23 questions about Textile class.
47290v3o0
chapter10rapanote_2.pptChapter 10
Yarn Processing
T101
Survey of the Textile Industry
Christina Rapa
215-490-7999
- A continuous strand of textile fibers, filaments, or material in a form suitable for knitting, weaving, or otherwise intertwining to form a textile material
Yarn:
- Smooth filament yarns
- regular or conventional filament yarns
- Production
- used as produced, no further processing required
- Uses:
- smooth, lustrous fabrics or where high strength, compact yarns are needed
Filament Yarns
Filament Yarn Production
Monofilament and Multifilament
- More expensive than staple to produce; low production rate, number of holes in spinneret equal to number of fibers in yarn
- Smooth with low or no twist, except crepe twist yarns
- No protruding ends (no lint, no pills)
- Sheds soil
- Compact with little bulk, cover, or loft
Filament Yarn Characteristics
Fabric Swatch Kit #25
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- Greater covering power or apparent volume compared to smooth filament yarn
- Also called bulk continuous filament (BCF) yarns
- Characteristics
- Less smooth
- More permeable to air & liquids
- Less slippery
- More comfortable (may be more absorbent)
- Less static prone
- More bulk, cover, and elasticity
Bulk Yarns
Bulk Filament Yarns
Smooth filament
Spun
Bulk filament yarns
High Bulk Yarns
- False twist
- Continuous process where yarns are twisted, heat set, uncoiled
- Widely used method
- Draw texturing
- Drawing & texturing in one step
- Faster
- Cheaper
Texturing Yarns
- Filaments are stuffed into heated box
- Increases volume 200-300%
- Widely used method
Texturing Yarns – Stuffer Box
- Air tangles fiber
- Increases volume 50-150%
- Little or no increase in stretch
Texturing Yarns – Air Jet
Filament yarns are:
- knit into fabric
- heat set
- Un-knit
Texturing Yarns – Knit-de-knit
- Continuous strand of fibers held together by some binding mechanism (TWIST!)
- Made from short fibers
Spun Yarns
- Fuzzy: fiber ends protrude along length of yarn
- Likely to pill as fiber ends break off
- More comfortable when in contact with skin
- (less area of yarn in contact with skin, the more comfortable and less clammy & confining it is)
- More likely to create problems with soiling
Spun Yarn Characteristics
Fabric Swatch Kit #113
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Early Yarn Spinning
Spinning Processes
Spun Yarn Sequence
Spinning Process: Fiber Selection
- Opening
- loosens, cleans, blends fibers; removes dirt; helps determine yarn quality
Spinning Process: Opening
- Drawing
- increases parallelism of fibers; combines carded slivers into a drawn sliver; continues blending for self-blended yarn, decreases sliver size
Spinning Process - Drawing
- Combing
- select yarns of high quality fibers; removes short fibers & increases parallelism of fibers
Spinning Process - Combing
Comparison of
Carded / Combed Yarns
| Component | Carded | Combed |
| Fiber length | Short staple | Long staple |
| Yarn | Less regular in size & appearance Medium to low twist More protruding ends Less parallel fibers, coarser Bulkier, softer, fuzzier More fibers present | More regular in size and appearance Medium to high twist Fewer protruding ends Parallel fibers, finer count Longer wearing, stronger Fewer fibers present |
| Fabric | May bag in stress areas Varies from soft to firm Wide range of uses Lower cost | Smoother surface, lighter weight Does not sag Takes and holds press Range from sheer to suiting Higher cost |
- Woolen system: wool fibers; soft, bulky, fuzzy yarns
- Worsted system: wool fibers; more even fiber distribution & more parallel; compact, smooth, strong yarns
- Flax system: tow yarns—shorter & less parallel fibers; line yarns: longer and more parallel fiber
Other Yarn Systems
Woolen yarn
Worsted yarn
- Roving—reduces size of drawn sliver, increases fiber parallelism; adds small amount of twist. Repeated several times (blending often occurs here)
- Inserting yarn twist—several options to reduce size & add full amount of twist; winds finished yarn on bobbins
Spinning Process - Roving
Spinning Process - Roving
Inserting Yarn Twist – Ring Spinning
- Open End rotor (OE)
- eliminates roving & ring twisting (better quality yarns, fewer knots)
Inserting Yarn Twist – Open End Rotor
Inserting Yarn Twist – Air Jet
- Air jet
- Similar to rotor, but twist formed by moving air
- Rougher & less elastic yarns than rotor spun yarns
Ring vs. Open End vs. Air-Jet
- Vortex (MVS)
- Twist develops as fibers swirl around spindle; eliminates shorter fibers
Murata Vortex Spinning
What fiber uses MVS to reduce pilling?
- Self-twist—inexpensive way to ply 2 yarns of different twist (1S & 1Z) direction
- Creates faux heather or marled yarn effects
Siro Spinning
- Blend:
- intimate mixture of different fibers (varied by type, length, size, color, etc.) in one yarn
- Mixture:
- one type of yarn used in one fabric place (i.e. warp) & another type used in another fabric place (i.e. filling)
- Combination:
- two unlike yarns twisted together to form a ply (simple or novelty yarn)
Fiber Blends
- Achieve better combination of characteristics in product (characteristics are combinations of fibers in the blend)
- Improve processing and uniformity
- Enhance hand, texture, and appearance
- Economize
- Obtain cross-dyeable effects
Reason for Blends
