Drafting Roller Control for Uniform Air-Jet Spinning Piecing
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Solution Overview
Problem
Existing spinning processes in air-jet spinning machines face issues such as fiber sliver compression and inconsistent yarn quality due to idle rollers, frequent shutdowns, and incorrect timing during yarn joining, leading to defects and resource inefficiencies.
Innovation Solution
A spinning unit with independently driven roller pairs and controlled operating modes, along with a method and control device that manage roller speeds and accelerations to prevent fiber sliver compression and ensure uniform yarn formation, including a drafting device with selective activation of rollers and coordinated fiber ribbon separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the drafting device rollers are stopped frequently for piecing operations, then the threading process can be maintained, but the fiber sliver becomes dented and yarn quality deteriorates
Solution Approach 1:
The control device maintains the drafting device in a ready state by keeping rollers rotating at low speed before piecing operations, preventing fiber sliver denting in advance. This preliminary action ensures the rollers are warm and the fiber path is maintained, eliminating the need for complete stops during piecing while preserving yarn uniformity.
2Loss of energy
If the drafting device is stopped completely for piecing, then resource consumption is reduced, but the rollers require warm-up time and thread uniformity suffers
Solution Approach 1:
The control device implements continuous low-speed rotation of drafting rollers during piecing operations, maintaining thermal state and fiber path continuity. This continuous action eliminates the need for warm-up periods while consuming minimal energy, achieving both resource efficiency and high thread uniformity simultaneously.
3Productivity
If multiple roller pairs are used in the drafting device, then the drafting capability is improved, but the complexity of controlling different speeds and accelerations increases
Solution Approach 1:
The control device uses feedback mechanisms to automatically coordinate the speeds and accelerations of multiple roller pairs during piecing operations. By monitoring the actual performance of each roller pair and adjusting their operation accordingly, the system maintains optimal drafting capability while simplifying control through automated coordination rather than manual adjustment of each roller independently.
Data Source
Figure 1
Figure 2A~2C
Figure 3A~3B
AI summary
The invention relates to a drafting device for a textile machine, in particular an air-jet spinning machine, wherein the drafting device can have several pairs of rollers that can be driven independently of one another. The roller pairs can be designed and arranged to guide a fiber ribbon between an upper roller and a lower roller of each pair during their rotational operation in order to stretch the fiber ribbon. The drafting device can be designed and configured to carry out a spin-up process after the fiber ribbon has been cut within the drafting device. To optimize the spinning process, the drafting device is designed and configured to selectively add at least two pairs of rollers via their drives during the spin-up process.