How to adjust heald frames and nozzles on air jet weaving machines

How to adjust heald frames and nozzles on air jet weaving machines

1-What is the effect of heald frame height on weaving?

① When it is too high, it will cause weft beating at the upper part of the air-guiding part of the reed or even at the upper jaw, resulting in cracks and holes in the fabric;

② When it is too low, the upper warp yarn will be slack, resulting in unclear opening, the opening angle will become shorter, which may cause an increase in weft stopping.

2-How should the frame height be set?

Heald frame height setting, in principle, should make the weaving mouth in the air-conducting part of the reed, to avoid causing holes in the fabric surface, the height of the heald frame is set with a clear weaving mouth, semi-clear weavingmouth, unclear weaving mouth, according to the warp density of the fabric to be selected, high-density fabrics and bad hairiness of the fabric, the general use of semi-clear weaving mouth or unclear weaving mouth, so that the warp yarns are layered to reduce the warps sticking; for twill and complex organisation of the fabric, the side yarn heald frame and ground organisation heald frame have a front and back position. For twill and complex fabrics, the heald frame of the side yarn and the heald frame of the ground organisation have a front and back position, and the setting should pay attention to the height of the heald frame so that the side yarns are not too loose, so as to reduce the weft stop.

3-How to set the main nozzle spraying angle?

The main nozzle spraying angle should be set, taking into account the clarity of the opening of the left side of the warp yarn, if it is set too early, it will hang the warp yarn, causing an increase in the weft stop, too late, it will produce defects such as weft shrinkage in the cloth edge, the need to increase the spraying pressure, if the left side of the warp yarn opening is good, it can be appropriate to advance the spray angle to save gas, the general end of the spraying angle of 180 ° ± 15 °.

4-What is the effect of main nozzle pressure on weaving?

When the main nozzle pressure is too high, the weft arrives earlier, the head end of the weft will be blown off or weft breakage will occur, which will produce weft shrinkage, loose weft, short weft and other phenomena in the cloth edge, the left side of the cloth edge is not good, and the scissor shear is not neat.

5-How to set the sub-nozzle spraying time?

The spraying time of the first group of sub-nozzles is generally the same as that of the main nozzles, or about 10° ahead, and the end angle is about +80° of the starting angle of spraying. According to the different types of weft, in order to get the full speed of weft drawing, the spraying angle of the first group of sub-nozzles can be extended appropriately, and the other sub-nozzles' spraying angle is generally delayed by 15°-20° in the order of the ending angle is about +80° of the starting angle of spraying. In actual production, the spraying angle is advanced, which can reduce the consumption of air-pressure gas.

6-What is the effect of sub-nozzle pressure?

If sub-nozzle pressure is too high, the weft arrives earlier, the weft is easy to be blown off, and air consumption increases; if sub-nozzle pressure is too low, the weft arrives later, easy to produce weft shrinkage, short weft and other weaving defects, and the weft flight state is not good, it will cause unexplained stoppage.