JPH0390636A - Method and apparatus for false twist cotten spinning - Google Patents

Abstract

PURPOSE: To provide the subject method to obtain higher-quality and uniform yarns through respectively specifying the draft ratio for a drafting unit and a false twister and the 2nd draft ratio for the drafting unit and a pair of draw off rollers. CONSTITUTION: This method comprises the following scheme and practice: a spinning arrangement 50 is made up mainly of a drafting unit 51, a yarn guiding element 55, a mechanical false-twisting device 58, and a pair of draw off rollers 59; the ratio of the draft ratio as the ratio of the speed of a sliver 60 at the mechanical false-twisting device 58 to that when the sliver 60 passes through the pair of front rollers 54 of the drafting unit 51 to the draft ratio as the ratio of the yarn speed at the pair of draw off rollers 59 to that when the sliver 60 passes through the pair of front rollers 54 is set so as to produce high spinning tension between the nip line of the pair of front roller 54 and the mechanical false-twisting device 58; thereby, in the triangle for spinning a sliver 60, vibrations are limited to only within a slight range along the nip line of the pair of front rollers 54.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for false twisting a spinning material supplied as a sliver, and to an apparatus for carrying out the method.

[Prior Art and Problems to be Solved by the Invention] In the above method, a plurality of outer fibers are twisted around a heated core at a pitch angle different from the heating pitch angle in the core. There must be separation between the fibers and the fibers of the core. Hans W Kra
Melliand-Textilbe by Dr. use
In the conventional spinning process known from J. Richte, January 1987, pages 7-11, the separation or division of the core fibers of the outer fibers is always influenced to some extent by the conditions in the twist insertion zone. This situation will be explained later with reference to the accompanying drawings in connection with various aspects of the false twist spinning process.

The present invention aims to provide a method and apparatus for producing yarn with better uniform quality.

[Means to solve the problem]

The objects of the invention will become clear in connection with the following description of the prior art. That is, the problems of the prior art are solved by the features of claims 1 and 3. Since the present invention creates a stable spinning triangle, i.e., the spinning triangle moves very little along the nip line of the front roller pair, the amount of outer fibers has no effect on twisting. It can be determined by the feed fibers without any slight influence.

An important aspect of such methods is that during the subsequent untwisting of the false twist, the outer fibers are arranged around the false-twisted core fibers such that the outer fibers have at least to some extent a real twist. It is to be wrapped around. All known methods for achieving this goal are based on a single principle.

Each outer fiber has one end connected to the rotating yarn, and the other portion of each outer fiber is braked such that rotation of the yarn causes the outer fiber to wrap around the false twisted core fibers. . All variants of this method are suitable for use in the new spinning method.

First, a known conventional spinning method will be described in detail with reference to the accompanying drawings.

FIG. 4 shows the air jet spinning method according to US Pat. No. 4,124,972. The explanation in this bulletin is not long, so
It can be said that this publication can be used as part of the explanation of the present application.

In FIG. 4, reference numeral 1O indicates the nip line of a pair of front rollers of a drafting device (not shown) that supplies the fiber material 12 to the spinning device 14. The spinning device 14 emerges from a guide section 16, a restraining section 1 and a twisting section 20. The twisting insert 20 has a heating chamber 22 and a plurality of air nozzles therein for creating a rotating air flow, whereby the fibrous structure 24 rotates within the guide section 16 about its own longitudinal axis. After leaving the heating chamber 22, the rotation of the plurality of fibers is largely eliminated based on the principle of false twisting, forming a substantially untwisted core portion. Some of the twist of the core portion is transferred to a plurality of fibers that wrap around the false twisted fiber structure 24 within sections 16, 20 at a pitch angle that is different from the pitch of the fibers of the core portion. Downstream of the draw roller 28, these outer fibers continue to wrap around the fibers of the core portions, determining the strength of the final spun yarn 26 drawn by the draw roller 28.

The fibrous material 12 supplied by the drafting device is a slightly compressed sliver in which the constituent fibers are arranged substantially in parallel at the nip line 10 .

The plurality of fibers must be combined to form a fiber structure organized into spinning triangles 30 by propagation of the twists of the false twisted core portions. Such fibrous structures must have sufficient strength to withstand spinning forces. The conditions for the spinning triangle 30 will be explained below with reference to FIGS. 6A to 6E. Before explaining these, the spinning conditions in another modification of the air jet spinning method will be explained with reference to FIG. 5. In FIG. 5, parts having substantially the same effect as in the example of FIG. 4 are given the same reference numerals as in FIG. 4.

