Insert Decorated Molding Boundary Gap Elimination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for creating insert decorated moldings with multiple continuous pictures face challenges such as registration difficulties, environmental concerns due to solvent use, and design property issues like gaps or peeling at the boundary parts between decorative sheets in insert molding processes.
Innovation Solution
A production process involving vacuum molding and injection steps, where the length of the upper base part and half-value width in the female metal die are controlled to specific ranges, and the end parts of decorative sheets are positioned at the side face of the convex part, ensuring proper contact and adhesion without resin visibility at the boundary, using decorative sheets with an acryl resin layer and an ABS resin backer layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If two decorative sheets are disposed apart in insert molding, then the molding process is simple, but a gap is formed at the boundary part and resin color becomes visible
Solution Approach 1:
A convex part is introduced as an intermediary structure between two decorative sheets. This convex part protrudes from the bottom surface of the molded article and prevents the decorative sheets from contacting each other at the boundary, thereby eliminating gaps and visible resin color while maintaining process simplicity
Solution Approach 2:
The convex part is pre-formed on the mold surface before injection molding. This preliminary structure ensures that decorative sheets are automatically positioned at appropriate intervals during molding, preventing gap formation without requiring complex post-processing or precise manual positioning
2Manufacturing precision
If two decorative sheets are superposed to avoid gaps, then boundary quality improves, but resin penetration occurs and decorative sheets peel off
Solution Approach 1:
The convex part acts as a physical barrier that prevents excessive compression of decorative sheets during molding. By maintaining appropriate spacing, it avoids resin penetration into the overlap region while still ensuring complete contact between sheets, thus preventing peeling
Solution Approach 2:
The convex part creates a localized structural feature at the boundary region. This local modification allows different areas of the molded article to have different properties: decorative sheets contact completely in most areas for adhesion, while the convex part maintains spacing at the boundary to prevent resin penetration
3Adaptability or versatility
If in-mold picture transfer method is used, then continuous pictures are provided, but registration is difficult for deeply drawn moldings
Solution Approach 1:
Instead of transferring pictures during molding, pre-formed decorative sheets with continuous pictures are used as inserts. This copying approach allows high-resolution pictures to be created separately and then inserted into the mold, avoiding registration issues while maintaining picture quality for deeply drawn moldings
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 process allows for the creation of insert decorated moldings with continuous pictures where the resin color is not visible at the boundary parts, maintaining high design properties and ensuring proper adhesion of decorative sheets.
Implementation Method 1
a vacuum molding step in which two or more kinds of decorative sheets are vacuum-molded
Data Source
AI summary
Provided is a production process for an insert decorated molding provided with two or more kinds of pictures, in which a color of a resin is not seen from a boundary part between pictures and which has a high design property. The production process includes a vacuum molding step in which two or more kinds of decorative sheets are vacuum-molded and an injection step in which at least two kinds of the vacuum-molded decorative sheets are disposed in line in a female metal die and in which a molding resin is injected onto the decorative sheets.