polyethylene is a non-toxic and odorless plastic with good impact resistance, corrosion resistance and weather resistance.
the longitudinal welding of aluminum alloy in the middle layer makes the pipe have the compressive strength of metal, and the impact resistance makes the pipe easy to bend and not rebound. The aluminum-plastic composite pipe has two characteristics of strong pressure resistance of metal pipe and acid, alkali and corrosion resistance of plastic pipe, which is a model of a new generation of pipes.
aluminum-plastic pipe (aluminum-plastic composite pipe) is a popular pipe in the market. At present, Rifeng and Jinde are well-known in the market. Because of their light weight, durability and convenient construction, and the flexibility of aluminum-plastic composite pipe (aluminum-plastic composite pipe), it is more suitable for home decoration.
the main disadvantage of aluminum-plastic pipe (aluminum-plastic composite pipe) is that when it is used as hot water pipe, the pipe wall will be dislocated due to long-term thermal expansion and cold contraction, resulting in leakage.
Aluminum-plastic pipe (aluminum-plastic composite pipe) is used in many residential areas in Beijing. In Guangdong and Shanghai, where the decoration concept is relatively new, aluminum-plastic pipe (aluminum-plastic composite pipe) has gradually lost its market. At present, aluminum-plastic pipe (aluminum-plastic composite pipe) is still active in Beijing market. I believe that in the near future, aluminum-plastic pipe (aluminum-plastic composite pipe) in Beijing market will also face elimination.
There are common drinking water pipes, high-temperature resistant pipes and gas pipes according to their uses. The characteristics and uses of all kinds of pipes are as follows:
①
Aluminum-plastic composite pipes for ordinary drinking water: marked with white
L, and applicable scope: domestic water, condensed water, oxygen, compressed air and other chemical liquid pipes.
②
High-temperature-resistant aluminum-plastic composite pipe: marked with red R, which is mainly used for hot water and heating pipeline system with long-term working water temperature of 95℃.
③
Aluminum-plastic composite pipe for gas: Q mark, mainly used for conveying natural gas, liquefied gas and gas pipeline systems.
④
During pipeline construction, corresponding technical regulations must be complied with.
application cold and hot water piping system aluminum-plastic pipe All-round aluminum-plastic composite pipe is smooth, non-corrosive and scale-free, and the flow rate is 3% higher than that of metal pipes.
it is easy to bend, can be directly installed by bypassing the beam and column, can be buried in the wall and concrete, and can be detected by a simple metal detector, so the pipe is very suitable for the cold and hot water pipeline system in industrial and civil buildings.
The indoor gas pipeline is a longitudinally welded aluminum pipe sandwiched between plastics, so that the all-purpose pipe can withstand higher working pressure, and the gas (oxygen) permeability is zero, and the length of the pipe can reduce joints and avoid leakage. Therefore, this kind of pipe is safe and reliable for compressed air, gas, oxygen and other gas transmission lines.
solar air conditioning piping system All-round aluminum-plastic composite pipe is not easy to frost and has good thermal insulation, which improves the efficiency of solar energy and air conditioning system.
Advantages of aluminum-plastic pipes Aluminum-plastic pipes can be summarized into the following three aspects:
1. Outstanding sanitary performance: the inner and outer layers of aluminum-plastic pipes are made of special polyethylene materials, which are clean and nontoxic.
the most important thing is that the middle layer of aluminum-plastic pipe is aluminum, which can not only block light, but also block oxygen.
as we all know, photoaerobic environment is necessary for the growth of microbes.
the middle aluminum layer of the aluminum-plastic pipe eliminates the breeding of microorganisms and algae, which is beyond the reach of the all-plastic pipe.
A large number of antioxidants are added to the all-plastic pipe to prevent the material from degrading, and the antioxidant is extracted into the water trapped in the pipe, which is easy to cause water pollution. Moreover, because there is no light-blocking oxygen material in the all-plastic pipe, microorganisms are easily generated, which leads to secondary pollution of water quality.
second, excellent high and low temperature resistance: the long-term service temperature is 95 degrees (5 years, IMPa), the maximum service temperature is 11 degrees, and the thermal expansion coefficient of aluminum-plastic pipe is small.
it is equivalent to the thermal expansion coefficient of aluminum, which is only one sixth of that of all-plastic pipe.
when the temperature changes, the deformation is small, and the aluminum-plastic pipe is a flexible coil, so the pipe itself can absorb a certain amount of deformation and will not cause thermal expansion deformation of the pipeline system.
however, the high and low temperature resistance of all-plastic pipes is relatively poor.
the long-term service temperature of p>PPR is only 7 degrees (5 years, IMPa), and the maximum service temperature is 95 degrees.
