CZ303824B6 - Method of drafting fiber bundle when spinning and apparatus for making the same - Google Patents

Abstract

As opposed to a drafting method employing thrust of a fiber bundle by a pressure roller to a drafting roller, the drafting of a fiber bundle (30) according to the present invention is carried out by antiskid retention by retention means (21, 22) on the periphery of an internal drafting roller (3, 4, 32, 33, 34, 42, 43). The drafting retention force is generated by embracement of the internal drafting roller (3, 4, 32, 33, 34, 42, 43) by the fiber bundle (30) in a contact section (35, 38, 39, 44, 45, 54) thereof. At least one drafting roller (3, 4, 32, 33, 34, 42, and 43) has antiskid retention means (21, 22) on its circumference in the form of small points. The drafted fiber bundle (30) is in the drafting field (A, B, C, D) in contact with the internal drafting rollers (3, 4, 32, 33, 34, 43, and 44). Drawing force causes drafting of the fiber bundle (30). Efficiency of the contact section (35, 38, 39, 44, 45, 54) increases by lengthening the embracement of the drafting roller by the fiber bundle (30) in excess of 25 degrees or by reverse direction (R) of rotation of some of the internal drafting rollers (3, 4, 32, 33, 34, 43, 44).

Description

Technical field

BACKGROUND OF THE INVENTION The present invention relates to the drawing of a fiber bundle on a spinning machine, in particular a sliver and a yarn, which are stretched to the desired linear weight and subsequently twisted to stretch the fiber bundle in the yarn.

BACKGROUND OF THE INVENTION

The stretching devices vary according to the type of fiber being processed and the spinning technology. The most widespread is the prestretch device with the prestretch rollers. Its basic function is to accelerate the fiber bundle by the tensile force caused in the line by the pressure of the pressure rollers on the stretch rollers that rotate at a gradually increasing speed. A small proportion of the so-called floating fibers contribute to the unevenness of the flow, which are uncontrolled between their lines of stretch rollers and move under the effect of mutual frictional forces between the flowing fibers. Cotton fibers have variable staple length. It is therefore necessary to adjust the length of the stretch field by adjusting the stretch rollers with respect to the longest fibers in order to prevent them from tearing at the same downward pressure in the adjacent line. In the prestretch field, the necessary fine pressure of the fibers is accelerated by mutual frictional forces. To control the movement of the fibers in the stretch field, a flat pressure using a soft strip, also called a strap, or a cuticle, is used to wrap the stretch and / or pressure rollers. The arrangement of the prestretch device with stretch strips suits the ring spinning technology. By simultaneous development of the air jet spinning technology, the spinning speed has been increased 20-fold, further using roller stretchers using stretch strips. They heat up and wear quickly at winding speeds of 400 to 500 m / min. Therefore, new ways of stretching are being sought which would better suit new spinning technologies. In order to achieve a satisfactory yarn quality and tear, fiber patterns of selected cotton types are usually prepared for jet spinning and with the removal of short fibers by the added combing technology. The spinning rotor spinning technology uses a combing roller from the sliver to prepare the linear weight of the yarn and the flow of loose fibers is combined to the desired linear weight by cycling in the spinning rotor.

SUMMARY OF THE INVENTION

During spinning, the fiber bundle is refined by stretching to the desired linear weight with a pulling force. The solution according to the invention, instead of pressing the fiber bundle with the pressure roller on the stretching rollers, draws through the stretching forces caused by the retention means on the circumference of the stretching roller. The retention means at least partially penetrate between the fibers and prevent the fibers from slipping along the circumference of the stretch roller in the touch section with an increased wrap angle. The wrap angle is preferably increased above 25 ° of the fiber bundle in the stretch field between the stretch rollers, preferably over an arcuate friction surface, which exerts a radial pressure on the fibers and imparts desirable interfiber friction contributing to uniformity of passage and presses the fiber bundle onto the retention means. Increasing the length of wrap of the stretch rollers and thus their pulling force is achieved by changing the direction of rotation of one of them. The elongation in the stretch field according to the invention is controlled by a rotating friction roller which is in frictional contact with the fiber bundle in the stretch field, preferably at a peripheral speed close to the speed of the fibers to be stretched, affecting their friction properties.

To increase the uniformity of the frictional forces, the elongated fiber bundle is guided along a stable friction surface through a lateral guide to narrow the fiber bundle in the direction of elongation.

