Mounting is an essential process before weaving on water jet looms. The quality of the mounting and the rationality of the mounting method play a crucial role in the smooth production of the fabric. It is vital to ensure this step is done correctly. Therefore, the following issues should be noted during the mounting process:
I. Different Positions of Heald Frames on the Loom
The lifting heights of heald frames differ during shedding based on their front-to-back position on the loom. Heald frames at the front of the machine have a lower lift height, resulting in smoother loom operation during lifting, and the warp threads passing through these frames experience less tension, reducing the likelihood of breakage. Heald frames at the rear of the machine have a higher lift height, causing greater vibration during lifting, and the warp threads passing through these frames experience greater tension, increasing the risk of breakage. The heald frame body can be driven by the slide bar to perform the reciprocating motion for weaving. A bent section, twisted along its axis, is arranged in the middle part of the heald frame body, and several heald eyes are penetrate through this bent section. If one of these heald eyes is damaged, the others can serve as replacements, thereby extending the service life of the heald frame body. This utility model is used on weaving machines, is simple in structure, low in cost, and has a long service life.
Therefore, after determining the drafting plan, attention must also be paid to deciding which set of warp threads is drafted through the front heald frames and which set through the rear ones. The rules for determining this are as follows:
1.When the fabric has only one type of warp combination, the heald frame carrying the larger number of warp ends should be placed at the front of the machine, and the one carrying the fewer number of warp ends should be placed at the rear. This contributes to smoother loom operation.
2.Compare the interlacing patterns of warp threads with different lifting laws. Warp threads that are lifted more frequently should be drafted through the front heald frames, and those lifted less frequently should be drafted through the rear frames. This helps reduce warp breakage.
3.When the fabric has two or more types of warp combinations, the warp yarns with better abrasion resistance should be drafted through the rear heald frames, and those with poorer abrasion resistance should be drafted through the front frames.
II. Pay Attention to the Heald Wire Density on Each Heald Frame
Generally, once the fabric weave is determined, the number of heald frames required is also fixed. However, sometimes there is a significant disparity in the number of warp ends carried by different frames – some frames might have only 1-2 heald wires per cm, while others might have over ten. The heald frame is an important component in the loom, a frame consisting of upper and lower rails connected by side pieces, equipped with heald carrying rods and drive elements. After heald wires are mounted on the frame, the warp threads drawn through them are gathered into a unified whole. Following the motion of the loom’s lifting mechanism, the heald frames move up and down according to the shedding device’s program, causing the warps to form layers (sheds) for the weft yarn to pass through, thus interweaving into fabrics with different patterns.
The density of the heald wires affects the difficulty of weaving. Excessive density increases friction on the warp threads from the heald wires, leading to breaks. Therefore, all looms have specific requirements regarding the heald wire density per frame during weaving. For water jet looms, the heald wire density generally should not exceed 12 ends/cm. Furthermore, heald frames that are lifted more frequently should have a lower density.
After the drafting plan is finalized, if it is found that the heald wire density on a particular frame is too high, consideration should be given to using two heald frames to carry the warp ends with the same lifting pattern. These ends should be distributed evenly (in a 1:1 ratio) across the two frames to maintain smooth weaving progression.
