How to production double wall pipe

The double wall pipe is a concave-convex shell on the surface, just like a corrugation, so it is called a double wall pipe. Because the double wall pipe have soft, foldable, and stretchable properties, it has been widely used in chemical engineering, electronics, electric power, civil engineering, aerospace, and other projects. In the equipment, it plays the role of sealing, isolation, noise reduction, drainage, and so on.

The development history of double wall pipe

Humans have been looking for flexible and foldable hoses. In ancient times, people first sewed animal skins into tubular structures.

In the seventeenth century, some people sewed canvas into a hose and could transport water at short distances. Later, this canvas hose was widely used in firefighting.

In 1855, the Germans used the principle of making jewelry at that time to successfully create double wall pipe and also applied for a patent.

In the 20th century, with the development of electronic technology, double wall pipe began to be used as various electronic instruments, and the instrument connection was used to protect components.

In modern times, with the development of plastic, rubber, and metal materials and processes, various plastic hoses and metal hoses have appeared one after another, and are widely used in people's lives.

Classification of double wall pipe

According to material classification, double wall pipe are mainly divided into metal double wall pipe and plastic double wall pipe.

Plastic corrugated pipe is a retractable tubular product made of plastic. Because of its material-saving, lightweight and excellent physical and chemical properties, plastic corrugated pipe is widely used in civil engineering, municipal engineering, highways, and bridges.

Metal double wall pipe are pipes with wavy shapes. The most common metal double wall pipe are carbon steel, and stainless steel, the inner layer is plastic and the outer layer is plated metal. The metal double wall pipe can be used for small-angle turning, transmission, expansion, and contraction. It is widely used in the machinery industry and other industries.

According to the classification of forming process, double wall pipe can be mainly divided into hydroforming double wall pipe, roll-forming double wall pipe, mechanical expansion double wall pipe, and deposition-forming double wall pipe.

Hydroforming is the most common and widely used forming method for double wall pipe. It is mainly used to manufacture annular double wall pipe. It can form double wall pipe with a wall thickness of 0.08~4mm. Hydroforming is to use the liquid pressure in the tube blank to expand the tube. After recompression, it is formed into a corrugated pipe, and this molding process is mainly used for small-diameter metal corrugated pipes.

The rolling forming process relies on the rolling of the forming wheelset in the tube blank, and the formed double wall pipe can only roll one corrugation at a time, and some can roll several ridges at a time. This process is mainly used for the manufacture of large double wall pipe.

Deposition molding is to deposit the double wall pipe material on the mold core and then erode the mold core away. This process is generally used to manufacture metal double wall pipe with lower hardness, and the manufacturing cost is relatively high.

The manufacturing process of plastic double wall pipe

It is often seen on the road that large trucks are pulling large and long pipes, and there are many corrugated pipes on the surface. I wonder how such pipes are made.

This kind of large pipe is called a perforated corrugated pipe. It has become the main product for drainage in civil engineering construction and is also widely used in highways, municipal engineering, and sports fields. How is it made?

The perforated double wall pipe adopt a one-time extrusion molding process, and the raw materials are mostly made of high-density polyethylene (HDPE) plastics. This material has strong corrosion resistance and very long service life. The prepared polyethylene plastic and some additives are put together and sent to the machine to be thoroughly stirred and mixed.

The agitated and mixed raw materials are fed into the extruder and heated to 230 degrees Celsius at a high temperature so that the plastic particles are melted and then extruded into a viscous liquid. Use them to make those nice corrugated tubes.

The forming mold of the double wall pipe is composed of hundreds of pairs of left and right separate modules, and the double wall pipe can be continuously manufactured through the cycle of closing and opening each pair of module

The extruder head extends into the mold cavity, and the molding cavity of the double wall pipe is formed with the closing of each set of molds. The extruder injects the molten polyethylene plastic into the mold, and the solution will quickly fill the lines, and with the As the mold moves forward, the cooling system in the mold will harden and form the double wall pipe, each pair of molds will automatically open and demould, and the mold moves forward to continue the cycle of forming the double wall pipe.

After demolding, the corrugated pipe is formed, and the plastic is completely hardened by water cooling, and the long corrugated pipe will continue to grow.

Through the rotation of several toothed turntables, holes are punched in the grooves around the double wall pipe. Generally, square holes are punched to increase the drainage area.

The surface of the double wall pipe is wrapped with a layer of filter cloth and hot-pressed to prevent the holes in the gutter from being blocked.

Finally, cut the water pipe to a certain length and wrap it on the reel, fix it with a rope, and then wrap it with a plastic film before leaving the factory.

Each product is tested on a sample basis, and the compressive strength test ensures that the pipe will not bend under load.