-1 CZ 303824 B6

Between adjacent stretching rolls there is a stretching field whose length is the distance between the extreme contact of the fiber bundle with the circumference of adjacent stretching rolls. In a stretch with retaining means on the circumference of the stretch rollers, the length of the stretch field may be shorter than in a roll stretch with a fiber bundle pressure in the line of the stretch rollers. The retention means acts on the fibers coming into frictional contact with them gradually increasing in intensity. Therefore, there is no sudden stretching and eventual tearing of the longest fibers in the elongated fiber bundle. By shortening the stretch field, the frequency of the floating fibers is reduced, which has a favorable effect on the uniformity of the stretch and thus on the uniformity of the yarn.

Overview of the drawings

Fig. 1 shows a four-roller stretcher with a vertical bottom-up stretch with stretcher rollers 2, 3, 4, 5 and pressure rollers 6, 7 for pressing the fiber bundle 30 onto the stretcher inlet roller 2 and the stretcher exit roller 5. Inner stretcher rollers 3 4 have retaining means 21, 22 on their periphery.

Fig. 2 shows a four-roller prestretch device with prestretch rollers 2, 3, 4, 15 arranged in an arc 33 and thrust rollers 6, 60 on the prestretch inlet roller 2 and the prestretch outlet roller 20 stitches 15. Between the prestretch inner rollers 3, 4 with fiber bundle touches the driven friction roller 24.

Fig. 3 shows a five-roller prestretch device with inner prestretch rollers 2, 5, 32, 33, 34, two of which 32, 34 have the opposite direction of rotation R. The stretching direction is from top to bottom.

In Fig. 4, a four-roll 2, 5, 42, 43 stretcher is provided with one stretch roller 43 having the opposite direction of rotation R and one friction support surface 9 in the stretch field A. The direction of stretching is from top to bottom.

DETAILED DESCRIPTION OF THE INVENTION

In Fig. 1 there is a prestretch device with four prestretch rollers 2,3,4, 5, wherein the thrust rollers 6, 7 press the fiber bundle 30 onto the prestretch inlet roller 2 in the direction 36 and the prestretch outlet roller 5 in the direction 37 by a mechanism (not shown). their peripheral velocities are the total throughput of the fiber bundle 30. The pressure roller 6 has an elastic coating 61 on its periphery. In the vertical frame 1, stretch rollers 2, 3, 4, 5 for a single-spinning unit with a jet spinning and unit winding unit are not shown. a cross spool located at the top of the spinning machine. The fiber bundle 30, for example in the form of a sliver, is clamped onto the prestretch inlet roller 2 in the direction 36 with the pressure roller 6 on the arm 17 and is further guided through the prestretch field A along the friction surface 11 to the inner prestretch roller 3 with the retaining means 21 machined. The contact of the fiber bundle 30 with the circumference of the extensible inner roller 3 is in the contact section 54 as it wraps its circumference. In another prestretch field B, the fiber bundle 30 directs the baffle 13, especially when initiating the spinning process along the friction surface 10, to the inner prestretch roller 4 with which it contacts in the contact section 44. The periphery of the prestretch roller 4 has retaining means 22 with spikes in the form small needles.

Further, the fiber bundle 30 is guided through a friction surface 9 with grooves 29 which narrows in the direction of passage of the fiber bundle 30 in accordance with the thinning thereof and is rectified by a baffle 12. The fiber bundle 30 leads into a groove at the exit of the stretch field C. 23 in the prestretch roller 5, in which in the direction 37 the elastic ring 20 rests on the thrust roller 7 on the arm 18, which presses the thrust roller 7 to the outlet prestretch roller 5 by a circumferential profile 71 coincident with the groove 23.

-2GB 303824 B6

In Fig. 2 there is a four-roller 2, 3, 4, 15 prestretch device having the prestretch rollers arranged in an arc 63 to enlarge the contact sections 35, 45 of the fiber bundle 30 with the inner prestretch rollers 3, 4 with retaining means 21, 22. The fiber bundle 30 with the pressure roller 6 with the elastic coating 61 presses in the direction 36 against the inlet prestretch roller 2 and is guided in the first prestretch field A on the friction pad H and in the second prestretch field B is in frictional contact in the contact section 55 with the rotating friction roller 24. The exit prestretch roller 15 has a cylindrical periphery and a compression roller 60 with a resilient coating 61 is pressed against it in a direction 37 by a mechanism (not shown).

