Ultrasonic online detection method and device for solid layer thickness of micro-foamed injection molded products

Abstract

The invention discloses an ultrasonic detection method of the solid layer thickness h in a microcellular foaming injection molding product. The method includes: (1) for an online injection molding system, a series of ultrasonic waves are emitted to the product in a molding process in a direction vertical to the flow direction of a plastic melt, and echo information of the series of ultrasonic waves is acquired; (2) after the plastic melt flows to a detection area, the ultrasonic waves are reflected from a contact surface of a template and a polymer, the maximum amplitude Amax of the echo information is received and analyzed (the maximum amplitude usually occurs at previous echo waves and is generally the first echo wave); and (3) the maximum amplitude Amax is substituted into a pre-obtained fitting formula between the maximum amplitude Amax and the solid layer thickness h to obtain the solid layer thickness h of the microcellular foaming injection molding product. The method is advantageous in that the measurement of the solid layer thickness h of the microcellular foaming injection molding product avoids waiting of take-down of the product, and online detection is achieved.

Description

technical field [0001] The invention relates to plastic molding technology, in particular to an ultrasonic on-line detection method and device for the thickness h of a solid layer in the micro-foaming injection molding process. Background technique [0002] Micro-foaming injection molding is a precision injection molding technology that generates countless tiny cells inside the polymer. The micro-foaming injection molding process breaks through many limitations of traditional injection molding, which can significantly reduce the weight of the part, shorten the molding cycle, greatly reduce the warping deformation of the part, and enhance the dimensional stability of the part. The micro-foaming injection molding process has great advantages in the production of precision products, and has been paid more and more attention and widely used. [0003] In microfoaming injection molding, the solid layer thickness of the product is one of the key parameters affecting the mechanical...

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Problems solved by technology

[0005] (1) This method needs to destroy the product and is destructive

[0006] (2) When developing a new product, a large number of experiments are required to adjust the process parameters to obtain a suitable surface thickness value, which is time-consuming and labor-intensive

Once the mold is changed, a lot of experiments need to be done again to adjust the process parameters, this method has poor flexibility

[0007] (3) Scanning electron microscope detection requires manual operation by workers, which takes a long time, has large errors, and is inefficient. Moreover, it can only do sampling inspection, and it is impossible to achieve full inspection of product batches.

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