Exam 2 Flashcards
Yarn
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
Filament yarns are produced from-
- filament fibers reeled from silk cocoons
- polymers extruded through a spinneret
multifilament yarns
yarns made of many filament fibers
spun yarns
- produced by twisting together staple fibers
- the twist holds the short fibers together
- made of naturally occurring staple fibers or filament fibers cut into short fibers for spinning
Blend
yarn obtained when two or more staple fibers are combined in a textile process for producing spun yarns
intimate blend
- has an even distribution of fiber
- ex) cotton/polyester blends commonly used for shirts and bed linens
combination/mixture yarn
- plied yarn containing two or more yarns that vary in fiber composition, content, and/or twist level
- plied yarn composed of both filament yarn and spun yarn
opening
loosens, cleans, blends, and prepares fiber by removing waste
carding
partially aligns the fibers and forms them into a thin web that is brought together as a soft, weak, rope called sliver.
drawing
increases the parallelism of the fibers and combines several carded and combed slivers into one drawn sliver
combing
an extra step to create a superior yarn with smoothness, fineness, evenness, and strength
Roving
this step reduces the drawn sliver, increases the parallel alignment of the fibers, and the inserts a small amount of twist in the strand
simple yarns
- have uniform size and regular surface.
- divided into single, plied, cord, and rope yarns
single yarn
- simplest type of yarn
- commonly produced by twisting together staple or filament fibers
- include spun, monofilament, and multifilament
plied yarn
- produced by twisting two or more single yarns
- each strand of single yarn is referred to as a ply; four single yarns twisted together would form a four-ply yarn
cord yarn
produced by twisting two or more plied yarns
rope yarns
produced by twisting two or more cord yarns
novelty/fancy yarn
- typically made of two or more strands, provides decorative surface effects
- strands may be referred to as base/core, effect, or binder depending on their purpose
base/core strand
provides structure and strength
effect strand
creates decorative details, knots, or loops
binder strand
ties the effect yarn to the base yarn if binding is necessary
yarn number
- relative measure of the fineness of yarns
- two classes of systems are in use: direct and indirect yarn number
direct yarn number
- mass per unit length of yarn
- system is used for silk and manufactured filament yarns
- the lower the number the finer the yarn
indirect yarn number
- length per unit mass of yarn
- system is used for cotton, wool, linen type spun yarns
- yarn size of a single yarn or strand is the number of hanks in one pound, the higher the number the finer the yarn
s-twist
yarns twisted clockwise
z-twist
yarns twisted counter clockwise
crepe effect
produced by alternating s and z twist yarns
woven fabrics
- produced by interlacing perpendicular yarns.
- includes a warp and weft
knitted fabrics
- formed by interlooping yarns in a horizontal or vertical direction
- includes wales (length) and courses (width)
non woven fabrics
- also called fiber webs
- manufactured directly from fibers
Warp
- yarn running lengthwise on the loom, parallel to the selvage, and perpendicular to filling yarns
- warp yarns must withstand stress during weaving
- warp yarn (ends) are stringer and closer together than filling yarns
filling
- (called weft yarns or picks) yarn running crosswise on the loom perpendicular to the selvage and the warp yarns
selvage
the narrow edge of woven fabric that runs parallel to the warp. Made with stronger yarns in a tighter construction than the body of the fabric to prevent raveling.
how has weaving evolved?
weaving has evolved from simple techniques (like card and backstrap) to very sophisticated. computerized, shuttleless machines that operate at very high speeds.
simple looms
still used despite technological advancements to produce hand woven fabrics
power shuttle looms
mechanized versions of simple shuttle loom, produces narrow and wide width fabrics
shuttleless looms
- produce fabrics at very high speeds, yarn is carried from one selvage to another without a shuttle
- divided into: projectile, rapier, air jet, and water jet
fabric weight
important characteristic for describing and identifying for trade, naming, and selecting a fabric for a specific end-use