US3556030A

US3556030A - High bulk yarns

Info

Publication number: US3556030A
Application number: US785254A
Authority: US
Inventors: Philip J Stevenson
Original assignee: Monsanto Co
Current assignee: Monsanto Co
Priority date: 1968-12-19
Filing date: 1968-12-19
Publication date: 1971-01-19
Anticipated expiration: 1988-01-19

Abstract

A high density bulked yarn having a bulk density of less than 0.050 g/cm3 is formed by stitching a matt comprised of bulkable synthetic continuous filaments to form a plurality of aligned seams by cutting the matt between the seams to form individual yarns and subsequently bulking the synthetic filaments locked in the seams by contacting the yarns with a heated fluid. Upon being bulked, the synthetic filaments curl to cover the seam.

Description

United States Patent Philip J. Stevenson Durham, N.C. 785,254 Dec. 19, 1968 Jan. 19, 1971 Monsanto Company St. Louis, Mo.

a corporation of Delaware [72] inventor [21 Appl. No. [22] Filed [45] Patented [73] Assignee [54] HIGH BULK YARNS 7 Claims, 4 Drawing Figs.

[52] 11.5. Cl. 112/400, 28/72.17 [51] Int. Cl B3211 7/08 [50] Field of Search 1 12/400;

57/143, 139, (inquired); 28/77, 72.17, (inquired) [5 6] References Cited UNITED STATES PATENTS 1,769,970 7/1930 Silve rman Jamieson et a1.

3,175,351 3/1965 Bloch 28/7Z.17X

3,330,896 7/1967 Fujita et al..... .28/72.17X

3,377,794 4/1968 Walker Z8/72.17X

3,400,531 9/1968 Ohfuka et a1. 28/7Z.17X FOREIGN PATENTS 9/1955 Germany 57/143 Primary Examiner-Alfred R. Guest Attorneys-J. Bowen Ross, Jr., Russell E. Weinkauf and John D. Upham ABSTRACT: A high density bulked yam having a bulk density of less than 0.050 g./cm.-" is formed by stitching a matt comprised of bulkable synthetic continuous filaments to form' a plurality of aligned seams by cutting the matt between the seams to form individual yarns and subsequently bulking the synthetic filaments locked in the seams by contacting the yarns with a heated fluid. Upon being bulked, the synthetic filaments curl to cover the seam.

EPATENTEUJANIQIBYI I 3.656030 I FORMING MATT OF'CO NTINUOUS BULKABLE FILAMENTS STITCHING THE MATT LONGITUDINALLY CUTTING THE MATT BETWEEN ROWS OF STITCHES LBULKING THE FBLAMENTS TO COVER THE STITCHES F I G. 4. INVENTOR.

PHILIP J. STEVENSON ATTORNEY area BULK YARNS BACKGROUND OFTHE INVENTION 1. Field of the Invention This invention relates to a bulked yarn and, more particularly, to a bulked yarn which is made by the seaming of a/nonwoven batt of synthetic bulkable filaments and by the sub sequent cutting and bulking of the filaments.

2. Description of Prior Art Bulked yarns are well known in the art and are generally formed by heat treating bicomponent synthetic filaments. The primary disadvantages of yarns of this type is that the bulk density cannot easily be controlled and the yarns are expensive to produce. Also, yarns of this type which are comprised of a plurality of continuous synthetic filaments produce products having a silky rather that a velvetlike hand.

SUMMARY OF THE INVENTION This invention relates to the Arachne process which is currently used in the making of blankets and other textile fabrics where the conventional weaving and knitting steps are omitted. The Ar'a'chne process includes the forming of a matt generally from staple fibers and the sewing of the batt along various directions to give the matt strength. A typical product of the Arachne process is disclosed in US. Pat. No. 3,365,918 which produces a simulated nonwoven corduroy fabric.

In the present invention, yarn strength is developed not by the conventional drafting and twisting of a fiber bundle which results in a great loss of volume but by the stitching of a fine sewing thread through a fibrous matt. As a result of the superior volume to weight ratio of the yarns, a savings in material of up to 20 percent can be obtained.

Therefore, an object of this invention is to provide highbulk yarns. Another object of this invention is to form highbulk yarns by sewing a series of threaded seams in the machine direction of a continuous filament matt and by subsequently slitting the matt between adjacent threaded seams.

A further object of this invention is to form high-bulk yarns from matts comprised of bulkable synthetic continuous filaments.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a matt of bulkable synthetic filaments having a series of substantially parallel threaded seams;

FIG. 2 is an enlarged view of a yarn having been cut from the seamed matt of FIG. '1 prior to bulking; and

FIG. 3 is the yarn of FIG. 2 after said yarn has been subjected to a bulking treatment;

FIG. 4 is a flow chart identifying the steps of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred process for forming the nonwoven web is carried out on a continuous basis as set forth in US. Pat. application Ser. No. 646,720. In that application, the filaments having been spun and laid down onto a belt was subsequently bonded by gaseous means; however, permanent bonding does not form a part of this invention and the matt is ultimately left unbonded. For ease of handling the nonwoven matt, a weak .water soluble cellulosic gum may be applied to the matt which is subsequently removed after seaming by washing in a hot water bath. The filaments as shown are bicomponent and may be freshly spun from two polyamides having different heat shrinkage characteristics, two polyesters having differential heat shrinkage characteristics or a polyester and a polyamide having different heat shrinkage characteristics. Also, the bicomponent filament may be formed at a prior time and supplied to the aspirator mechanism as shown in the mentioned application by means of a bobbin. Where the bicomponent filaments are formed at a prior time, two acrylonitrile-based polymers having different heat shrinkage characteristics may be used.

