PVC
It is polyvinyl chloride plastic with bright color, corrosion resistance, firmness and durability. Due to the addition of some toxic auxiliary materials such as plasticizers and anti-aging agents in the manufacturing process, its products generally do not store food and medicine.
PVC is polyvinyl chloride, a plastic product synthesized from 43% oil and 57% salt. Compared with other types of plastic products, PVC uses raw materials more effectively and reduces fuel consumption. At the same time, the energy consumption of PVC manufacturing is also very low. And in the later use of PVC products, it can be recycled and converted into other new products or incinerated to obtain energy.
Stabilizers are added during the production of PVC, but there are non-toxic and toxic stabilizers. Only when toxic stabilizers such as lead salts are added can hidden dangers occur. However, PVC products are mixed, and some small companies use lead salts as stabilizers, and it is difficult to meet relevant health standards. When consumers choose PVC materials, it is best to go to the building materials market with a formal reputation and quality assurance, and require the supplier to issue a test report. Consumers should pay attention to check the relevant certificates and signs, and only products that have obtained the "Hygiene Permit for Drinking Water Hygiene Safety Products" are safe.
UPVC (Unplasticized Polyvinyl Chloride)
UPVC, also known as hard PVC, is composed of an amorphous thermoplastic resin made by the polymerization of vinyl chloride monomer and certain additives (such as stabilizers, lubricants, fillers, etc.).
In addition to using additives, the method of blending with other resins is also used to make it have obvious practical value. These resins are CPVC, PE, ABS, EVA, MBS and so on.
UPVC has high melt viscosity and poor fluidity. Even if the injection pressure and melt temperature are increased, the fluidity will not change much. In addition, the molding temperature of the resin is very close to the thermal decomposition temperature, and the temperature range that can be molded is very narrow, making it a difficult-to-mold material.
UPVC pipe fittings, the advantages of pipes
Lightweight: The proportion of UPVC material is only 1/10 of that of cast iron. It is easy to transport and install, reducing costs.
Superior chemical resistance: UPVC has excellent acid and alkali resistance, except for strong acids and alkalis close to the saturation point or strong Oxidising agents atmaximun.
Non-conductive: UPVC material cannot conduct electricity, nor is it corroded by electrolysis or electric current, so there is no need for secondary processing. It can not burn, and it does not support combustion, and there is no fire protection concern.
Easy installation and low cost: cutting and connecting are easy, and the practice of using PVC glue to connect is proved to be safe, easy to operate, and low cost.
Durable: excellent weather resistance, and can not be corrupted by bacteria and fungi
Low resistance, high flow rate: smooth inner wall, low fluidity loss, and dirt is not easy to adhere to the smooth pipe wall, maintenance is relatively simple, and the maintenance cost is low.
PP (polypropylene)
PP is polypropylene plastic, non-toxic and tasteless, and can be immersed in boiling water at 100°C without deformation or damage. Common acid and alkali organic solvents have almost no effect on it. Mostly used for food utensils.
Polypropylene is polymerized with propylene monomer as the main component. According to the monomer composition participating in the polymerization, it is divided into two types: homopolymerization grade and copolymerization grade. Homopolymer grade polypropylene is polymerized from a single propylene monomer and has high crystallinity, high mechanical strength and heat resistance. Copolymer grade polypropylene is copolymerized by mixing a small amount of ethylene monomer during polymerization.
Its main features
Appearance and physical properties: the natural color, cylindrical particles are white translucent, waxy; non-toxic, odorless, yellow and blue on the flame when burning, a small amount of black smoke, molten dripping, paraffin odor.
Main use and output: The polypropylene delivered in the market is mainly used for woven products. It has a wide range of uses. It can be used as woven bags, packaging ropes, braided belts, ropes, carpet backings, etc. Its annual output is more than 800,000 tons, accounting for more than 800,000 tons in my country. 17% of total polypropylene production
PE polyethylene
PE is a polyethylene plastic with stable chemical properties. It is usually used to make food bags and various containers. It is resistant to corrosion by acid, alkali and saline solution, but it is not suitable to be wiped or soaked with strong alkaline detergents.
PPR (random copolymer polypropylene)
Macromolecules formed by polymerization of one molecular monomer are called homopolymers, and macromolecules formed by polymerization of two or more molecular monomers are called copolymers;
PP-B and PP-R are copolymers (Poly Propylene Copolymer, PP-C) formed by the polymerization of propylene monomer Propylene and ethylene monomer Ethene.
1) Using advanced gas phase copolymerization process, PE polymerizes randomly and uniformly in the molecular chain of PP. This raw material is called PP-R (random copolymer polypropylene).
2) The use of PP and PE block copolymerization, this raw material is called PP-B (block copolymer polypropylene).
PEX (cross-linked polyethylene)
Ordinary high-density polyethylene (HDPE and MDPE) pipes, whose macromolecules are linear knots, the biggest disadvantage is poor heat resistance and creep resistance, so ordinary high-density polyethylene pipes are not suitable for conveying temperatures greater than 45°C medium.
"Crosslinking" is an important method of polyethylene modification. After crosslinking, the linear macromolecular structure of polyethylene becomes PEX with a three-dimensional network structure, which greatly improves the heat resistance and resistance of polyethylene. Creep ability, and its aging resistance, mechanical properties and transparency have been significantly improved. The higher the degree of crosslinking, the more obvious the improvement of these properties. At the same time, it inherits the inherent chemical resistance and flexibility of polyethylene pipes. There are three commercial PEX tubes. PEXa tube/PEXb tube/PEXC tube.
PEX tube characteristics
Excellent heat and cold resistance, high thermal strength at high temperature; excellent low temperature resistance and toughness; resistance, heating does not melt.
Extraordinary creep resistance: Creep data is an important basis for product design and engineering material selection. Compared with traditional materials such as metals, the strain behavior of plastics is obviously dependent on loading time and temperature. The creep characteristics of PEX pipes are almost It is one of the most ideal pipes among common plastic pipes.
Extraordinary creep resistance
Creep data is an important basis for product design and engineering material selection. Compared with traditional materials such as metals, the strain behavior of plastics is obviously dependent on loading time and temperature. The creep characteristics of PEX pipes are almost the most ideal among common plastic pipes. One of the pipes.
Semi-permanent service life
After the PEX tube has passed the test at a temperature of 110°C, a ring stress of 2.5MPa, and a time of 8760h, it can be deduced that it has a continuous service life of 50 years at 70°C.