Views:0 Author:Site Editor Publish Time: 2020-10-24 Origin:Site
Control of blister packaging materials
Aluminum foil is the main material to cover the opening, is also a good barrier packaging material, pinhole is a fatal flaw in penetration. May occur during the process of packing, transporting and storing filler extrusion, extrusion is inevitable, so the increase of the diameter of the aluminum foil pinhole or range, which may lead to obvious crease, this can lead to a breakthrough in the aluminum material properties, it accelerated the gases and water vapor permeability, influence on the performance of the stability of aluminium material cut off.
In general, there are two methods for accurately assessing changes in pinhole conditions and covering material barriers. First of all, it is suitable for the kneading behavior that may occur during the circulation of packaging materials through the kneading test device. Secondly, the strength of coating material before and after friction is tested, and the change of data directly reflects the change of coating material strength. The above quantitative scientific experiments are helpful to objectively evaluate the lamination resistance and packaging adaptability of roofing materials and provide a convincing data reference for the selection of roofing materials.
Blister packaging consists of two parts: covering material and blister forming. It is affected by many uncertain factors such as production technology, technology and equipment. The barrier of blister packaging cannot be directly considered as the barrier superposition of two materials. Taking the water vapor barrier as an example, two commonly used blister laminating matrix PVC and PVC/PVDC, as well as the finished blister laminating matrix were selected for the test, and no obvious defects were found.
The experimental data show that with the increase of temperature, the penetration rate of water vapor between the base material and the formed bubble hood increases gradually. From the point of view of molecular thermal motion, the increase of temperature leads to the increase of water molecular motion and the increase of water vapor diffusion rate. At the same time, the conformational change of the molecular chain of the bubble substrate is accelerated, the polymer bond is reduced, and the channel between the parallel molecular chain is enlarged, which promotes the diffusion of water molecules. Both of these changes reduce the moisture resistance of the bubble cover material and the moisture resistance of the bubble cover forming material under high temperature environment.