Nondestructive measurement method for layer thickness of multilayer polymer tubular product

Abstract

The invention discloses a nondestructive measurement method for layer thickness of a multilayer polymer tubular product. The method comprises the steps of (1), calculating acoustic impedances which respectively correspond with one material layer and multiple material layers of which the thicknesses are to be measured; (2), calculating acoustic velocity of ultrasonic wave in the corresponding material layer by means of an acoustic impedance; (3), vertically transmitting the ultrasonic wave to the product, and recording time interval between receiving an echo reflected from the upper surface of a certain material layer and the receiving the echo reflected from the lower surface of the certain material layer by an ultrasonic detecting probe; and (4), obtaining the thickness of the layer by means of the acoustic velocity of the ultrasonic wave in the certain layer of which the thickness is to be measured and the time interval that corresponds with the layer, and furthermore obtaining the thickness of the layer or multiple layers of which the layer thickness is to be measured. According to the nondestructive measurement method for the layer thickness of the multilayer polymer tubular product, the propagation acoustic velocity of the ultrasonic wave is calculated, and furthermore the layer thickness of the corresponding layer is calculated according to the time interval in ultrasonic wave measurement. Destruction of the tubular product is not required in the whole process, thereby preventing wastage. Furthermore the nondestructive measurement method has advantages of high measurement precision and high practicability.

Description

technical field [0001] The invention belongs to the technical field of product layer thickness measurement, in particular to a method for non-destructive measurement of layer thickness of multilayer polymer tubular products. Background technique [0002] Plastic injection molding is widely used in the manufacture of plastic products, such as automotive components, home appliance housings, electronic product housings, etc. Co-Injection Molding (COIM for short) and Fluid-Assisted Co-Injection Molding (FACOIM for short) use two or more polymer melts to inject the mold cavity sequentially, and the melt injected first is the product The surface layer of the product, the melt injected later is the core layer of the product, and finally a product composed of inner and outer multi-layer polymers is formed. If the waste plastic is used as the inner layer polymer material, the recycling of the waste plastic can be realized. Co-injection molding or assisted co-injection molding can o...

AI Technical Summary

Problems solved by technology

[0004] The currently reported methods for measuring the layer thickness of multilayer polymer products all need to destroy the product, the measurement method has low efficiency, narrow scope of application, and poor practicability

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