Patent application title: COMPOSITE REGENERATED COTTON AND BAST FIBER YARN AND METHOD FOR MAKING THE SAME
Scott H. Silver (Annapolis, MD, US)
IPC8 Class: AD02G304FI
Class name: Textiles: spinning, twisting, and twining strand structure staple fiber blends
Publication date: 2009-12-03
Patent application number: 20090293443
A composite bast fiber and cotton yarn is formed by blending natural bast
fibers with cotton fibers which have been regenerated from waste cotton
material such as trimmings and cuttings from the apparel manufacturing
industry. The regenerated cotton and bast fibers are cleaned and blended,
then carded to align the fibers into strands. Depending on the size and
texture of the desired yarn, the fibers are stretched and drawn into
slivers prior to spinning to join the fibers together. The natural bast
fibers are up to two and one half to three time longer than the
regenerated cotton fibers, so that the natural bast fibers overlap and
braid onto the regenerated cotton fibers during spinning. The resultant
yarn is stronger and more absorbent than yarns made solely out of
regenerated cotton fibers, a blend of regenerated cotton and acrylic
fibers, or regenerated cotton and polyester fibers currently available.
1. A method for making pre-dyed eco-friendly yarn, comprising the steps
of(a) garnetting waste cotton fabric to produce cotton shoddy fibers
therefrom;(b) blending the cotton shoddy fibers with natural bast fibers;
and(c) spinning the blended cotton fibers and bast fibers to form a yarn.
2. A method as defined in claim 1, wherein said waste cotton fabric comprises cuttings and trimmings of previously bleached, dyed and treated and dyed cotton fabric used to manufacture clothing, household linens and other articles of manufacture.
3. A method as defined in claim 2, wherein the amount of cotton is less than the amount of natural bast fiber in the yarn.
4. A method as defined in claim 3, wherein the yarn comprises 30-45% cotton fibers.
5. A method as defined in claim 2, wherein said natural bast fibers are longer than said cotton fibers.
6. A method as defined in claim 2, and further comprising the step of cleaning said blended cotton shoddy and bast fibers prior to said spinning step.
7. A method as defined in claim 2, wherein said fibers are carded to align said fibers into strands prior to said spinning step.
8. A method as defined in claim 7, and further comprising the step of forming said fibers into smaller strands.
9. A method as defined in claim 8, wherein said forming step comprises drawing said carded fibers into slivers and subsequently roving said slivers into smaller strands.
10. A yarn for making fabric for clothing, household linens, and canvas, comprising(a) regenerated cotton fibers from waste cotton fabric that has previously been bleached, dyed and treated; and(b) natural bast fibers spun with said regenerated cotton fibers.
11. A yarn as defined in claim 10, wherein the amount of cotton is less than the amount of bast in the yarn.
12. A yarn as defined in claim 11, wherein the yarn comprises 30-45% cotton fibers.
13. A yarn as defined in claim 10, where in said natural bast fibers are longer than said cotton fibers.
14. A yarn as defined in claim 10 and having a fine count of up to 28 s Ne.
This application is a continuation-in-part of U.S. application Ser.
No. 11/971,473 filed Jan. 9, 2008.
Textile fabric treatment typically includes bleaching vast amounts of greige fabric and then dyeing the fabric to a desired color for use in manufacturing various fabric articles such as apparel, household linens, and canvas. Unfortunately, the effluents produced by the treatment processes can be harmful to the environment, thus increasing the costs of manufacture of such fabrics to safeguard the environment. In addition, waste fabric resulting from trimming and cutting the fabric during the formation of fabric articles must be discarded. The waste is typically dumped into landfills or incinerated, thereby releasing harmful pollutants into the environment and atmosphere.
Accordingly, there exists a need to recapture and reuse the waste fabric material, particularly bleached and dyed materials formed of cotton. The present invention relates to the production of yarn from a blend of regenerated cotton fibers from waste fabric material and of natural bast fibers. Bast fibers include flax or linen, hemp, sunn, kenaf, jute and ramie. Bast fibers normally require bleaching, dyeing and other treatment in order to be used in high fashion, high quality apparel and home textiles, thus in part negating their environmental and organic benefits by the caustic effluents produced in the normal bleaching and dyeing process. In the present invention, no further bleaching or dyeing of the yarn is necessary. The yarn can be woven or knit into new fabric for production of colorful and functional clothing, household linens, canvas and the like.
