Patent Application
20190233982
The present invention relates to fibers, yarns and fabrics in the arena of technical wear, athletic wear or “athleisure” wear.
The market for specialized garments for athletic and leisurewear has grown remarkably in recent years. This in turn has led to the development of, and the further desire to develop, specialized fabrics for such end uses. As is well understood by the skilled person in textiles, the performance of a garment is based upon the fabric from which it is cut and sewn, with the fabric in turn reflecting the properties of the yarn from which it is woven or knitted, and the properties of the yarn reflecting the staple fibers from which the yarn is formed.
Accordingly, since the development and understanding of polymers beginning in the early 20th century, textile, chemists have sought to mimic the best properties of natural fibers (cotton, wool, linen) as well as to tailor fiber properties to specific end uses.
Cotton is an extremely comfortable fiber in many circumstances and cotton garments remain ubiquitous based on their light weight, versatility, and favorable hand. The term “hand” is used throughout this application in the sense that is well understood to the skilled person. It can be defined as, “a characteristic of fabrics that is perceived by touching, squeezing, or rubbing them” (Tortora at page 262), or as, “the “term used to describe the feel of a substrate (i.e., soft, raspy, stiff, etc.)” (Textile Glossary; Cotton Incorporated; www.cottoninc.com; accessed Mar. 15, 2018).
Nevertheless, and with particular respect to athletic or active wear, cotton has certain disadvantages. Cotton is highly absorbent, taking up to 27 times its weight in water, which adds undesired weight in the athletic wear context. Cotton also loses its insulating properties and can be abrasive when wet. Thus, in cold weather, active exercise (or work, etc.) cotton layers next to the skin quickly become wet, heavy, and cold. Cotton undergarments become abrasive when wet in both hot and cold weather.
Wool has excellent insulating properties, can stretch as much as 30% beyond its relaxed length, and can absorb moisture in up to 50% of its dry weight without becoming saturated, Tortora, F
Accordingly, much effort (and with some success), has been placed into developing synthetic-based fabrics from synthetic fibers, or blends of synthetic fibers with natural fibers; e.g., Dacron and wool, cotton and polyester, etc. Additionally, further effort has been applied to developing fully synthetic garments that mimic the comfortable hand of cotton, while providing better moisture management then standard cotton or common cotton-synthetic blends.
The term moisture management is used to describe the capacity or ability of a fabric to pull or wick moisture (perspiration, humidity, rain) to an outer layer of a fabric from which it can evaporate. In many circumstances body temperature (98.6° F. 37°) can help drive wicking in fabric garments, particularly given that entropy will generally favor the vapor (i.e., more random) state. Moisture management is thus typically measured using water vapor transmission rate.
Synthetics are not an automatic cure-all, however, because overcooling can give a clammy feel to the wearer. Accordingly, modern “technical” wear often consists of two types of yarn formed into several layers that are arranged so that thermodynamics drives perspiration from the skin to the first layer and then from the first layer to the outer layer. Modern technical fabrics may have as many as four or five layers for this purpose.
Furthermore, because the starting fibers help establish the properties of the resulting fabric, the skilled person recognizes that with respect to (for example) cotton, shorter fibers produce yarns that in turn give fabrics with a better hand, while longer fibers give smoother more finished yarns, such as those that give a cotton business shirt (again, as just one example) a more finished look, but a rougher hand.
The spinning technique (ring versus open end) likewise makes a difference in the appearance and hand of a finished garment.
Accordingly the goal remains of designing specialized yarns that produce desired combinations of hand and moisture management.
In one embodiment, the invention is a yarn consisting essentially of a blend of polyester fibers customized by three parameters: (1) a combination of polyester staple fibers with staple lengths of 1.5 inches, 1.25 inches, 1.0 inch and 0.75 inch; (2) a combination of polyester staple fibers with staple deniers (tex, fineness) of 1.0 dpf, 1.2 dpf, and 1.5 dpf; and (3) a combination of polyester staple fibers with at least two different staple cross sections.
In another embodiment the invention is an intimately blended bale of polyester staple fibers in which the blend includes (1) a combination of staple fibers with staple lengths of 1.5 inches, 1.25 inches, 1.0 inch and 0.75 inch; (2) a combination of staple fibers with staple deniers (tex, fineness) of 1.0 dpf, 1.2 dpf, and 1.5 dpf; and (3) a combination of staple fibers with at least two different staple cross sections.
