Own Injection Molding Microcellular Foamed Of Polypropylene Material Behavior Regulation And Control

Microcellular polymer materials and products can satisfy the certain needs and reduce production costs, which have very important significance. The molding methods of microcellular polymer materials and products include mould pressing, extrusion and injection molding method. The injection molding method can achieve its complex shape, size precision foam products. And molding cycle is short. It’s easy to implement automation. In recent years, it become the study of hot point and difficulty. In current, the general release pressure molding method requires an instantaneous change in the volume of the mold cavity to achieve pressure release. It leads to incremental volume is difficult to control and equipment is complex. While the mold production cost a lot. In this paper, we use owe injection molding methods. The equipment and method of operation is simple, which means to overcome the problem of releasing the pressure difficult to control the volume of foam. For the foam products with complex structure, it’s better to reflect its advantages. And further to achieve a microcellular foam injection molding practical application.The owe method achieve a simple operation of the injection molding foamed, but the quality of its cell is worse than the pressure-release method. The morphology of cells is irregular, essentially due to its special foam environment. In order to obtain foam owe injection molding parts with high quality cells, this paper selects polypropylene material as matrix. In process of owe injection molding foaming, the effect of foaming environment, preparation of different process conditions, different shapes and sizes of foam samples on foaming behavior is studied. Different size of foam sample cell morphology were observed, this paper achieved the following key results:1. Foam samples are prepared by the use of pressure relief method and owe injection molding under the same conditions. We found that owe injection molding exist the characteristic below. Plastics and cells in plastic injection mold filling process large distance relative pressure relief instantaneous foaming method is a relatively slow process. Resin mold cavity by friction serious obstacle in the migration process, and the cell grew up in deformation phenomenon. But due to the migration of long distance result in different in different parts of the same sample foaming behavior.2. Changes in process conditions can be improved in a short shot foaming cell deformation and deterioration. In this paper, tensile specimens by varying the full speed, melt temperature, mold temperature and a resin filling amount of different preparation conditions of foam samples. The cell mass and cell morphology are improved.3. Large size sample have the same law as tensile specimens in foaming behavior. The cell quality may deteriorate after long-range cell migration. Under the same weight conditions, the thickness of different samples have the different foaming quality. The thicker the better.4. The shapes of actual injection molding is complex. The effect of Migration distance on the foaming quality is similar as small size and large-size molding, which has the same shape simple rules. Process optimization can be achieved under conditions of complex shapes short shot injection foaming product quality in cell size were 50 um or less. Because of its complex shape and the runner, the cell will appear deformed.