HIGH-DENSITY WARP-FIBER WOVEN FABRIC AND METHODS OF MANUFACTURING THE SAME

Abstract

A high thread count woven fabric for use in bedding products includes a 5-end sateen weave formed from a plurality of interwoven cotton warp and weft threads, wherein the number of warp threads per square inch of the fabric is at least about 240 and the number of the weft threads per square inch is about 9% to about 21% A higher than in conventional high thread count fabrics. A method of making the high thread count fabric includes setting up a weaving machine with a shed height and a backrest adjustment as described and shown herein to facilitate weaving the fabric with the high density of warp threads.

Description

TECHNICAL FIELD

The present invention relates generally to the field of home textiles, and more particularly to flat bedding products such as high thread count sheets.

BACKGROUND

Fabric for bedding sheets is identified by its “thread count” (TC), which is the sum of the threads (warp/vertical and weft/horizontal) counted in one square inch (a one-inch by one-inch square area) of the fabric. In other words, a 600 thread count fabric has 600 threads (warp plus weft) per square inch of the fabric. High thread count sheets are defined in the industry as having a thread count of 400 or more. Conventional high thread count bedsheets are limited in the number/density of warp threads because of the thickness of conventional warp threads and the density of conventional comb reeds (i.e., the width of the dents or gaps in the reeds) through which they pass. The number of warp threads per inch of woven fabric (the warp-thread density) is identified as “ends per inch” (EPI), and the number of weft threads per inch of woven fabric (the weft-thread density) is identified as “picks per inch” (PPI). Conventional high thread count bedsheet fabrics of the highest quality have a warp-to-weft ratio (EPI/PPI) of about 0.56/1.0 with an EPI of about 216 or a warp-to-weft ratio (EPI/PPI) of about 0.64/1.0 with an EPI of about 235.

Improvements in woven-fabric bedsheets are desired. It is to the provision of solutions to this and other needs that the present invention is primarily directed.

SUMMARY

Generally described, the present invention relates to a high thread count woven fabric for use in bedding products. According to one example, the high thread count fabric includes a 5-end sateen weave formed from a plurality of interwoven cotton warp and weft threads, wherein the EPI warp-thread density is at least about 260 and the EPI/PPI warp-to-weft ratio is typically about 21% higher than in conventional high thread count fabrics.

A method of making the high thread count fabric includes setting up a weaving machine with a shed height and a backrest adjustment as described and shown herein to facilitate weaving the fabric with the high density of warp threads.

The resulting fabric sheet has higher reed which makes it balance constructed fabric with a square weave geometry compared to conventional sheets of the same thread count, which results in sheets with attributes such as improved sheen, durability, and handle.

This provides silk-like sheets of 100% cotton or a cotton-blended fabric achieved by optimizing the warp density by unique machine settings as described and shown herein.

This results in a resulting fabric sheet with a long-lasting sheen, even after repeated washes, which overcomes a problem in conventional sateen sheets, as once the end customer uses and launders conventional sheets they start losing their sheen.

This also results in improved pilling performance in the high-density (HD) sateen sheets of the invention because of the higher warp density compared to conventional sateen sheets which have an unbalanced construction resulting in inferior pilling results after use and washing.

In addition, the high definition “sateen stripe” sheets of the invention have great definition due to the contact of shiny surfaces to non-shiny surfaces of the same fabric on the same side. This gives an ultimate luxury feeling in the fabric sheets of the invention.

Moreover, the fabric sheets of the invention can be made using other fibers and blends, including cotton fibers blended with fibers of silk, wool, TENCEL, modal, viscose, bamboo, linen, polyester, and/or other fibers, and/or any combination thereof.

These and other aspects, features, and advantages of the invention will be understood with reference to the drawing figures and detailed description herein, and will be realized by means of the various elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following brief description of the drawings and detailed description of example embodiments are explanatory of example embodiments of the invention, and are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a process flow diagram of a method of manufacturing a high-density warp-fiber woven fabric according to an example embodiment of the invention.

FIG. 2 is a perspective view of an example weaving machine for use in the method of FIG. 1.

FIG. 3 is a perspective view of an example weaving machine with a shed-height set-up for use in the method of FIG. 1.

FIG. 4 is a perspective view of an example weaving machine with a backrest set-up for use in the method of FIG. 1.

FIG. 5 is a weave configuration diagram for use in setting up a weaving machine for use in the method of FIG. 1.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

The present invention may be understood more readily by reference to the following detailed description of example embodiments taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this invention is not limited to the specific devices, methods, conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting of the claimed invention. Any and all patents and other publications identified in this specification are incorporated by reference as though fully set forth herein.

