Knitted Windproof Fabric Using Differential Shrinkage Yarn
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Solution Overview
Problem
Existing knitted fabrics are not windproof and water-resistant, making them uncomfortable and prone to damage due to low density and loose loops, while woven fabrics are stiff and uncomfortable for wear.
Innovation Solution
A method of knitting a windproof fabric using yarn made of two types of fibers with different boiling water shrinkage values, knitted at a speed 5-35% faster than feeding speed, resulting in tightly interlaced loops and increased density, and treated with a quality modification process for enhanced windproof and water-resistant properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If knitted fabric is made with long loops to be soft and comfortable, then wearing comfort is improved, but windproof and water resistant properties deteriorate
Solution Approach 1:
The patent changes the physical parameters of the yarn by using fibers with different boiling water shrinkage (BWS) values. The first fiber has BWS of 15-85% and the second fiber has BWS of 0-15%, creating differential shrinkage that tightens the loop structure during washing or thermal processing, thereby achieving windproof and water resistant properties while maintaining the softness of knitted fabric
Solution Approach 2:
The patent uses composite yarn made of two different fiber types with distinct properties: polyester fiber (15D-100D) with high BWS and another polyester or nylon fiber (15D-100D/20D-160D) with low BWS. This composite structure allows the yarn to exhibit both comfort and protective properties when knitted
2Productivity
If knitting speed is increased to improve productivity, then production efficiency is improved, but fabric density and quality may deteriorate
Solution Approach 1:
The patent specifies a precise relationship between knitting speed and feeding speed, where knitting speed is 5-35% faster than feeding speed. This controlled speed differential optimizes loop formation to achieve high density (50-150 g/in wale density, 80-140 g/in course density) while maintaining high productivity, resolving the contradiction between speed and quality
3Reliability
If woven fabric is used to achieve windproof and water resistant properties, then protective function is improved, but wearing comfort deteriorates due to stiffness
Solution Approach 1:
The patent utilizes the differential boiling water shrinkage between two fiber types to transform the loop structure of knitted fabric. When exposed to heat or washing, the high-BWS fiber shrinks more than the low-BWS fiber, causing the loops to tighten and close, thereby achieving windproof and water resistant properties similar to woven fabric while retaining the inherent softness and elasticity of knitted structure
Solution Approach 2:
The patent replaces the mechanical interlacing of woven fabric with a thermal-responsive mechanism. Instead of relying on tight mechanical weaving to achieve windproof properties, the invention uses thermal shrinkage differential to dynamically adjust the loop structure, substituting mechanical complexity with a simpler thermal response mechanism
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 resulting fabric is comfortable, elastic, and resistant to wind and water, with improved durability and reduced weight, eliminating friction noise and extending service life, while simplifying the manufacturing process and reducing costs compared to chemical coatings.
Implementation Method 1
the yarn being made of two types of fibers which have different boiling water shrinkage values
Implementation Method 2
a first type of the fibers being a 15D - 100D (Denier) polyester fiber with a BWS (boiling water shrinkage) value of 15 - 85 %, and a second type of the fibers being 15D ∼ 100D polyester fiber with a BWS value of 0 ∼ +15%
Data Source
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AI summary
A method for knitting a windproof fabric, wherein the fabric is knitted by a yarn which is made of two types of fibers which have different BWS values, so that the fabric knitted by this method is not only comfortable to wear, but also water resistant. Furthermore, the yarn is knitted at a predetermined knitting speed which is faster than the feeding speed, so as to increase the density of the knitted windproof fabric, and consequently achieving the function of windproof and water resistance.