The feed port method, standard, and distribution factor […]
The feed port method, standard, and distribution factors directly affect the flow direction, density distribution, packing pressure and molding time. The direct feed port and the feed port have a large cross section (the thicker outer section) is reduced but the directivity is large, and the feed port width and the short length are small. Shorter than the feed port or parallel to the flow direction, the diameter is shortened.
Molding conditions The mold temperature is high, the molten material cools slowly, the density is high, and the shortening is large. Especially for the crystallized material, the crystallinity is high and the volume is changed greatly, so the shortening is larger. The mold temperature distribution is also related to the cooling and density uniformity of the blow molding box, which directly affects the shortening amount and directionality of each part. In addition, adherence to pressure and timeliness also has a greater impact on shortening. Pressure is greater, and time is longer, but the direction is greater. The injection pressure is high, the viscosity difference of the melt is small, the interlaminar shear stress is small, and the elastic rebound is large after demolding, so the shortening can also be appropriately reduced, the material temperature is high and the diameter is shortened, but the directivity is small. Therefore, factors such as adjustment of mold temperature, pressure, injection speed, and cooling time during molding can also appropriately change the blow molding box shortening.