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Classification of Corrugated Pipes

Industrial Engineering Plastics,  
Corrugated pipes can be classified into two main categories based on the material used - metal corrugated pipes and plastic corrugated pipes. Plastic corrugated pipes are flexible tubes made of plastic. 

They are widely used in civil engineering, municipal projects, and highway bridges due to their lightweight, cost-effectiveness, and excellent physical and chemical properties. Metal corrugated pipes, on the other hand, are wave-shaped tubes made of materials like carbon steel, stainless steel, or plastic-coated metal. They are used extensively in industries like power and mechanical engineering due to their ability to withstand small angle bends, expansion, and contraction.

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Corrugated pipes can also be classified based on the forming process used. The main types are hydraulic forming corrugated pipes, rolling forming corrugated pipes, mechanical expansion forming corrugated pipes, and deposition forming corrugated pipes.

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Hydraulic forming is the most common and widely used forming process for corrugated pipes. It is mainly used to manufacture circular corrugated pipes with a wall thickness ranging from 0.08 to 4mm. The process involves expanding and compressing the pipe material using liquid pressure to form the corrugated shape. Small diameter metal corrugated pipes are often manufactured using this process.

Rolling forming involves using rolling wheels placed inside the pipe material to form the corrugated shape. This process is mainly used to manufacture large diameter corrugated pipes.
Deposition forming involves depositing the corrugated pipe material onto a mold core and then dissolving the mold core to form the corrugated shape. This process is generally used to manufacture low hardness metal corrugated pipes, but it is expensive.
Corrugated pipes are manufactured using the extrusion process, and the raw materials used are mostly high-density polyethylene (HDPE) plastic. This material has excellent corrosion resistance and a long service life. During the production process, the HDPE plastic and additives are mixed thoroughly and then fed into the extruder. The extruder heats the mixture to a high temperature of 230 degrees Celsius, melting the plastic particles and extruding them as a viscous liquid. The resulting unsightly blobs are then used to manufacture the beautiful corrugated pipes.
The molds used to form the corrugated pipes are made up of hundreds of pairs of separate modules. The molds are opened and closed in a cycle using each pair of modules to continuously manufacture the corrugated pipes.

The extruder head is inserted into the mold cavity, and as each set of molds closes, the forming cavity for the corrugated pipe is created. The extruder injects melted polyethylene plastic into the mold, and the solution quickly fills the grooves. As the mold moves forward, the cooling system in the mold will cause the corrugated pipe to harden and take shape. Each set of molds will automatically open and release the formed pipe, and the molds will move forward to continue the cycle of forming corrugated pipes. After the pipe is released from the mold, it needs to be completely hardened by water cooling. The long corrugated pipe will continue to grow.
By rotating several toothed turntables, holes are punched around the grooves of the corrugated pipe. Square holes are usually punched to increase the drainage area. The surface of the corrugated pipe is wrapped with a layer of filter cloth and heat-pressed to prevent the holes from being blocked in the drainage ditch. Finally, the water pipe is cut to a certain length, wound on a reel, and fixed with a rope. It is then wrapped in plastic film and ready for shipment.
Each product needs to undergo sampling tests, and the compression strength test can ensure that the pipeline will not bend under load.