In another embodiment the invention is a fabric that includes at least some yarns that consist essentially of (1) a combination of polyester staple fibers with staple lengths of 1.5 inches, 1.25 inches, 1.0 inch and 0.75 inch, (2) a combination of polyester staple fibers with staple deniers (tex, fineness) of 1.0 dpf, 1.2 dpf, and 1.5 dpf; and (3) a combination of polyester staple fibers with at least two different staple cross sections.
In another embodiment the invention is a resulting fabric according to selected from the group consisting of woven fabrics, nonwoven fabrics, and knitted fabrics.
In another embodiment the invention is a method of making a yarn precursor blend with selected properties of moisture management and hand that includes the steps of spinning continuous synthetic filament in each of at least three different deniers and at least two different cross sections, gathering the different continuous filaments into a single tow, using a common cutter to cut the tow into it at least four different staple lengths, and blending the different length, different denier and different cross-sectional staple fibers into an intimately blended bale.
In another embodiment the invention is a method of making a yarn precursor blend that includes the steps of spinning the continuous synthetic filament into staple deniers (tex, fineness) of 1.0 dpf, 1.2 dpf, and 1.5 dpf, and using the common cutter to cut the tow into staple lengths of 1.5 inches, 1.25 inches, 1.0 inch and 0.75 inch.
In another embodiment the invention is a method of making a yarn with selected properties of moisture management and hand, that includes the steps of opening an intimately blended bale of staple fibers in at least three different deniers, at least four different lengths, and at least two different cross sections, and forming the opened staple fibers into tow, forming the toe into a roving; and spinning the roving into yarn.
In another embodiment the invention is a method of making a yarn that includes comprising opening an intimately blended bale that consists essentially of (1) a combination of polyester staple fibers with staple lengths of 1.5 inches, 1.25 inches, 1.0 inch and 0.75 inch: (2) a combination of polyester staple fibers with staple deniers (tex, fineness) of 1.0 dpf, 1.2 dpf, and 1.5 dpf; and (3) a combination of polyester staple fibers with at least two different staple cross sections.
In another embodiment the invention is a reel assembly for use with a staple cutting apparatus that includes a cutter reel having a pair of annular reel members spaced axially one from the other with each reel member defining an outwardly facing axial surface having a predetermined diameter and a circumferential mating engagement portion; a plurality of cutter blades mounted in said reel members for engaging and cutting fiber; and a cover member encircling and affixed about one of the reel members; in which the improvement comprising cutter blades spaced to cut synthetic filament into discrete staple lengths of 1.5 inches, 1.25 inches, 1.0 inch and 0.75 inch.
The foregoing and other objects and advantages of the invention and the manner in which the same are accomplished will become clearer based on the followed detailed description taken in conjunction with the accompanying drawings.
As used herein, the term polyester refers to any polymer formed by joining hydrocarbon chains with ester groups (Tortora, page 437), The US Federal Trade Commission defines polyester as, “[A] manufactured fiber in which the fiber-forming substance is any long chain synthetic polymer composed of at least 85% by weight of an ester of a substituted aromatic carboxylic acid, including but not restricted to substituted terephthalate units,” 16 C.F.R. § 303.7(c)(2018).
Bale Density: A unit of measurement of weight per unit volume normally expressed as pounds per cubic foot. Density is calculated by dividing the net bale weight by the bale volume in cubic feet. Volume is determined by multiplying bale length, width and thickness dimensions expressed in feet. Thickness is determined by measuring from tie to tie across the crown of the bale.
Universal Density (UD): Cotton bale density of at least 28 pounds, per cubic foot
Standard Density (SD); Cotton bale density of at least 23 pounds per cubic, foot but less than 28 pounds per cubic foot.
Gin UD: Bale compressed at the gin to a density of at least 28 pounds per cubic foot.
(Bale must be tied with strapping or wire as defined under Section 1.1 and 12).
(Bales must be tied with strapping or wire as defined under Section 1.1 and 1.2).
Gin SD: Bale compressed at the gin to a density of at least 23 pounds per cubic foot but less than 28 pounds per cubic foot.
http://www.cotton.org/tech/bale/specs/definitions.cfm; accessed Feb. 17, 2018
Glossary from National Cotton Council of America7193 Goodlett Farms Parkway Cordova, Tenn. 38016
Spinning:
As used in the textile industry, the term “spinning” has two distinct meanings. In a classical meaning dating almost to antiquity, “spinning” refers to the step of twisting fibers together to make yarns. In modern technology this is (typically) carried out using “ring” spinning or “open end” spinning, each of which are Familiar to the person of ordinary skill in the art; e.g. Tortora, Fairchilds Dictionary Of Textiles, 7th Ed. (2009) at pages 473 and 395.
