What's the difference between upvc pipe and pvc pipe?

There are two kinds of common plastics: one is polyethylene film; One is PVC film. Plastic bags made of polyethylene film are non-toxic and can be used to hold food, but their strength is poor, they can't withstand the high temperature above 80℃, and they have certain air permeability, so they should not be used to hold tea and spices for a long time. Plastic bags made of PVC film are toxic and not suitable for direct contact with food. PVC plastics are often used to make raincoats, soles, bedspreads, curtains, tablecloths, handbags and so on.

A simple way to identify the above plastic bags:

1, touch method: it feels lubricated by hand, and the surface looks like a layer of wax (chemically called wax feeling), which is a non-toxic polyethylene film; And PVC film feels a little sticky.

2, shaking method: shaking by hand makes the sound brittle, which is a non-toxic polyethylene film; The sound of shaking hands is PVC plastic bags.

3. Combustion mode: when it burns in case of fire, the flame is yellow, paraffin-like oil drops drop when burning, and it smells like candle burning, which is a non-toxic polyethylene film; If it is not easy to burn, it will go out immediately after leaving the fire. The flame is green and it is a PVC plastic bag.

4. Immersion method: the plastic bag is immersed in water and pressed into the water by hand, so that the nontoxic polyethylene film can surface; PVC film plastic bags sink to the bottom. Polyethylene is abbreviated as PE in English. It is a polymer of ethylene, which is non-toxic. Easy coloring, good chemical stability, cold resistance, radiation resistance and good electrical insulation. It is suitable for packaging food and medicine, making tableware and medical instruments, and can also be used as insulating material in electronic industry.

Polyvinyl chloride (PVC) is a polymer of vinyl chloride. It has good chemical stability and is resistant to acid, alkali and some chemicals. It is moisture-proof, aging-resistant and flame-retardant. When using, the temperature should not exceed 60℃, which will harden at low temperature. PVC is divided into soft plastic and hard plastic. Soft ones are mainly made into films, which can be used as packaging materials, rain-proof products, agricultural seedling films and so on. It can also be used as insulation layer for cables, wires and artificial leather products. Hard materials are generally made into pipes and plates. Pipes are used as water pipes and pipes for conveying corrosion-resistant fluids, and plates are used as lining and bottom plates of various storage tanks. Polyvinyl chloride (PVC) resin is nontoxic, while PVC monomer is highly toxic. Whether PVC products are toxic or not depends on whether the residual monomers in the polymerization process have been removed to a certain extent and whether the additives added in the processing process are toxic or not. For example, the content of vinyl chloride monomer in PVC food preservative film is too high, especially in high temperature environment such as microwave oven, which is easy to decompose substances that are carcinogenic to human body; In addition, if the plasticizer and stabilizer used in processing PVC cling film are not well selected, it will easily cause certain harm to human body.