Warp Knitted Fabric Feeding for Stable 200% Longitudinal Stretch
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Solution Overview
Problem
Conventional warp knitted fabrics face challenges in achieving high longitudinal elongation while maintaining stable yarn tension, leading to variations in elongation and shrinkage, and increased risk of yarn breakage during production, especially when using elastic yarns.
Innovation Solution
The implementation of active feed means, comprising a single follower roller arranged above two drive rollers, ensures constant tension feeding of warp and inserting yarns to the warp knitting machine, stabilizing the yarn supply and enhancing the production of band-form warp knitted textures with higher longitudinal elongation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If elastic yarn is used to achieve high longitudinal elongation, then the elongation capability is improved, but the yarn tension becomes unstable and yarn breakage increases
Solution Approach 1:
The patent changes the physical state of the yarn by pre-stretching the elastic yarn to a specific elongation ratio (50-200%) before knitting. This parameter change stabilizes the yarn's molecular structure and reduces subsequent tension variations during the knitting process, thereby improving reliability while maintaining high elongation capability.
Solution Approach 2:
The patent applies preliminary action by stretching the elastic yarn before it enters the knitting machine. This pre-treatment removes internal stresses and aligns the yarn structure, preventing tension fluctuations and breakage during knitting. The pre-stretched yarn is then fed at a controlled rate to maintain stable tension throughout the manufacturing process.
2Length of moving object
If elastic yarn is used to achieve high longitudinal elongation, then the elongation capability is improved, but the risk of yarn breakage increases
Solution Approach 1:
The patent modifies the yarn's physical parameters by controlling the pre-stretching ratio and maintaining it within an optimal range during knitting. This parameter control prevents excessive stress concentration that would lead to breakage, while still achieving the desired high elongation in the final fabric.
Solution Approach 2:
The patent applies beforehand cushioning by using a tension control mechanism that detects and compensates for tension variations in real-time. This cushioning effect prevents sudden tension spikes that would cause yarn breakage, ensuring continuous production with high elongation elastic yarns.
3Device complexity
If conventional feeding method is used, then the manufacturing process is simple, but the yarn tension varies and elongation is inconsistent
Solution Approach 1:
The patent implements a feedback control system where tension detectors monitor the elastic yarn tension continuously and send signals to the active feed means. The active feed means adjusts the feeding rate based on this feedback, maintaining constant tension and ensuring consistent elongation throughout the knitting process, thereby improving manufacturing precision.
Solution Approach 2:
The patent replaces the conventional passive mechanical feeding system with an active feed means controlled by electrical motors and feedback signals. This substitution of mechanical control with an electromechanical control system enables precise tension management and consistent elongation, overcoming the limitations of simple mechanical feeding.
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
This method allows for the stable production of warp knitted fabrics with higher longitudinal elongation, reducing yarn breakage and tension variations, and enabling a single prescribed size to cover a wider range with reduced pressure, enhancing comfort and adaptability in clothing.
Implementation Method 1
active feed means, which are constituted by a single follower roller arranged above two drive rollers, are arranged on each of paths for the warp yarn and the inserting yarn, and the active feed means feed the warp yarn and the inserting yarn to the warp knitting machine while keeping the feed amounts thereof constant
Implementation Method 2
the active feed means feed the warp yarn and the inserting yarn to the warp knitting machine while keeping the feed amounts thereof constant
Implementation Method 3
the warp yarn and the inserting yarn are elastic yarn made of polyurethane, latex, elastomer, or natural rubber, or by compounding two or more kinds of them
Data Source
Figure 1~2
Figure 3A~3B
Figure 4~5
AI summary
The invention addresses the problem of providing a warp knitted fabric manufacturing method capable of stably producing a warp knitted fabric wherein the longitudinal stretchability is 200%. To solve the problem, the invention is a warp knitted fabric manufacturing method that forms bands of a warp knitted structure with increased longitudinal stretchability by forming stitches with an elastic warp (2) while knitting in an elastic inserted yarn (3) in the warp direction and knitting in the weft (4) in the course direction, wherein: active feed means (30), which are obtained by placing a single follower roller (323) above two drive rollers (321, 322), are disposed on the respective paths of the warp (2) and the inserted yarn (3) to feed the warp (2) and the inserted yarn (3) to the warp knitting machine while increasing the respective elongation percentage. The active feed means (30) keep the respective feed rates of the warp (2) and the inserted yarn (3) constant while feeding same to the crochet warp knitting machine (40).