MuCell microporous injection moulding process
June 05, 2022
Trexel Corporation in the United States based on MIT microcellular foaming concept, the microcellular foaming technology has been industrialized, and has been applied in injection molding, extrusion molding and blow molding. MuCellTM's breakthrough in injection molding technology provides injection molding production with unprecedented capabilities not found in other injection molding processes, opening up new markets for new product design, process optimization, and reduced product costs. Products molded with MuCellTM technology are being used in many industries, including automotive, pharmaceutical, consumer product, electronics, food packaging, industrial and consumer structural parts. The main advantage of the MuCellTM process for injection molding is that the reaction is an endothermic reaction, the melt viscosity is low, the melt and mold temperatures are low, so the product cycle time, material consumption, injection pressure and clamping force are all reduced, and its uniqueness It also lies in the injection molding of products that can be used for thin-walled products and other foaming technologies that cannot be foamed. The MuCellTM injection molding process has the following four steps: (1) Gas Dissolution Air (CO2 or N2) supercritical fluid (SCF) is injected into the polymer melt through a syringe mounted on the barrel to form a homogeneous polymer / Gas system. The screw and syringe used in the injection machine are specifically designed to dissolve the SCF quickly in the polymer melt. (2) Nucleation Forms a large number of gas nucleuses in the polymer during the injection molding process (magnitude of the conventional foaming process). In order to produce a large number of uniform gas cores, the pressure must be rapidly and greatly reduced. (3) Bubble growth The growth of the gas core is controlled by the injection molding process. Precise control of pressure and temperature is achieved by specially designed machine control software and hardware. (4) After the fixed melt is injected into the mold, the shape of the product is controlled by the mold design. Although the mold rebuild is not unnecessary, the mold rebuild will take full advantage of the MuCellTM. When using the MuCellTM process to inject foam products, the following improvements are required for existing equipment: (1) The SCF metering device must have sufficient capacity to deliver the SCF foaming agent to the screw at the speed and pressure required by the MuCellTM process. (2) A homogeneous system of a supercritical fluid foaming agent produced by a screw designed by Trexel is also required. (3) Some modifications to the system's software, hardware, and hydraulic systems are needed to create and maintain homogeneity of the homogenous system throughout the injection molding process. (4) The supercritical fluid injector needs to be installed.
