Shenzhen XLD Precision Mould Co., Ltd

At present, the mold industry has begun to use high-speed injection molding machines for injection molding. Products of different sizes need to use injection molding machines of different tonnages. In general, the injection speed of the injection molding machine is very important.

During injection, in order to make the melt fill the cavity in time, the injection molding machine should have a certain injection speed in addition to sufficient injection pressure to ensure a faster flow rate of the melt. During production, choosing a reasonable injection speed is an important factor to ensure the quality of plastic products. Generally, low-speed injection of melt, long filling time, products are prone to defects such as weld marks, uneven density and large residual stress, especially for crystalline plastics and thin-walled products with a narrow processing temperature range.

Although high-speed injection can reduce the temperature difference of the melt in the mold cavity, improve the pressure transmission effect, obtain precision products with uniform density and low stress, and shorten the molding cycle, but the excessive injection speed causes a large amount of melt flow through the nozzle The frictional heat of the plastic may cause the decomposition and discoloration of the plastic, as well as the maladies such as gas inhalation and poor exhaust, which directly affect the surface quality of the product. At the same time, the requirements for program control are higher.

At present, the injection speed has a trend of continuous improvement. Because increasing the injection speed can not only shorten the injection time, but also obtain high-quality products at a lower mold temperature and shorten the molding cycle. Especially in the injection molding of various thin-walled and long-process products, high injection speed is a prerequisite for obtaining high-quality products. In order to meet the processing requirements of different plastics and products with different structures, the injection speed of the injection molding machine also has a certain adjustment range. The injection speed can be adjusted by controlling the flow of pressure oil into the injection cylinder. In addition, multi-stage injection is currently used to meet the requirements of the product structure.