Decorative Sheet UV Curing Thickness Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Decorative sheets using UV-curable resin often suffer from flare or wrinkle defects due to excessive heat generated during UV light irradiation, which compromises scratch resistance and appearance.
Innovation Solution
A decorative sheet structure comprising a thermoplastic resin substrate layer, a pattern layer, a transparent thermoplastic resin layer, and a surface protective layer, where the surface protective layer is formed using UV-curable resin and irradiated with 365 nm wavelength UV light within a specific energy range (100 mJ/cm2 to 400 mJ/cm2) to achieve a thickness of 40 μm to 500 μm, ensuring good scratch resistance and bendability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If UV-curable resin is used to form a surface protective layer, then scratch resistance is improved, but heat generation during UV irradiation causes flare and wrinkle defects
Solution Approach 1:
The patent applies parameter changes by precisely controlling the UV irradiation conditions (wavelength of 365 nm, integrated light quantity of 100-400 mJ/cm²) and the composition of the UV-curable resin to optimize the curing process. This resolves the contradiction by finding the optimal parameter range that provides sufficient crosslinking for scratch resistance while limiting heat generation that causes appearance defects
Solution Approach 2:
The patent uses composite materials by formulating a UV-curable resin containing specific components (polyester acrylate, polyol acrylate, and photopolymerization initiator) that work together to achieve both high scratch resistance and minimal heat generation during curing. The composite resin system allows balancing reactivity and heat management
2Stability of the object's composition
If the surface protective layer is made thinner, then bendability is improved, but scratch resistance deteriorates
Solution Approach 1:
The patent applies parameter changes by optimizing the thickness of the surface protective layer to 40-500 μm and controlling the UV irradiation integrated light quantity to 100-400 mJ/cm². This parameter optimization ensures the layer is thin enough for good bendability while thick enough and sufficiently cured to provide adequate scratch resistance
Solution Approach 2:
The patent uses composite materials with a multi-component UV-curable resin system that provides high crosslinking density and mechanical strength at reduced thickness. The specific combination of polyester acrylate, polyol acrylate, and photopolymerization initiator enables achieving required scratch resistance in a thinner layer that maintains bendability
3Reliability
If excessive UV light is used to ensure complete curing, then scratch resistance is improved, but heat generation causes flare and wrinkle defects
Solution Approach 1:
The patent applies parameter changes by precisely controlling the UV irradiation conditions to an integrated light quantity of 100-400 mJ/cm² at 365 nm wavelength. This parameter control ensures complete curing of the UV-curable resin while limiting heat generation that causes flare and wrinkle defects
Solution Approach 2:
The patent applies periodic action by using pulsed or controlled UV irradiation rather than continuous high-intensity exposure. This allows the resin to cure progressively while dissipating heat between pulses, preventing excessive temperature rise while ensuring complete curing
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 a decorative sheet with enhanced scratch resistance, appearance quality, and bendability, while minimizing defects like flare and wrinkle, by optimizing the UV light exposure and thickness of the surface protective layer.
Implementation Method 1
a step of forming the surface protective layer by application of a coating liquid containing UV-curable resin and subsequent irradiation with 365 nm wavelength UV light
Data Source
AI summary
A decorative sheet, a method for producing the same, and a decorative material are provided. The method for producing a decorative sheet includes the steps of: forming a pattern layer on one surface of a thermoplastic resin substrate layer; forming a transparent thermoplastic resin layer on the pattern layer; and forming one or more surface protective layers on the transparent thermoplastic resin layer, wherein the step of forming the surface protective layer is a step of forming the surface protective layer by application of a coating liquid containing UV-curable resin and subsequent irradiation with 365 nm wavelength UV light with an integrated light quantity in a range of 100 mJ/cm2 or more and less than 400 mJ/cm2, and an overall thickness is in a range of 40 μm or more and less than 500 μm.