DENIM MANUFACTURING PROCESS

Yarn Manufacturing

Open End Spinning

Ring Spinning

The initial stage of denim production is Opening and Blending. Opening begins with baled cotton fiber being separated into small tufts. A blend of cotton fibers is made on each opening line. These bales are selected using USDA High Volume Instrument (HVI) data, and PCCA's unique computer blending software produces optimal yarn strength.

Cotton is delivered by air suction from the Opening and Blending lines, through additional cleaning and blending machines, to the Cards. The major functions of Carding are to remove foreign matter and short fibers, form the cotton into a web and convert the web into a rope-like form known as a sliver.

The drawing process produces a single, uniform sliver from six card slivers. The additional blending, paralleling of fibers and cleaning in this process produces a sliver for Open End and Ring Spinning. For Ring Spinning, however, the sliver must pass through an additional process called Roving.

Cotton Fibers are formed into a yarn by centrifugal action in Open- End Spinning. Individual fibers are laid down in the groove of a fast spinning rotor and twisted into yarn. After the cotton fibers are spun into yarn, the yarn is wound into a large package.

The Open End Spinning Machines have robots on each side which automatically pieces up (repairs broken ends). On a different track, they have another robot that automatically doffs (removes full packages) and starts up a new package. The size and quality of each yarn end are monitored by the Barco Profile System to ensure uniformity.

Indigo Dye Range

In Ring Spinning, the spinning frames receive Roving via a transit system from the roving machine. Yarn is formed from cotton fibers that are twisted together after being drafted by passing between three steel rolls and three rubber rolls. The yarn then is wrapped on a bobbin as it spins on a spindle by use of a traveler. The relationship between roll speeds, traveler speeds and spindle speeds controls the amount of twist in the yarn. Ends down levels and production information are gathered by the Uster Ring Expert System. The spinning frames automatically doff bobbins full of yarn and send them to package winding.

ACG also has the capacity to produce Amsler Open-End yarn, also known as Faux Ring Spun yarn. This technology enables ACG to impart various slub patterns into an Open-End yarn. Denim made from this type of yarn has yarn character and surface interest that cannot be achieved with traditional Open-End yarn.

Warp Preparation

In the warping process, individual strands of yarn are removed from yarn packages prior to being gathered into a rope form suitable for dyeing. Individual strands of warp yarn (the length-wise yarn in a fabric) are gathered into rope form and wound onto a log, thus forming a ball warp.

Two rope-dye ranges enable ACG to produce pure indigo, sulfur bottom, sulfur top, and colored denim yarn. The yarn goes through scour/sulfur dye, wash boxes, indigo dye vats, over a skying device (to allow oxidation to occur), through additional wash boxes, over drying cans and then is coiled into tubs which are transferred to the Long Chain Beaming process.

Long Chain Beaming separates the dyed yarn into individual strands, parallels the strands, and winds them onto a large section beam in preparation for Slashing. The Slashing process takes section beams, coats the yarn with a starch/wax solution, and winds the yarn onto a loom beam.

Omni Plus Looms

A starch/wax solution is applied to enable the yarn to withstand the abrasion and tension it will be exposed to in Weaving. The solution also reduces the fuzziness of the yarn, thus eliminating a pilling effect in Weaving.

Weaving

The weaving process interlaces the warp (length-wise indigo dyed yarn) and the filling (natural-colored cross-wise yarn) producing 100 percent cotton denim in a variety of weights and styles.

The Finishing Range

The Finishing Range brushes and singes the cloth prior to the cloth entering a finishing solution. The cloth is then pulled to the proper width, skewed, dried and rolled for the next process.

The Compressive Shrinkage process reduces the amount of shrinkage in the warp or lengthwise direction that a finished garment will have after laundering. As the cloth enters the machine, it is moistened with water and then fed between a thick rubber belt and a heated steel cylinder where approximately 14 percent shrinkage in the warp yarn takes place. After drying, the cloth is rolled onto an "A" frame.

The EVS uses cameras to inspect denim for defects.

Every yard of cloth must pass rigid inspection standards. An inspection process utilizes an I-Tex 200 model Elbit Vision System (EVS), an automatic fabric inspection system, that evaluates the quality of the denim by identifying visible defects that result during spinning, weaving, dyeing and finishing at Littlefield. This system can detect defects as small as 0.5 mm on fabric up to 68 inches wide at speeds up to 42 yards per minute. As denim is fed through the system, three cameras photograph the back of the fabric, and four cameras photograph the front. These cameras continually photograph the fabric and save only the frames containing identified defects. They also log all pertinent information such as lot number and the exact location of the defect on the fabric. This information then is fed to the cutting tables where computers help locate the defect. This high-tech system increases fabric inspection efficiency and reduces garment seconds. At the 3/1 process, the cloth is measured and cut into rolls of proper quality and size. Each roll is carefully weighed to ensure correct weight and yardage per roll.