Downstream Weft Retrieval Feeder for Air-Jet Weaving
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Solution Overview
Problem
Air-jet weaving machines often cause damage to the weft thread ends due to pressure pulses in the main nozzle, leading to fabric defects, which are mitigated by increasing thread length and resulting in waste, while existing retraction methods can disrupt weft insertion.
Innovation Solution
A method and device for temporarily storing weft thread on a drum, using a fixing element, releasing it for insertion, and retracting it with a retrieval device positioned downstream, allowing the thread to be gripped near the drum and retracted into the main nozzle, minimizing damage by ensuring only a short section is exposed to the nozzle's acceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the weft thread length is increased to avoid damage from pressure pulses in the main nozzle, then fabric defects are reduced, but thread waste increases and production efficiency decreases
Solution Approach 1:
The retrieval device is positioned downstream of the fixing element to perform preliminary retraction of the weft thread before it enters the main nozzle. This preliminary action ensures that only a minimal section of the thread is exposed to the damaging pressure pulses, thereby reducing both thread damage and waste simultaneously
2Object-affected harmful factors
If the weft thread is retracted using existing retraction methods positioned upstream, then thread damage is reduced, but weft insertion is disrupted
Solution Approach 1:
The retrieval device is positioned downstream of the fixing element in the thread path, changing the spatial dimension of the retraction operation. This downstream positioning allows the thread to be retracted after fixing has occurred, preventing disruption to the weft insertion process while still protecting the thread from damage
3Object-affected harmful factors
If the weft thread is retracted into the main nozzle, then thread damage is minimized, but the thread start timing is delayed
Solution Approach 1:
The retrieval device performs preliminary retraction of the weft thread into the main nozzle area before the actual weft insertion begins. This preliminary positioning allows the thread to be ready for insertion with minimal exposure to damaging forces, optimizing both protection and timing
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
Reduces fabric defects by limiting thread damage to a minimal, waste-able length, enhances weft insertion stability, and allows earlier thread start for increased production speed and efficiency.
Implementation Method 1
acceleration of the weft thread in the main nozzle
Implementation Method 2
a suction nozzle (22), which catches and takes up the inserted weft thread (5)
Data Source
Figure 1
Figure 2
Figure 3
AI summary
In a method for inserting and retrieving a weft thread (5) on a weaving machine (1), a weft thread (5) to be inserted is intermediately stored on a drum (8), wherein, during the intermediate storage, the weft thread (5) is fixed on the drum (8) by a fixing element (11) in a fixing position, the weft thread (5) is released for weft insertion, wherein the fixing element (11) is moved out of the fixing position and into a release position, and the weft thread (4) is unwound from the drum (8) in an unwinding direction, with formation of a thread balloon, and inserted. After weft insertion has occurred, the weft thread (5) is pulled back by means of a retrieval device (9). Here, the weft thread (5) is gripped in a pick-up position downstream of the fixing element (11) and in the region of the thread balloon and pulled back. In a corresponding feeder (7) for a weaving machine (1), the retrieval device (9) is arranged in the feeder (7) downstream of the fixing element (11) in the thread run, and the retrieval device (9) has a driver for the weft thread (5), which grips the weft thread (5) in the pick-up position. A corresponding weaving machine (1) has a weft thread insertion system (4) and such a feeder (7).