Polyvinyl chloride plastic is made by polymerizing vinyl chloride monomers and is one of the commonly used thermoplastics. Its trade name is abbreviated as "chlorine plastic", and its English abbreviation is PVC. Pure polyvinyl chloride resin is a hard thermoplastic substance, its decomposition temperature is very close to the plasticizing temperature, and its mechanical strength is poor. Therefore, it is impossible to use polyvinyl chloride resin to mold products. Plasticizers, stabilizers, fillers, etc. must be added to improve the performance to make polyvinyl chloride plastics, and then processed into various products. Polyvinyl chloride is divided into hard polyvinyl chloride and soft polyvinyl chloride according to the amount of plasticizer added.

Identification characteristics

The transparency of polyvinyl chloride film is higher than that of polyethylene. The product is bright in color, smooth to the touch, without waxy feeling, and a special smell can often be smelled; it becomes obviously hard when it is cold, and the use temperature is 60¡æ; the relative density is greater than 1, and it can sink underwater, which is a significant feature that distinguishes polyvinyl chloride; hard products are hard and smooth, and the sound is dull when knocked; soft products are soft and elastic. Polyvinyl chloride cannot be used to package food.

Combustion performance

The combustion performance of polyvinyl chloride is not good. It will go out immediately when away from the fire. The flame is yellow, the lower end is green, and white smoke is emitted. It is a flame-retardant plastic. When burning, it emits a pungent smell of hydrogen chloride and softens when burning.

In actual use, since PVC contains a large amount of organic ester (such as DOP) flammable plasticizers, flame retardancy should be considered. Antimony trioxide alone is flame retardant in PVC. If it is used in combination with chlorinated paraffin, the flame retardancy is better. Transparent PVC should use phosphate flame retardants, and tricresyl phosphate (TCP) is commonly used, but TCP has poor low-temperature performance. Halogen-containing phosphate esters have good performance, but the price is slightly more expensive

Performance

1. Soft polyvinyl chloride generally contains 30-50% plasticizer. Because of its soft texture and high strength, it has good air tightness and impermeability.

2. Rigid polyvinyl chloride is made with only a small amount of plasticizer. Its characteristics are hard texture, high mechanical strength and good chemical corrosion resistance.

3. PVC plastic has poor heat resistance, and its strength is greatly affected by temperature. The strength at -20¡æ is 80% lower than that at 20¡æ. Therefore, film products are not easy to store and use at low temperatures; the use temperature of soft products does not exceed 45¡æ, and the hard products do not exceed 60¡æ. They will age and become brittle when exposed to light for a long time.

4. When processing PVC film, heat stabilizers need to be added to prevent heating and decomposition. Since the heat stabilizer contains lead salts, etc., PVC plastic is toxic, so it cannot be used as food packaging.

5. When PVC plastic comes into contact with organic solvents and insect repellents such as naphthalene, it will become sticky and melt, and it is easy to absorb odors; since the plasticizer is highly volatile, it should not be stored for too long.

Use

Soft PVC can be made into better agricultural films, which are often used to make raincoats, tablecloths, curtains, ticket clips, handbags, etc. It is also widely used in the manufacture of plastic shoes and artificial leather. PVC is often used for the outermost surface of power cables.

Rigid polyvinyl chloride can be made into transparent, translucent and pearlescent products of various colors. It is often used to make soap boxes, combs, washboards, pencil cases, various pipes, etc.

Its characteristics are as follows:

1. Lightweight, easy to carry and load:

PVC pipes are very light, easy to carry, load and unload, and construct, saving labor.

2. Excellent chemical resistance:

PVC pipes have excellent acid resistance, alkali resistance, and corrosion resistance, and are very suitable for use in the chemical industry.

3. Low flow resistance:

PVC pipes have smooth walls and low fluid resistance. Their roughness coefficient is only 0.009, which is lower than other pipes. Under the same flow rate, the pipe diameter can be reduced.

4. High mechanical strength:

PVC pipes have high water pressure resistance, external pressure resistance, and impact resistance, and are suitable for piping projects under various conditions.

5. Good electrical insulation:

PVC pipes have excellent electrical insulation properties and are suitable for protective casings for wires and cables.

6. No impact on water quality:

PVC pipes and pipe fittings have been proven by dissolution experiments to have no impact on water quality, and are currently the best pipes for tap water piping.

PVC Rongsheng Refrigerator Pipes

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