A method of detecting air leakage point of vacuum bag film by using pressure-sensitive substance

Abstract

The invention relates to a method for detecting the air leakage point of a vacuum bag membrane using a pressure-sensitive substance. The method comprises the steps that the pressure-sensitive substance is added to the vacuum bag membrane, then pressure difference between the inside and the outside of the vacuum bag membrane is adjusted to be equal to or greater than a critical pressure, and a point where its color does not change is the air leakage point, wherein the critical pressure refers to a pressure at which the pressure-sensitive substance starts to change color, and the pressure-sensitive substance is a spiropyran-containing polymer with the polymerization degree larger than or equal to 5. According to the method for detecting the air leakage point of the vacuum bag membrane using the pressure-sensitive substance, the air tightness of the vacuum bag membrane is automatically detected based on the changes of the external pressure of the vacuum bag membrane, manpower and material resources are greatly saved, the place of air leakage is accurately and quickly found, remedial measures are taken in time, the molding pressure of composite components is guaranteed, production cost is saved, production efficiency is improved, and the method has the advantages of industrialized promotion.

Description

technical field [0001] The invention belongs to the field of air tightness detection of vacuum bag films, and relates to a method for detecting air leakage points of vacuum bag films by using pressure-sensitive substances. Background technique [0002] With the increasing demand for composite material components in aerospace, ships, trains and other fields, the performance requirements of the auxiliary materials used in the forming process are also higher. Vacuum bag film is a kind of vacuum auxiliary material for the preparation of composite material components by autoclave forming or vacuum assisted forming. It provides a vacuum-tight environment for the composite material together with the sealing tape, and the components are compacted by vacuuming to ensure the forming pressure. However, in the production process of vacuum bag film, trachoma is easy to appear, and trachoma cannot be observed with the naked eye. Composite components have internal quality defects or dry ...

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Problems solved by technology

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art that the air leakage point cannot be accurately detected, and provide a method for detecting the air leakage point of the vacuum bag film by using a pressure-sensitive substance, adding a pressure-sensitive substance to the vacuum bag film, and then continuously increasing The pressure difference between the inner and outer sides of the large vacuum bag film will change the color of the vacuum bag film under the action of pressure. The leak point is connected to the atmosphere and is not affected by the pressure, so the color change will not occur. Just observe the color change. Realize the detection of air leaks

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