Also, as used in the specification including the appended claims, the singular forms “a,” “an,” and “the” include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment.

With reference now to the drawing figures, wherein like reference numbers represent corresponding parts throughout the several views, FIGS. 1-5 show a method 100 of manufacturing a high-density warp-fiber woven fabric 110 according to an example embodiment of the invention. The resulting special high thread count (high TC) fabric 110 is typically used to make flat woven bedding products such as sheets, pillow cases, comforters, blankets, duvets, and duvet covers, and even mattress covers and skirts, though it can be used in other applications.

As shown in FIG. 1, the method 100 includes at 102 selecting the fibers to be used, including the warp and weft fibers. As used herein, the term “fibers” is intended to be synonymous with terms including threads, yarns, and the like for weaving textile fabrics. The warp fibers selected are typically 100-percent cotton, for example conventional long-staple cotton threads (e.g., ring-spun compact yarn) or other types of conventional single-ply cotton threads including cotton blends with other fibers such as polyester, wool, silk, tencel, etc. And the weft fibers selected are 100-percent cotton, for example the same fibers used in the warp direction or other conventional cotton threads.

At 104, the weaving machine is set up to specifications for weaving the special fabric 110. An example/representative weaving machine 150 that can be used in the process is shown in FIG. 2. Suitable weaving machines include air-jet looms, rapier looms, projectile looms, and other conventional weaving machinery. Other than as expressly set forth herein, the weaving machine 150 can be set up in a conventional manner with common settings well known in the art of weaving cotton fabrics for bedsheets.

In order to weave the special fabric 110, the weaving machine 150 is set up with special settings for the shed height 152 (see FIG. 3) and the backrest 154 (see FIG. 4) and with a special weave configuration 170 (see FIG. 5). The shed height 152 can be set higher than normal, at about 55 mm to about 60 mm, typically at about 60 mm, whereas normal for sateen sheets is about 50 mm. The backrest 154 is set lower than normal, at about 35 mm to about 45 mm, typically at about 40 mm, whereas normal for sateen sheets is about 30 mm. And the weave configuration 170 is set up as 5-end sateen, typically using multi-pick insertion. In some embodiments, the heald frame height is specially set, for example with the first heald frame height at about 72 mm to about 74 mm (whereas 74 mm is normal), the second heald frame height at about 70 mm to about 72 mm (whereas 72 mm is normal), the third heald frame height at about 68 mm to about 70 mm (whereas 70 mm is normal), the fourth heald frame height at about 66 mm to 70 mm (whereas 68 mm is normal), and the fifth heald frame height at about 72 mm (whereas 72 mm is normal). The other loom settings (e.g., backrest depth) can be conventional for weaving sateen fabrics.

The 5-end sateen weave configuration 170 is a simple draft and forms the basis of many others drafts. In this configuration 170, each respective warp thread/fiber is drawn on a respective shaft, thus, the first warp thread/fiber is drawn through the first heald shaft, the second warp thread/fiber is drawn through the second heald shaft, and so on, with the number of heald shafts equalling the number of warp threads/fibers. When weaving high thread count fabrics, the warp density is limited due to workability issues with the weaving machine, specifically, a thread-to-thread gap should be maintained between the warp yarns/threads/fibers being run on the weaving machine to avoid thread-to-thread abrasion and weakening/breakage during the weaving process. But for weaving the special fabric 110, the density of the warp fibers can be increased using the 5-end sateen weave configuration 170 to make the fabric with the higher warp density which results in the stable sateen fabric with exceptional lasting sheen.

In addition, the frame-to-frame crossing position is typically kept lower than normal at about 290 to 300, typically about 295, compared to 300 to 310 in conventional flat woven fabrics like sateen or satin.

With the 5-end sateen weave configuration, the denting order is five warp fibers 102 per dent (gap) of the reed 156, which provides for an increased warp fiber density. However, this increased warp fiber density produces increase vibrations in the weaving machine 150 and increased surface abrasion of the warp fibers 102. These problems are overcome by the special settings for the shed height 152 and the backrest 154 of the weaving machine 150, as described herein.

In addition, the increased density of the warp fibers 102 passing through the reed 156 can produce increased tension in the warp fibers which can in turn cause slippage of the resulting special fabric 110 as it is reeled in onto the cloth beam 158. To eliminate or minimize such slippage, a liner can be provided on a drive roller (not shown) positioned adjacent the cloth roller beam 158 and around which the raw fabric runs. The liner can be emery paper or another conventional frictional lining material known in the art.

