Polyurethane Elastic Fiber Composition for Adhesion and Unwinding
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Solution Overview
Problem
Existing polyurethane elastic fibers face issues with heat resistance, adhesion, and unwinding properties, particularly when used in gather members and hygienic materials, due to the trade-off relationship between these properties, which previous methods have not adequately addressed.
Innovation Solution
Control the ratio of urea bonds to urethane bonds in the polyurethane elastic fiber to a specific value of 0.05% to 5%, along with controlling polydispersity, monofilament size, and filament number, to enhance heat resistance, adhesion, and unwinding properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If treatment agents are applied to improve unwinding property, then unwinding property is improved, but adhesion becomes insufficient and yarn slips into the product
Solution Approach 1:
The invention changes the chemical composition parameters of the polyurethane elastic fiber by controlling the ratio of urea bonds to urethane bonds within 0.05% to 5%. This parameter change simultaneously improves unwinding property while maintaining sufficient adhesion, resolving the trade-off between these two properties that previously required treatment agents.
2Strength
If low melting point polyurethane is used to improve adhesion, then adhesion is improved, but heat resistance deteriorates and yarn breakage occurs
Solution Approach 1:
The invention changes the chemical structure parameters by controlling the urea bond to urethane bond ratio and the molecular weight distribution (polydispersity). This allows the fiber to maintain adhesion through controlled melting behavior while achieving heat resistance through the specific bond ratio, preventing yarn breakage in hot-melt coating steps.
3Duration of action of stationary object
If polyurethane elastic fiber is stored for prolonged periods, then production capability is maintained, but unwinding property deteriorates due to friction resistance
Solution Approach 1:
The invention performs preliminary action by controlling the chemical structure (urea bond to urethane bond ratio) during fiber production to pre-establish properties that resist deterioration during storage. The specific bond ratio creates a stable structure that maintains unwinding property even after prolonged storage, eliminating the need for storage-related treatment agents.
Data Source
AI summary
Provided are: polyurethane elastic fibers that achieve heat resistance, adhesiveness, and reelability and that are suitable for a gather member; a winding body therefor; a gather member; and a sanitary material. The present invention relates to: polyurethane elastic fibers that are multifilaments and that contain urethane bonds and urea bonds, the polyurethane elastic fibers being characterized in that the ratio of the urea bonds with respect to the urethane bonds is 0.05 to 5%; a winding body of said polyurethane elastic fibers, wherein the elongation rate of the polyurethane elastic fibers on the winding body is 0.05 to 10%; a gather member; and a sanitary material.