Optimizing Weft Insertion Process To Improve Weaving Efficiency

< p > < strong > a href= < http://www.91se91.com/news/index_c.asp > fabric > /a > organization specification design < /strong > /p >

< p > the warp and weft combination of fabrics should be determined according to the actual production conditions and the use of fabrics.

In order to achieve good shade effect, the shading fabrics sold on the market usually use a more compact tissue structure and weave black silk into the fabric. Generally, the black silk and the warp threads are interwoven into a shading layer to achieve a lasting shading effect.

The test fabric is mainly used for making curtain of high-grade Gaestgiveriet Hotel. The structure is double organized and combined (1: 1): polyester 83.3dtex72f flame retardant and matte low elastic yarn (upper warp shaft), polyester 83.3dtex72f flame retardant and low extinction yarn (lower warp), weft combination: polyester 333.3dtex96f black flame retardant low elastic yarn, machine width 351 cm, machine density 133 root / centimeter, machine weft density 28 cm / cm, weaving on HY700 type wide width electronic dobby water jet loom, and in the finishing process, by increasing shrinkage of fabric, it can achieve flame retardant, all shading, fine cloth and fine decorative requirements.

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< p > < strong > optimization < a href= "http://www.91se91.com/news/index_c.asp" > water spray > /a > weft insertion process < /strong > /p >

Weft insertion is one of the most important processes in the weaving process of water jet looms, and its technological parameters should be determined according to the variety of fabrics and the characteristics of weft material P.

Under other conditions, the setting of weft insertion determines the efficiency of weaving.

Reasonable parameters can not only improve the quality of fabrics, but also reduce the labor intensity and increase the number of stands.

The weft insertion process includes weft insertion time, water pressure, water volume and nozzle configuration.

The following precautions for weft insertion process are introduced from various configuration parameters.

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< p > antecedent angle refers to the angle of water ejecting from the nozzle to < a href= "http://www.91se91.com/news/index_c.asp" > the yarn holder < /a > opening the crankshaft. The most important function is to straighten the crooked weft yarn.

In the free flight process, the first jet water straightens the weft head to achieve stable weft insertion.

Generally speaking, in the wide range of water spraying weaving, the setting of the prior water is mainly adjusted according to the yarn thickness, water absorption and fabric width. For example, the FDY of polyester filament has little water absorption, and the initial angle is generally set at about 15 degrees; the polyester twisting silk (DTY) is generally set at 15 degree to 20 degrees; the DTY of the polyester thread and the setting of the antecedent angle should be adjusted according to the number of the network points, generally 18 to 25 degrees.

The wider the width of the fabric, the longer the yarn flying, the greater the probability of being affected midway, the higher the stability of weft flying, and the more water it needs.

To sum up, when the width of the fabric is wider, the front angle should be properly increased to ensure that the yarn does not shake during the whole flight.

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< p > free flight angle refers to the angle of weft yarn pre weft when the yarn holder is opened, and the time when the weft begins to fly to the clipped yarn by the weft insertion from water flow to the angle that the crankshaft is turned off.

The larger the free flight angle is, the less resistance the weft is flying, and the more stable it is when approaching the weft.

Generally speaking, the free flying time of weft should be increased as far as technological adjustment is concerned, so as to avoid stopping.

The starting angle of flight angle should be combined with the antecedent angle, which can be appropriately advanced when meeting the requirements of the preceding water.

When weaving the extra wide fabric, the free flight angle should be larger as the flight distance is longer, which is conducive to flying the weft yarn and reducing the occurrence of short weft and broken weft.

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< p > the constrained flight angle refers to the angle of the weft yarn which has been pre weft on the weft feeder until the crank ends when the weft is flying.

In the weaving machine with electronic weft accumulator, the binding time is starting from the closing of the electromagnetic needle, and the weft yarn needed by the fabric has been pre arranged to achieve the weft insertion under the gravitation of the water flow.

In order to ensure that the weft yarn is always in the straightening state during the beating process, a certain amount of water is needed to extend it fully.

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< p > the setting of the amount of water should have enough water in advance and suitable residual water to ensure enough weft insertion force in the whole weft insertion process.

Generally speaking, in order to prevent the restraint angle from being unstable in weaving wide fabrics, the proper way to increase the water volume is usually adopted to ensure the weft insertion state is stable.

The size of the water pressure is generally determined by the time of water to the yarn. The high water pressure will shorten the weft insertion time, and make the restraint angle advance, affecting the normal weaving.

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< p > residual water refers to the remaining amount of water after weft flying to the end of beating.

Excessive water volume can easily lead to an increase in false detection of weft. There will be air stopping or weaving of looms. If the residual water is too small, the restraint angle will be wrong. There will be air stopping of looms, wrong weft insertion, weft relaxation, short weft and so on. The angle of observing residual water is generally 305 to 310 degrees.

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Below P, the weft yarn is straightened under the friction of water and enters the photoelectric weft detector under the action of beating up motion.

If the loom does not receive the weft signal at 305 degrees to 310 degrees, it will stop automatically.

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< p > < strong > actual machine test analysis < /strong > < /p >.

< p > weaving the upper shaft and weft yarn of the warp shaft on the extra wide electronic dobby loom. The loom speed is 390 revolutions / minutes, and the nozzle is configured as 75/40.

For better analysis.

Under the condition of constant warp tension and constant water pressure, that is, the specifications of the pump are 28 millimeters, the P value of the spring diameter is 11.5 mm, the number of turns is 7.5 rings, and the length is 145 millimeters. The weft insertion process parameters are debugged and the test time is 24 hours.

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In the second test, the loom efficiency is not high; in the test 2, because the water is too long and the water is small, the time of flow and yarn to the waste side yarn is ahead, and the weft yarn is easily towed under the traction of the lack of residual water, causing the weft yarn not to enter the weft opening properly, causing the loom to stop and the weft on the cloth. In test 3, under the condition of reasonable water volume, the first water volume is properly increased, and the weft yarn is always wrapped by water in the flight. The time of the flow and yarn to the waste yarn is punctual, the residual water is just right, the weft yarn goes smoothly into the weft opening during the weft insertion time, the loom runs well, and the weaving efficiency is 99%, which can meet the requirements of normal production. < p > from the following table, it is known that in Experiment 1, due to the shorter initial water and larger water volume, the flow of yarn and yarn to the waste side yarn is later than that of the weft yarn entering the weft opening.

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< p > when weaving weave fabric with water jet weaving, the width of weft yarn is longer and the flying time of weft yarn is longer.

In addition, the water pressure should be increased to make the weft yarn straightened into the fabric, and the weft can arrive at the design time to form the fabric.

After repeated commissioning, the loom's overall efficiency can be over 98% and efficient production can be achieved.

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