Development of foam molding technology
DATE：2021/12/16 9:07:46 / READ： / SOURCE：This station
Development of foam molding technology
1. Micro cellular plastic
Microcellular foam technology has actually been applied in the packaging field for nearly 10 years. However, it has only been vigorously developed as a hot technology in the plastics industry in recent years. The diameter of the usual closed-cell foam is about 150-250m, and the diameter of the micro-bubble closed-cell foam is about 50m or less. The corresponding density of the micro foam is 0.035-0.gcm, and this technology is released by MT (Massachusetts Institute of Technology), Dupont (Society), Boeing (Boeing), dk (Da), Lockheed (Lockheed), etc. . Now Trexel in the United States holds the right to use and develop this technology. According to the English word for Microcellular (Microcellular),
T=The company names its products MC. At present, the commercial product that has been mass-produced is the extruded sheet of microfoam. In the processing of styrene extruded sheet in Muc case, non-flammable inert gas, such as hydrogen or carbon dioxide gas, is directly injected into the extruded plastic melt. The technical key here is that the injected passion gas must first be pressurized and compressed to a supercritical state. In this supercritical state, the gas already has liquid-like solubility. Such gas can be in the plastic melt and thus result in a very fine bubble core. Once such a mixture of plastic melt and gas is extruded from the extrusion die and the pressure is released to expand, very fine and dense microbubbles can be obtained. Because the gas has solubility before injection, the bubbles can be evenly distributed throughout the extruded melt, so that the bubbles of the micro-bubble structure foam are evenly distributed, and the performance of the part can be basically isotropic. This is one of the important factors that greatly improve the physical and mechanical properties of the polystyrene board with a microbubble structure. Comparison of physical performance between MuCl styrene board and ordinary polystyrene foam board of the same size. It can be seen from the figure that when the density is 0.03g/cm3, the performance of the two plates is the same. However, as the density increases, the physical and mechanical properties of the two types of plates have obviously different trends. When the density of the two types of plates are equally doubled, the strength of the Mucell plate is more than double that of the ordinary plate.
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