Elastic Yarn Supply Velocity Control for Stress Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing elastic thread supply devices with tension controllers still experience variations in stress acting on elastic threads during overend unwinding, especially when conveyance velocities change, leading to quality defects in absorbent articles.
Innovation Solution
An elastic thread supply device equipped with a stress control unit and a drive roll that adjusts the supply velocity to maintain a consistent stress level below the processing line's stress, and increases or decreases supply velocity based on conveyance velocity fluctuations, ensuring a controlled percentage of stretch between the drive roll and processing line.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a tension controller is used to control the stress acting upon the elastic thread during overend unwinding, then the quality defect of the absorbent article can be inhibited, but a variation in the stress acting upon the elastic thread still continues to occur when the conveyance velocity of the processing line changes suddenly
Solution Approach 1:
The drive roll's rotation speed is made dynamically adjustable rather than fixed. The control unit receives information about the processing line's conveyance velocity and automatically adjusts the drive roll's rotation speed accordingly, enabling the system to adapt to changing conditions and maintain consistent elastic thread supply without stress variations.
Solution Approach 2:
The system implements a feedback mechanism where the control unit monitors the conveyance velocity of the processing line and uses this information to adjust the drive roll's rotation speed. This closed-loop control ensures that the elastic thread supply remains synchronized with the processing line's actual speed, preventing stress variations even during sudden velocity changes.
2Productivity
If the elastic thread is drawn by overend unwinding without rotation of the elastic thread package, then the lead portion of a spare elastic thread package can be connected to the end portion of the elastic thread package in use, but it is difficult to unwind the elastic thread smoothly and the stress acting upon the elastic thread changes successively
Solution Approach 1:
The drive roll automatically adjusts its own rotation speed based on feedback from the control unit about the processing line's conveyance velocity. This self-regulating mechanism ensures that the elastic thread is unwound at the appropriate rate to maintain consistent stress, eliminating the need for manual intervention while preserving the benefits of overend unwinding.
Solution Approach 2:
The system changes the operational parameter (rotation speed) of the drive roll dynamically based on processing conditions. By adjusting the rotation speed parameter in response to conveyance velocity changes, the system maintains stable stress on the elastic thread while continuing to operate in overend unwinding mode for continuous productivity.
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 configuration effectively inhibits quality defects in absorbent articles by maintaining consistent stress on the elastic threads, even with changes in conveyance velocity, thereby ensuring reliable product quality.
Implementation Method 1
an elastic thread supply device configured to supply an elastic thread to a processing line, by overend unwinding for sequential drawing of the elastic thread in an axial core direction of a cylindrical elastic thread package around which the elastic thread is wound
Implementation Method 2
a stress control unit configured to control the stress acting upon the elastic thread drawn from the elastic thread package
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An elastic thread supply device 100 including a tension controller 130 configured to control the stress acting upon an elastic thread TH drawn from an elastic thread package P, and a drive roll 140 configured to supply the elastic thread TH dispensed from the tension controller 130 to a processing line 30. The drive roll 140 operates at a supply velocity v2 slower than a conveyance velocity v1 of a web W, and increases or decreases the supply velocity v2 depending on the fluctuation in the conveyance velocity v1.