalline plastics, engineering plastics. Most of them come from textile accessories, automobile headlights, taillights, turn signals, candy making molds, discs, telecommunications equipment, photographic equipment, etc.

1. First, select the purchased PC. There are transparent and opaque ones, and blue, red, green and black must be separated. There are also modified ones, such as most of the textile accessories are modified; such as discs and lamp holders are all coated.

2. Cleaning of various PCs, and the deplating process of disc lamp holders, etc., is also operated in the same principle as ABS. Then dry, classify, and send to the extruder for production.

3. Some PCs are yellowish and can be produced into porcelain white; transparent ones can still be produced into transparent ones; other colors can be added with colorants and material additives.

4. Use a special extruder to granulate, but PC itself is easy to age, so it cannot be recycled many times. Be careful when granulating and cut the pellets for packaging.

Recycled polyvinyl chloride (PVC) hard material process flow

Most PVC hard materials come from building materials, plastic steel windows and doors, electroplated hard panels, plastic valves used in chemical plants, sewer pipes, and decorative materials.

1. First, select the process and separate the colors. These materials are generally divided into three types: white, gray, and black, but do not mix PP and PE.

2. Grind it in a grinder, but it will also be ground with water. Remove the pollution, wash it with water, and then dry it in the sun to prevent secondary pollution.

3. Put the ingredients in a mixer and mix them. If it is white material, add some colorant and add additives as needed.

4. Special PVC extruder is used to scrape particles, cool, bag and label them before shipment.

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