Air bubble bags are mostly made of low-density polyethylene, with many small bubbles on the surface, each of which contains a certain amount of gas. When impacted or squeezed by external force, these gases will play a buffering role, making air bubble bags have shock resistance, wear resistance, sound insulation, and other functions. They are commonly used in electronic products, precision instruments, ceramics, handicrafts, household appliances, bicycle stores, kitchenware, furniture, hardware tools, glass products, and other anti-seismic cushioning and protective packaging.
Electronic products, precision instruments, and other delicate products are sensitive to water vapor. Contact with too much water vapor can cause the product to become damp, resulting in a decrease in performance or even scrapping. The moisture resistance of air bubble bags, which are used as the protective packaging for these products, is an important factor affecting the water vapor content in the environment where the product is placed.
The water vapor permeability is the index used to evaluate the moisture resistance of air bubble bags. This article aims to test the water vapor permeability of air bubble bag samples.
Currently, there are four main methods for testing the water vapor permeability of plastic materials: cup method, electrolytic sensor method, infrared sensor method, and humidity sensor method. In order to prevent the bubbles in the sample from being damaged by compression, it is best to keep the original appearance of the air bubble bag.
This article used the cup method principle to test the water vapor permeability of the sample, and the testing standard is GB 1037-1988 "Test methods for water vapor transmission of plastic films and sheets - Cup method."
White transparent air bubble bags for packing were used as the test samples to test their moisture resistance.
(1) Cut three pieces of 74 mm diameter samples from the sample surface, clamp them in three breathable cups filled with distilled water respectively;
(2) Place the breathable cups on the breathable cup holder of the equipment and close the test chamber door;
(3) Set the sample name, test temperature, humidity, test mode, and other parameters, click the test option, the equipment will carry out the test according to the set parameters, and automatically display the water vapor transmission rate test value of the sample after the test is completed.
The average water vapor permeability of the air bubble bag sample tested this time was 13.913 g/(m2·24h).
Air bubble bags, as a protective packaging for products, can effectively prevent the product from getting damp and keep the product in a relatively low humidity environment due to their good moisture resistance. Choosing a high-quality air bubble making machine for the production of these bags is crucial to ensure the bags provide the necessary safeguards for delicate items.
Based on the cup method principle device-W3/030 water vapor permeability tester, this article tested the water vapor permeability of air bubble bag samples. The test process is simple, the equipment is easy to operate, and the automation degree is high, which can accurately reflect the moisture resistance of air bubble bags.