Patent Application
20130118209
The present invention is directed to fabric construction, and more specifically to aspects of constructing fabric that feels soft to the touch.
The standard and traditional cotton fabric is created by weaving a tightly spun cotton yarn with a soft twist cotton yarn. When woven, this allows soft twist yarns to be held in place by tightly spun warp yarns. The conventional fabric product has been prone to shrinkage and wrinkling. It is an object of the present invention to provide a stable fabric product that does not shrink or wrinkle, and is soft to the touch.
A fabric that is soft to the touch is made using an underlying base yarn to provide skeletal support, and a surface yarn that has been subjected to a napping process. The base yarn is a full drawn polyester yarn (also known as filament yarn). A non-limiting example of a suitable base yarn is a multifilament full drawn polyester yarn FDY 54D/24F (54 dernier/24 filament).
According to certain embodiments, the surface yarn is a drawn texture polyester yarn DTY 75D/144F. Both the base yarn and the surface yarn is made using polyester pre-oriented yarn or partially oriented yarn that is warp spun at high speed.
The invention further discloses a method of constructing fabric comprising weaving a polyester base yarn and a polyester surface yarn using a warp knit process to form a warp knit fabric having a top side and an underside, wherein the top side is napped. The method of the invention may further comprise napping the underside of the warp knit fabric. The method of the present invention may also comprise heating the warp knit fabric under pressure and adding one or more dyes.
According to certain embodiments, a fabric that is soft to the touch is made using an underlying base yarn to provide skeletal support, and a surface yarn that has been subjected to a napping process. The base yarn is a full drawn polyester yarn (also known as filament yarn). A non-limiting example of a suitable base yarn is a multifilament full drawn polyester yarn FDY 54D/24F (54 dernier/24 filament).
According to certain embodiments, the surface yarn is a drawn texture polyester yarn DTY 75D/144F. Both the base yarn and the surface yarn is made using polyester pre-oriented yarn or partially oriented yarn that is warp spun at high speed.
According to certain embodiments, the drawn texture polyester yarn (DTY) is a false twisted texture yarn, also known as a low stretch yarn is manufactured using Barmag and thermal mechanical treatment advanced elasticizing equipment. The false twisted drawn texture polyester yarn is “false twisted” by combining two yarns with a degree of twist. After sizing, the two yarns are unwound resulting in a curvature of the yarns that is distinctive to DTY.
According to certain embodiments, the full drawn yarn (FDY), also known as filament yarn, is a FDY yarn manufactured by Barmag. The yarn is wound through melt spinning. Stretching during the spinning process achieves a highly oriented, medium crystalline filament.
According to certain embodiments, the weaving process includes a first combing procedure where the underlying base yarn is combed. There is a second combing where the surface yarn is combed. For example, the combing can be performed by a high speed warp knit machine such as a Karl Mayer HKS-4 high speed knit machine. As a non-limiting example, the settings for the underlying combing procedure can be inlay reed first guide bar GB 1: 1-1/1-2. Similarly, the settings for the surface yarn combing can be inlay reed second guide bar GB 2: 1-0/3-4 or 1-0/2-3. According to certain embodiments, the weaving procedure uses 30 inch weave harnesses. Each harness has 630 warp ends, according to certain embodiments. The number harnesses used depends on the fabric width. For example, a fabric width of 2.8 m is woven using 8 harnesses denoted as 630*8. The rotation speed of the warp knit machine is approximately 1,880 revolutions per minute.
According to certain embodiments, the dyeing of the greige fabric includes the following procedures. The greige fabric is vat dyed or cylinder dyed using high speed pressure dyeing. The dye cylinder is an overflow cylinder. The dye cylinder is first heated and the greige fabric is deposited in the dye cylinder. When the cylinder is heated to approximately 80° C., the appropriate dyes and additives are deposited in the dye cylinder. The cylinder is then heated to approximately 130° C. at which point the temperature and pressure in the cylinder is suitable for the greige fabric to absorb the dye. The greige fabric absorbs the dye for approximately 30 minutes. Next, the temperature of the dye cylinder is reduced to approximately 80° C. and the temperature is maintained for 2 to 2.5 hours. This allows for dye absorption while preserving the surface features of the fabric. Next, the temperature of the dye cylinder is further reduced and the fabric removed from the dye cylinder. The dyeing process is complete.
According to certain embodiments, after the dyeing process is complete, moisture is removed from the fabric and softeners are added to the fabric. The fabric is heated to 190° C. to 220° C. The working speed is approximately 35 yards per minute.
According to certain embodiments, after moisture removal, the fabric undergoes a napping process. A nap raising agent is added to the fabric and the surface of the fabric is mechanically napped by passing the fabric through raising machine several times. For example, the surface of the fabric can be passed three to four times through a Lianyungang Yirigyou 36-roller raising machine.
According to certain embodiments, as an optional step, the other side of the fabric (the underside surface) may be mechanically napped by passing the underside of the fabric through a multi roller raising machine. The napping of the underside of the fabric is option and is not required.
After napping either one surface or both surfaces of the fabric, the fabric is heated to approximately to 160° C. The working speed is approximately 45 to 50 yards per minute.
The resulting fabric made suing the method described herein is soft to the touch, is durable and resists shrinking. Such a fabric can be used for a variety of consumer products. Examples include bedding materials, bed sheets, comforters, apparel, blankets, quilts, etc.
In the foregoing specification, embodiments of the invention have been described with reference to numerous specific details that may vary from implementation to implementation. Thus, the sole and exclusive indicator of what the invention is and what is intended by the applicants to be the invention, is the set of claims that issue from this application, in the specific form in which such claims issue, including any subsequent correction. Any express definitions set forth herein for terms contained in such claims shall govern the meaning of such terms as used in the claims. Hence, no limitation, element, property, feature, advantage or attribute that is not expressly recited in a claim should limit the scope of such claim in any way. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.