The method shown in FIG. 5 corresponds to the description of FIG. 5 of US Reapplication No. 31,705. The fiber materials (2) on the nip line 10 of a drafting device (not shown) are combined to form a fiber structure 24A by the propagation of the twists of the false twisted yarns. and a heating chamber 34.The apparatus shown in FIG. The second false-twisting device 36 differs from the device shown in FIG. 4 in that it is disposed between the false-twisting device 32 and the draft device.
Create a twist that gives the opposite effect to that produced by.

As disclosed in U.S. Re. Pat. Allowing the development of outer fibers. This effect of the first false twisting device 32 is to be created by ballooning within the heating chamber 38, and for this purpose the inlet 40 and outlet 42 of the heating chamber 38 are arranged to create a ballooning node. must be narrowed to There is no need to discuss here whether this explanation of the effect of the second false twist device 36 is completely accurate.

The conditions in heating chamber 22 and heating chamber 32 will first be described in detail. The heating chamber of US Pat. No. 4,124,972 and the heating chamber of US Pat. No. 31,705 are not the same.

Therefore, the same reference numbers are not used here. However, if they are between the heating chamber and the drawing roller 28,
6. Regarding forming a spiral in 26A,
must act in the same way. Without this spiral movement, there is no rotation of the core portion of the yarn and therefore no propagation of twist in the core portion to the point where the spinning triangle 30 occurs.

Nip line 10 to allow spiral movement
It is necessary to limit the tension in the fiber structure with the pull-out rollers for two days. This fact can be seen, for example, in German patent 20.
As disclosed in No. 42387, it has been recognized relatively early. In newer spinning methods using false twist spinning, instead of an air jet twist insertion device, e.g. DE 34 37 343 and DE 3 639
Mechanical devices have been used, as disclosed in No. 031.

In such a method, it is necessary to create a tension in the fiber structure to create a twist in the core section, i.e. to create a ballooning by means of a toe twist insertion device, which is only possible by reducing the tension in the fiber structure. In order to do this, the inlet of the false twisting device must be narrowed to ensure that the ballooning forms a knot, which is arranged downstream of the drafting device, as described below.

6A-6E for the apparatus shown in FIG. 4 and 7A for the apparatus shown in FIG. Figure and 7th
This will be explained below with reference to Figure B. In FIG. 6A, the guide member 16 of the spinning device, the rainbow pline 10. Fibrous material 12 and spinning triangles 30 are shown. The guide member 16 is the sixth
Although omitted in Figures B to 6E, Figures 6A to 6A
FIG. 6E shows the situation at different times in the same spinning device. Assume that the draft device is feeding a plurality of fibers at a predetermined width at the nip line 10.

Most of the fibers in the plurality of fibers 12 are incorporated into a portion of the false twisted core within the spinning triangle 30. In the following explanation, it is assumed that the end fiber F is separated from the spinning triangle at the right end of the fiber supply width S. The end fibers F enter the inlet of the guide member 16 in a spiral state due to the suction air flow. The guide element 16 is constructed in such a way that the front end K of the end fiber F in the spinning direction is guided over the spinning triangle of the false twisted core section. Then, as shown in FIG. 6B, the front end of the end fiber F engages with the rotating fiber structure and begins to wrap around the fiber structure.

The other end of this end fiber (outer fiber) is then held temporarily on the nip line, as disclosed in more detail in US Pat. No. 4,124,972.

As a result, the portion of the end fiber F that has not yet engaged with a portion of the core increases its angle with the spinning direction and moves toward the spinning triangle, as shown in FIG. 6C.

This action will create the required difference between the pitch angles of the fibers of the core portion and the wrapped fibers. The rotation of a portion of the core has been intentionally omitted from FIGS. 6A-6E in order to explain the winding behavior in detail.

Finally, the remaining part of the end fiber F is pressed against the spinning triangle and incorporated into the spinning triangle (Fig. 6D);
Alternatively, the ends of the end fibers F are released from the nip line 10.

If the end fibers F are extremely short and are not released from the nip line very quickly, the tension applied to the end fibers F will cause the fiber structure 24 to move over the initial feed width shown in FIG. 6A. 6C and 6D in the direction toward the still gripped end of the end fiber F as shown in FIGS. 6C and 6D. As a result, the spinning triangle becomes asymmetrical, as shown in Figure 6D. This asymmetry, as shown in Figure 6D,
It serves to provide the spinning triangle with conditions suitable for producing end fibers R at the left end of the feed width S. U.S. Patent No. 41249
In the method according to No. 72, therefore, the fiber structure 2
4 is given vibration in both directions of its supply width S, as shown in FIG. 6E. This vibration, ie side-to-side movement, is extremely important for producing a plurality of end fibers in this type of method. Note that the horizontal movement of the spinning triangle is influenced by the degree of decrease in the tension of the fiber structure 24. Thread 2
The tension exerted by the pull-off roller 28 on the spindle 6 must not exceed a predetermined value so that the conditions for the formation of spinning triangles are not adversely affected.

