Process for reducing gate blush and mold design for same

A system for injection molding a polymer article from a thermoplastic material comprising:

• a mold defining a mold cavity, the mold cavity including an interior curved surface;
• a compression zone for heating and compressing a thermoplastic material;
• a flow path in fluid communication with the compression zone for receiving a flow of a molten polymer material;
• and
• a gate in fluid communication with the polymer flow path, the gate including an exit that leads into the mold cavity, the gate being positioned such that a flow of molten polymer material exits the gate at a location that is tangent to the interior curved surface of the mold cavity;
• wherein an arc defined by the interior curved surface follows a circle, and wherein the exit of the gate forms an angle with the arc defined by two radii of the circle, the angle being greater than 30° and less than 90°;
• and the gate has a fan shape, the gate including a width and a height and wherein the width is at least four times greater than the height at the exit of the gate.