In Fig. 3 there is a five-roller 2, 5, 32, 33, 34 stretching device having a fiber bundle thrust 30 on the prestretch inlet roller 2 by a thrust roller 6 and on the outlet prestretch roller 5 by a thrust roller 7. Inner prestretch rollers 32. 33, 34 they have retaining means (not shown) on the circumference, for example, a tapered anti-slip of the fiber bundle 30 in the contact section 38, 39. The extensible inner rollers 32, 34 have the opposite direction of rotation R relative to the other extensible rollers 2, 5, 33. 61. The stretch device is oriented vertically with the exit of the fiber bundle 30 downward, where the spinning device is, for example, annular, including the yarn winding device.

In Fig. 4, there is a four-roller 2, 5, 42, 43 stretching device having a fiber bundle thrust 30 on the inlet prestretch roller 2 by a pressure roller 6 in the direction 36 and on the outlet prestretch roller 5 by a pressure roller 7 in the direction 37. The inner prestretch roller 43 has the opposite direction of rotation R relative to the other prestretch rollers 2, 5, 42. In the prestretch field A, the arcuate friction pad 9 of the fiber bundle 30 with the contact section 40 is stretched. 5, 42, 43 have contact portions 38, 39 and between them the fiber bundle 30 extends in the stretch fields B, C. The prestretch device is oriented vertically with the fiber bundle outlet 30 downward.

Claims (9)

PATENT CLAIMS A method of drawing a fiber bundle (30) during spinning, wherein the fiber bundle (30) is thinned by stretch rollers (2, 3, 4, 5, 32, 33, 34, 42, 43) with progressively higher peripheral speed in the direction of travel the fiber bundle (30) from the inlet prestretch roller (2) through the contact portions (35, 38, 39, 44, 45, 54) of the internal prestretch rollers (3, 4, 32, 33, 34, 42, 43) to the outlet prestretch roller (5, 15), wherein the linear weight of the fiber bundle (30) for spinning is adjusted by the ratio of the peripheral velocities of the inlet to the exit prestretch roller (2,5), characterized in that the fiber bundle (30) extends in at least one prestretch field (5). A, B, C, D) stretch rollers (3, 4, 32, 33, 34, 42, 43), at least one of which is provided with retaining means (21, 22) on its periphery, which in the contact section (35, 38) , 39, 44, 45, 54) prevent the fiber bundle fibers (30) from slipping freely. Method for drawing a fiber bundle (30) according to claim 1, characterized in that the retention means (21, 22) in the contact section (35, 38, 39, 45) with the fiber bundle (30) penetrate at least 25 ° of wrapping between fibers of the fiber bundle (30), where they prevent the fibers from slipping freely in the circumferential direction. Method for drawing a fiber bundle (30) according to claim 1, characterized in that in at least one prestretch field (A, B, C, D) the fiber bundle (30) is in frictional contact in the contact section (55) with the rotating friction with a roller (24). -3GB 303824 B6 • 5 liters j j j Method for drawing a fiber bundle (30) according to claim 1, characterized in that Although the fiber bundle (30) is inspected on the inlet prestretch roller (2) with a pressure roller j (6) with a cylindrical flexible coating (61) and on the outlet prestretch roller (6). 5, 15), the fiber bundle (30) is inspected by an elastic coating (61) or by an elastic coating (20) with a peripheral profile (71) corresponding to the peripheral profile of the groove (23) against which the fiber bundle (30) is pressed against roller (7). Method for drawing a fiber bundle (30) according to claim 1, characterized in that: A method according to claim 1, characterized in that the fiber bundle (30) is guided in at least one stretch field (A, B, C, D) over a stable friction surface (9, 10, 11). Method for drawing a fiber bundle (30) according to claim 1, characterized in that on at least one friction surface (9, 10, 11), the fiber bundle (30) tapers laterally in its direction of elongation in its groove-shaped lateral guide (29). consistency with its thinning. Method for drawing a fiber bundle (30) according to claim 1, characterized in that the at least one inner prestretch roller (3, 4, 32, 34, 43) has a reverse rotation direction (R) than the inlet prestretch roller (2). 20 May Device for drawing a fiber bundle (30) for carrying out the method according to claims 1 to 7, characterized in that the inlet prestretch roller (2) bears a pressure roller (6) and the outlet prestretch roller (5, 15) bears a pressure roller (7, 60) and at least one inner prestretch roller (3, 4, 32, 33, 34, 42, 43) has retaining means (21, 22) on its circumference to prevent the fibers of the fiber bundle (30) from slipping freely. A fiber bundle drawing device (30) according to claim 8, characterized in that the exit stretch roller (5) has a groove (23) on its periphery, which abuts with the same The elastic ring (20) of the pressure roller (7) also has a circumferential profile (71).