Chapter 15: Textile Fibers

Metallic

Composed of metal, plastic- coated metal, metalcoated plastic, or a core completely covered by metal.

Chemical Analysis

Involves extracting the dye and characterizing or identifying its chemistry.

Mineral Fibers

May be composed of silica obtained from rocks or sand.

Delustrants

Finely ground particles of materials, such as titanium dioxide, that are introduced into the spinning dope.

Metameric Colors

Those that appear to match in one set of lighting conditions but do not in another.

Ramie

________ has frequent, short dislocations, and longer transverse striations.

Pigment

Are microscopic, water- insoluble particles that are either incorporated into the fiber at the time of production or are bonded to the surface of the fiber by a resin.

Lyocell

Composed of precipitated cellulose and produced by a solvent extrusion process where no chemical intermediates are formed.

Rayon

Composed of regenerated cellulose, as well as manufactured fibers composed of regenerated cellulose in which substituents have replaced not more than 15 % of the hydrogens of the hydroxyl groups.

Dye

An organic chemical that is able to absorb and reflect certain wavelengths of visible light.

Simultaneous Contrast

The tendency of a color to induce its opposite in hue, value and intensity upon an adjacent color and be mutually affected in return.

Thermal properties

________ relate to the softening and melting temperatures for manufactured fibers and the changes the fiber exhibits when heated.

Wales

Rows of loops along the length of the fabric.

Optical properties

________, such as refractive index, birefringence, and color, are those traits that relate to a fibers structure or treatment revealed through observation.

FTIR

________ is the preferred method because it is not destructive of the fibers.

Yarn

Continuous strands of textile fibers, filaments, or material in a form suitable for weaving, knitting, or otherwise entangling to form a textile fabric.

Abaca

May present spiral elements, but often will have small crown-like structures.

Microspectrophotometer

An instrument that allows for the color measurement of individual fibers.

Novoloid

The fiber- forming substance is any long- chain synthetic polymer composed of at least 85 % of a long- chain polymer of vinylidene dinitrile where the vinylidene dinitrile content is no less than every other unit in the polymer chain.

Polyester

The fiber- forming substance is any long- chain synthetic polymer composed of at least 85 % by weight of an ester or a substituted aromatic carboxylic acid, including but not restricted to substituted terephthalate units and parasubstituted hydroxybenzoate units.

Denier

A direct numbering system in which the lower numbers represent the finer sizes and the higher numbers the larger sizes.

Modacrylic

The fiber- forming substance is any long- chain synthetic polymer composed of less than 85 % but at least 35 % by weight of acrylonitrile units.

Courses

Rows of loops across the width of the fabric.

Vinyon

The fiber- forming substance is any long- chain synthetic polymer composed of at least 85 % by weight of vinyl chloride units.

Crimp

The waviness of a fiber expressed as ________ per unit length.

Spandex

The fiber-forming substance is any long- chain synthetic polymer composed of at least 85 % of a segmented polyurethane.

Coir

________ comes from the husk of the coconut and, accordingly, is a very dense, stiff fiber easily identified microscopically.

Nylon

The fiber- forming substance is any long- chain synthetic polyamide in which less than 85 % of the amide linkages are attached directly to two aromatic rings.

Saran

The fiber- forming substance is any long- chain synthetic polymer composed of at least 80 % by weight of vinylidene chloride units.

Mature cotton

________ has a flat, twisted, ribbon- like appearance that is easy to identify.

Instrumental Analysis

Are objective and repeatable, the results are quantitative, and the methods can be standardized.

Aramid

The fiber- forming substance is any long- chain synthetic polyamide in which at least 85 % of the amide linkages are attached directly to two aromatic rings.

Anidex

The fiber- forming substance is any long- chain synthetic polymer composed of at least 50 % by weight of one or more esters of a monohydric alcohol and acrylic acid.

Visual Examination

This method is subjective and because of day- to- day and observer- to- observer variations, it is not always a repeatable method.

Technical Fiber

Used in cordage, sacks, mats, etc.

Sisal

________ is relatively easy to identify due to its irregular lumen size, crystals, spiral elements, and annular vessels.

Filaments

A type of fiber having indefinite or extreme length, such as silk or a manufactured fiber.

Becke Line

A thin bright line that appears when light rays slightly converge or diverge.

interference colors

The ________ seen after crossing the polarizing filters relate to a fibers material nature, orientation, and crystallinity.

Acrylic

The fiber- forming substance is any long- chain synthetic polymer composed of at least 85 % by weight of acrylonitrile units.

