The parting line, also known as the extrusion line, mainly depends on the design requirements and appearance requirements of the product, as well as the feasibility of processing and the position of the mold arrangement and adhesive. No matter how plastic products are molded, there will always be relatively obvious parting line marks. Conversely, by looking at the parting line, one can know the structure of the mold. Now, Long Resources will tell you how to determine the parting line

Determination of the parting line

Before designing the parting surface, it is first necessary to determine the shape and position of the parting line on the plastic part. Once the mold opening direction is determined, it becomes relatively easy to determine the parting line. Because the projection of the parting line in the mold opening direction coincides with the outer contour line of the plastic part's projection in that direction, a straight line parallel to the mold opening direction can be moved along the outer contour line of the object's projection, and the intersection of this line with the object's surface at each position can be calculated.

If a straight line intersects the surface of an object at a point, then that point is a point on the parting line.

(2) If a straight line intersects the surface of an object at a straight line segment, any point on this straight line segment can be taken as a point on the parting line. Generally, the principle of determining which point to take as a point on the parting line is based on the shortest line connecting it with adjacent points. It can also be determined through interaction.

(3) If a straight line intersects an object at multiple points or multiple straight line segments, it indicates that the intersection of the global approach cone and the mold opening direction at this location is 0. Therefore, when designing core-pulling in this area, the mold parting line should be determined based on the shape and size of the core-pulling.