The conditions in the method shown in FIG. 5 are clearly different from those shown in FIG.
suppresses the vibration at the top of the

Also, in a device of the type shown in FIG. 5, there is no free end of the end fibers that is moved up to a portion of the rotating core. In the apparatus of FIG. 5, the foot of the end fiber RF must be previously engaged into the spinning triangle 30, as shown in FIG. 7A, otherwise this end fiber will Upon leaving the line 10, it will be lost during spinning as fluff. As shown in FIG. 7B, the false twisting device 3 is attached to the head end of the end fiber RF by the moving movement of the fiber structure 24A.
must be drawn into 6. This false twisting device 3
In 6 the free portion of the end fiber is stretched by friction with the passage wall. Using compressed air, a swirling air stream is created through the holes 38 of the false twister to deflect the free ends of the end fibers RF' in the direction of yarn travel. and end fiber RF'
wraps around a rotating core portion in the opposite direction to the rotational direction of the core portion. In this case the spinning triangle 30 remains stable and symmetrical. These conditions are created by the narrow inlet 40 and the narrow vicinity of the inlet 40 closer to the apex of the spinning triangle 30.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The false twist spinning method and device thereof according to the present invention will be described in detail below with reference to the accompanying drawings showing an example of the device.

FIG. 1 shows a first embodiment of an apparatus for implementing the novel spinning method, and FIG. 2 shows a second embodiment thereof.

Substantially the same reference numerals are used for identical elements of each device shown in FIGS. 1 and 2. The spinning device 50 mainly consists of a drafting device 51 , a guiding element 55 , a mechanical heating element 58 and a pair of drawing rollers 59 . The draft device 51 includes a pair of back rollers 52, an apron type draft device 53, and a pair of front rollers 54. In the device shown in FIG. 1, the guide element 55 has a nozzle 55A with a funnel-shaped inlet and a nozzle passage 56. In the device shown in FIG. Multiple horizontal holes 57A
is located directly below the end of the funnel-shaped inlet and is connected to a negative pressure source (not shown) for suction. A plurality of inclined holes 57B are arranged downstream of the suppression zone 56A of the nozzle passageway 56. Mechanical heating element 58 consists of two discs 58A
The two disks 58A are arranged in parallel planes with overlapping areas and are rotatable in opposite directions. As a result, two disks 5
The sliver passing between 8A is rotated by friction in the shaded area in FIG. 1 and spun into yarn 61. The guide element 55 of the device 50 shown in FIG. 2 has a nozzle 55B with a continuous unidirectional nozzle passage 56;
A plurality of holes 57B are provided inclined toward the nozzle passage 56, and the holes 57B intersect at an obtuse angle with respect to the direction of movement of the yarn.

The mechanical heating element 58 of the device shown in FIG. 2 consists of two aprons 58B running in opposite directions, the aprons 58B being endless and driven on two rollers (not shown). . The sliver passing between the surfaces of the two aprons is rotated and tensioned in the friction area shaded in FIG. The two main drafts in the actual spinning zone are the draft ratio d1, which is the ratio of the speed VD at the mechanical heating element 58 to the speed when the sliver 60 passes through the pair of front rollers 54 of the drafting device 51; Draft ratio d2, which is the ratio of yarn speed ■ at the pair of drawer rollers 59 to ■
It is. The ratio of dl:dz for the two draft ratios is determined such that a high spinning tension is generated between the nip line of the pair of front rollers 54 and the mechanical heating element 58. Applying a high spinning tension ensures that the spinning triangle 30 (FIG. 3) of the sliver 60 oscillates only to a very small extent along the nip line of the pair of front rollers 54. do. The advantage of forming a partially stable spinning triangle is that it can clearly be expected to have an effect on the stability of the spinning conditions. Substantially all of the fibers fed over the length SD in the nip line 10 reach a portion of the core where they are to be heated.

Fibers F+ and Fz supplied to the outside of length SD are end fibers,
That is, the outer wrappings are used as fibers. Wrapping near the spinning triangle 30 provides optimal conditions for fiber deposition. These optimal conditions depend on the fiber length of the particular fiber material used and the ratio between the draft ratio d1 and the draft ratio 42 in the spinning device. Also, the distance between the entrance of the passage 56 of the guide element 55 and the nip line 10 is 6 times the average fiber length of the raw material fibers to be spun.
It has been shown that a range of 0% to 75%, more preferably 68% to 72%, gives satisfactory results.

