The production process of fancy thread fabric
(1) Winding process
In order to check the quality and facilitate dyeing, fancy yarns are generally supplied in twisted packages, which must be made into bobbins after entering the factory. Since the core thread and reinforcing yarn of fancy thread are generally thinner and have lower strength, the winding speed should be reduced or the weight of the tension sheet should be appropriately reduced. When piecing, care should be taken to cut off the part of the yarn tail without flower shape. When using chenille yarn as weft yarn, first of all, pay attention to its direction. Therefore, the head and tail of the yarn must be marked when twisting to ensure that the head and tail must be connected when winding. It is easy to cause a horizontal color profile due to different reflections on the cloth surface. When using the circle thread, if it is a product of two manufacturers or two batches, it should be used in separate stages or different varieties, otherwise the weft color file will be generated due to the subtle difference in the production process of fancy thread.
(2) Warping process
Fancy thread fabrics generally use fancy threads as inserts, and the fancy threads are often many times thicker than the bottom yarns. Differences in yarn length and tension create difficulties when weaving. Therefore, the number of pierced threads should be reduced in the reed teeth of the fixed-width reed of the warping machine. If the thickness difference is large, an empty reed should be added next to the fancy thread, so that the fancy thread has more room for movement during warping. It will not bulge on the beam and cause length differences. If you use knot thread or discontinuous loop thread or discontinuous corrugated thread as warp, it is better to use equidistant fancy thread. The knots do not overlap each other. If the fancy thread is broken and reconnected, it should also be noted that the knots and the adjacent warp yarns on both sides are staggered (even if the knots do not overlap). Non-equidistant knots are also available.
(3) Sizing process
Cotton yarn must be sizing before weaving, and machine sizing is generally used. Since the fancy thread is thicker and rougher than the base yarn, if it passes through the size tank together with the base yarn, the fancy thread will be very hard, which is not conducive to weaving. Therefore, in the sizing process, the fancy wire can be lifted up with a twist rod alone, so that it can directly enter the drying room above the sizing roll without passing through the pulp tank. When some products only use a small amount of fancy threads as inserts, a gallows can also be temporarily made behind the sizing machine, so that the fancy threads can enter directly without going through the sizing tank. In this method, the tension must be well controlled, otherwise it is not conducive to weaving . State-of-the-art equipment features dual warp beams to maintain equal output for even tension and flat fabric.
(4) Harnessing process
No matter what shape the fancy thread is, its appearance is relatively rough, and there will be more friction when passing through the heddle eye. In order to reduce the friction of the fancy wire at the heald eye, the welding eyelet with a larger heald eye must be selected according to the thickness of the fancy wire. Surface effects that cause warp yarn breaks or damage fancy threads at the junction of the heald eye.
(5) Reeding process
Fancy yarns are often interlaced with yarns of different thickness and linear density, so the number and density of thick and thin yarns need to be different relative to their linear density, that is, the number of warp yarns inserted into each reed should be different. However, sometimes it is difficult to pass even a single reed. At this time, two methods can generally be used: if the product is produced in a small batch, the method of pulling the reed teeth can be used, that is, the reed teeth that penetrate the knot line can be used. Pull out a reed piece in the middle to double the spacing of the reed teeth; if the production batch is large and relatively fixed products, a thin and dense reed can be designed according to the process requirements. The distance between each tooth of this reed is based on the fabric structure. It is specially designed according to the number of warp threads per reed. This kind of fabric can achieve better effect and more balanced appearance through different finishing processes.
(6) Weaving process
Many fancy threads are used as weft yarns, and the quality requirements of weft yarns are lower than that of warp yarns. For example, when the knot thread is used as the weft yarn, the reinforcing yarn can be omitted, but the selection of the knot spacing is higher than that of the warp yarn. For general weft yarns, the knot spacing is preferably both irregular and regular, that is, adding a small gap at the beginning of each regular to avoid overlapping knots or stair-like appearance on the cloth surface. Tortoise and other phenomena. When designing the knot spacing, it cannot be a common multiple of the reed width (width), so that the knots can be evenly distributed on the cloth surface. Others such as interrupted terry, slub yarn, etc. should pay attention to these problems. If weaving with a rapier loom, the choice of the rapier is very important. It must have good thickness and fine yarn adaptability (the thickness of the weft and the fancy thread is very different), otherwise, because the rapier head does not clamp the fancy thread tightly, On the exit side, the fancy thread is often pulled apart. Because the core yarn of the fancy thread is often very thin filament, if the clamping is not tight, the core thread will slip off from the sword head, so that the sword head only clamps the decorative thread, and when it is pulled forward, the fancy thread will be pulled. scattered. The second is that the let-off and take-up mechanism of the loom should be adapted accordingly. Since thick and thin yarns are alternately woven in the weft direction, in order to ensure a uniform appearance in the weft direction, the weft density should be unevenly woven during weaving, that is, the weft density of thick fancy yarns is thin, and the weft density of thin plain yarns should be dense. . To this end, Italian looms are equipped with a thin beating-up device.
This equipment relies on mechanical transmission, so it is more reliable, and it is much better than the passive let-off coiling in our country at present, so that the appearance of the product is more balanced and stable. For general products, in order to reduce the weft stopper caused by uneven yarn evenness. Especially for products with large differences in warp and weft colors, in order to improve the rate of first-class products, the density of weft yarns is often adjusted by passive let-off and winding, that is, the amount of warp let-off is controlled according to the thickness or thinness of the weft yarns. If it is too small, the weft spacing of the fabric will also change with the amount of warp let-off, so that the cloth surface will appear more uniform. However, such methods are generally suitable for products such as herringbone twill or mountain twill, but are not suitable for lattice fabrics, which will cause uneven size of the lattice. The foreign novel rapier looms are equipped with a device that can automatically adjust the weft density according to different kinds of yarns, and the speed will automatically decrease when weaving fancy weft yarns, which can be competent for weaving fancy thread products.
(7) Application of semi-synthesis
Fancy threads are used in woolen woolen wool, especially in tweed products, and the warp and weft densities are often smaller than normal products, so it is usually called loose tweed. Due to the loose structure of such products, the shrinkage between warp and weft is larger than that of conventional products, and the dimensional stability is poor. In order to solve these problems, in the production of fancy thread fabrics abroad, the fabric structure is often woven into a leno weave with half healds, and the warp direction uses finer worsted wool yarn or chemical fiber silk, normal yarn, and the weft direction is all Or part of the use of various types of loops or knots, belly yarn, wavy yarn and composite fancy yarn. In this way, the warp yarns are knitted with the weft yarns, so that the weft yarns cannot be slipped at will, so that the fabric is not skewed even though the structure is loose, the fabric is soft and not easily deformed, and the appearance of the fancy thread is fully highlighted. This is the development direction of various products of cotton, linen, silk and wool.