The causes of uneven weft density：
(1) Due to the change in circumference of the warp wire on the warp roller, when the machine is first started, the warp wires on the roller is thick and the circumference is large. As the machine runs, there are only a few rounds of warp yarn left on the roller, and the circumference is much smaller than when the machine was first started. Therefore, without adjusting the density box, the closer the fabric is to the machine, the higher the weft density becomes.
（2）During the weaving process, the tension of the net constantly changes. As the tension increases, the warp and weft become sparser. For example, changes in the weight of the pressure bar and rod length, imbalance of the rolling roller, and variations in the thickness of the net wound on the rolling roller. The thicker the net wound on the rolling roller, the lower the net tension, and the sparser the net, especially for mesh nets.
(3) The clearance of the gear key in the rolling mechanism is large.
(4) During one revolution of the reverse inverter, there is partial slipping and severe unevenness in the mesh.
(5) The top wire of the rolling worm gear is loose, causing slipping.
(6) The rolling worm gear is not rotating smoothly.
(7) The top wire of the tensioning roller support rod is not tightened, which causes the tensioning roller support rod to be not securely fixed on its axis, resulting in a change in mesh density.
(8) The rotation of the roll net corner rod is not flexible, and sometimes it does not contact with the roll net cam, resulting in a suspended state, and the mesh density sometimes changes.
(9) The installation position of the roll net adjustment slider is not firmly fixed, causing up and down movement and instability.
(10) The wire on the stopper of the roll net is loose, causing the inner and outer keys to loosen and the roll net angle to be inconsistent.
(11) The pressure of the roll net involute gear spring is adjusted too small, causing the cone gear to have an up-movement phenomenon along the worm when rolling the net.
(12) Loosening of the top wire of the press roll bracket or the lifting rod of the weft density slider can cause the automatic adjustment mechanism of the roll net to malfunction.
(13) When the slider position on the roll net rocker arm is too low and reaches the lowest limit position, the roll net action becomes unstable.
(14) When the roll net pull rod is not in a horizontal position, the connection point at the corner of the roll net is high and the connection point on the rocker arm is low, causing unstable roll net action.
(15) Improper roll net timing can result in frequent machine stops (when hand-pulling and straightening, roll net action should be completed).
(16) The adjustment screw of the density box is bent or the wire buckle is worn, making it impossible for the density box to accurately adjust the weft density, resulting in the inability to adjust the weft density to the desired density.
Methods for preventing uneven warp density:
(1) Timely eliminate various malfunctions in the warp feeding mechanism.
(2) During the weaving process, strive to keep the tension of the net consistent.
(3) As the length of the warp yarn on the warp beam decreases, adjust the density box in a timely manner.
