Localized Over-Molding Die With Undercut Slide
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Solution Overview
Problem
In localized over-molding processes, excessive pressure at the material boundary leads to overflow issues, limiting design freedom and product quality due to inadequate injection pressure control and material boundary sealing.
Innovation Solution
A localized over-molding die structure with an undercut on the slide die's step portion forms a forced sealing area through interference with the first injection material, preventing overflow by ensuring proper adhesion and stabilizing injection conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the width of the second injection part is increased, then the design freedom is improved, but the pressure at the material boundary becomes excessive causing overflow
Solution Approach 1:
The invention applies a localized groove structure at the specific location where the first and second injection materials meet (the material boundary). This groove is positioned only at the critical overflow-prone area rather than uniformly across the entire mold, allowing the second injection material to be contained while maintaining design freedom for the overall component geometry.
Solution Approach 2:
The groove structure is pre-formed in the mold before the injection process begins. This preliminary structural preparation creates a predetermined containment path for the second injection material, preventing overflow before it occurs by establishing a physical barrier at the material boundary.
2Quantity of substance
If injection pressure is increased to fill wide second injection parts, then the filling capability is improved, but overflow occurs at the material boundary
Solution Approach 1:
The groove structure provides localized pressure relief and material containment exactly where needed - at the material boundary between first and second injection materials. This allows high injection pressure to be applied globally to fill wide sections, while the localized groove prevents overflow at the critical boundary interface.
Solution Approach 2:
The groove acts as an intermediary structure between the two injection materials and the mold cavity. It serves as a buffer zone that accommodates the high-pressure second injection material, allowing the material to be contained and directed properly without overflowing into unwanted areas.
3Object-generated harmful factors
If a simple groove is formed to prevent overflow, then the overflow prevention is improved, but the injection pressure control capability is limited
Solution Approach 1:
The groove dimensions (depth, width, length) are specifically optimized to change the pressure distribution parameters at the material boundary. By carefully controlling these geometric parameters, the groove can accommodate varying injection pressures and material volumes without requiring complex pressure control systems, thus preventing overflow while maintaining simple pressure control.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution effectively prevents overflow at the material boundary, enhances design flexibility, and improves product quality and yield, particularly in vehicle components with wide second injection parts, reducing manufacturing costs.
Implementation Method 1
an adhesion is applied by the interference between the first injection material and the slide die
Data Source
AI summary
A localized over-molding die structure may include a core die, a cavity die having an inner space therein and placed onto an upper surface of the core die, and a slide die including a step portion on a lower surface thereof and slidably engaged with the cavity die in the inner space thereof to move upward and downward, wherein, the step portion includes an undercut formed at a lateral side thereof such that when at least two materials are successively injected into the cavity die, a corresponding part to the undercut is formed to at least one of the at least two materials.