Vacuum aluminum plating film is currently the most representative product of vapor deposited composite films. It melts and evaporates aluminum wires at high temperatures under high vacuum conditions, and the aluminum vapor precipitates on the surface of the plastic film to form a barrier layer with a thickness of about 35-40nm. The plastic film used as the substrate can be PE, PP, PET, PA, PVC, etc. Vacuum aluminum plating film has excellent barrier properties. Without requiring transparent packaging, vacuum aluminum plating film is an excellent choice. In addition, aluminum plating film has good fragrance retention, metallic luster, and decorative beauty. However, due to the ductility of aluminum metal and the limitations of aluminum plating technology, the aluminum plating layer is prone to pinholes or cracks after bending and rubbing, which affects the oxygen and moisture resistance of vacuum aluminum plating packaging.

ASTM F392 is a method standard specifically used to test the anti rolling and bending properties of flexible packaging materials. Through this test, the bending, rolling, folding, and other behaviors of films during production, processing, transportation, and other processes can be simulated. By detecting the changes in the number of pinholes or barrier properties of the sample before and after the rubbing test, the anti rubbing performance of the material can be judged, which can provide quantitative basis for packaging design and practical application of the material. </P>

1. Introduction to ASTM F392 Testing Method

Firstly, prepare a certain number of samples that meet the testing requirements according to the standard requirements, and test the number of pinholes, barrier properties, or other parameter indicators of untested materials. Pre treat the sample according to the standard requirements for a period of time, then select the test environment conditions and test mode to start the test.

The anti rubbing performance of the sample can be judged by the following two methods: first, measuring the number of pinholes formed during the rubbing process with dyed turpentine; Secondly, compare the breathability or moisture permeability of the sample before and after the experiment. The pinholes formed in the rubbing test can only be measured by dyeing turpentine. However, if only one layer of the multi-layer composite material is broken, or if some plastic films are difficult to form pinholes in the rubbing test, then the determination of the anti rubbing performance of these materials needs to be completed through professional barrier testing equipment. Setting multiple testing modes is to ensure that the number of pinholes or barrier properties formed by the sample during the rubbing test are within a reasonable testing range. When evaluating the anti rubbing performance of materials, the average measurement of multiple samples should be taken to avoid the influence of accidental factors in the experiment.

2. Application detection

Recently, LABTHINK Languang Laboratory used Labthink FDT-01 Rubbing Tester T3 Moisture Permeability Tester to compare the anti rubbing performance of vacuum aluminum plated PET, PET, PE/EVOH/PE materials according to ASTM F392. Three modes, B, C, and D, were used for the kneading test, and the kneading effect was judged by detecting the moisture permeability of the sample.

The moisture permeability of vacuum aluminum plated PET, PET, and PE/EVOH/PE materials is within the range of medium to high barrier properties, but their anti rubbing performance differs significantly. The material with the best anti rubbing performance is PE/EVOH/PE, and its moisture permeability remained consistent throughout this experiment. Next is PET, which can maintain its initial moisture permeability when subjected to fewer rubs. However, when the number of rubs increases to 900, its moisture permeability also shows a significant increase. However, the widely recognized high barrier material vacuum coated aluminum PET has the worst anti rubbing performance, with its moisture permeability increasing by more than 10 times even after only a few rubbing actions.

3. Summary

The anti rubbing performance of materials will affect the stability of the barrier performance of packaging materials throughout the entire circulation process. If the barrier layer of the material loses its barrier effect due to poor resistance to bending or rubbing, resulting in product deterioration and failure, the losses for packaging manufacturers and product manufacturers will be enormous. Although aluminum-plastic composite packaging has excellent mechanical and barrier properties, it has many disadvantages in terms of poor resistance to rubbing and bending. Vacuum aluminum plating material, which is regarded as a substitute for aluminum foil, has made significant improvements in folding resistance and toughness. However, from the comparison data of this experiment, there are still differences in rubbing resistance between aluminum plating material and other polymer materials. To ensure its comprehensive performance after bending and ensure the safety of product packaging, it is essential to conduct resistance to bending testing.