Textiles - Exam 3 Flashcards
S-twist
In this twist, the yarns run upward to the left.
Z-twist
In this twist, the yarns run upward to the right.
Ring spinning
In this method of spinning, fibers are carded to bring them to a more parallel position and bundled into a loosely formed rope about one inch in diameter. It can produce novelty yarns to uniform yarns. The softest yarns are produced this way, but they tend to be more costly.
Open-end spinning
In this method of spinning, only one process form carded sliver to spun yarn is required. Carded sliver is fed into the open-end spinning unit, which separates the fibers, twists them together to form completed spun yarn, and then winds the yarn onto spools or cones. There tends to be better regularity and uniformity; improved abrasion resistance, especially in high twisted yarns; improved distribution of fibers in blends; and improved abrasion resistance resulting in brighter shades and print-patterns. This type is limited to coarse and medium-size yarns. Denim is commonly made through this process.
Air-jet spinning
In this method of spinning, it uses compressed air to aide in the spinning process. One end of the fiber is pushed toward the center of the yarn and the other end to the outside to wind around other fibers. This process is very fast with production twice that of open-end production and 20 times faster than ring spinning. The fibers are more securely locked into the yarn, don not slide as easily, and exhibit less fuzz. Though they have less uniformity, are limited t coarse yarn sizes, and have a lower yarn strength. Fabric shows fewer pills and does not show wear easily. Ideal for sheets, active wear, uniforms, and sweatshirts.
Blended yarn
A yarn made of two or more fiber types.
Mixture
A fabric composed of two or more different types of yarn.
Chenille yarns
These yarns have a soft pile protruding from their surface and resembles pipe cleaners without the wire. They are soft, supple, and very flexible. These are made by slitting narrow lengths from 1/8” to 1/4” of a fabric that has been woven for this purpose. It is a leno-effect weave. Commonly made from cotton, wool, or rayon.
Metallic yarns
These yarns are ribbon like or elliptical in cross-section as are other yarns. Can increase strength and abrasion resistance.
Woven fabrics
These types of fabrics are made by interlacing two sets of yarns at right angles to each other.
Warp beam
This part of the loom is located at the back and is a large roller on which all the warp yarns to be used fo the fabric are parallel to each other.
Harness
A part of the loom that looks like a picture frame that holds many thinvertical wires called heddles. The sequence in which it is raised or lowered determines the weave.
Heddles
A piece of the loom that is within the harness that holds thin, vertical wires.
Shed
A v-like opening on a loom.
Reed
A comb-like device on a loom that pushes the filling yarn in the shed into the body of the cloth.
Shuttle
A wooden device with a bobbin placed inside with filling yarn wound around it. The filling yarn unwinds from the bobbin through this, leaving a trail of yarn behind.
Shuttleless
This gets rid of a piece of the loom that allows the yarn comes directly from cones placed at the side of the loom.
Projectile loom
This type of loom uses a projectile to insert the filling yarns. It is small, light gripper devic that is propelled across the loom, pulling the filling yarn behind it. It can produce fabrics of a variety of widths: 75-213”. It can produce sheeting,denim, and carpet.A strain is placed on the filling yarn thus making it unsuited for weaving. Has a 400 ppm.
Rapier loom
This loom uses a rapier rod or steel tape to pull the filling yarn across the loom or a double rapier where the filling yarn is transferred at the midway point from one rapier to the other. It is used to produce high-quality wool and silk fabrics.
Jet loom
This type of loom takes the filling yarn across the loom by using a high-speed jet of either air or water. The force of the air or water carries the yarn from one side to the other. These are faster (higher picks per minute), but they cannot produce a great variety of fabrics (no heavy and bulky yarns) nor wide fabrics because they have less carrying power. Less damage is done to the warp yarns because there is no abrasion of this yarn by the jets.
Multiphase looms
This type of loom offers enormous output for light to medium weight fabrics. Multiple sheds are used that operate seperately across the loom instead of only one shed. Can produce fabric at a rate of 2800 ppm with a weft insertion rate of 6015 yards/minute. It is used for staple fabrics of basic weaves, such as plain, rib, or basic twills.
Selvage
A lengthwise edge of a fabric. It is usually between 1/4 and 1/2 inch wide and exists on both edges of the cloth. The main purpose of this ot ensure that the edge of the fabric will not year when the cloth is undergoing stress and strain of the finishing process. It is usually left as a finished edge on sheets and bath towels.
Weave float
When one yarn does not interlace with the next adjacent yarn, but passes over two or more adjacent yarns. These tend to makes the fabric surface flat and incresases the amount of luster. When it is long, snagging can occur and it weakens the fabric because it reduces the frequency with which yarns pass from one side of the fabric to the to the other.
Plain weave
This type of weave is the simplest and the most used weave. The fabrics that are typically made with this are reversiable unless one side is made the face by a finishing or printing process. Examples of fabrics: gauze, chiffon, chambray, canvas, and chintz. This requires only two harnesses. The tearing strength is lower than any other weave and it wrinkles easily.