The main function of the stretched film is to consolidate, cover and protect the product. It is generally applicable to the whole package packaging of products such as alcohol, cans, mineral water, various beverages, cloth, etc. The product has poor flexibility, weak impact resistance and tear resistance, easy to break, not afraid of moisture, shrinkage rate small.
If we go shopping, the store habitually picks up a plastic bag for you to dress, no matter what you buy is definitely not food, such pictures can be seen everywhere in life, and it is appropriate for people to see the time when it was commonplace last year. "Plastic orders", this much difficulty also evokes the understanding that plastics are harmless in Weinan, so common packaging materials are generally free of additives, such as polyethylene, polypropylene, food bags, oil drums, and fast food boxes made from these materials. Waiting is non-toxic.
First, cut the sample into a strip, clamp it with tweezers, and extinguish it on the extinguished alcohol lamp (for example, non-alcohol lamps can also be replaced by extinguished candles), then observe the difficulty of extinguishing, the condition after the fire, the flame The color of the smoke, the scene when it is extinguished, and the breath to be recovered can be determined by comprehensive judgment.