At the same time, the expansion coefficient of PPR pipeline is large, and when the external water temperature (cold and hot water) changes, there is a large amount of original deformation. Because PPR pipe is rigid and straight, it cannot digest the deformation itself, so it is easy to cause the system to bend and even leak.
third, long service life: when it comes to service life, the most impressive sentence for everyone is "the daily abundant tube can be used for 5 years".
As the leading enterprise of aluminum-plastic pipe, Foshan Rifeng Enterprise's "fifty years of service" is a promise to consumers and also a confidence in aluminum-plastic pipe. The molecular chain structure (-CH2-CH2-) of PE plastic used in aluminum-plastic composite pipe is relatively stable among plastics, and because the aluminum layer in the middle of aluminum-plastic pipe separates the inner and outer layers, the stabilizer enough to resist light and oxygen aging is allowed to be added to the outer plastic without affecting the hygiene of the inner layer that contacts water.
Disadvantages: 1. The expansion coefficient is large, and if it is laid too long, some unexpected results can occur due to excessive expansion. 2. How to identify the quality of aluminum-plastic composite pipes when the price is higher? There are the following methods:
impact method: randomly select a section of aluminum-plastic composite pipe and impact it with something hard, the pipe surface will be bent, and if it is deformed to rupture, it will be inferior; If the deformed surface cannot be recovered, it is of general texture; After deformation, it can be restored to its original shape immediately, and it is a high-quality aluminum-plastic pipe.
Visual inspection method: Take a section of aluminum-plastic pipe and follow the light to see that the high-quality aluminum-plastic pipe has uniform color and no chromatic aberration; The interface of the middle aluminum layer is tight, and there are no rough marks; The whole pipe surface is smooth and standard in arc.
touch method: take a section of aluminum-plastic pipe and cut it vertically, and put your finger into the pipe, so that the nozzle of the high-quality pipe is smooth and has no feeling of grain; The nozzle has no burrs.
comparison method: 1. comparison of raw materials. at present, the PE materials of high-quality aluminum-plastic composite pipes in the domestic market are all from abroad, such as the United States. if the raw materials come from recycled materials, the quality cannot be guaranteed.
2. physical comparison: different brands of aluminum-plastic pipes are compared one by one from the above aspects, so as to achieve the best selection.
note: the "Jinde" brand aluminum-plastic composite pipe recently appeared on the market is made of PE material produced by Dow Company of the United States, the second largest chemical company in the world, with chemical adhesive imported from the Netherlands and patented technology from Yunik Company of Germany, which realizes five-layer extrusion and one-step forming production, and the five-layer material is integrated seamlessly.
Another important feature of this product is that it uses non-crosslinked polyethylene as raw material, so it is a green product!
choosing aluminum-plastic pipe joints people may not be too familiar with the word aluminum-plastic pipe, but to really understand it, we should start from its origin.
the full name of aluminum-plastic pipe should be aluminum-plastic composite pipe, and its invention originated in Britain. In 197s, Dr. Lzhak
Barnoach of Britain put forward the idea that high-density PE (plastic) was molded with aluminum alloy by high temperature and high pressure like a five-splint, and the aluminum-plastic composite pipe was compounded by combining physical and chemical compounding.
after years of improvement in Europe and America, great progress has been made in production technology and quality.
By the end of 198s, aluminum-plastic composite pipes had been widely used in developed countries. At present, the utilization rate of water supply pipes is 87%, and the utilization rate of gas pipelines in the United States and Denmark is as high as 9%.
As aluminum-plastic composite pipe is a new type of pipeline material in line with China's industrial policy and the development direction of high-tech products, the Ministry of Construction put forward the idea and plan of developing and selling aluminum-plastic composite pipe in 1992. In 1995, it was officially issued to promote aluminum-plastic composite pipe to replace metal pipe, which has a huge potential market in China.
