What are the methods for measuring the wall thickness of plastic preforms?

1. Contact measurement method. This kind of wall thickness test method is a widely used wall thickness measurement method. The principle is: put the measuring support rod into the bottle, use its dart head to touch the measuring part, and place the measuring head of the capacitive sensor on the corresponding part outside the body of the Plastic bottle to contact the bottle body and correspond to the dart head. Take the thickness reading on the gauge.

The accessories of the wall thickness gauge of this principle are easy to replace and the cost is low. However, the requirements for the stability of the mechanical structure of the instrument are relatively high, and a large amount of manpower is required for measurement operations and numerical analysis.

2. Thickness test by magnetic induction method. The principle of this method is based on the Hall effect theory. When measuring thickness, a small steel ball is placed on one side of the test material, and the probe is placed on the other side. Turn the bottle, the steel ball receives the magnetic force of the probe and moves at the same time.

The magnetic induction sensor can measure the distance from the probe to the steel ball, so as to obtain the wall thickness value of the plastic bottle. The characteristic of this instrument is that it does not destroy the sample and is convenient for measurement. However, it is not easy to measure the concave and convex parts of plastic bottles, and it cannot fully meet the needs of customers to achieve differentiated precision control for different parts and different samples.

3. Test the thickness by slice method. This is the original method of wall thickness measurement. Restricted by the limitations of technology at the time, when testing plastic bottles in the early days, many analysts cut the bottles into pieces, and then tested their thickness values with screw micrometers and calipers. The cost of this method is very low, but it is believed that the error is large and the test efficiency is low, so it is a method that is gradually eliminated.

Heshan Yecheng Plastic Products Co.,Ltd. was established in 2001. After 20+ years of unremitting efforts, we now become the leading manufacturer of PET preform in China. Products are mainly used for cosmetics, mineral Water preform & beverage, pesticide, bottles, Cream Jar. etc. For more details about the product, please contact us:
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