Elastic Core Yarn Speed Ratio Adjustment for Bobbin Change Reliability
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Solution Overview
Problem
Automatic bobbin changing in ring spinning machines is disrupted due to the elasticity of spun elastic yarn, leading to unreliable yarn separation during the process.
Innovation Solution
Adjusting the peripheral speed ratio between the output rollers and delivery rollers to reduce the elongation of the continuous thread, ensuring the core yarn is less elastic, allowing for reliable separation using a knife blade during automatic bobbin changing, with a preferred ratio of less than 3, ideally between 1 and 1.5, and utilizing electronic or mechanical coupling for speed adaptation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the peripheral speed ratio between output rollers and delivery rollers is increased to achieve higher productivity, then the elongation of the continuous thread increases, but the yarn becomes too elastic and cannot be reliably separated during automatic bobbin changing
Solution Approach 1:
The patent applies dynamics by making the peripheral speed ratio between output rollers and delivery rollers variable rather than fixed. The control unit dynamically adjusts this ratio based on the spinning phase: during active spinning a higher ratio (1.5-3.0) maintains productivity, while during bobbin changing a lower ratio (1.0-1.5) ensures reliable yarn separation. This temporal variation in operational parameters resolves the contradiction between productivity and separation reliability.
Solution Approach 2:
The patent changes the operational parameter (peripheral speed ratio) to resolve the contradiction. By adjusting the speed ratio from high (1.5-3.0) during spinning to low (1.0-1.5) during bobbin changing, the elastic elongation of the continuous thread is controlled. This parameter change allows the system to achieve both high productivity during production and reliable separation during maintenance operations.
2Reliability
If the peripheral speed of delivery rollers is increased to match output rollers, then the continuous thread passes through with minimal stretch, but the yarn lacks the necessary elastic properties
Solution Approach 1:
The patent applies periodic action by alternating between two operational modes: during normal spinning, the peripheral speed ratio is set high (1.5-3.0) to create elastic yarn with appropriate stretch; during bobbin changing, the ratio is reduced (1.0-1.5) to minimize stretch and facilitate separation. This periodic switching between operational states allows the system to achieve both yarn elasticity and ease of separation at different times in the production cycle.
3Productivity
If automatic bobbin changing is implemented to increase productivity, then manufacturing efficiency improves, but disruptions occur due to unreliable yarn separation
Solution Approach 1:
The patent applies feedback by using the control unit to monitor the spinning state and automatically adjust the peripheral speed ratio accordingly. The control unit receives information about the operational phase (spinning vs. bobbin changing) and adjusts the speed ratio to maintain optimal conditions. This closed-loop control ensures that the system adapts to different operational requirements, maintaining both productivity and reliability in automatic operation.
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
Enables trouble-free separation of the spun elastic yarn during bobbin changes, maintaining the same properties as non-elastic yarn, allowing the same equipment to be used for both elastic and staple fiber yarns, reducing disruptions and ensuring consistent operation.
Implementation Method 1
When passing through the drafting system, which consists of several pairs of rollers, the fiber strand is drawn by the different speeds of the pairs of rollers.
Implementation Method 2
The peripheral speed of the pair of delivery rollers is matched to the peripheral speed of the pair of output rollers in such a way that the endless thread is stretched between the pair of delivery rollers and the pair of output rollers.
Implementation Method 3
the continuous thread is passed on to the spinning device with less stretch
Implementation Method 4
Through the action of the runner and the spindle, the continuous thread is spun into the fiber structure
Data Source
Figure 1
AI summary
The invention relates to a method for producing elastic core yarn using a ring spinning machine, wherein a fiber bundle (2) is fed to a drafting unit (1), the fiber bundle (2) is stretched as it passes through the drafting unit (1), exits the drafting unit (1) through the output roller pair (3), and is guided via a yarn guide (4) to a runner (5) and wound onto a rotating bobbin (7) via the runner (5), which rotates on a ring (6). As the fiber bundle (2) enters the output roller pair (3), an elastic continuous filament (8) is fed to it via a feed roller pair (9) and spun into the fiber bundle (2). According to the invention, when spinning a full bobbin (7), the circumferential speed ratio between the output roller pair (3) and the feed roller pair (9) is adjusted such that the elongation of the continuous filament (8) is reduced. The invention also relates to a corresponding device.