Multilayer Resin-Coated Metal Sheet for Slip and Ink Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing resin-coated metal sheets face issues with fracturing or scraping during can body production due to thinning materials, and the added lubricating component compromises ink adhesion, leading to peeling of printing ink.
Innovation Solution
A resin-coated metal sheet with a three-layer structure, comprising a metal sheet and a resin coating layer containing 75% polyester resin, where the outermost layer includes polyolefin with a specific particle size and melting point range, ensuring slidability and scraping resistance, and the intermediate layer contains inorganic particles for ink adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a lubricating component is added to the resin coating layer to enhance slidability and scraping resistance, then the resin coating layer becomes more resistant to fracturing and scraping during can body production, but the affinity between the surface of the resin coating layer and printing ink deteriorates, causing ink to peel off during processing
Solution Approach 1:
The resin coating layer is divided into multiple layers (outermost layer, intermediate layer, undermost layer) with different functions. The outermost layer contains the lubricating component for scraping resistance, while the intermediate layer provides ink adhesion, thus segmenting the conflicting functions into separate layers that work together without interfering with each other.
Solution Approach 2:
Different regions of the resin coating layer are given different properties: the outermost layer has high lubricating component content for scraping resistance, while the intermediate layer has specific properties for ink adhesion. This local differentiation allows each layer to optimize its specific function without compromising the other.
2Loss of substance
If materials are made thinner to save resources and reduce material cost, then resource consumption and material cost decrease, but the amount of deformation during can body production increases, raising the possibility that the resin coating layer is fractured or scraped
Solution Approach 1:
The resin coating layer is designed as a composite material containing polyester resin as the base and polyolefin as a dispersed lubricating component. This composite structure provides both the thinness required for resource saving and the enhanced mechanical properties needed to resist fracturing and scraping during deformation-intensive can body production.
Solution Approach 2:
The invention changes the chemical composition parameters of the resin coating layer by incorporating specific ratios of polyester resin and polyolefin, and controls the particle size distribution of the polyolefin. These parameter changes enable the coating to maintain integrity during deformation even at reduced thickness, preventing fracturing while saving materials.
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
The solution provides enhanced slidability, scraping resistance, and improved ink adhesion, preventing fracturing and scraping during processing while maintaining print quality.
Implementation Method 1
the lubricating component may impair the affinity between the surface of the resin coating layer and the printing ink applied by printing treatment
Implementation Method 2
a resin coating layer containing 75 mass % or more of polyester resin relative to total resin, on at least one side of the metal sheet
Data Source
AI summary
Provided is a resin-coated metal sheet that achieves both the slidability and scraping resistance of the resin coating layer and the ink adhesion. A resin-coated metal sheet 1 comprises: a metal sheet 2; and a resin coating layer 3 containing 75 mass % or more of polyester resin relative to total resin, wherein the resin coating layer 3 has at least a three-layer structure including an outermost layer 3a, an intermediate layer 3b, and an undermost layer 3c, a melting point of the resin coating layer 3 is 230° C. or higher and 254° C. or lower, the outermost layer 3a contains a polyolefin, a melting point of the polyolefin is 80° C. or higher and 140° C. or lower, and a dispersed particle size of the polyolefin measured by Raman spectroscopy is 0.018 μm or more and 5.0 μm or less.