Flat Glass Yarn Cloth for Thin Prepreg Pinhole Control
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Solution Overview
Problem
Conventional glass cloths with high weaving density struggle to achieve sufficient weight reduction and thickness reduction, leading to inefficient production processes and pinhole generation in prepregs, especially when thickness is reduced below 10 μm.
Innovation Solution
A glass cloth with warp and weft yarns composed of 30 to 44 bundled glass filaments, featuring a flat cross-sectional shape with specific dimensions and twist rates, optimized to achieve a weaving density of 85 to 125 yarns/25 mm, inhibiting pinhole formation and improving production efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If weaving density is increased to inhibit pinhole generation, then pinhole generation is reduced, but weight reduction and thickness reduction cannot be sufficiently achieved
Solution Approach 1:
The patent changes the physical parameters of glass filaments by introducing flat cross-sections with specific major axis (3.3-6.0 μm) and minor axis (2.0-3.9 μm) dimensions, and controls the number of filaments per yarn (30-44) and twist rate (≤0.70 twists/25 mm). These parameter changes enable the glass cloth to achieve both pinhole inhibition and weight/thickness reduction by optimizing the balance between structural integrity and material efficiency
Solution Approach 2:
The patent creates a composite structure by bundling multiple flat glass filaments into yarns with specific twist rates, and weaving these yarns into a cloth with controlled density (85-125 yarns/25 mm). This composite approach allows the material to combine the strength needed for pinhole prevention with the reduced density required for weight and thickness reduction
2Reliability
If weaving density is increased to inhibit pinhole generation, then pinhole generation is reduced, but production efficiency deteriorates due to time-consuming preparations
Solution Approach 1:
By standardizing the glass filament parameters (flat cross-section with specific dimensions) and controlling yarn construction (30-44 filaments, ≤0.70 twists/25 mm), the patent enables more efficient weaving operations. The optimized parameters reduce preparation time for warping and weaving while maintaining pinhole inhibition, thereby improving production efficiency
Solution Approach 2:
The patent uses a moderate weaving density (85-125 yarns/25 mm) rather than extremely high densities. This partial action approach achieves sufficient pinhole inhibition without the excessive complexity that would slow down production processes, balancing quality and productivity
3Weight of moving object
If thickness is reduced to less than 10 μm for weight reduction, then weight reduction is achieved, but pinhole generation increases
Solution Approach 1:
The patent changes the geometry of glass filaments from round to flat cross-sections with specific dimensions, and controls the number of filaments per yarn (30-44) and twist rate (≤0.70 twists/25 mm). These parameter changes enable the glass cloth to maintain structural integrity at thicknesses below 10 μm while preventing pinhole formation through optimized yarn construction and weaving density (85-125 yarns/25 mm)
Solution Approach 2:
The patent creates a composite structure by bundling multiple flat glass filaments into yarns with specific twist rates, and weaving these yarns into a cloth with controlled density. This composite approach allows the material to combine the strength needed for pinhole prevention with the reduced density required for weight and thickness reduction
Data Source
AI summary
A glass cloth including warp yarns and weft yarns that are glass yarns each formed by bundling 30 to 44 glass filaments each having a circle-equivalent diameter of 3.0 to 4.4 μm, wherein the weaving density of the warp yarns and the weft yarns is 85 to 125 yarns/25 mm, at least either of the warp yarn and the weft yarn is a flat glass yarn formed of flat glass filaments, the weaving density thereof is less than 100 yarns/25 mm, the major axis DL of the flat glass filament is 3.3 to 6.0 μm, the minor axis DS is 2.0 to 3.9 μm, the number of twists T of each of the flat glass yarns is 0.70 twists/25 mm or less, and the number of the flat glass filaments F constituting each of the flat glass yarns, T, DL, and DS satisfy the following expression:89.0≤F×(DL×(1-T1/2)+DS×T1/2)/(DL/DS)≤129.0.