Loop Fastener with PBT-PPT Copolymer for Peeling Durability
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Solution Overview
Problem
Hook-and-loop fasteners with polybutylene terephthalate-based multifilament yarns face issues with peeling durability due to filament damage and insufficient engagement strength when repeatedly used, especially after 5000 cycles, and lack flexibility for applications requiring soft skin touch.
Innovation Solution
A hook-and-loop fastener with a base fabric featuring loop engagement elements made from a polybutylene terephthalate-based polyester blended with 1 to 8% polytrimethylene terephthalate, where the yarns are woven in a specific pattern to enhance peeling durability and engagement strength by preventing filament cutting and improving flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a polyethylene terephthalate-based multifilament yarn is used as a yarn for loop engagement elements, then the base fabric has good dimensional stability and dyeability, but the multifilament yarn is less divided and the loop is liable to be deformed due to repeated peeling, resulting in decreased engagement force and peeling durability
Solution Approach 1:
The invention changes the material composition parameter by using a copolymer polyester resin containing both terephthalic acid units and cycloaliphatic dicarboxylic acid units. This chemical composition change enables the multifilament yarn to be easily divided while maintaining loop shape stability, resolving the contradiction between dimensional stability and peeling durability
Solution Approach 2:
The invention uses a composite polyester resin system combining aromatic dicarboxylic acid units (providing strength and stability) with cycloaliphatic dicarboxylic acid units (providing flexibility and divisibility). This material composite allows the yarn to maintain structural integrity while being easily divided for improved engagement force
2Reliability
If a polybutylene terephthalate-based multifilament yarn is used as a yarn for loop engagement elements, then the multifilament yarn is easily divided and the engagement force and peeling durability are improved, but when engagement and peeling are repeated 5000 times or more, individual filaments are gradually damaged and eventually cut, resulting in poor peeling durability
Solution Approach 1:
The invention modifies the polymer chain structure by incorporating cycloaliphatic dicarboxylic acid units with flexible bonds between carbonyl groups. This structural parameter change reduces filament brittleness and prevents filament cutting during repeated engagement cycles, extending service life while maintaining peeling durability
Solution Approach 2:
The cycloaliphatic dicarboxylic acid units act as flexible intermediary segments between the rigid aromatic units in the polyester chain. These intermediary segments absorb stress during repeated engagement and peeling, preventing filament damage and extending the fastener's service life
3Strength
If a polyethylene terephthalate-based loop engagement element is used, then the engagement element has high rigidity, but it has hard skin touch and is not suitable for applications requiring flexible skin touch feeling
Solution Approach 1:
The invention changes the molecular structure parameters by incorporating cycloaliphatic dicarboxylic acid units with flexible bonds. This reduces the glass transition temperature and increases chain flexibility, providing a soft skin touch feeling while maintaining adequate structural strength through the aromatic units
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 significantly improves peeling durability and engagement strength by preventing filament damage and enhancing flexibility, allowing for repeated use without loss of performance, making it suitable for applications requiring soft skin touch.
Implementation Method 1
the weft yarn is a heat fusible multifilament yarn, and the yarn for engagement elements is fixed to the base fabric by the heat fusible multifilament yarn
Implementation Method 2
the yarn for loop engagement elements is fixed to the base fabric by melting of the yarn constituting the base fabric
Data Source
Figure 1~2
Figure 3
AI summary
The present invention relates to a hook-and-loop fastener including a base fabric having existing on a surface thereof plural loop engagement elements, wherein fibers constituting the loop engagement elements are formed of a polybutylene terephthalate-based polyester containing 1 to 8% by mass of polytrimethylene terephthalate.