HDPE, it is an abbreviation for high-density polyethylene, also known as low-pressure polyethylene. It is a thermoplastic resin with high crystallinity and a semitransparent non-polar surface. In terms of physical properties, its operating temperature can reach 100℃ and melting temperature can reach 120-160℃. It has good heat and cold resistance, as well as high rigidity and toughness, and high mechanical strength; In terms of chemical properties, it is insoluble in any organic solvent at room temperature and resistant to corrosion by acids, bases, and various salts.
Due to their low processing difficulty, good chemical stability, and recyclability, these materials have a wide range of market applications and can be preliminarily classified into the following five categories:
(1) Injection molded products
Mainly including turnover boxes, bottle caps, barrels, safety helmets, food containers, trash cans, packaging boxes, and plastic flowers.
(2) Blow molded products
Mainly including blow molded barrels, daily chemical containers, cleaning agent containers, chemical containers, cosmetics packaging, gasoline containers, and other daily necessities and other hollow formed products; In terms of blown film products, they are mainly used for food packaging bags, miscellaneous shopping bags, and fertilizer lining films.
(3) Extruded products
Mainly including various types of pipes and fittings, such as building materials drainage pipes, gas pipes, hot water pipes, etc., which can be used for gas transportation, public water and chemical transportation; In terms of sheet materials, they are mainly used for seats, suitcases, and handling containers.
(4) Rotating molding
Mainly including large containers, storage tanks, chemical barrels, transportation boxes, and other injection molded products.
(5) Other products
Mainly including industrial films, wire and cable sheaths, pipes, and fibers, it can be widely used in fields such as agriculture, packaging, electronics, machinery, automobiles, and daily necessities.
The widespread use of HDPE products has also led to the gradual maturity of waste recycling and reuse. Although there is a huge demand gap for recycled products in the recycling market, the variety of front-end recycling poses a significant challenge to manual sorting. As practitioners in this field, it is crucial for us to classify the massive amount of waste HDPE products, which plays a decisive role in the recycling price of broken and cleaned products. In this issue, we will briefly share our professional experience on the classification of materials and products.
Recycling classification
How to classify recycled waste HDPE products
To clarify the classification of HDPE products, we must know what categories they usually have in the industry. Here, we will briefly classify them into three categories: Large white materials, Small white materials, and Variegated material, collectively referred to as B materials. (PE polyethylene is called B materials, PP polypropylene is called C material.)
1. Large white material consists of packaging containers that are semitransparent throughout the body and packaging bags that are highly white. After processing, the recycling price of these products is generally over 5000 RMB per ton, including milk bottles, beverage bottles, meal box containers, putty powder bags, and some daily necessities containers. Among them, dry powder bags are cheaper than water powder bags in terms of recycling price. Pure rinsing material bags are 5500 RMB/ton, and dry powder bags are 4800-5000 RMB/ton. The profit margin of bulk cargo is higher than that of compressed blocks.
2. Small white materials include milk white opaque packaging containers and low degree white packaging bags. The processing and recycling price of these products is basically over 4000 RMB per ton, including detergent bottles, laundry detergent bottles, oil drums, water pipes, plastic films, feed bags, and white plastic bags. It is worth noting that the plastic PVC label paper on the surface of the packaging container must be removed thoroughly, and the caps of detergent bottles and large plastic buckets, if made of C material, must also be removed separately. It can be determined by the color and odor of the flame after burning with fire.
3. Variegated material belonging to colored miscellaneous materials, generally have a recycling price of over 3000 RMB after processing. Packaging of daily necessities with colors in daily life belongs to this category. If a lot of green bottles and Lehu bottles are mixed in, they can also be separately selected for making packing straps. The price of this type of recycled material is generally around 2500 RMB. In addition, Class B and Class C packaging can sometimes be too close in appearance and difficult to judge with the naked eye. For example, a common whitening chemical bucket is made of C material, and products with words are several hundred RMB cheaper than those without words. Manufacturers must carefully sort and avoid excessive confusion when recycling. Finally, it is important to pay attention to some white plastics with loud knocking sounds, which are usually made of ABS and POM materials. If mixed up, they must also be individually selected.