Flash Prevention Member in Injection Mold for Dome Covers
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Solution Overview
Problem
The existing injection molding process for dome-type covers in surveillance cameras often results in flash formation due to the fitting gap between the convex and stationary side die sets, leading to unstable attachment and increased post-processing costs, as well as reduced productivity from accumulated flashes on the mold sliding surfaces.
Innovation Solution
An injection mold design featuring a flash formation preventing member that is pressed against the convex surface mold by resin pressure, preventing the expansion of the gap between the mold members and thus eliminating flash formation during the molding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a side gate is provided at one end of the flange portion, then the gate mark does not deform the optical surface, but resin pressure expands the fitting gap between mold members causing flash formation
Solution Approach 1:
The flash prevention member is positioned in advance at the fitting gap between the convex surface mold and stationary side die set. Before resin injection occurs, this member is ready to counteract the harmful effect of gap expansion by physically blocking the path where flash would form, thus preventing the problem before it occurs
Solution Approach 2:
The flash prevention member acts as an intermediary element between the resin flow and the fitting gap. Instead of allowing resin pressure to directly expand the gap and create flash, the intermediary member intercepts the resin pressure and redirects it, preventing the harmful expansion while maintaining the beneficial side gate configuration
2Productivity
If high injection speed and high pressure are used, then the flow length is covered and channel resistance is overcome, but resin pressure deforms the convex surface mold and expands the fitting gap
Solution Approach 1:
The harmful effect of resin pressure on the mold surface is extracted and isolated by introducing the flash prevention member. This member specifically addresses the gap expansion problem caused by high pressure injection, allowing the high injection pressure to be maintained for productivity without transferring the harmful deformation effect to the optical surface
Solution Approach 2:
The flash prevention member is a simple, easily replaceable component that absorbs the wear and deformation caused by high-pressure resin injection. Instead of damaging the expensive and precision-crafted convex surface mold, the simpler prevention member takes the hit and can be replaced if needed, protecting the critical optical surface
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 design ensures continuous production of dome-type covers without flashes, enhancing attachment stability and reducing post-processing costs by maintaining the gap closed with resin pressure, thereby improving productivity and optical surface integrity.
Implementation Method 1
is pressed against the convex surface mold by resin pressure
Data Source
AI summary
An injection mold includes a cavity formed by a plurality of members including at least a convex surface member and a concave surface member, and a gate formed by a plurality of members including at least a flash formation preventing member. One of the members forming the gate is disposed so as to be adjacent to one of the members forming the cavity, and is pressed against the adjacent member forming the cavity by a pressure of injected resin.