Metal plastic composite tube with thermoplastic tube end contact flange

[0025] Example 1:

[0026] figure 1 The figure of this embodiment 1 is shown. The metal-plastic composite pipe 1 in this embodiment 1 has a cylindrical metal pipe wall 2 without holes (which can be a seamless steel pipe or other seamless metal pipe, or it can be longitudinally buttted or overlapped with aluminum or steel strips. The cylindrical metal frame formed by welding), the cylindrical metal pipe wall 2 has a high-density polyethylene plastic outer layer 3 and a plastic inner layer 4 respectively inside and outside the plastic inner layer of the composite pipe wall at the end of the metal plastic composite pipe There are many holes 5, and these holes 5 are filled with thermoplastic that has the ability of hot-melt connection with the plastic outer layer 3 and the plastic inner layer 4. The thermoplastic plastic wraps the cylindrical metal pipe wall through the holes and interacts with the plastic outer layer 3 and the plastic inner layer. Layer 4 is hot-melt connected to form a thermoplastic pipe end connecting flange 6 that has a connection function and can withstand the axial tension of the pipe. The cylindrical metal pipe wall 2 has no holes, and many holes 5 are processed at the end of the composite pipe. Using a forming mold, the thermoplastic plastic that can be thermally connected with the plastic layer in the composite pipe is pressed into the mold cavity by an injection molding machine or an injection molding machine. , So that the hot-melt plastic will fill many holes processed on the end of the tube in the cavity under pressure, and the hot-melt plastic will also heat-melt the plastic outer layer 3 and the plastic inner layer 4 of a certain length at the end. Connected as a whole to form a complete covering of the wall of a cylindrical metal pipe with a certain length at the end. After cooling and shaping, the formed thermoplastic pipe end connecting flange can be filled with many plastic columns in the many holes on the pipe wall. The pin and the plastic pipe wall with a certain tensile fracture area integrally connected with the inner and outer plastic wall by thermal melting can bear the axial tensile force that the composite pipe must bear after the composite pipe is connected as a pipe network. Since the thermoplastic pipe end connecting flange is used at the end of the metal-plastic composite pipe, the thermoplastic pipe end connecting flange can be made directly when the metal composite pipe is manufactured in the factory, which makes the on-site construction extremely convenient. The connecting flange completely tightly wraps the plastic outer layer and the plastic inner layer of the end of the metal frame reinforced plastic composite pipe and the pipe end surface. The connection is firm, reliable, and leak-free. The mechanical strength of the connection is high, and fluid is prevented from entering the metal frame. Corrosion to it, the pipeline has a long service life.

[0027] Example 2:

[0028] figure 2 A diagram of Example 2 of the present invention is shown. The second embodiment is basically the same as the first embodiment. The difference is that the metal-plastic composite pipe is a 90° composite pipe joint 7.

[0029] Example 3:

[0030] image 3 A diagram of Example 3 of the present invention is shown. The third embodiment is basically the same as the first embodiment. The difference is that there is no plastic outer layer in the metal-plastic composite pipe.