JPH0261116A - Production of spun yarn having two-layered structure - Google Patents

Abstract

PURPOSE:To feed a sliver for a sheath without twisting and obtain the subject spun yarn without exposing fibers in the core part by predrafting the sliver for the sheath between a guide roller and back rollers for drafting of a roving machine. CONSTITUTION:A sliver (A) for a sheath is taken from a can 1 through a guide roller 2 by feed rollers (7a) and (7b) and slightly predrafted between the feed rollers and back rollers (34a) and (34b) of a drafting part 3 to eliminate the twisting thereof. The sliver for the sheath or fibers in a fleece in the drafting part are equalized parallel to completely cover a roving (B) for the core part with the sheath fibers to afford a roving (Y) without exposing the fibers in the core part.

Description

Detailed Description of the Invention (Industrial Application Field) This invention provides a method for producing a two-layer spun yarn comprising two types of stables, one forming a core and the other forming a sheath layer. It is related to.

(Prior Art) Many methods are known for producing a two-layered spun yarn. For example, in Japanese Patent Application Laid-Open No. 55-116824, a sliver for a sheath is supplied to a draft back roller of a rover, a fiber bundle for a core is supplied in front of this back roller, and the sliver for a sheath is These are stacked on top of each other, drafted and heated to obtain a two-layered roving, which is then drafted with a spinning machine and heated to produce a two-layered roving. It is disclosed that the spun yarn is made of In. Also, JP-A-58-4191
Publication No. 6 discloses that when the sliver for the sheath and the fiber bundle for the core are overlapped on the roving frame, drafted, and then heated as described above, a guide is provided between the front roller and the flyer 4, By fully contacting the sheath fiber group that has come out of the front roller with the guide and bringing one end in the width direction into contact with the guide earlier and more strongly than the other end to delay heating, the core yarn portion is brought into contact with the sheath. It is disclosed that wrapping with a group of fibers for

(Problems to be Solved by the Invention) In all of the above conventional techniques, the sliver for the sheath, which is coiled and filled in the can at the rear of the roving frame, is pulled up as it is, and passed through a guide roller to the back of the draft section. Since the sheath sliver is fed to the roller, the sheath sliver enters the back roller without being untwisted in the coil. The above twist occurs once for every turn of the coil in the can, and the twisting period is 0.001 for an 18-inch can.
It is 95m long and 1m long for a 20 inch can, which is relatively short.

As a result, the draft force fluctuates greatly between the back roller and the third roller in front of it, making the width of the fleece non-uniform. There was a problem in that the covering of the core fiber bundle was incomplete and the core fiber bundle was exposed. In addition, in order to improve the above-mentioned covering and prevent the core fiber bundle from being exposed, a guide is provided in front of the front roller to prevent the sheath fiber group (fleece) from being exposed. The method of completely enveloping the core fiber bundle by heating one side later than the other side is to ensure that the distance from which the sheath fleece exits the front roller until it is wrapped around the core fiber bundle is It is shorter on one side and longer on the other side, and the contact pressure with the above guide is stronger on one side of the fleece.

Since the tension of the fleece is made to be weaker on the other side, it is difficult to manage the tension of the fleece, and since the sheath fleece is wrapped around the core fiber bundle to make roving, this roving is fed to the spinning machine and drafted. There was a problem in that the draft during spinning was difficult and it was not possible to spin fine yarn.

This invention provides a sheath sliver without twisting to the back roller of the draft section of a roving frame, thereby making the width of the fleece uniform, completely covering the core fibers with the sheath fibers, and ensuring that the core fibers are not exposed. The aim is to obtain a spun yarn with a layered structure.

(Means for Solving the Problems) In order to solve the above problems, the present invention supplies a sheath sliver pulled up from a can at the rear of the roving frame to a draft back roller via a guide roller, and the back roller A roving or sliver for the core is supplied in front of the sliver and layered on the sliver for the sheath, these are drafted and heated to obtain a roving, and this roving is supplied to a spun yarn to separate the core and this sliver. In the method for producing a two-layer spun yarn consisting of a sheath covering a sliver, a slight pre-draft is applied to the sheath sliver between a guide roller and a drafting back roller of the roving frame. It is characterized by eliminating twist.

