Definitions & Terms

Crimp:

1. The waviness of a fiber expressed as crimps per unit length.
2. The difference in distance between two points on an unstretched fiber and the same two points when the fiber is straightened under specified tension.  Crimp is expressed as a percentage of the unstretched length.

Denier:  A weight-per-unit length measure of any linear material.  Officially, it is the number of 0.05 grams per 450 meter length.  This is numerically equal to the weight in grams of 9,000 meters of the material.  The lower the number, the finer the yarn.  Denier is common in the US.  Tex is common outside the US.

Doff:  A set of full bobbins produced by one machine (a roving frame, a spinning frame, or a manufactured filament extrusion machine).

Drawing:  The hot or cold stretching of continuous filament yarn or tow to align and arrange the crystalline structure of the molecules to achieve improved tensile properties.

Fiber:  A unit of matter, either natural or manufactured, that forms the basic element of fabrics and other textile structures.  A fiber is characterized by having a length at least 100 times its diameter or width.  The term refers to units that can be spun into a yarn or made into a fabric by various methods including weaving, knitting, braiding, felting and twisting.

Fiberfill:  Manufactured fibers that have been specially engineered for use as filling material for pillows, mattress pads, comforters, sleeping bags, quilted outer wear, etc.  Polyester (PET) fibers are widely used.

Filament:  A fiber of an indefinite or extreme length such as found naturally in silk.  Manufactured fibers are extruded into filaments that are converted into filament yarn, staple or tow.

Filament Count:  The number of individual filaments that make up a thread or yarn.

Filament Number: The linear density of a filament expressed in units such as denier, denier per filament (dpf), dTex, or Tex.

Filament Yarn:  A yarn composed of continuous filaments assembled with or without twist.  Generally considered to be fully oriented, but could also be Partially or Un-oriented.

Flock:  The material obtained by reducing textile fibers to fragments by cutting or grinding.  There are two main types: Precision Cut Flock, where all fiber lengths are approximately equal, and Random Cut Flock, where the fibers are ground or chopped to produce a broad range of lengths.  Frequently defined where filament diameter equals length.

Hand:  The tactile qualities of a fabric, e.g., softness, firmness, elasticity, fineness, resilience, and other qualities perceived by touch.

Intermingling:  Use of air jets to create turbulence to entangle the filaments of continuous filament yarns, without forming loops, after extrusion.  Provides dimensional stability and cohesion for further processing but is not of itself a texturing process.  It is compatible with high-speed spin-draw and high-speed take-up.  When compared with twisting processes, it also permits increased package size.  Combining two or more yarns via an intermingling jet.  Can be used to achieve special effect yarns, i.e., mixing dye variants to get heather effects upon subsequent dyeing.

Loft:  The properties of firmness, resilience, and bulk of fiber batting, yarn, fabric, or other textile material.

Lubricant:  An oil or emulsion finish applied to fibers to prevent damage during textile processing or to knitting yarns to make them more pliable.

Manufactured Fiber:  A class name for various genera of fibers (including filaments) produced from fiber forming substances which may be:

1. Polymers synthesized from chemical compounds (acrylic, nylon, etc).
2. Modified or transformed natural polymers (alginic, acetates and rayons),
3. Minerals (glasses).

Micro denier:  Refers to fibers having less than 1 denier per filament or 0.1 Tex per filament.

Nonwoven Fabric:  An assembly of textile fibers held together by mechanical interlocking in a random web or mat, by fusing the fibers or by bonding with a cementing medium.  Normally, crimped fibers that range in length from 0.75 to 4.5 inches are used.

Orifice:  Generally, an opening.  Used specifically to refer to the small holes in spinnerets through which the polymer flows in the manufacture of fibers.

Pack Life:  The time during which a pack assembly (spin pack) can remain in use and produce good-quality yarn.

Packages:  A large selection of forms for winding yarn is available to meet the requirements of existing machinery and a variety of package builds is used to ensure suitable unwinding in later stages of manufacturing.  Since a package with flanges cannot be unwound easily and quickly by pulling yarn off overend, most packages are flangeless with self supporting ends.

POY:  Partially oriented yarn is a filament yarns in which the draw ratio is less than normal resulting in only partial longitudinal orientation of the polymer molecules.

Quenching:  The cooling of fiber filaments after extrusion by carefully controlled air flow.

Sanforized©:  A trademark of Cluett, Peabody & Co., Inc. denoting a controlled standard of shrinkage performance.  Fabrics bearing this trademark will not shrink more than 1% because they have been subject to a method of yarn annealing.

Slub:  A yarn defect consisting of a lump or thick place on the yarn caused by lint or small lengths of yarn adhering to it.  Generally, in filament yarn, a slub is the result of broken filaments that have stripped back from the enc to which they are attached.

Spin Pack (Pack):  The complete assembly of filters and spinneret through which polymer flows during extrusion.

Spinning:  The process or processes used in the production of single yarns or of fabrics generated directly from polymer.

1. Yarn from Staple Fiber: The formation of a yarn by a combination of drawing or drafting an twisting prepared strands of fibers, such as rovings.
2. Filament Yarn: In the spinning of manufactured filaments, fiber-forming substances in the plastic or molten state, or in solution, are forced through the fine orifices in a metallic plate called a spinneret, or jet, at a controlled rate.  The solid filaments are drawn-off by rotating rolls, or godets, and wound onto bobbins or pirns.

Staple:  Natural fibers or cut lengths from filaments.  The staple length of naturnal fibers varies from less than 1” as with some cotton fibers to several feet for some hard fibers.  Manufactured staple fibers are cut to a definite length, from 8” down to about 1-1/2”, or less, so they can be processed cotton spinning systems.  Distinguishes cut fibers from filament yarn.

Synthetic Fiber:  Another term for Manufactured fiber.

Tex:

1. A unit for expressing linear density, equal to the weight in grams of 1 kilometer of yarn, filament, fiber or other textile strand
2. The system of yarn numbering based on the use of tex units.

1. Yarn:  A generic term for a continuous strand of textile fibers, filaments or material in a form suitable for knitting, weaving or otherwise intertwining to form a textile fabric.  Yarn occurs in the following forms:
1. A number of fibers twisted together (spun yarn).
2. A number of filaments laid together without twist (zero twist yarn).
3. A number of filaments laid together with a degree of twist.
4. A single filament with or without twist (monofilament).
5. A narrow strip of material, such as paper, plastic film, or metal foil, with or without twist, intended for use in a textile construction.

 

Textile:  Originally, a woven fabric, now applied generally to any one of the following:

1. Staple fibers and filaments suitable for conversion to or use as yarns, for the preparation of woven, knit, or nonwoven fabrics.
2. Yarns made from natural or manufactured fibers.
3. Fabrics and other manufactured products made from fibers as defined above and from yarns.
4. Garments and other articles fabricated from fibers, yarns or fabrics when the products retain the characteristic flexibility and drape of the original fabrics.

Textured:  An adjective used to describe continuous filament manufactured yarns (and woven and knit fabrics made therefrom) that have been crimped or have had random loops imparted, or that have been otherwise modified to create a different surface texture