Tufting Machine Yarn Waste Reduction via Presser Foot Mediation
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Solution Overview
Problem
In tufting machines, when transitioning from one yarn to another, especially in changes of color, yarn waste occurs due to uncontrolled cut ends trailing behind, causing interference and tension issues that affect the quality of the tufted pattern.
Innovation Solution
The method involves forming additional loops of yarn after cutting the end of the first yarn, which serves as an anchor point, ensuring the yarn remains under the presser foot and is pulled out of the way as the second yarn is tufted, thereby maintaining control and reducing tension-related problems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the needle bar reciprocates laterally to enable pattern flexibility, then adaptability is improved, but yarn control deteriorates causing cut ends to trail uncontrolled
Solution Approach 1:
The presser foot acts as an intermediary device between the needle bar and the backing medium. It follows the lateral movement of the needle bar while maintaining continuous pressure on the yarn, thereby mediating the conflict between lateral reciprocation for pattern flexibility and yarn control for preventing uncontrolled trailing of cut ends.
2Ease of operation
If pressure from the presser foot is increased to control cut ends, then yarn control is improved, but the backing stitch is damaged
Solution Approach 1:
The presser foot applies pressure locally and selectively to the yarn and cut ends without excessively pressing the backing stitch. By concentrating the controlling action on the yarn while minimizing contact pressure on the backing, the system achieves yarn control without causing damage to the backing structure.
3Object-generated harmful factors
If pressure from the presser foot is reduced to protect the backing stitch, then harmful factors are reduced, but yarn control deteriorates causing cut ends to lift
Solution Approach 1:
The presser foot is designed to move dynamically, following the lateral reciprocation of the needle bar throughout its stroke. This dynamic movement allows the presser foot to maintain consistent contact with and control of the yarn and cut ends across the entire lateral range, preventing lift-off without requiring excessive static pressure that would damage the backing.
4Ease of operation
If yarn is overfed to compensate for lateral shift, then yarn control is improved, but yarn waste increases
Solution Approach 1:
The presser foot serves as a mediator that enables precise yarn control through mechanical contact and guidance, eliminating the need for overfeeding yarn as a compensatory measure. By providing continuous lateral support and control, the presser foot allows exact yarn delivery matching the actual consumption, thereby preventing waste.
Data Source
AI summary
A method of operating a tufting machine including a sliding needle bar with a plurality of needles, a presser foot mounted slidable with the needle bar, an end yarn feed, a needle selection mechanism, a plurality of loopers, a plurality of knives to cut a loop of yarn on a respective looper, and a dislodge mechanism to selectively dislodge a loop of yarn from the looper before the yarn is cut. The method controls the feed of yarn to the needles and, when a cut end is required, a determination is made whether a predetermined yarn condition is present in the yarn at its cut end and, in response to such a determination, an additional loop of yarn, not required by the pattern data is formed, such that the additional loop of yarn forms a yarn buffer that can be pulled back through the backing medium.