A device and method for dynamic testing of liquid reaction molding shrinkage

Abstract

The invention provides a device and a method for dynamically testing liquid reactive molding shrinkage. The device comprises a base, a test cavity fixing base, a test cavity, an annular plunger, fourcylinders, a sample injection plunger, an electric cylinder fixing base, an electric cylinder, a coupler, a displacement sensor, an electric heater, a sample injection valve and a to-be-tested sample.The method comprises the steps of sucking the sample into a cylindrical cavity by moving the cylindrical plunger upwards, carrying out preliminary metering, and preheating the sample to a reaction temperature, pushing the sample into an annular cavity around the cylindrical plunger, and pushing the annular plunger to move upwards. The precise size of the sample at the test temperature can be precisely measured according to displacement of the annular plunger, and the displacement of the annular plunger is monitored in real time, thus a real-time shrinkage rate of the sample can be obtained; the size of the sample is metered and measured after the sample is heated until the temperature is stable, and the interference of thermal expansion on the test process is avoided; and the columnar plunger is pressed downwardly to the bottom, so that the sample injection pipeline can be completely isolated from the to-be-tested sample, and the interference of residual liquid in the pipeline to thetest is avoided.

Description

technical field [0001] The invention relates to a device and method for dynamically testing liquid reaction molding shrinkage, belonging to the field of measurement and testing. Background technique [0002] Liquid reaction molding mainly refers to the process of injecting liquid resin raw materials into the mold, curing the liquid resin raw materials by heating or mixing two active components, and finally forming solid products. The outstanding feature of this type of reaction is that it is accompanied by a chemical reaction during the molding process, which will produce a large shrinkage, which will affect the accuracy of the product size. Therefore, the dynamic shrinkage curve of the resin during the curing process is of great significance to the formulation of the specific process, and it is necessary to develop suitable equipment to test it. [0003] The plunger cylinder method is the most commonly used shrinkage test method. This method uses a piston and a piston cyli...

AI Technical Summary

Problems solved by technology

However, this method has some disadvantages

First of all, in this method, the liquid resin sample needs to be sucked into the piston barrel through the relevant pipeline, and the resin in the pipeline will also shrink, which will interfere with the final test value; secondly, many of these processing processes need to be heated to a certain degree of reaction Temperature, the thermal expansion and reaction shrinkage of the sample will be reflected on the shrinkage curve eventually, and the mutual interference between them makes it difficult to obtain the real reaction shrinkage in actual operation; Interference removal with extra resin in the tubing for accurate determination of shrinkage during reaction

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