In another sense, the word “spinning” is used to refer to the step of extruding a polymer melt into individual filaments which are then processed further, typically including texturing, cutting into “staple” lengths, and spinning the polymer staple fibers into yarns in the open end or ring spinning sense. Tortora at page 536.
The term “opening” is likewise well understood by the skilled person and generally represents a preliminary step in separating staple fibers taken from a compressed bale into looser tufts and removing (where necessary) heavier impurities. Tortora page 395.
As used herein, the term polyester refers to any polymer formed by joining hydrocarbon chains with ester groups (Tortora at page 437).
In a first aspect, the invention is a yarn consisting essentially of a blend of polyester fibers customized by three parameters: (1) a combination of polyester staple fibers with staple lengths of 1.5 inches, 1.25 inches, 1.0 inch and 0.75 inch; (2) a combination of polyester staple fibers with staple deniers (tex, fineness) of 1.0 dpf, 1.2 dpf, and 1.5 dpf; and (3) a combination of polyester staple fibers with at least two different staple cross sections.
In exemplary embodiments, the yarn consist essentially of a blend of polyester fibers in the amounts of 20% by weight staple length of 1.5 inches or greater; 54% by weight staple lengths of 1.25 inches or greater; 77% by weight staple lengths of 1 inch or greater; and 96% by weight staple lengths of 0.75 inch or greater; with all lengths and percentages expressed to 2 significant figures.
In such exemplary embodiments the yarn includes 94% by weight of fibers at least 100 mtex; 87% by weight of fibers of at least 125 mtex; 76% by weight of fibers having at least 150 mtex: and 63% of fibers having at least 175 mtex; with all percentages expressed to 2 significant figures.
Table 1 sets forth exemplary length and dpf blends according to the invention.
As used in Table 1, 30's SIRO 100% means a 30 Ne yarn. (English yarn count; 3×840 yds=25,200 yards of this yarn weighs 1 pound). It was spun on a SIRO ring spinning machine, in which 2 roving bobbins draft into 1 spinning bobbin, and this yarn was made of 100% polyester fiber in the indicated proportions.
40's CPRS 60/40 means a 40 Ne yarn (English yarn count: 40×840 yds=33,600 yards of this yarn weighs 1 pound). The CP descriptor means combed cotton, so this sample represents 60% combed cotton blended with 40% polyester according to the invention. The RS designation means that this yarn was spun on a standard ring spinning frame, where 1 roving bobbin feeds 1 spinning position. To set forth an alternative, the nomenclature would use the acronym OE, which stands for open end spinning, also called rotor spinning.
The yarn count numbers above are based on length/weight with the standard of yards/pound of yarn. This is the inverse of the denier system, which is based on weight/length.
The data in Tables 2 and 3 were collected on samples of yarn made according to the invention and tested on an USTER® AFIS PRO 2 fiber process control system (Uster Technologies AG, Sonnenbengstrasse 10, 8610 Uster, Switzerland; www.uster.com; https://www.textilemates.com/siro-spinning-application; accessed Feb. 24, 2018). The listed values are defined as follows:
Tables 2 and 3. Numerical Output of Results
Neps (a nep is defined as small knot of entangled fibers commonly regarded as a fault but sometimes introduced as an effect. http://www.textileglossary.com/terms/nep.html; accessed Feb. 25, 2018).
Total nep cnt: Count of all neps in a sample (fiber and seed mat neps).
Total nep mean size: Average size of all neps (fiber and seed coat neps) counted in microns.
Fiber nep cnt: Count of all fiber neps.
Fib nep mean size: Average size of all fiber neps in microns
SC nep count: Count of all seed coat neps.
SC nep mean size: Average size of all seed coat neps in microns.
Length
L (w) Average fiber length by weight of all the cotton fibers in the sample.
L (w) CV % Variation of the fiber length around the average is expressed as length variation by weight or CV %. CV is used in its well-understood statistical sense to express the ratio of the standard deviation to the mean.
SFC (w) % Percent of all fibers in a cotton sample that are shorter than 12.7 mm (0.5 in.) by weight.