The production technology of aluminum-plastic composite pipe is the most advanced in Germany, especially Yunik Company in Germany has the most advanced patented technology.
At present, there is no patented technology of aluminum-plastic composite pipe in China, and many brands have imported German patented technology in production technology. It is absolutely incorrect to say that "aluminum-plastic composite pipe originated from Germany".
how can we choose an authentic aluminum-plastic composite pipe? First of all, we must understand its basic structure and advantages.
The aluminum-plastic composite pipe has five layers, the inner and outer layers are made of polyethylene, and the middle layer is made of thin aluminum. There is also a layer of adhesive between the two materials, and the five layers are tightly integrated.
its superior properties are: stable chemical properties, corrosion resistance, non-toxicity, no pollution, smooth surface and inner wall, no scaling, light weight, free bending, good toughness, and unique advantages of environmental protection and energy saving.
At present, there are many brands of aluminum-plastic composite pipes in China, and the selection of raw materials, chemical additives, production technology and production equipment is uneven.
some brands choose low-quality and low-cost materials with poor performance in the selection of raw materials and adhesives, and the production technology is backward, so they can't achieve five-layer extrusion. The quality, price, installation and use of aluminum-plastic composite pipes produced in this way are naturally far lower than those of excellent brands.
to pass the product quality test, there must be corresponding and perfect supporting services.
the brand with excellent product quality and complete service measures is the first choice for consumers.
every penny spent by consumers can reflect its value, which is not only reflected in product quality, but also in after-sales service.
the quality of low-quality and low-priced products cannot be guaranteed, let alone the service. Only by establishing a correct consumption concept can we choose a truly satisfactory aluminum-plastic composite pipe so that consumers can have a perfect home.
The competition of various indoor water supply pipes is becoming more and more fierce. There is a saying that "PP-R plastic pipe is a substitute for aluminum-plastic pipe" in the building materials market, and consumers are like looking at flowers in the fog.
PP-R pipes with aluminum-plastic pipes holding high the banner of a new type of environmental protection water pipe, when the pipe consumer market "swaggered through the market", poured a pot of cold water on it, thinking that its development prospect could not be smooth due to technical defects.
On October 28th, 22, at the second annual meeting of "Water Supply Branch of China Building Water Supply and Drainage Committee", Huang Ruhong, Chairman of the Pipeline Committee of the Water Supply and Drainage Equipment Branch, wrote that "pipe fittings and connections are an easily overlooked but critical issue in pipe selection.
"The article points out that it is unwise for many developers to pay insufficient attention to pipe fittings and connections.
in the history of pipe development, there have been many precedents in which the fate of pipe was decided by pipe fittings.
for example, in the 197s, the soldering iron used for PP-R pipes was widely used for socket hot-melt connection.
It is also claimed that after careful and rigorous tests and optimization of various connection methods, it is concluded that this connection method is the most reliable.
this connection is also promoted as a national standard (JIS standard).
However, after more than 1 years' practice, there are objections to the original method, and it is found that this connection method is difficult to grasp the degree of heating and melting, and the joint is loose and cracked. Therefore, it is considered that the mechanical joint made of metal to press the rubber ring should be developed.
"Inspection" Yokohama Waterway Bureau has abandoned its use since the late 198s.
Among all the new plastic pipes, the performance is superior or inferior, and it has been decided here: aluminum-plastic composite pipes are "handpicked" as the preferred cold and hot water supply pipes and ideal heating pipes with unparalleled advantages.
Compared with other pipes, the development of aluminum-plastic composite pipe in China is quite mature, with perfect product standards and application specifications, which are widely accepted by the market.
The rapid development trend of aluminum-plastic composite pipes abroad also confirms this fact: According to the statistical results of KWD Plastic Information Center in Germany, in Europe, aluminum-plastic pipes are increasing at an annual rate of more than 2%, and the consumption far exceeds that of other plastic pipes such as PPR and PB.
I believe that in China, the "royal" water pipe-aluminum-plastic composite pipe will have a broader market space.
reference
building materials network, China
/system/21/7/23/229444.shtml.