How to adjust the weft draw-in system of a water jet loom?

Water jet loom Parameterization of the weft drawing-in process

The weft draw-in process needs to be adjusted according to the fabric's reed width, weft type, thread density and other factors, in order to achieve the purpose of smooth weft draw-in and normal weaving, and the adjustment of weft draw-in process parameters includes the adjustment of water pumps, nozzles and grippers.

1-Adjustment of water pumps

 The water pump consists of pump body, plunger, pressure spring and adjustment nut. The adjustment of the water pump includes the adjustment of water spraying time, water volume and water pressure, and its main parameters are:

    a. Water jet time adjustment. Refers to the highest point of the water pump cam and rotor contact time, expressed in terms of angle, generally set to 85 ° ~ 90 °, the tip of the water pump cam and the center of the camshaft, the center of the rotor three points in a straight line, locking cam set screw. Water spray time is too early or too late will affect the water column of the cluster or lead poor.

    b. Adjustment of water volume. Refers to a jet, the water pump through the nozzle jet how much water.

    Adjustment of the amount of water, by adjusting the pump below the adjustment screw, by changing the movement of the water pump plunger range to complete. Water pump cam surface has three scale points, the number of large water volume, the number of small water volume. Adjust the adjusting screw, so that the water pump camshaft axis and the cam on the desired scale point, the cam rotor center of the three points into a line that is completed. Too much water or too small will cause the weft flight in the introduction of the weft is bad.

c. Adjustment of water pressure. Water pressure adjustment method is to use a special tool to rotate the pump cylinder nut, by adjusting the cylinder nut to adjust the pressure of the spring to adjust the water pressure. Generally to the pump cylinder nut within the edge of the tightening nut to the size of the distance p to the apocalyptic. p large, low water pressure. p small, high water pressure. Water pressure is too small, will make the weft easy to wrap around the storage weft disk pressure broken weft. Water pressure is too large, will make the weft set bundle flight angle in advance, easy to cause air stop.

2-Nozzle Adjustment

   The good or bad nozzle collection is related to its own type, opening degree and spraying position. In order to make the weft threads pass through the bobbin mouth smoothly when drawing in the weft, it is necessary to correctly adjust the up and down, front and back position of the nozzle. The nozzle up and down position adjustment is to adjust the screw on the nozzle bracket when the loom is healded to make the center of the nozzle flush with the warp wire, if the reed width is more than 160cm, the center of the nozzle is slightly lower than the warp wire by 1~2mm.The nozzle front and back position adjustment is to move the nozzle bracket forward and backward to make the center of the nozzle and the front of the reed flush when the loom is at 85°.

    Nozzle opening is small, the jet beam is relatively long and thin, the opposite is true for large openings, the general nozzle opening in the range of 0 to 2, the adjustment method is to rotate the needle completely into the spray body for the zero openings, the needle will be reversed a circle for a degree of openness, reversing the two circles for the second degree of openness.

3-Gripper and apex angle adjustment

The function of the gripper is to control the start and stop of the weft introduction by the opening and closing of the two pieces of the gripper. The method of adjustment is to adjust the clamp cam linkage, to control the gap between the clamp open 0.5 ~ 1mm, by adjusting the clamp inside and outside the position of the two pieces of cam, to control the clamp opening and closing angle. Generally the gripper opening time is 105°～115°; the closing time is 260°～270°. Before the start of the introduction of the weft, in order to straighten the bent filament, it is necessary to set a pilot angle, the setting of the pilot angle varies depending on the type of weft yarn, thread density, generally:

    Polyester, nylon filament 15°

    Polyester twisted yarn 15 ° ~ 20 °

    Low elasticity polyester DTY 111dtex (100 denier) or less 20 ° ~ 25 °

    Low elasticity polyester DTY 167dtex (150 denier) or more 25°～30

    Clamping device open and close time sooner or later, related to the weft flight status, clamping device closed too early to make the weft constrained flight too early, resulting in the end of the weft flight, the amount of water is not enough, the weft is easy to shake, the loom produces empty stop. Clamp off too late will cause the weft storage device on the winding weft threads caused by head breakage. General weft set flight angle 20 ° ~ 30 ° ahead of the clamp closing angle, with the adjustment of the pump pressure to regulate.