The influence of injection molding machine back pressure on the quality of modified plastic products

The backpressure of injection molding should be adjusted according to the properties of the raw materials, dry conditions, product structure, and quality conditions. The backpressure is generally adjusted at 3-15kg/cm3. When the product surface has a little air bloom, color mixing, shrinkage, and large changes in product size and weight, the back pressure can be appropriately increased. When the nozzle leaks, salivates, melts overheated, and decomposes, the product discolors, and the material return is too slow, you can consider appropriately reducing the backpressure.

Proper back pressure can compact the modified plastic melt in the barrel, increase the density, increase the injection volume, and ensure the stability of the weight and size of the modified plastic products;

Proper back pressure can "squeeze out" the gas in the melt, reduce air blooms and internal bubbles on the surface of modified plastic products, and improve gloss uniformity;

Properly increasing the back pressure can improve the shrinkage of the product surface and the glue running around the product;

Proper back pressure can increase the humidity of the melt, improve the plasticization quality of the melt, improve the fluidity of the melt when filling the mold, and there is no cold glue pattern on the surface of the modified plastic product.

The influence of injection molding machine back pressure on the quality of modified plastic products

The effect of excessive back pressure on modified plastic products: reduced low plasticization efficiency, decreased production efficiency, prone to molten glue drooling, nozzle leakage, waste of raw materials, and burnout and pre-plasticizing of the heating ring near the nozzle Mechanical wear of the mechanism and screw barrel increases.

The effect of too low back pressure on modified plastic products: it will lead to poor plasticization quality, unstable injection volume, large changes in product weight and product size, and shrinkage, air blooms, cold material lines, uneven gloss, etc. on the surface of the product. Unfavorable phenomena, bubbles are prone to appear inside the product, and the periphery of the product and the bones are easily dissatisfied with the glue.