Molded gate splay

Gate blush (gate splay) n. A blemish or disturbance in the gate area of an injection-molded article. It occurs when the melt fractures as it emerges from the gate due to sudden release of large elastic stresses. 

Splay Mark Also called silver streak. Fan-like or streaking on the surface of fabricated plastic parts. Causes include moisture in the plastic material, thermal degradation of plastic material, relatively cold plastic on mold or die surface due to fast an operation (called jetting), injection mold gate restriction, foam molding, etc. 

As usual, the injection speed depends on the size and complexity of the part, as well as on the gate and runner system. Slow to moderate speeds give the best results — too fast speeds result in excessive shear heating, degradation and splay. For small parts or parts with relatively simple geometry, a constant filling speed is recommended, while for larger or more complex parts, it may be helpful to profile the speed. Mold... 

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