Introduction of knowledge of recycled plastics

The recycling industry is now getting more and more attention, but to truly integrate into this industry, we must understand the basic knowledge of entry. The following is an article from the China Plastics Industry Network. This article introduces the knowledge of recycled plastics and is available for your reference.

In view of the current situation of many inferior and toxic plastic bags, they are often drowning in the market, and because their appearance is the same as ordinary non-toxic plastic bags, the status quo that ordinary consumers are more difficult to distinguish is expert advice: they can be learned from three sources. ".

All plastic products containing food should be made of non-toxic plastics, that is, processed with polyethylene as raw materials. However, at present, many inferior and toxic plastic bags, especially some black plastic bags used to hold various agricultural and sideline products in the country's bazaars, are unclear, and they are more likely to be suspected of being “stuffed”. Plastic bags made of polyvinyl chloride are certainly toxic. Because polyvinyl chloride resin contains unpolymerized vinyl chloride monomer, it is a compound that can poison the human body.

In addition, some plasticizers, stabilizers, pigments, and other auxiliary materials are added to the process of processing polyvinyl chloride resin into plastic bags. Some of these auxiliary materials are toxic and are easily extracted by oil or water in food. "Out, contaminate food and cause harm to human health. The melting process will also be poisoned. Secretary-General Chen Changjie of the Shanghai Packaging Technology Association’s Green Packaging Committee said that many recycled black plastic bags in the bazaars are reprocessed from recycled polyethylene bags.

Although most of the recyclates were washed, crushed, and other processes before reprocessing, it was not known what they had packed before being recycled. If they have ever loaded chemical fertilizers, pesticides and other substances, it is impossible to remove all toxic and harmful substances completely by simple washing. The use of such recycled plastic bags for food, although high-temperature cooking may not be able to "drive poison." In addition, some food bags are printed with the words “trademarks” on the outside. The pigments themselves may be toxic, and some people prefer to turn the food bags over and use them again. It is also unsafe to store foods with these pigments.

To find “poisonous” plastic bags, there are the following methods: First, sensory detection method, non-toxic plastic bags have flexibility, lubrication when touched by hand, and wax on the surface; toxic plastic bags are turbid or light yellow in color, feel Sticky. The jitter detection method grasps the end of the plastic bag and shakes it hard. The person who makes the crisp sound is non-toxic; if the sound is boring, it may be toxic. Burn detection method, non-toxic polyethylene plastic bags can be burned, the flame is blue, the upper flame is yellow, the paraffin odor is emitted when burning; toxic PVC plastic bags are more difficult to burn, yellow when the fire, outside the flame It is green and emits a pungent smell of hydrochloric acid.