BRIEF DESCRIPTION OF THE PRIOR ART
It is known in the art to produce a composite yarn formed of vegetable and cotton fibers as disclosed in the Haughey U.S. Pat. No. 1,986,970. Among the vegetable fibers disclosed in Haughey are linen, hemp, ramie, and jute. It is also known in the art to recycle cotton waste material by breaking the material down into fibers and then blending the recycled fibers with virgin cotton fibers to manufacture yarn having a recycled content as disclosed in the Heifetz U.S. Pat. No. 5,331,801.
While the composite yarns of the prior art are satisfactory, they each suffer from certain inherent drawbacks. Neither yarn according to the prior art comprises a composite of natural bast and recycled/regenerated cotton fibers which can be blended into fine count yarns for manufacturing a variety of fabrics without further bleaching, dyeing or treatment of the yarn, or woven or knit fabrics produced from this yarn, and with minimal damage to the environment. The present invention was developed in order to provide such a pre-dyed yarn.
SUMMARY OF THE INVENTION
The invention relates to an eco-friendly yarn and a method for manufacturing the same. Waste cotton fabric is collected and sorted by color and the pieces of fabric of the same color are broken down into cotton fibers by a garneting process. The cotton fibers are referred to as shoddy or fluff. The regenerated cotton shoddy fibers are then blended with natural bast fibers and spun into pre-dyed yarn. By recycling waste cotton fabric and combining the regenerated cotton fibers derived therefrom with bast fibers, a composite pre-dyed yarn is developed which is environmentally friendly and which does not require any further bleaching, dyeing or treatment prior to weaving or knitting of the yarn into articles of clothing, household linens, or other fabric articles.
The finished yarn is between 30 and 45% recycled and regenerated cotton fibers which are generally shorter than the natural bast fibers. Prior to spinning the fibers into yarn, they are blended and cleaned to remove any impurities from the mixture. Next, the blended fibers are carded to form aligned strands of fibers. The strands may be drawn roved into smaller finer strands depending on the type of fabric to be formed from the yarn. Finally, once the desired strand size has been obtained, the fibers are spun to form the finished yarn.
BRIEF DESCRIPTION OF THE FIGURES
Other objects and advantages of the invention will become apparent from a study of the following specification when viewed in light of the accompanying drawing in which,
FIG. 1 is a flow diagram illustrating the method steps used to form the eco-friendly yarn of the present invention.
Textile waste in the form of cuttings, trimmings and clippings is collected from manufacturing facilities around the world before it is discarded for deposit in a landfill or incinerated. The waste cotton fabrics have previously been bleached and dyed, so additional treatment or dyeing is not required and therefore no additional industrial effluents which could add to additional pollution of the environment are produced. The waste materials are sorted by color and cleaned to remove any foreign material such as paper or metal from labels, buttons, or the like.
Bast includes herbaceous plants of dicoeyledons such as flax or linen, hemp, sunn, kenaf, jute and ramie, which are grown and cultivated for their long sinuous fibers. The fibers are very strong with a very high tensile strength and extremely absorbent. Bast fibers are naturally organic and do not require the use of herbicides or pesticides which are used extensively in the traditional cultivation of cotton. One acre of linen, hemp or ramie can produce as much useable fiber as two acres of traditional cotton, without the need for intensive use of water irrigation or fertilizers as is required in traditional cotton farming.
Bast fiber is formed by processing the stalks of the plants which contain long sinuous fibers. The stalks are cut and left in the field for 30-45 days to ret, a natural process that begins to separate the fibers. Once retted, the stalks are run through a decoration process which separates the fibers by length. The cut stalks are then soaked in water and mechanically pulverized to remove and further separate the fibers. This process is the same for flax, hemp and ramie which are the most commercially viable types of bast. The bast fibers are then washed to remove natural glues which can be used for industrial adhesives. The washed fibers are then dried and cut, and then sent to conventional carding machines to produce fibers and card-sliver which are then spun into yarn.
