Current situation and development trend of PVC pipe production
Hard PVC pipe, pipe fittings in many PVC products, in our country is growing rapidly, and is also the largest variety of plastic pipes consumption. PVC pipes in China after years of promotion, especially the national related policy support, production and application of PVC pipe has achieved great development, PVC pipe plastic pipe production has accounted for more than 50% of the total production, widely used in many industries, industrial construction, agriculture etc..
Development of PVC pipe material
1.1 PVC pipe material advantages
In the production of general resin, the ethylene consumption of PVC resin is the lowest and the production cost is the lowest. Domestic production of PVC per ton needs 0.5314 tons of ethylene, while the average ethylene consumption per ton of polyethylene is 1.042 tons. The consumption of ethylene per ton of PVC resin in China is less than that of polyethylene, which is about 50%. The production of chlorine gas from the raw materials used in PVC is an important way to balance the production of chlorine in the production of caustic soda. Caustic soda is an essential raw material for the national economy. In addition, from the perspective of plastic products, PVC has good compatibility with various auxiliaries, and a large number of cheap fillers can be added to the production pipes, which greatly reduces the production cost.
PVC pipe and metal pipe production, the production of PVC per cubic meter and production per cubic meter of steel and aluminum calculation, the energy consumption of steel is 316KJ/m3, the energy consumption of aluminum is 619KJ/m3, the energy consumption of PVC is 70KJ/m3, that is, the energy consumption of steel is 4.5 times of that of PVC, and the energy consumption of aluminum is 8.8 times of that of PVC. The production energy consumption of PVC tube is only 1/3 of the same caliber metal pipe. At the same time, due to the smooth wall of the PVC tube, no corrosion of the tumor, high efficiency of water transport, the infusion can save about 20% of the electricity.
PVC pipe has good mechanical properties, and has excellent corrosion resistance, in the process of using light weight, convenient installation, no maintenance, and the use of steel for sewer utilities, in use because of easy corrosion, often must be coated with paint, high maintenance costs. The metal pipes for general buildings and public utilities need to be replaced for about 20 years, and the working PVC pipes, which have a good working life, have a service life of up to 50 years. Therefore, PVC pipe is a kind of good plastic products with low production cost, high strength and corrosion resistance.
Generally speaking, in the sewage, waste water and ventilation pipe, PVC pipe than using iron pipe installation and labor cost savings of about 16-37%; as a conduit than cost saving 30-33% use metal wire casing; and the effect of chlorinated polyvinyl chloride (PVC) pipe in hot and cold water, than to use the same size of the copper tube to save cost for 23-44%. Therefore, because of the advantages of PVC pipes, all countries are actively developing and popularizing PVC pipes.
1.2 PVC pipe production and consumption
Since 80s, China has introduced different types of PVC pipe extrusion production line 1000, emerged as Dalian Shide, Zhejiang Yong high, Shanghai Tangchen large pipe manufacturer. At present, China's UPVC (hard PVC) pipes and fittings production factory has more than 600, more than the total production capacity of 1 million 100 thousand tons / year, manufacturers in the production scale of 10 thousand tons / year of above more than 30, the scale in the 0.5-1 million tons / year of more than 60 manufacturers, UPVC pipes and fittings production equipment basically achieved domestically.
In China, PVC tube is PE pipe and PP tube development early, many varieties, excellent performance, wide use, occupies an important position in the market. By the end of 1999, there were about 2000 plastic pipe production lines nationwide, of which about 15% of the imported equipment were introduced. In 1999, the production capacity of various plastic pipes in China was more than 1 million 650 thousand tons per year, and the actual production was about 1 million tons, and the UPVC pipes accounted for more than 50%.
In the market applications of PVC in the world over the years, the building materials market is the largest and the fastest increasing. In recent years, building materials in the United States have been 60% of their total products, 62% in Western Europe, 50% in Japan, less than 30% in China, and a great increase in space. In the building materials products, the main products are pipe and special-shaped material, including the building and down pipe, agricultural irrigation pipe, gas pipe, crude oil pipeline and so on.
The production and application of UPVC pipes in China has been developing rapidly during the "95" period, mainly due to the strong support of the government and the recognition of UPVC pipes.
At present, the application of plastic pipe in China is not only in quantity but also in variety and specification. For example, the UPVC pipe has reached more than 90% in some urban construction drainage applications, and most of the UPVC pipe enterprises have a good benefit in the past few years.
In the period of "fifteen", the main application of plastic pipes is UPVC and PE plastic tubes, and other new plastic pipes are vigorously developed. By 2005, the national construction, renovation and expansion project, building drainage pipeline with 50% plastic pipe, plastic pipe by 20% city drainage pipeline, building water supply, water supply and heating pipes 60% using plastic pipe, city water supply pipe (Dn400) with 50% plastic pipe, rural water supply pipeline 60% using plastic pipe, city gas pipeline (low pressure pipe) with 50% plastic pipes, building wire protecting pipe with plastic pipe 80%. It is expected that in 2005, more than 2 million tons of plastic pipes are needed, most of which are PVC pipes.
In developed countries, the consumption of PVC pipe generally accounts for 70-80% of the plastic pipe market, while the PVC pipe accounts for only about 50% of the total plastic pipe in China. The development potential of PVC pipe in our country is huge. The consumption ratio of PVC pipes in developed countries is: water supply pipe accounts for 33%, sewer pipe accounts for 22.3%, sewage pipe accounts for 15.7%, irrigation pipe accounts for 5.2%, gas pipe accounts for 0.8%, and other pipes account for 22.7%. The consumption ratio of pipe fittings and pipe is about 1:8.