A means for giving a draft to the sheath sliver going from the guide roller to the back roller of the roving frame is to provide a set of supply rollers consisting of a bottom roller and a top roller between the guide roller and the back roller, and Examples include a method of applying a draft between the supply roller and the back roller, or a method of providing two sets of supply rollers between the guide roller and the back roller and applying a draft between the two sets of supply rollers. 6. The bottom roller may be either a striped roller similar to the bottom roller for drafting or a roller with a smooth surface, and the top roller may be a rubber roller or a metal roller. In this case, the size of the pre-draft is 1.01 to 1
．． 0111 is preferred.

(Function) The sheath sliver is drafted from the guide roller at the rear of the roving machine to the draft back roller, and its twist is eliminated, so that the sheath sliver or fleece fibers in the draft section are made parallel and even, and their width is It becomes uniform. Therefore, a roving can be obtained in which the core fibers are completely covered with the sheath fibers and the core fibers are not exposed. Please note that the pre-draft is 1. A roving with a preferable two-layer structure can be obtained by setting the value to 1.08, whereas if it is less than 1.01, twist removal will be insufficient, and if it exceeds 1.08, incorrect draft will occur and unevenness will occur. Cause.

(Example) The drawing shows an example of a roving frame used in the present invention. In this figure, 1 is a can, and a sliver A for the sheath
The sheathing sliver A is wound into a coil, filled, and placed on the floor at the rear of the roving frame, and this sheath sliver A is pulled up through the guide roller 2 at the rear of the roving frame, drafted by the drafting section 3, and then sent to the front section of the roving frame. The roving Y is heated by a flyer 4 and wound around a bobbin 5. The draft section 3 includes front rollers 31a, 31b and a second roller 32.
a, 32b, third rollers 33a, 33b, back rollers 34a, 34b, and aprons 35a, 35b attached to the third rollers 33a, 33b, and behind the back rollers 34a, 34b there is a trumpet 6 and a pair of upper and lower supply rollers 7a. , 7b are provided, and these supply rollers 7a and 7b pull out the above-mentioned sheath sliver A from the can 1 via the guide roller 2, and further feed the trumpet 6.
It is supplied to the nip portion of the back rollers 34a, 34b of the draft section 3 through the.

Note that the above-mentioned supply rollers 7a and 7b are metal rollers in which both the top roller 7a and the bottom roller 7b are formed with smooth surfaces, and the bottom roller 7b is driven at a peripheral speed lower than that of the back rollers 34a and 34b. , on which the top roller 7a is pressed, and the back roller 34a,
34b, a slight pre-draft is given to the sheath sliver A. Above the trumpet 6, there is an upper guide roller 8 for the core roving B, and in front of it, on the side of the top back roller 34a, a roving guide 9, third rollers 33a, 33b and the back roller 34a, 34b, which has two upper and lower guide passages between it.
Step guides 10 are provided, and the core roving B is moved between the upper guide roller 8, the roving guide 9, and the second step guide 10.
The sheath sliver A is supplied to the nip portion of the third rollers 33a and 33b through the upper guide passage of the second guide 10, and is stacked on the center of the upper surface of the sheath sliver A supplied through the lower guide passage of the two-stage guide 10. A collector 11 is provided behind the front rollers 31a and 31b.

In the above structure, the sheath sliver A is the can 1
When being pulled up from the can 1, each turn of the coil in the can 1 is twisted once to generate the above-mentioned twist, and in that twisted state it moves forward and is nipped by the supply rollers 7a and 7b, and then the supply roller 7a, 7b and back roller 34a,
By being drafted between the back rollers 34a, 34b and the third rollers 33a, 33b, the above-mentioned twist is removed, and then nipped between the back rollers 34a, 34b and the third rollers 33a, 33b. The roving B is overlapped with the core roving B at the nip between the third rollers 33a and 33b. and.

The core roving B and the sheath sliver A stacked one above the other are moved between the third rollers 33a, 33b and the second roller 3.
A main draft is simultaneously applied between the rollers 2a and 32b, and a front draft is applied between the second rollers 32a and 32b and the front rollers 31a and 31b.
Thereafter, it is sent out from the front rollers 31a and 31b and wound onto the bobbin 5 while being heated. Note that second supply rollers 7c and 7d may be provided behind the supply rollers 7a and 7b, and a draft may be applied between them to remove twisting of the sheath sliver A.

