Preparation process of biaxial orientation polyvinyl chloride (PVC)-U pipe

Abstract

The invention discloses a preparation process of a biaxial orientation polyvinyl chloride (PVC)-U pipe, which is characterized in that a cold air pipe I and a cold air pipe II are arranged on a process production line, cold air flows through a plurality of air outlet convex caps I uniformly distributed on the cold air pipe I and is sprayed to the inner wall of a pipe blank, so that traction slipping is avoided, and a pipe subjected to axial traction stretching is prepared; cold air flows through a plurality of second air outlet convex caps evenly distributed on a second cooling air pipe and is sprayed to the inner wall of the flaring pipe, traction slipping is avoided, the biaxial traction and stretching flaring pipe is manufactured, in addition, the flaring die is composed of a column table part, a frustum part and an extension column table part, a heating fluid cavity and a cooling fluid cavity are conveniently arranged, and the production efficiency is improved. The heating fluid cavity and the cooling fluid cavity are beneficial to reducing the internal and external temperature at the radial flaring stretching position and reducing the traction stretching friction force. By adopting the technical scheme, the cooling air flow can balance the temperature difference inside and outside the pipe on the process production line, traction slip is avoided, and the process production is continuous and reliable.

Description

technical field [0001] The invention relates to the technical field of polyvinyl chloride pipe production, in particular to a preparation process of a biaxially oriented polyvinyl chloride (PVC-U) pipe. Background technique [0002] The PVC-O pipe is a pipe manufactured by a special orientation process. The PVC-U pipe produced by the extrusion method is stretched axially and radially, so that the long-chain PVC molecules in the pipe are biaxially regular. Arrange to obtain a new type of PVC pipe with high strength, high toughness, high impact resistance and fatigue resistance. [0003] In the prior art, such as figure 1 The process line shown is biaxially oriented to prepare the polyvinyl chloride pipe, and the plastic liquid in the molten state is extruded through the extruder 1. The extruded plastic liquid is quickly shaped by the sizing sleeve 1 2 and the cooling water tank 1 3, and then by the tractor. One 4 is axially stretched and pulled, and the stretched pipe enter...

AI Technical Summary

Problems solved by technology

[0005] A preparation process of biaxially oriented polyvinyl chloride PVC-U pipe is proposed, which is used to solve the problem of large temperature difference between the expanding die and the heating water tank located inside and outside the stretched pipe, and to solve the problem of radial stretching of the pipe by the expanding die. Traction slipping problem caused by high resistance

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