In the building market, there are two kinds of PVC pipes used: one is a pressure tube, the other is a non - pressure tube. In the past, the cast iron pipe and copper tube used as the building materials are not only serious corrosion, but also need regular maintenance and replacement, and the cost is high. Most of the foreign buildings now use the pressure water pipe, hot water supply pipe most of the use of PVC tube. The small caliber PVC tube (UPVC tube, CPVC tube) has the advantages of low cost, corrosion resistance, no regular maintenance and replacement. The large caliber PVC pressure tube (diameter in 100-900mm) replaced the cast iron pipe and reinforced the small mud pipe. The water supply system has good fluidity, corrosion resistance and low weight. Electricity saving and water quality are good. The PVC core layer is used as an indoor sewer pipe and a rainwater system tube, which can solve the noise problem of the indoor water pipe very well. Utility draining pipe adopts pressure free PVC pipe. It has corrosion resistance and is not corroded by hydrogen sulfide. It has long service life, light weight, low installation cost, easy to connect and seal, and is not easy to break. In addition, building string and underground cables are another market for PVC pipes. At present, the domestic varieties are straight expansion, double wall pipes and single wall bellows.
The agricultural pipe is another wide field in the application of PVC. China is a country that lack water resources, at present, China has the most farmland irrigation canal, water waste is very serious. Because of the lack of water, a large number of cultivated land can not be well irrigated and the yield of crops is low. Irrigation with PVC tube can save about 50% of the water. The use of PVC fixed or semi fixed irrigation system not only saves water, but also improves production and equipment. It saves the cost of irrigation and drainage facilities greatly. At present, no county has fully managed irrigation in China. In most parts of the country, there is a lack of basic understanding of pipe irrigation. Therefore, increasing the propaganda and promotion efforts of PVC irrigation in rural areas has great potential.
1.3 commonly used PVC pipes at home
UPVC tube: the largest application of the UPVC tube is the construction industry. At present, it is widely applied in various provinces and cities, such as water pipe system and residential water supply pipe, and is mainly used for drainage pipes, rainwater pipes and threading pipes in construction industry. UPV tube has chemical corrosion resistance, self extinguishing and flame retardancy, good resistance to primary chemicals, smooth inner wall and good electrical properties, but UPVC tube has low toughness, large linear expansion coefficient and narrow temperature range. The development of UPVC pipe production efficiency obviously, and the use of UPVC pipe cast iron pipe production and use of such 55-68%, UPVC water supply pipe than galvanized pipe such 62-75%, and the same size per unit length of the price of only 1/2 galvanized pipe, galvanized pipe installation costs than low 70%, using 1 tons of UPVC water supply pipe can replace 12 tons of cast iron pipe, application 1 tons of UPVC corrugated pipe can save 25 tons of steel.
The core layer foaming pipe: the core layer foaming pipe is the three layer co extrusion production process of the two layer and the UPVC tube, the middle is a new type of tubing with relative density of 0.7-0.9 low foam layer, the circumferential rigidity is 8 times that of ordinary UPVC tube, and a change in temperature scale has good stability, heat insulation well, especially the foam core layer can make out the noise propagation, more suitable for the high-rise building drainage system.
The foam core tube can save more than 25% of the raw material, and the inner wall compression ability can be greatly improved. In the wall with a foam core muffler several convex spiral tube water continuously along the inner wall of the pipe free spiral flow in the central drainage pipe to form a gas column, the tube pressure is reduced by 10%, the general capacity increased by 10 times, the drainage amount increases 6 times, lower noise than ordinary 30-40db UPVC drainage pipe.
PVC radial stiffened tube: the production of this kind of pipe with special mold and molding follow-up device, is a heavy caliber super strong reinforcement ring glass tube. It is characterized by a radial stiffener on the outer wall of the tube, which can greatly improve the stiffness and pressure strength of the pipe, and is especially suitable for the drainage in municipal engineering.
Double wall bellows: double wall bellows are made by extruding two concentric tubes at the same time, and then melting the outer tube of the bellows on the smooth tube of the inner wall. It has smooth inner wall and corrugated outer wall, light and high strength, and can save 40-60% raw material than ordinary UPVC pipe. It is mainly used as communication cable protection pipe, building exhaust pipe and agricultural drainage pipe.
PVC transdermal reinforced tube is made by extrusion of two layers of plastic inside and outside, with synthetic fiber in the middle, good flexibility and bending. PVC transparent tube has good acid resistance, alkali resistance, oil resistance and aging resistance, and can replace rubber tube with cheap price. Widely used in nitrogen, oxygen, carbon monoxide and other gases and water, dilute alkali, oil and other liquid transport, also can be used as water heater, sprayer, gas cooker and other catheter.
CPVC tube: CPVC pipe is a kind of good heat-resistant plastic pipe made from chlorinated polyvinyl chloride with more than 66% chlorine content. The heat resistance of CPVC pipe is above 30 centigrade higher than that of UPVC tube, and the dimensional stability is improved and the coefficient of linear expansion is reduced. The CPVC tube has excellent heat resistance, aging resistance and chemical corrosion resistance. It is also not deformed in boiling water. It can be used for the transportation of hot water, corrosion resistant liquid and gas.
Hangzhou Neetrue Irrigation Facilities Co.,Ltd
Add:West 57th Avenue, Riverside, 12C-02
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