Product parameter ultrasonic on-line measuring method in co-injection

Abstract

The invention discloses a product parameter ultrasonic on-line measuring method in co-injection, comprising: (1) in a direction perpendicular to plastic melt flow, emitting ultrasonic wave to a product in a molding process, and collecting the reflection echo LB and reflection echo LS of the ultrasonic wave of a same time: the reflection echo LB is generated by the ultrasonic wave on a molding interface; and the reflection echo LS is generated by the ultrasonic wave on a plastic mold interface; (2) calculating the time interval delta t between the LB and the LS, and obtaining the surface wall thickness h of a plastic product; and (3) calculating the core layer length of a plastic product according to the surface wall thickness h. According to the invention, the method can measure the wall thickness and length of each layer of a plastic product without damaging the product, and has the advantage of nondestructive measurement; the method can obtain the wall thickness and length of each layer through ultrasonic wave signals, does not need off-line operation after preparation of a product, can perform real-time on-line lossless measurement, and has the characteristics of simple operation and high precision.

Description

technical field [0001] The invention relates to plastic forming technology, in particular to an ultrasonic on-line measurement method for product parameters in co-injection molding. Background technique [0002] Co-injection molding process, also known as sandwich injection molding or multi-layer co-injection molding, is a molding method that uses two or more injection systems to inject different types of plastic melts into the same mold simultaneously or sequentially. With the enhancement of people's awareness of environmental protection, and the development of injection molding machinery industry and automatic control technology, the co-injection molding process has received more and more attention, and its application has become more and more extensive. [0003] In co-injection molding, the wall thickness of the surface layer and the middle layer are two important parameters of co-injection molding products. The precision of the wall thickness of the surface layer and th...

AI Technical Summary

Problems solved by technology

The disadvantages of this method are: (1) This method needs to destroy the product, which is destructive; (2) It needs a large number of trial production experiments to adjust the process parameters to obtain relatively accurate surface layer and middle layer wall thickness. The method is time-consuming and labor-intensive; (3) Once the mold is changed or the injection molding material is changed, it is necessary to re-adjust the process parameters through a large number of experiments, and this method has poor flexibility

[0005] In co-injection molding, the length of the middle layer and core layer of the injection molded part affects its mechanical and mechanical properties. However, the middle layer and core layer materials are usually covered by opaque surface materials, so they cannot be measured optically unless the injection molded part is cut off. measurement, otherwise it is very difficult to measure the length of the middle layer and the core layer

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