Metal skeleton reinforced non-cross-linking refractory polyethylene pipe

Abstract

a non-crosslinked refractory polyethene pipe reinforced by metal skeleton is composed of a main body made of non-crosslinked refractory polyethene and a cylindrical reinforcing metallic skeleton skeleton embedded in the main body and made of curled reticular steel sheet or wound and welded steel wires. Its advantages are high resistance to low temp., high temp. and environment stress, good thermofusibility and long service life.

Description

Technical field: [0001] The invention relates to a metal-plastic composite plastic pipe, in particular to a non-crosslinked high-temperature-resistant polyethylene (PE-RT) plastic composite pipe reinforced by a metal skeleton. Background technique: [0002] There have been quite a lot of reports and patents on plastic composite pipes composed of thermoplastics and metal skeletons with holes. They have made important contributions to the reinforcement of plastic pipes and the anti-corrosion effect of metal pipes such as steel pipes, especially plastics. Composite pipe with a cylindrical skeleton formed by rolling and welding steel plates with holes, composite pipe with a cylindrical skeleton formed by welding plastic and latitudinal steel wires around warp steel wires, composite pipe with a cylindrical skeleton formed by plastic and spirally wound or braided steel wires Pipes have formed a considerable industry, and the technology has been continuously improved and improved. ...

AI Technical Summary

Problems solved by technology

[0004] Due to the use of general thermoplastics, although copolymerized polypropylene with a higher temperature resistance level can also be used, due to the presence of metal skeleton reinforcements in the pipe wall, the plastic composite pipe introduces internal stress that does not usually exist in pure plastic pipes. , when the thermoplastic material with poor environmental stress cracking resistance is used to make this kind of plastic composite pipe, and it is used under the working conditions of high temperature and harsh environment, the plastic layer of the composite pipe is prone to cracking and stress cracking , especially the random copolymerized polypropylene (PP-R) with good thermal properties in the copolymerized polypropylene, because the metal skeleton introduces internal stress into the pipe wall, the composite pipe made of this material is easy to crack

To this end, to solve the problem of high temperature resistance and better resistance to environmental stress cracking, people have adopted the well-known cross-linked polyethylene with good heat resistance and environmental stress resistance to make plastics with metal skeletons. Composite pipes, because the pipes are inconvenient to connect, so the inner layer of the metal skeleton is made of cross-linked polyethylene, and the outer layer is made of thermoplastics that can be hot-melt connected. The first solution is still not the best solution, and there are some technical problems in the compounding of the inner and outer layers that need to be improved

[0005] At this time, the application technology of non-crosslinked high temperature resistant polyethylene (PE-RT), which has the heat resistance and environmental stress cracking resistance of crosslinked polyethylene, began to mature. The new non-cross-linked high-temperature-resistant polyethylene material is easy to install and has the same thermal performance as cross-linked polyethylene. In 1991, an improved resin □DOWLEX※2344E was successfully developed. This series of non-cross-linked high-temperature-resistant pipe polyethylene resin was approved by German standards It is classified as PE-RT series. Although there are PE-RT series standards, only DOWLEX※2344E has passed this standard, and in 2000, the high temperature field allowed in the TR-4 technical report and list is 180F ( 82.2°C), the long-term stress-life curve of DOWLEX※2344E has the same service life, service temperature and design stress as cross-linked polyethylene (PEX) for 50 years, and DOWLEX※2344E products meet and exceed the requirements of DIN16833 for PE-RT pipes , under the stress conditions of 110°C and 1.9MPa, the life of the material exceeds 8760 hours. According to the extrapolation basis of IS09080, the life of the material at 70°C exceeds 50 years

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