The matt which is comprised of continuous bicomponent synthetic filaments and which has been formed on a conveyor belt is moved by the conveyor belt to a bank of sewing needles which are positioned across the width of the matt. Each of the needles is adapted to sew a seam along the length of the matt with the seams being separated from each other a distance, the distance being determined by the ultimate denier of the produced yarn. The matt having the seams formed along the length thereof is then fed to a slicer which is adapted to cut the matt equidistantly between adjacent seams. The yarns may then be bulked, wound onto bobbins or wound onto a beam. Where bulking is to take place immediately after the formation of the yarns, the yarns are contacted with a heated gaseous medium or submerged in hot water whereupon the portions of the bicomponent fibers having the greatest heat shrinkage characteristics causes the filaments to bend back on themselves and to cover the threaded seam.

In reference to FIG. 1, matt 10 is comprised of a plurality of bicomponent filaments 11 which are laid down in a manner as herein set forth. Matt 10 is provided with seams 12 which are comprised of a plurality of linearly interlocking stitches 13. As shown in FIG. 1, the preferred orientation of filaments II is normal to the direction of seams 12.

The density of the bulked yarns of this invention vary from 0.02 to 0.10 gms/cm. In comparison, cotton yarns generally have densities of between 0.45 and 1.28 gms/cm and worsted yarns have densities ranging generally between 0.38 and 0.73 gms/cm. Turbo-stapled acrylic fiber yarns after bulking have densities of about 0.25 gms/cm. It can be seen that considerably savings of material can be made by following the teachings of this invention.

For some end use applications, elastic yarns find utility. The bulked yarns of this invention are easily provided with the required elasticity by substituting threads comprised of an elastomeric urethane rubber or the like for the mentioned threads. Such threads are generally stitched into the matt under tension to increase the bulk density of the yarn.

EXAMPLE I Continuous bicomponent nylon filaments, 15 denier, were spun from an extruder in the conventional manner. The filaments were passed through an aspirator jet and laid randomly onto a foaminous conveyor belt. The weight of the matt was approximately 1.5 oz/yd The matt was passed through a bank of sewing needles which formed a threaded seam in the machine direction every 0.40 inch. The stitching thread was 040 cotton. The stitching needles were set to sew approximately six stitches in the matt per linear inch in the machine direction. The seamed matt was comprised of 82 percent by weight of the bicomponent continuous nylon filaments and 18 percent by weight of the sewing thread. A seamed matt was then passed through cutters which slit the matt equidistantly between each of the seams.

The density of the yarn before bulking was 0.089 gms/cm. The yarn was then passed through a hot water bath, the water being heated to approximately 212 F., where bulking occurred. After bulking and drying, the density of the yarn was 0.035 gms/cm. The denier of the bulked yarn was 5,670 and the bulked yarn had a tenacity of 4.81 lbs. and a tenacity per denier of0.38.

EXAMPLE II The procedure as set forth in example I was repeated with the exception that the matt weighed approximately 1.0 ozlyd and the bicomponent continuous nylon filaments were laid down preferentially normal to the machine direction. The seaming width was 0.5 in. and the matt after seaming was comprised of 83 percent by weight of the synthetic nylon fibers, 17 percent by weight of the sewing thread. After slitting, the density before bulking of the yarn was 0.102 gms/cm and the density after'bulking was 0.029 gms/cm. The bulked yarn had a denier of 5,000 a bulked yarn tenacity of 3,95 lbs. and a tenacity in grams per denier of 0.36. It can be seen that by orienting the filaments slightly in the direction normal to the machine direction, the density after bulking decreases.

The specification has set forth a preferred embodiment of the invention and, although specific terms are employed, they are used in a descriptive sense only and not for the purposes of limitation only, the scope of the invention being defined in the claims.

lclaim:

l. A high-bulked textile yarn comprising a stitching including individual and interconnected stitches of fine threads extending continuously in a given direction and a plurality of bulked staple bicomponent synthetic fibers having been trapped by said individual stitches along a given direction with a number of sald fibers being arranged transversely with respect to said given direction and being of such lengths to be entangled and curled about said stitching to substantially cover the same.

2. The high-bulked textile yarn of claim 1 wherein said bicomponent synthetic fibers are comprised of two polyamides having different shrinkage characteristics.

3. The high-bulked textile yarn of claim 1 wherein said bicomponent synthetic fibers are comprised of two polyesters having different shrinkage characteristics.

4. The high-bulked textile yarn of claim 1 wherein said bicomponent synthetic fibers are comprised of polyesters and polyamides having different shrinkage characteristics.

5. The high-bulked textile yarn of claim 1 wherein said bicomponent synthetic fibers are comprised of two acrylonitrile-based polymers having different shrinkage characteristics.

6. The high-bulked textile yarn of claim 1 wherein said yarn has a bulk density of less than 0.001 gms/cm" per cubic centimeter.

7. The high-bulked textile yarn of claim 1 wherein said stitching consists of an elastic yarn.

Claims

2. The high-bulked textile yarn of claim 1 wherein said bicomponent synthetic fibers are comprised of two polyamides having different shrinkage characteristics.
3. The high-bulked textile yarn of claim 1 wherein said bicomponent synthetic fibers are comprised of two polyesters having different shrinkage characteristics.
4. The high-bulked textile yarn of claim 1 wherein said bicomponent synthetic fibers are comprised of polyesters and polyamides having different shrinkage characteristics.
5. The high-bulked textile yarn of claim 1 wherein said bicomponent synthetic fibers are comprised of two acrylonitrile-based polymers having different shrinkage characteristics.
6. The high-bulked textile yarn of claim 1 wherein said yarn has a bulk density of less than 0.001 gms/cm3 per cubic centimeter.
7. The high-bulked textile yarn of claim 1 wherein said stitching consists of an elastic yarn.