Polygon Mirror Gate Mark Placement for Injection Molding Accuracy
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Solution Overview
Problem
The existing methods for manufacturing plastic polygon mirrors often result in inaccurate shaping of reflecting surfaces due to high fluid pressure during the injection molding process, as the gates are typically located close to the reflecting surfaces, leading to degradation in the accuracy of the ideal shape desired for the mirrors.
Innovation Solution
The polygon mirror is designed with gate marks located on straight lines passing through the center and vertices of the first surface, which are rotationally symmetric, allowing for a more even distribution of molten plastic and reducing pressure on the reflecting surfaces, thereby improving the accuracy of the shape formed during the injection molding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the gates are located close to the reflecting surfaces (on a straight line passing through the center and the center of each reflecting surface), then the injection molding process is simplified and productivity is improved, but the accuracy of the reflecting surface shape degrades due to high fluid pressure in narrow spaces
Solution Approach 1:
The gate marks are positioned asymmetrically relative to the traditional gate placement, specifically located on straight lines passing through the center and vertices of the first surface rather than through the centers of reflecting surfaces. This asymmetric positioning moves the gates away from the narrow spaces between the through-hole forming portion and reflecting-surface forming surfaces, thereby reducing fluid pressure in critical areas while maintaining manufacturing efficiency
Solution Approach 2:
The gate marks are strategically positioned at specific locations on the first surface (on straight lines passing through the center and vertices) to create different flow conditions in different regions. This local optimization ensures that the plastic flow does not concentrate in narrow spaces near reflecting surfaces, reducing localized pressure effects while maintaining overall process efficiency
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 configuration enhances the accuracy of the reflecting surfaces by minimizing the impact of plastic flow on the shape, reducing residual stress, and allowing for a more uniform flow of molten plastic, resulting in improved precision and ease of handling during the manufacturing process.
Implementation Method 1
a plastic polygon mirror manufacturing method in which a polygon mirror having a through hole provided at its center is molded by injecting molten plastic through a plurality of gates into a cavity of a mold
Data Source
AI summary
A polygon mirror made of plastic is provided. The polygon mirror has a plurality of reflecting surfaces, a first surface intersecting the plurality of reflecting surfaces at a first side, a second surface intersecting the plurality of reflecting surfaces at a second side opposite to the first side, with a through hole provided to extend through the first surface and the second surface at a center of the polygon mirror. The polygon mirror includes a plurality of gate marks of injection molding. When viewed from an extending direction of the through hole, the gate marks are located on straight lines passing through the center and vertices of the first surface, and are rotationally symmetric with respect to the center.