Parting Line Analysis

In case of numerous choices available, the most appropriate parting line is identified as the one, which meets certain component design conditions. These conditions are geometrical functions of certain design parameters with respect to the parting line. They have a value lying between 0 and 1. A higher value of such parameters signifies better features and better efficiency.

• Undercuts - it is a section of the part geometry that prevents the component from being ejected from a straight-pull mold with no portion of the mold passing through the part. With an increase in the number of undercuts, there's an increase in the number of elements in the mold and the cost related to core for producing a particular feature also increases as compared to an average mold of equal volume. Ideally, undercuts should be absent.
• Flatness - this is the measurement of the closeness of a given parting to a flat plane by comparing the projected length of the parting line on a plane perpendicular to the draw direction in reference to the actual length of the parting line. Parting can be flat or non planar.
• Draw distance - it is the measurement of the relative movement between a mold segment and the pattern along the draw direction. Draw distance affects the time required in a complete manufacturing cycle and the consistency of compaction in the case of manufacturing sand molds. The draw distance is measured in reference with half the smallest overall dimension of the product.
• Draft - It is used to ease the removal of the pattern from the mold and is drawn from parallel to the draw direction. It increases the weight of the product and hence, the overall cost of the production of the additional amount of the product.
• Flash - This is calculated by using all the edges of the parting line. If the parting line is located along convex or sharp edges of the component, flash returns a higher value because of trimming in flash.
• Mismatch - This disparity criterion is evaluated by comparing the areas of two portions of faces, which lies on both the sides of the parting line to the total area of these faces. High dimensional stability is reflected when such faces lie to one side of the parting line.
• Mold cavity shape - This helps to make manufacturing process easier. Mold cavity shape is determined by the volume ratio of the solid corresponding to the cavity in a single segment in the mold and the bounding cuboids.
• Sub-surface quality - This quality function is important for production faces of a component. It is influenced by the orientation and location of such faces in the mold.
• Solidification - this is referred to the ratio of the largest section in the casting to the smallest one.
• Side thrust - This may occur due to permanent molds filled under pressure if the parting is nonlinear and are asymmetrical around a vertical plane. This also indicates the balancing of the extent of force along the horizontal axis.