RU2100201C1 - Method of manufacturing combined pipes - Google Patents

Abstract

FIELD: manufacturing polymeric pipes. SUBSTANCE: plastic pipe is set on a mandrel. On the pipe an reinforcing layer is wound. The layer is polymerized and combined pipe is removed from the mandrel. The plastic pipe of the inner diameter smaller than that of the mandrel is simultaneously moulded for the greater diameter and set on the mandrel with a spaced relation. The pipe is conditioned until it abuts against the mandrel. After that the reinforcing layer is wound and polygamized. The finished pipe is then removed from the mandrel. A ring shaped mandrel is used for mandrelling. EFFECT: simplified method. 2 cl, 4 dwg

Description

 The invention relates to the field of manufacture of plastic products, more specifically to methods, and can be used in the manufacture of long biplast pipes.

 A known method of manufacturing biplastic pipes of thermoplastic and fiberglass by winding fiberglass onto a sleeve of thermoplastic with its subsequent heating, expansion from the inside and subsequent polymerization (SU, ed.St. N 193046, class B 29 C 53/56, 1967).

 The disadvantage of this method is the low quality of the manufactured pipes.

 This drawback is explained by the uneven tension of the layers of reinforcing fibers due to the "subsidence" (reduction in diameter) of the sleeve with the previously wound layers under the action of the next wound layer and fixing this unevenness in the finished pipe, which leads to a decrease in accuracy, and when loading to non-simultaneous entry into operation texture layers of the pipe, and thereby significantly (up to 40%) reduces its mechanical strength, reliability and geometric accuracy.

 There is another method of manufacturing combined pipes, including installing a plastic pipe on the mandrel, winding a reinforcing layer on it, polymerizing and removing the combined pipe from the mandrel (SU, ed.St. N 331914, class B 29 C 53/64, B 29 D 23 / 00, 1972).

 In this method, a plastic pipe with a guaranteed clearance is mounted on a metal mandrel, the pipe is secured against rotation, and by rotating the mandrel with the pipe, a reinforcing layer is wound on it. The accuracy of the pipes obtained in this way (due to winding and polymerization on the mandrel) is slightly increased.

 The positive effect achieved in this method, however, remains insufficient, since the mechanical strength and reliability of the pipes manufactured by this method remained virtually unchanged, and the increase in their hermetic accuracy is insignificant.

 The objective of the invention is to improve the quality of manufactured pipes.

 According to the invention, this problem is solved by improving the method of manufacturing combined pipes, including installing a plastic pipe on the mandrel, winding a reinforcing layer on it, polymerizing and removing the combined pipe from the mandrel.

 This improvement consists in the fact that a plastic pipe with an inner diameter smaller than the diameter of the mandrel is flared to a larger diameter and installed with a gap on the mandrel, then it is held until it is gaplessly adjacent to the mandrel during relaxation, after which the reinforcing layer is wound, polymerized and removed combination pipe with mandrel.

 Burning of the plastic pipe can be carried out in the process of installing it on the mandrel.

 Burning of a plastic pipe with an inner diameter smaller than the diameter of the mandrel to a larger diameter provides the possibility of relaxation of the plastic pipe in the radial direction along its entire length.

 Installing a plastic pipe with a clearance on the mandrel speeds up and simplifies the assembly process.

 Exposure to the gap between the plastic pipe and the mandrel during the relaxation process eliminates the need to attach the plastic pipe to the mandrel and eliminates its further "subsidence" in the radial direction.

 Subsequent winding, polymerization and removal of the combined pipe from the mandrel provides increased uniformity of tension of the layers of the reinforcing material, maintaining uniformity of tension and geometric accuracy in the above processes due to the increased rigidity of the power closure of the winded layer on the mandrel, thereby improving quality (mechanical strength, reliability and geometric accuracy ) manufactured pipes.

 Burning of a plastic pipe during installation on a mandrel allows you to shorten the manufacturing cycle of the combined pipe and simplify the equipment used.

 In FIG. 1 shows a plastic pipe mounted with a clearance on the mandrel; in FIG. 2 plastic pipe, gapless joined to the mandrel, in the operations of winding the reinforcing layer and polymerization; in FIG. 3 combined finished pipe in the process of removing the mandrel; in FIG. 4 operation of the burning of a plastic pipe in the process of installing it on a mandrel.

 The arrows in FIG. 3 and 4 show the direction of action of the applied forces.

 The proposed method is as follows.

 Set the plastic pipe 1 on the mandrel 2, wrap the reinforcing layer 3, carry out the polymerization and remove the combined pipe 4 from the mandrel 2.

 In the implementation of the proposed method, the plastic pipe 1 with an inner diameter smaller than the diameter of the mandrel 2 is flared to a larger diameter (which makes it possible to relax in the radial direction along the entire length) and is installed on the mandrel 2 with a gap of 5 (Fig. 1), which accelerates and the assembly process is simplified, then it is held up to its gapless adjacency to the mandrel 2 during the relaxation process (this eliminates the need to fix the plastic pipe to the mandrel and eliminates its further "subsidence" in the radial direction), why they wind the reinforcing layer 3 and polymerize (Fig. 2), remove the combined pipe 4 from the mandrel 2 (Fig. 3), which ensures increased uniformity of the tension of the layers of reinforcing material, maintaining uniform tension of the layers and geometric accuracy in the above processes due to the increased the stiffness of the power circuit of the wound layer on the mandrel.

 In an embodiment of the method (Fig. 4), a mandrel ring 6 is installed on the mandrel 2 and the plastic pipe 1 is burned during installation on the mandrel 2 (which reduces the manufacturing cycle of the combined pipe and simplifies the equipment used).

 The proposed method allows to significantly (up to 30%) improve the quality of manufactured pipes by increasing their mechanical strength, reliability and geometric accuracy.

Claims (2)

 1. A method of manufacturing combined pipes, including installing a plastic pipe on the mandrel, winding a reinforcing layer on it, polymerizing and removing the combined pipe from the mandrel, characterized in that the plastic pipe with an inner diameter smaller than the mandrel diameter is simultaneously flared to a larger diameter and with a gap they are installed on the mandrel, then they are kept until it gaplessly adjoins the mandrel during the relaxation process, after which the reinforcing layer is wound, polymerized and the finished pipe is removed from the mandrel.  2. The method according to claim 1, characterized in that the burnishing is carried out using an annular mandrel.

Images