Four Advantages Of Utilizing A Domestic Tooling Source:

Part Warping

Warpage happens when different sections of the molded part cool at different rates, causing the plastic to bend or warp. There are several ways we attempt to minimize part warpage:

• We try to achieve a uniform wall thickness throughout the part.
• Where possible, we incorporate ribs or gussets to add structural support.
• We can also incorporate fillets and radii to minimize stress concentrations.
• We precisely adjust gate locations to facilitate even material flow into the mold and cooling after injection.

Sink Marks

Sink marks are shallow depressions or indentations on the surface of the part caused by variations in cooling rates of the plastic material. A few ways we try to prevent sink marks include:

• We carefully maintain consistent wall thickness to ensure uniform cooling.
• We can adjust gate location and size to modify the flow of molten plastic.
• We will sometimes increase injection pressure and temperature to improve material flow and fill the mold completely.

Flash

Flashing occurs when excess material escapes from the mold cavity, resulting in thin fins or protrusions along the parting line. There are several ways we reduce injection molding flash:

• We may increase tightening on the mold clamp force to prevent material leakage.
• We ensure precision of the mold sections and all components.
• We carefully select draft angles in the part design to facilitate easy ejection from the mold cavity.
• Our mold designs integrate proper venting to allow trapped air and gasses to escape, further preventing flash.

Short Shots

Short shots occur when the mold doesn’t completely fill with molten plastic material. That leaves room for voids or incomplete sections in the final part. To avoid short shots we can make a few adjustments to the production process:

• We will sometimes increase injection pressure and temperature to improve material flow.
• We carefully optimize the gate size and location to ensure proper material distribution within the mold.
• We might increase shot size or cycle time to allow more time for filling the mold if required.

Weld Lines

Weld lines occur when two or more flow fronts meet and join together. The lines can be aesthetically displeasing, and they can also create weak points in the part. To minimize weld lines we make several careful adjustments:

• In product design we try to avoid abrupt changes in part thickness or geometry to prevent weld lines from ever forming.
• We precisely set the gate locations and part geometry to promote a single, uniform flow of material.
• We will sometimes increase temperature and injection speed to encourage material fusion and further minimize the risk of weld lines.

Undercuts

Undercuts are features or geometries that prevent the part from being ejected from the mold in a straight pull direction. If your part requires undercuts, we can make several unique accommodations:

• We may utilize side-actions, slides, or lifters in the mold design to help smoothly inject the part.
• If required, we provide secondary operations like post-mold CNC machining services to achieve the required undercut geometry.