UQL (w) % Length by which 25% of all fibers by weight exceed in a cotton sample.
L (n) Average fiber length by number of all cotton fibers in the sample.
Variation of the fiber length around the average is expressed as length variation by number or CV %.
SFC (n) % Percent of all fibers in a cotton sample that are shorter than 12.7 mm (0.5 in.) by number. 5% L (n) Length of the longer 5% of all fibers in a cotton sample.
Trash
Total trash count: Count of all particles (dust and trash particles).
Total trash size: Average size of all particles counted (dust and trash particles).
Dust count: Count of all particles less than 500 microns in size.
Dust mean size: Average size of all dust particles counted.
Trash count: Count of all particles greater than 500 microns in size.
Trash mean size: Average size of all trash particles counted VFM %: Calculation taking both dust and trash content as well as size into account; relates to gravimetric trash measurement methods such as Shirley Analyzer.
Statistics Statistical values: Overall measurement protocol with statistical data in the result.
Columns: Mean (Average), Standard deviation, Coefficient of variation CV %, 99% confidence range, Min, value, Max, value.
Some of the data in Tables 2 and 3 is illustrated as the histograms in
Method
In another aspect the invention is a method of forming a yarn precursor blend with selected properties of moisture management and hand. In this aspect, the invention includes the steps of spinning continuous synthetic filament in each of at least three different deniers and at least two different cross sections, gathering the different continuous filaments into a single tow, using a common cutter to cut the tow into it at least four different staple lengths, and blending the different length, different denier and different cross-sectional staple fibers into an intimately blended bale. In particular, the method includes spinning the continuous synthetic filament into staple deniers (tex, fineness) of 1.0 dpf, 1.2 dpf, and 1.5 dpf; and using the common cutter to cut the tow into staple lengths of 1.5 inches 1.25 inches, 1.0 inch and 0.75 inch.
In exemplary embodiments, the filament (and then the fiber) cross sections are circular and oval. The oval (or elliptical) cross section offers increased surface area relative to an otherwise similarly sized round filament or fiber, and thus provides an additional design factor for moisture management.
The common cutter allows feeding and opening from one bale as opposed to drawing from multiple bales, each of which would have one, of the separate characteristics. As known to those of skill in the art, the sooner different fibers are blended (i.e., earlier in the spinning process; baling, opening, drafting, etc.), the more consistent will be the characteristics for which the yarn was blended.
Thus, in another aspect, the invention is an intimately blended bale of polyester staple fibers that includes the combination of staple fibers with staple lengths of 1.5 inches, 1.25 inches, 1.0 inch and 0.75 inch; the combination of staple fibers with staple deniers (tex, fineness) of 1.0 dpf, 1.2 dpf, and 1.5 dpf; and the combination of staple fibers with at least two different staple cross sections. It follows that an opened bale of this type, and a yarn spun from this bale share the length, denier and cross-sectional characteristics of the intimately blended bale.
The intimately blended bale allows adjustment within a single bale and avoids the necessity to carefully meter fibers from multiple bales of different characteristics. The result is a yarn, and thus resulting fabrics, that are more consistent and precise on a weight for weight basis, and likewise avoid some of the more cumbersome aspects of other blending methods.
Therefore, in another aspect, the invention is a fabric that includes at least some yarns that consist essentially of: (1) a combination of polyester staple fibers with staple lengths of 1.5 inches, 1.25 inches, 1.0 inch and 0.75 inch; (2) a combination of polyester staple fibers with staple deniers (tex, fineness) of 1.0 dpf, 1.2 dpf, and 1.5 dpf, and (3) a combination of polyester staple fibers with at least two different staple cross sections.
Such a fabric cab be selected from the group consisting of woven fabrics, nonwoven fabrics, and knitted fabrics.
Exemplary fabric embodiments include a blend of polyester fibers in the amounts of 20% by weight staple length of 1.5 inches or greater; 54% by weight staple lengths of 1.25 inches or greater; 77% by weight staple lengths of 1 inch or greater; and 96% by weight staple lengths of 0.75 inch or greater; with all lengths and percentages expressed to 2 significant figures.
Such exemplary fabrics can also be described as including 94% by weight of fiber at least 100 mtex: 87% by weight of fibers of at least 125 mtex: 76% by weight of fibers having at least 150 mtex: and 63% of fibers having at least 175 mtex; with all percentages expressed to 2 significant figures.
