In-Mold Decorating Foil Peeling with Push Pin
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In conventional in-mold decoration systems, the foil tends to break at the corners of the rising wall of the case molded article due to insufficient tensile strength, leading to incomplete pattern transfer and potential scratches on the design, resulting in lower yields and damaged products.
Innovation Solution
The in-mold decorating method involves a system with slide cores and push pins that retract to peel the foil from the surface of the case molded article while leaving the pattern layer on the corners and other areas, using a push pin or tilting pin to manage the foil's peeling direction and reduce stress on the foil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the foil is stretched into the dented cavity-forming surface to extend along the surface, then the pattern layer can be transferred to the molded article, but the foil becomes thin and has insufficient tensile strength, causing it to break at the corners during mold opening
Solution Approach 1:
The push pin is positioned in advance at the corner portion of the molded article before mold opening. When the mold opens, the push pin proactively presses the foil at the corner to guide peeling, preventing the foil from breaking due to insufficient tensile strength during the natural peeling process.
Solution Approach 2:
The push pin acts as an intermediary tool between the mold and the foil. It mediates the peeling process by applying localized pressure at the corner portion, ensuring the foil peels smoothly without breaking while maintaining complete pattern transfer.
2Productivity
If the in-mold decoration die is opened to quickly peel the pattern layer from the foil, then productivity increases, but the foil breaks at the corners where it is most stretched
Solution Approach 1:
The push pin is pre-positioned at the corner portion before mold opening. During the quick peeling process, it proactively guides the foil peeling at the vulnerable corner area, allowing fast production while maintaining foil integrity through localized stress management.
Solution Approach 2:
Instead of uniformly treating the entire foil surface, the push pin applies localized pressure only at the corner portion where the foil is most stretched and vulnerable. This local intervention maintains foil integrity at critical areas while allowing rapid peeling elsewhere, balancing productivity and reliability.
3Area of stationary object
If the foil is stretched to cover the rising wall surface including corners, then complete surface coverage is achieved, but the foil thickness decreases and tensile strength becomes insufficient at the corners
Solution Approach 1:
The push pin provides localized support at the corner portion where the foil is thinnest and weakest. This local intervention compensates for the reduced tensile strength at corners while maintaining complete surface coverage, allowing the foil to be stretched thin across the entire rising wall without breaking at vulnerable points.
Solution Approach 2:
The push pin is positioned in advance to provide cushioning support at the corner portion before the mold opens. This beforehand preparation prevents the foil from breaking by distributing stress during peeling, allowing complete coverage with thin foil while maintaining strength at critical corner areas.
Data Source
AI summary
A case molded article is molded by injecting resin into a molding space formed in an in-mold decoration die; meanwhile, foil is joined to the surface of the case molded article. After that, the foil is peeled off from the surface of the case molded article while leaving a pattern layer at least on the upper ends of the corners of the rising wall on the case molded article. Subsequently, the foil is peeled off from the surface of the case molded article while leaving the pattern layer at other points where the foil is joined to the surface of the case molded article.