How To Develop New Yarn With Embedded Spinning

This paper discusses the development of new products based on the principle of embedded spinning, introduces the design principles of some new products developed, and emphatically analyzes several key points of twisting in spinning process, so as to provide a theoretical basis for the correct application of the embedded spinning technology and the development of new products.

As a new ring spinning technology, the embedded composite spinning technology (hereinafter referred to as embedded spinning) can not only make use of low grade raw materials to spin fine yarns, but also adjust the yarn according to its principle to develop new yarns.

1 embedded spinning mechanism

The principle of embedded spinning is shown in Figure 1.

　　 Each spindle is fed by double roving double filament, the roving bar is drawn to the front jaw of the spinning machine through drafting, and the filament is fed directly into the front jaw. The short fiber whiskers BE and CF intersect with filament AE and DF at the point of E and F after spinning out of the spinning frame. The two binary components of spinning EG and FG are combined together and become embedded spinning.

2 way of twisting

According to the mechanism of embedded spinning, the most important function of this technology is twisting and twisting without embedding. In terms of twisting, there are generally two forms: one is symmetrical twisting, the other two is asymmetrical twisting, as shown in Figure 2. The so-called symmetrical twisting is the single yarn twisted by two components of filament and staple fiber as the axis. The filament and the staple fibers are twisted around the axis symmetrically. From the point of view of mechanics, the angle between filament and staple fiber is equal to that of the twisted yarn, alpha = beta, as shown in Figure 2 (a). The so-called asymmetric twisting is that the angle between the filament and the staple fiber is not equal to that of the twisted yarn. It also has some special twisting forms, that is, alpha =0 or beta =0, as shown in Figure 2 (b).

　　 Obviously, the twisting mode and yarn structure of the yarns are much more complicated than the traditional siro spinning and two-component spinning. Different twisting modes determine the different structure of yarns, and different structures make the yarn have different styles and performances, that is, the change of product style can be realized by changing the form of twisting.

3 variety development

3.1 low grade raw materials for spinning fine tex yarn

The distance between filament and short fiber must be properly adjusted, and the pretension of filament should be adjusted to make the staple fiber vertical output. The angle between filament and staple must be the same as that of twisted yarn. When alpha = beta, the distance between BE in Figure 1 will be stabilized in a certain range. At this time, the distance between BE is the extreme length of fiber, and the staple fibers with length shorter than EB in the short fiber will be twisted into yarn effectively. This means that the embedded spinning requires shorter fiber content.

It provides technical support for spinning low-grade yarn with low grade raw materials.

3.2 spinning super fine yarn

Soluble filament and short fiber rod are twisted, and the filament is dissolved after finishing, so that the superfine yarn can be spun.

3.3 multi component spinning

Filament can be replaced by spun silk, cotton thread, linen, gold and silver wire and antistatic wire. For example, a group of short staple fiber and polyester filament compound, and another group of linen fiber and soluble vinylon filament composite, two groups of 4 raw materials after the composite symmetry, the finished yarn after the dimension is reduced into wool, hemp and polyester 3 component yarn, this 3 component products and traditional blended wool, linen and polyester three in one product, in appearance and handle and wear performance are significantly different.

3.4 color effect of fancy yarn

The fineness of the two components is different, and the color effect will also be caused by compounding. See Figure 3.

　　 3.5 wrapped yarn

When the angle between the filament and the staple fiber and the twisted yarn is equal to that of the beta yarn, the filament and the staple must be twisted and wrapped together and the wrapping angle is equal. When alpha =0 or beta =0 occurs, a fiber is wrapped around another fiber, and when the alpha is 0 or beta 0, the wrapping is between the above two. If silk and wool are combined, when the product is alpha = beta, the product has smooth and glossy silk and soft and elastic wool. If the polyester filament and wool compound are combined with alpha =0 (see Figure 2), the polyester filament is wrapped in wool fibers, and the yarn appearance is similar to wool yarn, as shown in Figure 4.

　　 3.6 core spun yarn

Adjust the filament input position, put the filament AG as the core, put it in the middle, and give a certain pre tension. Two strand short fibers must be placed on both sides of BG and CG. With the twisting, the two or so strands will be wrapped on the core line in turn. The core spun yarn produced in this way has few defects which are not exposed on the core line. The schematic diagram is shown in Fig. 5.

　　    4 points for attention

4.1 tension

In the embedded spinning, the tension on the staple fiber is an important parameter. If the tension is too high, the fiber will slip, causing the yarn to deteriorate. Under the condition of fixed position of filament and staple fiber and tension on single yarn, the tension of staple fiber bar depends on the tension of filament. Obviously, there must be a certain amount of pre tension on the filament inserted into the filament, so that the tension on the short fiber must not damage the evenness. However, it should be noted that when the tension on the filament is large enough, filament and twisting yarns are in a straight line, that is, the angle between them is zero. The tension on the short fiber must be zero. The original symmetrical twisting will become wrapping, that is, the short fiber will wrap around the long silk.

4.2 twists and turns

When the two component twist is inserted, the tension on the short fiber will be used to twist the torque of the component. If the tension on the component is zero, it means that the fibers on the component can not be twisted back. This condition can avoid the transfer of the outer layer in the twisting fibers, reduce the hairiness, but also make the radial pressure between the fibers very small, and the fibers are not tightly clasped, and the fiber bands are easily broken. Obviously, it is necessary to have some tension to twist the fiber bar to increase the cohesion between the fibers.

4.3 angles

The tension of the spinning is fluctuating, and the size and angle of the two trigonometric regions are constantly changing. The broken ends in spinning are mostly due to the excessive tension on the short fiber bar, and the insufficient cohesion between the fibers to resist tension. The tension on the staple fiber decreases with the decrease of the angle between the filament and the single yarn, and increases with the increase of the angle between the whisker and the single yarn. That is to say, in order to avoid breakage of staple fibers, the angle between filament and single yarn is small.

5 Conclusion

The biggest feature of embedded spinning is that the content of short fiber and the shortest length of fiber are relatively loose, which provides a new way for the use of short fiber raw materials. Moreover, the use of embedded spinning has less yarn hairiness and evenness. The application of embedded spinning provides the possibility for the rational use of low grade raw materials to spin high-grade products. (author: Fang Lei)