Vinyl

The fiber- forming substance is any long- chain synthetic polymer composed of at least 50 % by weight of ________ alcohol units and in which the total of the ________ alcohol units and any one or more of the various acetal units is at least 85 % by weight of the fiber.

lower refractive index

If the fiber has a(n) ________ than the mounting medium, it acts as a "diverging "lens and the light rays diverge from the fiber.

Nonwoven Fabrics

An assembly of textile fibers held together by mechanical interlocking in a random web or mat, by fusing of the fibers or by bonding with a cementing medium.

higher refractive index

If a fiber has a(n) ________ than the medium in which it is mounted, it acts as a converging lens, concentrating light within the fiber.

Natural Fiber

any fiber that exists as a fiber in its natural state

Manufactured Fiber

any fiber derived by a process of manufacture from any substance that, at any point in the manufacturing process, is not a fiber

Protein fibers

composed of polymers of amino acids

Cellulosic fibers

made of polymers formed from carbohydrates

Mineral (inorganic) fibers

may be composed of silica obtained from rocks or sand

Synthetic fibers

made of polymers that originate from small organic molecules that combine with water and air

Staple Fibers

natural fibers (except silk) or cut lengths of filament, typically being 7/8-8in (2.2-28.5cm) in length

Denier

a direct numbering system in which the lower numbers represent the finer sizes and the higher numbers the larger sizes

Acrylic

the fiber-forming substance is any long-chain synthetic polymer composed of at least 85% by weight of acrylonitrile units

Anidex

the fiber-forming substance is any long-chain synthetic polymer composed of at least 50% by weight of one or more esters of a monohydric alcohol and acrylic acid

Aramid

the fiber-forming substance is any long-chain synthetic polyamide in which at least 85% of the amide linkages are attached directly to two aromatic rings

Glass

the fiber-forming substance is glass

Lyocell

composed of precipitated cellulose and produced by a solvent extrusion process where no chemical intermediates are formed

Metallic

composed of metal, plastic-coated metal, metalcoated plastic, or a core completely covered by metal

Modacrylic

the fiber-forming substance is any long-chain synthetic polymer composed of less than 85% but at least 35% by weight of acrylonitrile units

Nylon

the fiber-forming substance is any long-chain synthetic polyamide in which less than 85% of the amide linkages are attached directly to two aromatic rings

Polyester

the fiber-forming substance is any long-chain synthetic polymer composed of at least 85% by weight of an ester or a substituted aromatic carboxylic acid, including but not restricted to substituted terephthalate units and parasubstituted hydroxybenzoate units

Saran

the fiber-forming substance is any long-chain synthetic polymer composed of at least 80% by weight of vinylidene chloride units

Spandex

the fiber-forming substance is any long-chain synthetic polymer composed of at least 85% of a segmented polyurethane

Vinyon

the fiber-forming substance is any long-chain synthetic polymer composed of at least 85% by weight of vinyl chloride units

Yarn

continuous strands of textile fibers, filaments, or material in a form suitable for weaving, knitting, or otherwise entangling to form a textile fabric

Z-twist; S-Twist

no twist at all

Plied Yarn

formed from a number of smaller single yarns twisted together

Fabric

a textile structure produced by interlacing yarns, fibers, or filaments with a substantial surface area in relation to its thickness

Woven Fabrics

those fabrics composed of two sets of yarns, called warp and weft, and are formed by the interlacing of these sets of yarns

Courses

rows of loops across the width of the fabric

Wales

rows of loops along the length of the fabric

Nonwoven Fabrics

an assembly of textile fibers held together by mechanical interlocking in a random web or mat, by fusing of the fibers or by bonding with a cementing medium

Crimp

the waviness of a fiber expressed as crimps per unit length

Cross-sectional shape

the shape of an individual filament when cut at a right angle to its long axis, is a critical characteristic of fiber analysis

Animal Fibers

come either from mammals (hairs) or from certain invertebrates, such as the silkworm

Manufactured fibers

the various families of fibers produced from fiber-forming substances, which may be synthesized polymers, modified or transformed natural polymers, or glass

Synthetic fibers

those manufactured fibers that are synthesized from chemical compounds

Spinning Dope Synthetic fibers

are formed by extruding a fiber-forming substance, through a hole or holes in a shower head-like device called a spinneret

Polarized light microscope

the primary tool for the identification and analysis of manufactured fibers

Pigment

are microscopic, water-insoluble particles that are either incorporated into the fiber at the time of production or are bonded to the surface of the fiber by a resin

Visual Examination

this method is subjective and because of day-to-day and observer-to-observer variations, it is not always a repeatable method