Continuing with the process 100 of FIG. 1, with the weaving machine 150 specially set up at 104, then at 106 the weaving machine 150 is operated to weave the fibers 102 into unfinished/greige high thread count fabric at 108. Next, at 108 the unfinished/greige fabric 108 is finished by for example bleaching, dyeing, stentering, sanforizing, calendering, and/or other conventional techniques for make the high thread count fabric 110, which can then be made into flat woven bedding products such those described herein.

In this way, the high thread count fabric 110 has a higher density of warp fibers than conventional sheets. In example embodiments, for example, the special fabric 110 has an EPI (warp-thread density) of about 260 warp threads per inch. According to one example embodiment, the special fabric 110 comprises an EPI of 260 warp threads per inch. In other example embodiments, for example, the special fabric 110 may have an EPI of about 240 to about 260 warp threads per inch, This is a significant increase over conventional high-thread count bedsheets, which have an EPI of about 216 warp threads per inch at the most for the highest quality sheets. In addition, the higher density of warp fibers in the high thread count fabric 110 (compared to conventional flat woven sheeting fabrics) results in a squarer weave geometry, which improves the sheen of the fabric, the durability of the fabric sheets, and the handle of the fabric sheet products.

In addition, the high thread count fabric 110 has a higher warp-to-weft ratio (EPI/PPI) than conventional sheets. In example embodiments, the special fabric 110 has a weft-thread density (PPI) of about 340. According to one example embodiment, the special fabric comprises a PPI of 340 weft threads per inch. In other example embodiments, for example, the special fabric 110 may have a PPI of about 325 to about 355 weft threads per inch, for example about 240 picks (60/4) for 500 thread count (TC), about 340 picks (85/4) for 600 TC, about 440 picks (74/6) for 700 TC, and about 540 picks (90/6) for 800 TC. Based on the EPI being 260 as described herein, the special fabric 110 has a warp-to-weft ratio (EPI/PPI) or, for example, about 0.76/1.0 (e.g., 76%) according to example embodiments of the present invention. This is a significant increase (typically about 21%) over conventional high thread count bedsheets, which have a warp-to-weft ratio of about 0.56/1.0 (e.g., 56%) at the most for the highest quality sheets.

It will be noted that a lower PPI could be used to produce a higher EPI/PPI ratio, but such a sheet would be low thread count and not have a balanced square weave geometry, and thus would be of low quality. This is in contrast to the fabric 110 with its higher EPI/PPI ratio, high thread count, and balanced square weave geometry, and thus its high quality.

The higher EPI (warp-thread density) and the higher warp-to-weft ratio (EPI/PPI) results in the special fabric 110 being a much more balanced fabric. That is, the thread counts in the warp and weft direction are much closer to each other, so that the warp-to-weft ratio is much closer to even (1.0/1.0). This results in the special fabric 110 having improved performance, for example it is stronger and has a longer life.

In addition, the higher warp-thread density and the higher warp-to-weft ratio results in the special fabric 110 being much softer and having much more sheen than conventional high-thread count bedsheets. This is demonstrated by testing done by Hohenstein Laboratories GmbH & Co. KG of Bonnigheim, Germany on 11 Nov. 2016, which test report is marked “Exhibit A,” filed herewith, and incorporated by reference herein. The test was done to compare the high thread count fabric 110 and a conventional high thread count bedsheet by testing their surface indexes. The test showed that the high thread count fabric 110 has a surface index of 2.20 and the conventional high thread count bedsheet has a surface index of 3.40. The significantly lower surface index of the special fabric 110, relative to the conventional high thread count bedsheet, indicates a much softer and higher quality fabric. According to other example embodiments (as will be described below), the surface index value for the high thread count fabrics of the present invention is generally between about 1.95 to about 2.20.

Additional details of example weaving settings and resulting fabric properties for the high thread count fabric 110 are provided in Tables A-C below. Table A highlights some typical/representative weave settings such as the shed height adjustment 152, backrest adjustment 154, frame-to-frame crossing position, weave configuration 170, frame heald heights utilized in the fabrication of the high thread count woven fabric 110 as described herein. Table A also shows the typical/representative resulting fabric properties, such as the denting order, EPI, PPI, construction, thread count, and surface index value, for the selected weave settings. Table A further includes common values or ranges of the same weave settings and resulting fabric properties for conventional woven fabrics relative to those of the high thread count fabric 110.

