In the process of plastic molding, there is a phenomenon worthy of attention.

We look at how the plastic is actually flowing into the mold, which will help to understand the cause of the plastic surface and core orientation.

An amorphous polymer glass state, high elastic state and the viscous flow and the crystalline polymer amorphous part, under certain conditions, the presence of a molecular orientation. When the stress of the liquid state of plastic in injection molding machine, high-speed through the nozzle and mold runner, long linear polymer will along the flow direction are arranged parallel to each other, once these permutations before plastic cooling solidification not eliminate in the solid plastic parts, orientation of the molecules and therefore formed the orientation effect will remain down.

Generally speaking, the orientation effect will make the integrity of the parts have been weakened, the performance of the plastic parts everywhere within the physical and mechanical properties are not balanced. As a result of the molecular arrangement, and molecular chain is perpendicular to the direction, intensity and the difference in the direction parallel to the. Obviously, when the strong orientation, pieces of the system is likely to warping or cracking.