Line marking device for longitudinal retraction rate test of plastic pipe

Abstract

The invention relates to the technical field of plastic pipe retraction rate tests and especially relates to a line marking device for a longitudinal retraction rate test of a plastic pipe. The line marking device comprises a supporting frame, wherein a needle bearing support used for placement of a pipe sample is fixed on one end of the supporting frame; a support of a line marking pen distance adjustment rod is fixed on the other end of the supporting frame; a line marking pen distance adjustment mechanism is disposed on the support of the line marking pen distance adjustment rod; the line marking pen distance adjustment mechanism is connected to a line marking pen supporting device; a line marking pen is disposed on the line marking pen supporting device; and a rotation mechanism is disposed on the pipe sample. After adoption of the structure, the invention proposes the line marking device with flexible operations, accurate distance marking and high practicability based on further improvement and perfection of a line marker.

Description

technical field [0001] The invention relates to the technical field of plastic pipe retraction rate test, in particular to a marking device for plastic pipe longitudinal retraction rate test. Background technique [0002] The standard GB / T 6671-2001 stipulates the longitudinal shrinkage test of thermoplastic pipes. The principle is to place a sample of a specified length in a heating medium at a given temperature for a certain period of time, and measure the shrinkage of the sample before and after heating. The distance between the lines expresses the longitudinal retraction of the pipe in percent relative to the original length change. The standard mentions that a scriber is required for the sample marking line, and it is proposed that the scriber should ensure that the distance between the two marking lines (in the circumferential direction) is 100mm. Although this standard proposes the requirement of scriber, does not propose a kind of device that can meet this requireme...

AI Technical Summary

Problems solved by technology

At present, although there are scribing devices for plastic pipes on the market, there are the following problems in the actual use process: first, it is inconvenient to use and operate, and it is laborious to operate for samples with large pipe diameters or large pipe out-of-roundness; The second is that the accuracy of the marking position cannot be guaranteed, and the marked line is often not on the same circumference, resulting in the inability to close the circumferential line, which seriously affects the accuracy of the results

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