Cut Sheet with Controlled Particle Occupancy for Water Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cut sheets with a large amount of inorganic particles face challenges in achieving sufficient water resistance and minimizing sharp protrusions at the end face, leading to potential cuts during use.
Innovation Solution
A cut sheet composed of a resin composition with inorganic particles making up 50% or more of the mass, featuring a water absorption rate of 10% or lower, and an actual occupancy rate of exposed inorganic particles on the end face at least 2% lower than the theoretical rate, with a cured film optionally applied to the surface to reduce sharp protrusions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a large amount of inorganic particles is blended into the sheet to improve brightness and opacity, then the brightness and opacity are improved, but the water absorption rate increases and water resistance deteriorates
Solution Approach 1:
The patent controls the occupancy rate of inorganic particles in the end face section to be 55% or less, and specifically ensures that the occupancy rate in the outer peripheral section is 5% or less. This parameter control allows the sheet to maintain high brightness and opacity while limiting water absorption, achieving both improved illumination properties and maintained water resistance.
Solution Approach 2:
The patent applies different occupancy rate requirements to different sections of the sheet. The outer peripheral section (within 5mm from the end face) has a strictly controlled occupancy rate of 5% or less, while the inner section can have higher occupancy rates up to 55%. This local differentiation ensures water resistance at the cut edges while maintaining brightness and opacity in the bulk material.
2Illumination intensity
If a large amount of inorganic particles is blended into the sheet, then the opacity is improved, but sharp protrusions are generated at the end face causing cuts
Solution Approach 1:
The patent implements different occupancy rate controls for different sections: the outer peripheral section (within 5mm from the end face) maintains an occupancy rate of 5% or less to prevent sharp protrusions, while the inner section can have occupancy rates up to 55% to ensure opacity. This local quality differentiation eliminates the harmful sharp edges while preserving the desired optical properties in the bulk.
Solution Approach 2:
The patent introduces a transition zone (the outer peripheral section within 5mm of the end face) that acts as an intermediary between the high-opacity inner section and the clean edge requirement. This transition zone with controlled low occupancy rate (5% or less) serves as a buffer that prevents the formation of sharp protrusions while allowing the inner section to maintain high inorganic particle content for opacity.
3Illumination intensity
If stretching treatment is carried out on the sheet with inorganic particles, then the brightness is improved, but the water absorption rate increases
Solution Approach 1:
The patent controls the occupancy rate parameter of inorganic particles in the end face section to be 55% or less, with the outer peripheral section specifically controlled to 5% or less. This parameter control enables the sheet to undergo stretching treatment while maintaining both improved brightness and acceptable water resistance, resolving the contradiction between these two properties.
Data Source
AI summary
Provided is a cut sheet having sufficient water resistance and having fewer sharp protrusions in the end face despite including a large amount of inorganic particles and a method of reducing cuts. The cut sheet is formed of a resin composition including inorganic particles of 50% by mass or larger relative to the total mass of the composition and a thermoplastic resin. The cut sheet has a water absorption rate of 10% or lower measured in accordance with JIS K-7209. The actual occupancy rate of the exposed area of the inorganic particles is lower by at least 2% than the theoretical occupancy rate of the area of the inorganic particles in at least one end face.