The composite yarn forming method according to the invention will be described with reference to FIG. 1. The sorted cotton waste materials are subjected to garnetting 2 which is a process by which materials such as clippings and trimmings, threads, woven cloth scraps and the like are broken up and returned to a fluffy fibrous condition similar to the original state of the cotton. This is preferably accomplished by first cutting or chopping the waste materials into smaller pieces of approximately two to six inches in either direction. The pieces are then fed through a series of high speed cylinders having jagged edged surfaces to break down the pieces into individual cotton fibers. While any fiber length greater than about 0.4 inches is useful, garnetting rarely produces fibers having a length greater than one and one-eighth inches. Lengths of 0.4-0.8 inches are typical, with a length of about 0.5 inches being average and the vast majority being over 0.4 inches.
After the garneting process, bales of regenerated cotton shoddy fibers are lined up in a row or arranged in a circular configuration to be blended by a vacuum head and separated into large tufts. Long natural bast fibers on the order of two and one half to three inches are added so that the cotton and natural bast fibers are blended together 4.
The tufts of cotton and natural bast fiber are air blown into hoppers to clean the blended fibers of any remaining dirt or trash 6 prior to delivery to carding machines 8. The carding machines use air to align the fibers into a picker lap of parallel fibers. Any remaining dirt or other particulates are separated from the picker lap by the air flow. The picker lap is in the form of a sheet approximately forty inches wide and one inch thick. The sheet is then processed into a thin mist-like sheet by the carding machines and then formed into loose rope-like strands referred to as card-sliver.
A number of card-slivers are brought together and drawn out 10 to form a single rope like strand known as drawn sliver. The fibers of the drawn sliver are further straightened to improve uniformity. The drawn sliver is further drawn or stretched into smaller strands of fiber by roving 12. Finally, the sliver or rope is still further drawn out into a tiny strand of fibers and twisted or spun into yarn 14 using conventional open end spinning frames. With the fibers aligned in parallel and spun, they twist together until they cling to each other. The finished yarn counts range between 6 s Ne and 28 s Ne. The physical difference between the relatively short recycled cotton fibers, typically less than one inch, and the relatively long natural bast fibers, on the order of two and one half to three inches, results in a very strong yarn as the fibers tend to overlap and braid onto each other. The pre-dyed spun yarn is now suitable for knitting or weaving into apparel and home fashion textiles, without the requirement for bleaching and dyeing to achieve the desired fashion colors.
Preferably, the amount of cotton fiber in the yarn is less than the amount of natural bast fiber. For example, the yarn may comprise 30-45% regenerated cotton fibers, with the balance comprising natural bast fibers. The natural bast fibers are neutral in color, almost translucent, so the resulting yarn takes on the color of the original cotton waste materials, although the color is muted somewhat by the blending of the natural bast fibers. This muted color is desirable in the fashion conscious market of apparel and home textiles.
The benefits of the yarn produced according to the method are many. First, no man-made fibers such as acrylic or polyester are used, which allows for the production of truly sustainable and eco-friendly yarn and subsequent woven and knit textile products. Since these products are petroleum based, there is a net saving in energy cost. Second, because the regenerated cotton fibers originate from waste products of previously treated fabric, no further treatment, bleach, or dye is used, nor are the waste products deposited into landfills. By blending the natural bast fibers with the regenerated cotton fibers, the fibers may be spun into finer yarn counts to manufacture better quality products than are currently available with conventional regenerated cotton products. In addition, the yarn is stronger and more absorbent than conventional cotton yarn.
While the preferred forms and embodiments of the invention have been illustrated and described, it will be apparent to those of ordinary skill in the art that various changes and modifications may be made without deviating from the inventive concepts set forth above.
Patent applications by Scott H. Silver, Annapolis, MD US
Patent applications in all subclasses Staple fiber blends