Advantageously, the draft ratio d is greater than 1 and the draft ratio d2 is s'l, such that a spinning tension of at least 1.5 CN/lex is generated. Spinning triangle (
The size and shape of FIG. 3) are determined by the spinning tension (yarn tension). However, the number of end fibers can be determined independently of the total feed width B of the sliver delivered from the drafting device.

[Brief explanation of drawings]

FIG. 1 is a side view showing a first embodiment of the apparatus for implementing the novel spinning method according to the present invention, and FIG. 2 is a side view showing a second embodiment of the apparatus for implementing the novel spinning method according to the present invention. 3 is a side view showing an example, FIG. 3 is a front view illustrating the conditions of the spinning triangle in the novel spinning method shown in FIGS. 1 and 2, and FIGS. 4 to 7 are conventionally known spinning methods. FIG. 4 is a diagram illustrating the spinning conditions in the first false twist spinning method, and FIG. 5 is a diagram illustrating the spinning conditions in the second false twist spinning method. FIGS. 6A to 6E are diagrams explaining the behavior of a plurality of fibers in order when using the first false twist spinning method shown in FIG. 4, and FIGS. Figure 7B is the fifth
It is a figure explaining the behavior of a plurality of fibers when using the 2nd false twist spinning method shown in a figure. 10... Nip line, 30... Spinning triangle,
50... Spinning device (present invention), 1... Draft device, 5... Guide element, 9... Pulling roller, ■... Yarn. 54... Front roller, 58... Mechanical heating element, 60... Sliver,

Claims (1)

[Claims] 1. Spinning raw material supplied as one sliver (60) using a draft device (51), at least one mechanical false twisting device (58) and a pair of drawing rollers (59) A first draft ratio (d_1) between the draft device (51) and the false twist device (58), and a second draft ratio between the draft device (51) and the pair of pull-out rollers (59). (d_2)
, a high spinning tension is created between the nip line (10) of the front roller (54) of said drafting device and the false twisting device (58), so that the false twisted sliver (60) passes through at least the false twisting device (58). A fiber guiding element (5
5) A method for false twisting a spinning material, characterized in that the area between the nip line (10) and the nip line (10) is adjusted to prevent it from taking a spiral shape. 2. The first draft ratio (d_1) is greater than 1 and the second draft ratio (d_2) is approximately 1, such that the spinning tension is at least 1.5 CN/tex. Method described. 3. A false twisting spinning apparatus for carrying out the method of claims 1 and 2, comprising a draft device (51), a guide element (55) and a pair of drawing rollers (59), wherein said guide element (55) is used for twist production. A false twist spinning device characterized by having nozzles (55A, 55B). 4. Device according to claim 3, characterized in that the twisting nozzle (55A, 55B) has a funnel-shaped inlet. 5. A suppression zone (
5. Device according to claim 4, characterized in that a restraint zone (56A) is provided, the suppression zone (56A) having a diameter substantially smaller than the diameter of the longitudinal passage (56) of the nozzle. 6. Device according to claim 5, characterized in that a plurality of transverse holes (57A) communicating with a source of negative pressure are arranged upstream of the suppression zone at the funnel-shaped inlet. 7. The twisting nozzle (55B) has a one-way continuous passage (56) which is a cylindrical through hole, and in the passage (56),
4. Device according to claim 3, characterized in that it is provided with a plurality of holes arranged at an angle oblique to the direction of thread travel. 8. The passageway (56) of the twisting nozzle (55A, 55B)
) and a pair of front rollers (54) of the draft device.
) is between 60% and 70% of the average fiber length of the sliver (60) to be spun.
8. Device according to any one of claims 3 to 7, characterized in that the %, more preferably between 68% and 72%. 9. The mechanical false twisting device (58) comprises two counter-rotating disks (58A), the two disks (58A) having a plane substantially parallel to the direction of yarn movement. 9. The device according to claim 3, wherein the devices are arranged in a friction region and are brushed against each other in the friction region. 10. Claim 9, characterized in that said disc (58A) is made of an elastic material, preferably polyurethane.
The device described. 11. The mechanical false twisting device (58) is two intersecting aprons (58B) driven in opposite directions, and the aprons (58B) are arranged obliquely in the running direction of the yarn and are spun. 9. Device according to claim 3, characterized in that the respective sliver (60) passes between intersecting planes of the two aprons.