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I. Process flow for recycling low-density polyethylene (LDPE). LDPE, whose scientific name is high-pressure polyethylene, generally refers to plastic packaging films. Such as: lining film for woven bags, food packaging film, packaging film for daily necessities, and greenhouse film. Most of these films are in their natural color, but there are also light blue and black ones; it is best to separate the different colors before recycling. Low-pressure films and PP films should not be placed together, nor should OPP and PVC films be put in there. The recycling and reuse of LDPE is the process flow of recycled LDPE. The entire recycled LDPE production process consists of four main steps. 1. Crushing process. The effect of crushing and flushing with water is even better. Since some high-quality high-pressure membranes can be blown into film again without the need to add new material, as long as they are kept sufficiently clean. Therefore, attention should be paid to cleanliness during the crushing process; it is advisable to roll the crushed material again once it reaches the water tank, in order to further clean it. 2. Drying process. Generally, the excess water is removed using a dryer; if possible, the material is also dried in the sun, which helps to save on electricity costs and improve quality. Of course, it is important to prevent secondary contamination of the material during drying. 3. Granulation process. The pellets produced by dedicated extruders have two basic uses: re-extrusion into films and injection molding. The material that passes through 60- to 80-mesh filters can be re-blow molded; the material that passes through 40- to 60-mesh filters meets the quality requirements for injection molding. Generally, high-pressure material is used again for film blowing; when blown in its original color, the quality is good, while when blown into black film or garbage bags, the quality is poorer. The price is even lower when it is used for injection molding. 4. Pelletizing process, which is generally cold-water pelletizing. Attention must be paid to distinguishing the labels during packaging for this process. One for blow molding, one for injection molding, to avoid confusion. Additionally, for blow-molded packaging bags, an outer bag must be used along with an inner liner to prevent secondary contamination. II. Process flow of recycled polypropylene (PP): Most PP products are found in daily items such as plastic boxes, basins, buckets, rice-washing baskets, plastic chairs and stools, woven bags, as well as other packaging materials like woven fabrics and packing straps. 1. First, separate the colors of the various materials; doing so will be convenient for customers, and the price can also be higher. 2. Crush and wash with water, then use a spin dryer to remove excess water, followed by drying and bagging. Mix it with a mixer and add some color and additives. 3. Use a specialized plastic machine for granulation on the production line, but the granulation temperature should not be too high, as this can cause the material to become brittle; therefore, it is essential to pay attention to the temperature. 4. For water-cooled pelletizing, the standard size should be 3X4mm; otherwise, even the best-quality material will result in pellets with an unattractive and non-standard appearance. III. Process flow for recycling polyethylene terephthalate (PET). PET, whose scientific name is polyethylene terephthalate, is a linear thermoplastic material. It is usually a crystalline plastic. Due to its advantages such as light weight, resistance to breaking, and low energy consumption, PET bottles have replaced some traditional packaging materials and are widely used in industries such as food, beverages, and cosmetics. The recycling and reuse of PET is the process of recycled PET. The recycling process for PET bottle flakes involves separating the PET bottle body from the lid, labels, etc., and then crushing, cleaning, and drying it. Its specific process is as follows: 1. First is the selection step: various PET bottle flakes are selected and sorted into different categories. Peel off the outer trademarks; most of these are made of OPP, with some being polyvinyl chloride shrink film, which must be removed first. 2. Crushing process: Water is used for flushing during crushing to remove dirt from various PET bottle fragments. 3. Put these fragments into a steam treatment device, add caustic soda, and remove grease and other stubborn impurities. 4. Rinse thoroughly with clean water, shake off the excess water, and put into a bag. Then it is dried in a vacuum oven. 5. Spinning, setting, stretching with hot steam, then setting again. IV. Process flow of ABS plastic: Most ABS plastics originate from electrical products, various daily necessities, and small components used in some machinery. 1. For ABS, it is mainly used in computer cases, TV cases, instrument casings, car panels, and decorative materials. When sorting this material, items such as those that require electroplating or painting should be separated out. 2. Chemical treatment, stripping of plating and paint; however, plating and paint stripping must be carried out with caution. Since chemical solutions have specific mixing ratios, protective gear and containers must be used; otherwise, injuries or other incidents may occur. 3. Clean it in the cleaning tank, then dry it; apply color or add auxiliary materials to improve quality. 4. Use a dedicated extruder for granulation, but be sure to install a filter screen, with the type of filter screen determined by the product requirements. V. Process flow for recycled polycarbonate (PC): Polycarbonate is an amorphous plastic, belonging to the category of engineering plastics. Most of them come from textile accessories, car headlamps, tail lamps, turn signals, candy-making molds, discs, telecommunications equipment, photographic equipment, etc. 1. First, select the PCs to be acquired – there are transparent and opaque ones, and blue, red, green, and black ones must be separated; there are also modified versions, such as most textile accessories which are modified; items like discs and lamp bases are coated as well. 2. Cleaning various colors of PC materials, as well as processes for removing plating from disk lamp bases, are carried out using the same principle as with ABS. Then it is dried, sorted, and sent to the extruder for production. 3. Some PC is relatively yellow in color; it can be processed to achieve a porcelain white shade. Those that are transparent remain transparent; for other colors, colorants and material additives can be used. 4. Granulation is carried out using a dedicated extruder; however, PC tends to age easily, so it cannot be reused multiple times. Care must be taken during granulation, followed by cutting and packaging. VI. Process flow for recycled PVC rigid materials. Most PVC rigid materials come from building materials, plastic-steel windows and doors, electroplated rigid panels, plastic valves used in chemical plants, drainage pipes, and decorative materials. 1. First, select the processing steps to separate the different colors. These materials are mainly divided into three colors: white, gray, and black, but do not mix in PP or PE. 2. Send it to the crusher for grinding, but also grind it while it is wet. Rinse off the contaminated water, then dry it in the sun to prevent secondary contamination. 3. Put it into the mixer for batching and mixing. If it is a white material, add some coloring agent, and incorporate additives as needed. 4. Use a dedicated PVC extruder for granulation, cooling, bagging, labeling, and shipment