Draw Frame Sliver Thinning for Jam-Free Can Changes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing draw frame methods for starting and stopping, particularly during can changes and sliver threading, face complications due to continuous sliver supply, leading to reduced process reliability and potential jams.
Innovation Solution
A method involving a draw frame with a controller to control drafting system rollers, where the sliver is stretched and a thin point is created to facilitate controlled separation, allowing for defined starting and stopping phases, including a holding phase to prevent jams and enable maintenance, with parameters like fiber material and strength influencing the thin point's length and thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the sliver is continuously supplied during can change and sliver separation, then the production process can continue without interruption, but this leads to complications such as sliver jams and reduced process reliability
Solution Approach 1:
A thin point is created in the sliver before the can change operation, and the draw frame is stopped in advance to allow controlled separation at this predetermined location. This preliminary preparation enables smooth can changes without continuous sliver supply complications
Solution Approach 2:
The draw frame operates in periodic cycles of running and stopping. During can changes and sliver separation, the machine is deliberately stopped to allow controlled operations, then resumes normal operation. This periodic stopping prevents jams while maintaining overall productivity
2Reliability
If the draw frame is stopped for can change and sliver separation, then process reliability is improved and jams are prevented, but production time is lost
Solution Approach 1:
The thin point is created in the sliver before stopping the draw frame. This preliminary action ensures that when the machine stops for can change or separation, the thin point is already positioned and ready, enabling rapid controlled separation and minimizing downtime
Solution Approach 2:
The stopping phase is minimized to only the essential time needed for controlled separation at the thin point. The machine quickly transitions from running to stopped state, performs the necessary separation operation, and immediately resumes operation, reducing overall time loss
3Productivity
If the thin point is created with high drafting speed, then productivity is maintained, but the sliver mechanics are stressed and material may be damaged
Solution Approach 1:
The high drafting speed is applied periodically during the running phase to maintain productivity, then the machine stops during the separation phase. This periodic cycling allows aggressive drafting when needed while protecting the material during vulnerable separation operations
Solution Approach 2:
The thin point is created in advance during a controlled drafting phase, preparing the sliver for future separation. This beforehand preparation cushions the material by creating a predetermined weak point that will fail cleanly during separation, preventing damage to the rest of the sliver
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 approach enhances process reliability by ensuring controlled separation and easy sliver handling, reducing the risk of jams and allowing for smoother maintenance, while protecting the mechanics and material through gentle speed reduction and braking.
Implementation Method 1
The sliver is passed between drafting system rollers of a drafting system, which stretch the sliver
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a method for operating a line (1), in particular for starting and/or stopping the line (1), for example for changing cans and/or for subsequently threading a fiber strip (2) into a strip channel, in which a fiber strip (2) is guided between drafting rollers (4, 5, 6) of a drafting unit (3), which draw the fiber strip (2), and in which a thin spot (7) is created in the fiber strip (2) so that the fiber strip (2) can be cut at the thin spot (7). According to the invention, the thin spot (7) is created in the fiber strip (2) during a holding phase and/or a starting phase of the line (1). Furthermore, the invention includes a line for drawing a fiber strip (2) with a control system by means of which at least drafting rollers (4, 5, 6) of a drafting unit (3) can be controlled. According to the invention, the control system is configured such that it can carry out the method.