#5 Weaves & Knits

 

Weaves & Knits
Gina Christopher 

Weaving:

 The weaving sequence includes four steps. Harnesses are lifted creating a V-shaped shed that the weft yarn passes through. Next, one or more filling yarns travel through the shed. After the weft thread is inserted, the warp yarns are lowered and the reed moves forward, pushing or beating the filling yarns in place so that it aligns parallel to the other filling yarns. Woven fabric is then taken up on the cloth beam, and more warp yarn length is let off from the yarn beam. The three basic weaves include the plain, twill, and satin weaves. The plain weaving is 1X1, which means that one warp yarn and one filling yarn alternately pass over one another. Twill weaves are 2/1, which means that each warp yarn passes or floats over two filling yarns. Satin weaves have a smooth surface designed to hide the weaves or interlacing. This pattern is described as five-shaft construction, indicating that each warp yarn is floating over four picks and under the fifth.  

Twill Weaving:

There are many variations of twill weaving. Notations used with twill weaves describe the interlacing pattern of each warp yarn. The 2/1 notation indicates that each warp yarn passes or floats over 2 filling yarns. The weaving steps either to the right or the left, creating an obvious diagonal pattern in the fabric. Twill weaves are usually more flexible and drapable than plain weaves. Twirls can either be warp face, weft faced, or even.

Jacquard Weaving:

Jacquard fabrics often have extremely complex interlacing patterns combining 2 or more simple weaves, multiple sets of yarns, and strategically placed colors. Oftentimes the pattern repeats are large and composed of various motifs, each having finely detailed curved and swirled shapes. Jacquard fabrics are woven on jacquard looms that have the capacity to form an almost unlimited variety of multicolored fabrics with intricate patterns.   

Fire (Fiber Identification by burning):

If you have a fabric that is unidentified you can do a burn test to find out what type of fiber content, you are dealing with. It is important to know this information if you need to dye a fabric because many dyes are specific to what type of fiber they can dye. Before doing a burn test you should make sure you are in a well-ventilated area, using metal tweezers, and make sure you have fire extinguishing materials nearby. Cellulose fibers will ignite and burn quickly, may flare, and leave a glowing ember after the flame is extinguished. Cellulose fibers smoke will be white or light colored and smell like burnt paper or leaves, and the ash will be light Gray or white and very soft. Protein fibers burn slowly and shrink or curl away from the flame. Protein fibers will not stay lit after the flame is removed and very little smoke will be produced the smoke smells like burnt hair or feathers. Protein fibers ash is a gritty powder or a dark brittle bead. Synthetic fibers ignite and burn quickly and can continue to burn after a flame is removed. Synthetic fiber may shrink from the flame, melt, and drip, leaving a hard plastic-like bead. Synthetic fiber smoke is black and has hazardous fumes.

 

Testing:

NFPA 260:

The NFPA 260 standard measures fire resistance of upholstered furniture when exposed to cigarettes. This standard includes cover fabrics, interior fabrics, cords, decking, barrier materials, and filling or padding.

Tensile Strength Testing:

Tensile strength measures a fabric resistance to being pulled apart lengthwise. It evaluates the maximum force the fabric can withstand before breaking and its elongation properties.

Abrasion Testing:

 Abrasion Testing evaluates how well a fabric resists wear and surface damage from rubbing and friction overtime. The machines that test the material rub the textile under controlled pressure and motion to see how long the textile takes to show wear.

One Step Further:

I wanted to learn more about different weaving techniques, so I decided to look into satin fabrics. Satin fabrics have floating warp yarns. Satin leaves have a smooth surface designed to hide the weaves or interlacing’s. They require more harness than basic twill patterns. To produce satin weaving at least 5 harnesses are needed. This pattern is described as five shaft construction, indicating that each warp yarn is floating over 4 picks and under the 5^th. Satin weaves are characterized by high luster and Sheen, produced by light reflection from the uninterrupted warp floats.

References:

Dharma Trading Co. (n.d.). Burn test. https://www.dharmatrading.com/home/the-fire-test.html

NFPA 260. TVF. (2024, June 27). https://www.tvfinc.com/article/nfpa-260/

Yates, M., & Concra, A. (2019). Textiles for residential and commercial interiors. Fairchild Books, Bloomsbury Publishing Inc.