Table B provides other examples of high thread count fabrics fabricated with weaving settings with values representative of high thread count fabrics 110 as described in Table A and else herein which further shows that fabrics fabricated with such weaving settings achieve significantly lower surface index values, relative to conventional high thread count fabrics, indicating softer and higher quality fabric.

Table C provides example properties of high thread count fabrics fabricated with weaving settings outside the ranges or configurations of the HD warp fiber woven fabric 110 as described in Table B and else herein. Table C shows that weaving settings outside the values or ranges for HD warp fiber woven fabric 110 results in significantly higher surface index values which indicates less soft and lower quality fabrics. For example, the high thread count fabric represented by Example 1 in Table C has a surface index value of 3.20, Example 2 has a surface index value of 3.50, and Example 3 has a surface index value of 4.80. In comparison, Table B shows example HD warp-fiber woven fabrics having surface index values of 1.95, 2.00 and 2.20, representing a minimum improvement of at least 31% and a maximum improvement of at least 59% in surface index value.

	TABLE A
	Conventional High	HD Warp-Fiber
	Thread Count Fabric	Woven Fabric
Settings
Shed Height	50 mm	55 mm-60 mm
Adjustment
Back Rest Adjust-	30 mm	35 mm-45 mm
ment
Frame-to-Frame	300-310	290-300
Crossing Position
Emery Paper	No	Yes
Weave	5-End Sateen	5-End Sateen
Frame Heald
Heights
1st	74 mm	72 mm-74 mm
2nd	72 mm	70 mm-72 mm
3rd	70 mm	68 mm-70 mm
4th	68 mm	66 mm-70 mm
5th	72 mm	72 mm
Denting Order	5 warp per dent	5 warp per dent
EPI	216	260
PPI	384	340
Construction	80 s × 100 s/216 × 96/4	80 s × 100 s/260 × 85/4
Thread Count	600	600
Surface Index	3.40	1.95-2.20
Value

	TABLE B
	HD Warp-Fiber	HD Warp-Fiber	HD Warp-Fiber
	Woven Fabric	Woven Fabric	Woven Fabric
	Example 1	Example 2	Example 3
Settings
Shed Height	60 mm	57.5 mm	60 mm
Adjustment
Back Rest Adjustment	40 mm	41.25 mm	45 mm
Frame-to-Frame	295	292.5	291
Crossing Position
Emery Paper	Yes	Yes	Yes
Weave	5-End Sateen	5-End Sateen	5-End Sateen
Frame Heald Heights
1st	72 mm	72 mm	74 mm
2nd	70 mm	70 mm	72 mm
3rd	68 mm	68 mm	70 mm
4th	66 mm	66 mm	70 mm
5th	72 mm	72 mm	72 mm
Denting Order	5 warp per dent	5 warp per dent	5 warp per dent
EPI	260	260	260
PPI	340	340	340
Construction	80 s × 100 s/	80 s × 100 s/	80 s × 100 s/
	260 × 85/4	260 × 85/4	260 × 85/4
Thread Count	600	600	600
Surface Index Value	2.20	2.00	1.95

	TABLE C
	Example 1	Example 2	Example 3
	Outside	Outside	Outside
	Range	Range	Range
Settings
Shed Height Adjust-	45 mm	50 mm	50 mm
ment
Back Rest Adjustment	25 mm	50 mm	30 mm
Frame-to-Frame	310	305	300-310
Crossing Position
Emery Paper	Yes	No	No
Weave	5-End Sateen	5-End Sateen	7-End Sateen
Frame Heald Heights
1st	72 mm	74 mm	74 mm
2nd	70 mm	72 mm	72 mm
3rd	68 mm	70 mm	70 mm
4th	66 mm	68 mm	68 mm
5th	72 mm	72 mm	72 mm
Denting Order	5 warp per dent	5 warp per dent	5 warp per dent
EPI	216	216	236
PPI	385	384	364
Construction	80 s × 120 s/	80 s × 100 s/	100 s × 100 s/
	216 × 77/5	216 × 64/6	236 × 91/4
Thread Count	600	600	600
Surface Index Value	3.20	3.50	4.80

