At present, there are still many people using plastic packaging bags. Food, washing powder, fertilizers, etc. are all packaged in plastic bags. Vegetables and fruits bought in supermarkets and vegetable markets are also packed in plastic handbags. Food plastic packaging bags should be non-toxic, and the chemical name of the material is polyethylene or polypropylene. It has low strength, cannot withstand high temperatures above 80°C, and has a certain degree of air permeability. Therefore, it is not suitable for tea, beverages, etc. Plastic packaging bags such as washing powder and fertilizers are generally toxic, Packing Machine and their materials are mostly polyvinyl chloride. This plastic is added with auxiliary materials such as plasticizers and stabilizers to increase its strength, and it contains lead or other harmful substances, which is harmful to human health.
1. The non-toxic polyethylene plastic is milky white and translucent. It has a paraffin waxy feel to the hand, and the texture is soft and bendable. It can float on the water surface when placed in water, and it will soften significantly in boiling water. It is easy to burn in case of fire, dripping waxy substance when burning, and smells of burning wax. The flame tip is yellow, the bottom is blue, and there is little smoke. It continues to burn after leaving the fire.
2. The non-toxic polypropylene plastic is milky white and translucent. It is smooth to the touch but not slippery. The texture is firm and tough, and the sound is crisp when shaking. It can float on the water surface when placed in water, but the softening in boiling water is not significant. It burns easily in fire, dripping wax when burning, swells, and smells of petroleum. The flame tip is yellow, the lower end is blue, and a small amount of black smoke. It continues to burn after leaving the fire.
3. The transparency of toxic polyvinyl chloride plastic is not as good as that of polyethylene. It feels sticky to the touch, soft and elastic in texture, and hardens when exposed to cold. Sink in the water. It is not easy to burn, softens when burned, can be drawn, and has a pungent and spicy taste. The tip of the flame is yellow, and the lower end is green with black smoke. Slowly extinguished after leaving the fire. public