When you install guide pins and guide bushings within the ejector housing, it is called a guided ejection system. Guided ejection systems greatly increase the longevity of a mold — but they also increase the cost. So, when are they needed and when are they not? In order to answer that question, we need to [...]
An injection-molded part should have a uniform wall thickness for even filling and cooling as much as possible. It is better to modify the geometry of a part to eliminate thick sections rather than design special cooling for the thick sections to prevent or only reduce unsightly sinks, voids and warpage. The poor design will [...]
Injection molding technology continues to evolve, demanding greater efficiency, precision and reliability from moldmakers and processors alike. Recent technical discussions have highlighted practical solutions for addressing persistent challenges in cooling, lubrication, actuation and mold plate control. This article breaks down these themes into actionable insights to help manufacturers achieve better performance and longer tool life. [...]
Venting is one of the most crucial, but often overlooked, aspects of mold design and manufacturing. Parting line vents typically include a primary vent and secondary and tertiary relief channels. The primary vent should be deep enough to evacuate air and gases quickly but not so deep as to create flash. Polishing the vents helps [...]
When a mold is designed with decoupling in mind, the result is lower scrap, faster startups, better part quality and happier customers. For many scientific or decoupled molding has become the gold standard for delivering consistent, high-quality parts, especially as industries demand tighter tolerances, advanced geometries and greater traceability. However, the key to successful decoupled [...]
A mold design review serves as the critical checkpoint before production begins, verifying that the mold satisfies both engineering requirements and manufacturing constraints. 1. General Design Integrity Is there a complete 3D CAD model of the mold? Have all major assemblies and moving components been clearly defined? Have design-for-manufacturing (DFM) and design-for-assembly (DFA) principles been [...]
Conducting a flow simulation before designing an injection mold is a crucial step that helps mold designers predict and optimize how molten plastic behaves as it fills the mold cavity. This process enables designers to visualize material flow and identify potential issues such as air traps, weld lines and short shots. It also enables them [...]
For cold runner systems, the runner is the first place where air and gases can be removed during injection. To assess whether runner venting is necessary, consider the following factors. Hot runner systems feeding the part directly do not have a large volume of air and gases ahead of the melt that need to be [...]
The reasons for a high-gloss finish in plastic molding vary. Some examples include extreme transparency of the molded part, reduced localized corrosion or highly crack-sensitive tooling (due to design or operational stresses). Then there is the impact of mold surface finish on injection molding productivity, as the release forces of the plastic part from the [...]
For many plastic parts, basic parting line vents are adequate. However, with complex geometries, knowing where and how to vent air traps may not be intuitive. Locating Potential Air Traps It is not always obvious how molten plastic will flow in complex mold cavities. If there is any question as to how the cavity will [...]