As highlighted in Tables A-C, the weaving settings can vary the surface index values of the high thread count fabrics. Specifically, proper weave settings are critical to producing high thread count fabrics with surface index values lower than those of conventional high thread count fabrics—generally, 3.40. Weave settings for the high density warp fiber woven fabric 110 as described herein provides significant improvements in the surface index value and the overall quality of high thread count fabrics. More specifically, the use of the preferred weaving settings, and ranges thereof, namely, the shed height adjustment, backrest adjustment, frame-to-frame crossing position, use of emery paper, weave configuration, EPI, PPI and frame heald heights as described herein, provides high thread count fabrics with surface index values in the preferred range between about 1.95 and about 2.20. As shown in Table C, high thread count fabrics produced with one or more weaving settings outside the weaving settings for high density warp fiber woven fabrics 110 (see Table A) fail to achieve surface index values within the preferred range. Thus, the use of at least one or some of the preferred weaving settings for high density fiber woven fabrics as shown in Table A is critical to producing significantly improved high thread count fabrics.

While the invention has been described with reference to example embodiments, it will be understood by those skilled in the art that a variety of modifications, additions and deletions are within the scope of the invention, as defined by the following claims.

Claims

1. A high thread count fabric comprising a 5 end sateen weave formed from a plurality of interwoven warp and weft threads, the warp threads comprising at least about 65% of the number of weft threads per one square inch of fabric.

2. A high thread count flat woven bedding product made from the fabric of claim 1.

3. A method of making the fabric of claim 1, including setting up a weaving machine with a shed height and a backrest adjustment as described and shown herein.

4. A method of making the fabric of claim 1, comprising a surface index value ranging from 2.2 to 2.5 which is achieved by using yarn in a higher density.

5. A method of making the fabric of claim 1, wherein in order to control vibration in warp sheet and warp breakage in higher thread density flat fabric level 2 is to be selected to weave the fabric on a weaving machine.

6. A method of making the fabric of claim 1, wherein a frame to frame crossing position is kept at 290 to 300 compared to 300 to 310 in conventional flat woven fabric like sateen or satin.

7. A method of making the fabric of claim 1, wherein a long lasting sheen is achieved by using a higher number of threads per inch in warp compared to conventional sateen sheets.

8. A method of making the fabric of claim 1, wherein a silk kind of sheen is achieved in a 100% cotton or cotton blended flat woven fabric like sateen or satin.

9. A high density warp fiber fabric comprising a thread count of at least 400 and a surface index value between 1.95 and 2.20, inclusively.

10. A high density warp fiber fabric of claim 9, further comprising a warp-thread density between 240 warp threads per inch and 260 warp threads per inch, inclusively.

11. A high density warp fiber fabric of claim 9, further comprising a weft-thread density between 325 weft threads per inch and 355 weft threads per inch, inclusively.

12. A high density warp fiber fabric of claim 9, further comprising a denting order of 5 warp per dent.

13. A method of fabricating the fabric of claim 9, including a weaving setting wherein the weaving setting comprising a shed height between 55 mm and 60 mm, a backrest between 35 mm and 45 mm, a frame-to-frame crossing position between 290 and 300.

14. A method of fabricating the fabric of claim 12, the weave setting further comprising a 5-end sateen weave configuration.

15. A method of fabricating the fabric of claim 12, the weave setting further comprising a first frame heald height between 72 mm and 74 mm, a second frame heald height between 70 mm and 72 mm, a third frame heald height between 28 mm and 70 mm, a fourth heald height between 66 mm and 70 mm, and a fifth heald height of 72 mm.

16. A method of fabricating a high density warp fiber fabric comprising selecting warp and weft fibers for weaving;configuring a weaving machine, wherein configuring the weaving machine includes setting a weave configuration as a 5-end sateen weave;weaving the fibers into an unfinished high thread count fabric; andfinishing the high thread count fabric.

17. A method of fabricating a high density warp fiber fabric of claim 16, wherein configuring the weaving machine further includes setting a shed height adjustment between 55 mm and 60 mm.

18. A method of fabricating a high density warp fiber fabric of claim 16, wherein configuring the weaving machine further includes setting a backrest adjustment between 35 mm and 45 mm.

19. A method of fabricating a high density warp fiber fabric of claim 16, wherein configuring the weaving machine further includes setting a frame-to-frame crossing position between 290 and 300.

20. A method of fabricating a high density warp fiber fabric of claim 16, wherein configuring the weaving machine further includes setting a first frame heald height between 72 mm and 74 mm, a second frame heald height between 70 mm and 72 mm, a third frame heald height between 28 mm and 70 mm, a fourth heald height between 66 mm and 70 mm, and a fifth heald height of 72 mm.