In yet another aspect, the invention is a method of making a yarn with selected properties of moisture management and hand. In this aspect, the method includes the steps of opening an intimately blended bale of staple fibers in at least three different deniers, at least four different lengths, and at least two different cross sections, and forming the opened staple fibers into tow; forming the toe into a roving; and spinning the roving into yarn.
The intimately blended bale includes a combination of polyester staple fibers with staple lengths of 1.5 inches, 1.25 inches, 1.0 inch and 0.75 inch; a combination of polyester staple fibers with staple deniers of 1.0 dpf, 1.2 dpf and 1.5 dpf a combination of polyester staple fibers with at least two different staple cross sections; 20% by weight staple length of 1.5 inches or greater; 54% by weight staple lengths of 1.25 inches or greater; 77% by weight staple lengths of 1 inch or greater; and 96% by weight staple lengths of 0.75 inch or greater; with all deniers, lengths and percentages expressed to 2 significant figures.
In this aspect, the method can include opening a bale that includes 94% by weight of fibers at least 100 mtex; 87% by weight of fibers of at least 125 mtex; 76% by weight of fibers having at least 150 mtex; and 63% of fibers having at least 175 mtex; with all percentages expressed to 2 significant figures.
A combination wire is typically used for carding a mixture of synthetic and natural fibers. Because the fiber blends according to the invention have a variable cut length that replicates the cumulative fiber length distribution curve of the pima cotton fibers as tested on the Uster AFIS (Advance Fiber Information System), a card with a combination wire was used to produce a 75 grain/yard sliver.
When fibers are only extended slightly in drafting there is a tendency for the high fiber-to-fiber cohesiveness to cause the fibers to snap back. To produce a yarn with better evenness values and fewer objectionable thin and thick places, the synthetic fibers should be extended far enough past each other to reduce fiber to fiber cohesion to a level that eliminates the snap back tendency.
When processing 100% cotton fibers the drawing creel weights re typically higher (500 grains or higher) and the drawing drafts are usually low (5.0 to 5.5) based upon the low fiber to fiber cohesion of cotton. Nevertheless, a high creel grain weight using synthetic fibers may create too much bulk between the steel roll and the top cot, limiting the amount of fiber control and degrade quality.
To manage the fiber to fiber cohesion, a two-step drawing process was utilized to combine different slivers creating a more homogeneous blending of the fibers. At the same time, a medium high draft (6.3 to 6.9) was utilized to extend the individual fibers further past each other which reduced the cohesiveness between the fibers.
By selecting a finer 1.3 HR (hank roving), the draft in roving was moved upward toward the mid-to-high range (9.67), which further extended the fibers past each other and further controlled the fiber to fiber cohesion.
The finer 1.3 HR reduced the ring spinning draft, which in turn allowed the ring frame drafting rolls to gain better control of the fibers. When spinning synthetic fibers it is important to manage roll chatter that is created by high fiber to fiber cohesion and an improper total draft and draft distribution. A high break draft (1.4 to 1.53) caused a slip-stick drafting of the fibers. The lower break draft (1.20) eliminated the chatter effect and produced better yarn evenness with fewer imperfections.
In all drafting processes, breaker drawing, finisher drawing, roving and, spinning, the roll space settings were adjusted based on the longest 5% length as measured on the Uster AFIS (Advance Fiber Information System) to prevent unwanted fiber damage and at the same time to further extend the longest fibers by removing hooks that were formed in carding. Each process was also evaluated on the Uster Evennes' tester (i.e., CV). The roll space and break drafts were adjusted to achieve a mass diagram without thick or thin places and a spectrogram without build ups (indicating fiber floating) or mechanical faults. Table 4 lists the settings in each process.
Other descriptions of the overall process in bringing staple to finished yarn can be found in Tortora, supra; or from Reiter Corporation (www.reiter.com/en/rikipedia) or from Cotton Incorporated (www.cottoninc.com).
In another aspect, the invention is an improvement in a cutter reel in which the improvement comprises spacing the blades in positions that cut the fibers to the desired combination of lengths on a single reel.
As illustrated, the cutter reel is based on U.S. Pat. No. 4,497,231, the contents of which are incorporated entirely herein by reference.
In the drawings and specification there has been set forth a preferred embodiment of the invention, and although specific terms have been employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.
| Number | Date | Country | |
|---|---|---|---|
| 62746619 | Oct 2018 | US | |
| 62624422 | Jan 2018 | US |