Cotton sliver (average fiber length 28
I, thickness 300 gelen/6 yards) is pulled up from the can 1, guided through the guide roller 2 to the nip between the supply rollers 7a, 7b, and connected to the supply rollers 7a, 7b and back rollers 34a, 34b. A pre-draft with a ratio of 1.05 is applied between the back rollers 34a, 34b and the third rollers 33a, 33b, and a brake draft with a ratio of 1.30 is applied between the back rollers 34a, 34b and the third rollers 33a, 33b. A main draft with a ratio of 5.21 was provided between the two rollers, and a front draft with a ratio of 1.05 was provided between the second rollers 32a, 32b and the front rollers 31a, 31b. On the other hand, the core roving B
As, polyester fiber roving (1! fiber cut length 38
nm, thickness 400 gel/30 yards), is supplied to the nip portion of the third rollers 33a and 33b, and overlapped on the center of the upper surface of the above-mentioned sheath sliver A. Hereafter, together with this sheath sliver A, a main draft and a front draft are used. In addition, it was then heated and wound into one roll to obtain a two-layer structure roving with a thickness of 250 gelen/30 yards, which was then fed to a spinning machine and drafted 35 times to produce a 34-count two-layer structure spun yarn. Manufactured. When a 28-gauge jersey knitted fabric was knitted using this two-layer spun yarn and the resulting knitted fabric was directly dyed, the cotton fibers in the sheath layer completely covered the polyester fibers in the core. As a result, a uniformly dyed knitted fabric with no uneven color was obtained.

On the other hand, a two-layer spun yarn of a comparative example was produced in exactly the same manner except that the supply rollers 7a and 7b were omitted,
When a cotton jersey fabric was knitted in the same way and dyed with direct dye,
Because the core polyester fiber is not dyed and this polyester fiber is partially exposed without being covered with the cotton fiber of the sheath layer, this undyed part appears as white dots on the surface of the knitted fabric. This resulted in a deterioration of the appearance.

(Effects of the Invention) This invention, when producing a two-layered roving using a roving machine, applies a draft to the sheath sliver pulled up from a can to remove twisting of the sliver, and then supplies the sliver to a draft section. Since the sliver for the sheath is drafted and heated while being overlapped with the roving or sliver for the core, the sliver for the sheath can be easily drafted and a uniform fleece in which each fiber is aligned in parallel can be obtained. Therefore, the two-layered roving obtained by the spinning machine has the core fibers completely covered with the sheath fibers, and the two-layered spun yarn obtained by feeding this roving to the spinning frame is The result is a good yarn with no exposed core fibers, and when this yarn is knitted and woven and sheath fibers are dyed, uneven dyeing will not occur even if the core fibers are undyed.

[Brief explanation of the drawing]

The drawing is a side view of an example of a roving frame used to carry out the present invention. A: sliver for sheath, B: roving for core, Y: two-layer roving, 1: can, 2 guide roller, 3 draft part, 4: flyer, 5: bobbin, 7a, 7b, 7c, 7d
: Supply roller. Patent Applicant Toyama Boseki Co., Ltd. Agent Patent Attorney Yoshi 1) Ryo Tsukasa Procedural Amendment September 20, 1988 Patent Application No. 209753 Relationship with the Invention Title Incident Patent Applicant Residence Higashi-ku, Osaka City Azuchi-cho 2-12 Name Name Toyama Boseki Co., Ltd. 4 Agent Residence Shin-Toyama Building, 2-10 Azuchi-cho, Higashi-ku, Osaka Telephone: 06 (264) 65555 Date of amendment order Issued Paper Claims [1] The sliver for the sheath pulled up from the can at the rear of the roving frame is supplied to the back roller for drafting through a guide roller, and the roving or sliver for the core is supplied in front of this back roller, and the sliver for the sheath is In the method for producing a two-layer spun yarn consisting of a core and a sheath covering the core, the roving is produced by stacking them on top of each other, drafting and heating them to obtain a roving, and supplying the roving to a spinning machine. A method for producing a two-layer spun yarn, characterized in that a slight pre-draft is applied to the sheath sliver between a guide roller and a back roller to remove twisting of the sheath sliver.

Claims (1)

[Scope of Claims] [1] The sliver for the sheath pulled up from the can at the rear of the roving frame is supplied to a back roller for drafting via a guide roller, and the roving or sliver for the core is fed in front of this back roller. The slivers are supplied and stacked on the sheath sliver, drafted and heated to obtain rovings, and the rovings are supplied to a spinning machine to produce a two-layered spun yarn consisting of a core and a sheath covering it. A method for producing a two-layer spun yarn, characterized in that a slight pre-draft is applied to the sheath slide between a guide roller and a back roller of the roving machine to remove twisting of the sheath sliver. manufacturing method.