Weaving Machine Weft Insertion Timing for Edge Quality
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Solution Overview
Problem
As weaving machine speed increases, there is insufficient time to position additional weft effect threads correctly between successive weft threads, leading to uneven tucked-in edges in fabrics with additional weft effects.
Innovation Solution
The method involves selecting and inserting weft threads using weft thread selection and insertion means, holding them in position with mechanical or pneumatic means, and then cutting and displacing them to create ends, which are inserted into the shed, with an additional reed beat-up cycle between weft insertions to maintain edge quality, and shifting an effect thread in the weft direction to facilitate this process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the weaving machine speed is increased to improve productivity, then the production efficiency is improved, but the time available for positioning the guide means and effect thread becomes insufficient, leading to poor manufacturing precision
Solution Approach 1:
The guide means is moved in the weft direction in advance during the previous movement cycle, so that the effect thread is already positioned in the correct location before the current movement cycle begins. This preliminary positioning action eliminates the need for time-consuming positioning operations during the current cycle, allowing high weaving speeds to be maintained while still achieving precise positioning of the effect thread for creating tucked-in edges.
2Manufacturing precision
If the guide means is moved vertically and in the weft direction to position the effect thread correctly, then the additional weft effects are achieved, but the time required for positioning increases, reducing productivity
Solution Approach 1:
The guide means performs the weft direction movement during the previous movement cycle, positioning the effect thread in advance. This way, when the current movement cycle begins, the effect thread is already in the correct position, and no additional time-consuming positioning operations are needed, thus maintaining high productivity while achieving precise positioning.
Solution Approach 2:
The positioning process is divided into two independent stages: vertical positioning (done during previous cycle) and weft direction positioning (done in advance during previous cycle). This segmentation allows each positioning task to be completed independently without interfering with the main weaving process, reducing total positioning time while maintaining precision.
3Manufacturing precision
If a movement cycle without weft insertion is implemented to position the effect thread between two weft threads, then the additional weft effects are achieved, but the number of productive weaving cycles decreases, reducing overall productivity
Solution Approach 1:
The guide means moves the effect thread in the weft direction during the previous movement cycle, so that when the current movement cycle begins, the effect thread is already positioned between the correct weft threads. This eliminates the need for dedicated positioning cycles, allowing every movement cycle to be a productive weaving cycle while still achieving precise effect thread positioning.
4Ease of manufacture
If the cut thread end of the weft thread is inserted into a shed without an inserted weft thread, then the tucked-in edge formation is attempted, but the tucked-in edge becomes uneven, reducing manufacturing quality
Solution Approach 1:
A weft thread is inserted into the shed in advance of the intended tucked-in edge position, and this preliminary weft thread is then beaten up by the reed to create a uniform reference surface. When the actual tucked-in edge weft thread end is subsequently inserted and beaten up against this reference surface, it achieves uniform positioning and creates an even tucked-in edge, eliminating the unevenness that occurs when inserting into empty sheds.
Data Source
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AI summary
The invention relates to a method for inserting weft ends into a shed (1.1, 1.2) of a weaving machine. Wefts (3) are selected using weft selection means (19) which are inserted into the shed by means of weft inserting means and are fastened to a fabric edge by a weaving reed device (7, 7.1, 10). A fastened weft (3) is held in the region of the fabric edge in a specific position by holding means for the weft, wherein a change of the shed is carried out by the shedding means (4) after the weft insertion. The wefts are moved using the holding means for the wefts such that they reach a position in which they are cut by weft shears. A weft end is thus created, which is then detected by an inserting means and inserted into the shed. Between two successive weft insertion processes for a first and a second weft, the following processes occur: an additional weaving reed stop occurs via the weaving reed device, wherein no weft is entered and fastened to the fabric edge, however; and no weft end of the first inserted weft is inserted into the shed; and an effect thread extending in the warp direction for creating additional weft effects is moved in the weft direction on the weaving machine by means of a moving device.