Thermal Molding of Core-Sheath Composite Filaments
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Solution Overview
Problem
Existing thermal molding methods for products made from multifilament yarns with core-sheath type composite filaments result in insufficient abrasion resistance of the melt-bonded parts.
Innovation Solution
A thermal molding method using core-sheath type composite filaments with a specific copolyester as the sheath component and polyamide 6 as the core component, where the copolyester has a melting point adjusted to 140-180°C to improve abrasion resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional thermal molding is applied to melt-bond intersections of woven fabric or net, then the threads are prevented from distortion or slippage, but the abrasion resistance of the melt-bonded part is insufficient
Solution Approach 1:
The patent changes the material parameters by selecting specific copolyester compositions with controlled melting points (100-150°C) and molecular weights, as well as specific mass ratios of core-sheath components (1:4 to 1:10), to optimize both thermal bonding performance and abrasion resistance
Solution Approach 2:
The patent employs composite materials by using core-sheath type composite filaments where the core component (polyester) and sheath component (copolyester) have different properties, combining the strength and stability of the core with the melt-bonding capability and abrasion resistance of the sheath
2Ease of manufacture
If polyethylene is used as sheath component for thermal molding, then melt-bonding of intersections is achieved, but abrasion resistance remains insufficient
Solution Approach 1:
The patent changes the material from conventional polyethylene to specifically formulated copolyesters with controlled melting points and molecular weights, achieving better balance between ease of thermal molding and abrasion resistance
Solution Approach 2:
The patent applies local quality by having the sheath component specifically positioned at the intersection areas where thermal molding is applied, while the core component maintains filament integrity throughout the fabric structure
3Strength
If high melt flow rate polyethylene is used to improve abrasion resistance, then abrasion resistance of melt-bonded part improves, but control over melting behavior becomes more difficult
Solution Approach 1:
The patent precisely controls multiple parameters including copolyester melting point (100-150°C), molecular weight, and mass ratio with the core component to achieve optimal balance between abrasion resistance and manufacturing precision
Solution Approach 2:
The patent utilizes controlled phase transitions by selecting copolyesters with specific melting points that allow predictable melting behavior during thermal molding, enabling precise control over the bonding process
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 method significantly enhances the abrasion resistance of the thermally molded articles, particularly in applications like fishing nets and mesh sheets, by maintaining the initial filament form of the core component while fusing the sheath components.
Implementation Method 1
a step of heating the product of filaments to melt the copolyester and fuse the core-sheath type composite filaments to each other
Implementation Method 2
a step of heating the product of filaments to melt the copolyester
Data Source
AI summary
Provided is a thermal molding method for producing a thermally molded article having excellent abrasion resistance at its melt-fused part. Polyamide 6 and a copolyester are prepared separately. The copolyester contains terephthalic acid, ethylene glycol, and 1,4-butanediol as copolymerization units. The copolyester may further contain ε-caprolactone and/or diethylene glycol as a copolymerization unit. A multifilament yarn in which core-sheath type composite filaments each containing a core component and a sheath component at a ratio of 1 to 4:1 by mass are bundled is produced by a composite melt-spinning method using the polyamide 6 as the core component and the copolyester as the sheath component. Using the multifilament yarn, a product of filaments is produced by weaving, knitting, knitting and braiding, or braiding. The product of filaments is heated to melt the copolyester and fuse the core-sheath type composite filaments to each other while retaining the initial filament form of the polyamide 6, thus thermally molding the product of filaments.