Chapter 9 Knitted Fabrics and
Their Properties
y
Knit fragments dating back to 250 BC
◦ Compared to 9,000 years for wovens
y
Introduced to Europe by the Arabs
◦ Did not gain popularity until around 1,000 AD
Knitting
The act of interlooping yarn to create fabric as opposed
to weaving, which is interlacing yarns to create fabric.
Loop Components
y
Loop Appearance
Knitting Industry
y
Two main segments
◦ Knitted yard goods
◦ Knitted apparel
y
Advances in computer technology
◦ Ability to respond quickly to the rapidly
changing fashion industry
Knitting Machines
y
Two basic types of knitting machines
◦ Flat knitting machines – Fig. 9-2 p. 140
x Produce flat fabric
x Produce both warp and
weft knits
Knitting Machines
◦ Circular knitting machines – Fig. 9-3
x Predominately weft knits
x Produce tubular fabric
x Faster than flat knitting machines
Knitting Machines
y
Seamless knitting machine
◦ Seamless garment is made from a very special
state of art tube knitting machine
Categories of Knits
y
Two main categories
◦ Weft knits (on left)
x Sometimes called filling knits
◦ Warp knits
(on right)
Knit v. Woven
y
Major difference between knitted and
woven fabrics
◦ Knitted fabrics – interlooping yarns to create
fabric
◦ Woven fabrics – interlacing yarns to create
fabric
Knit vs. Woven
Knit v. Woven
y
KNITS (slide 1)
◦ Cheaper to produce
◦ Require higher quality yarns
◦ Yarns must be uniform so that thin spots don’t form
on the fabric
◦ Looped structure =
x Knit fabric is less opaque
x provides less cover
x Allows for stretch + recovery as body moves
x Requires thicker and/or heavier yarn to provide
equal cover to that of a woven
x Tendency to snag /run in weft knits
Knit v. Woven
y
KNITS (slide 2)
◦ Easier / quicker to change design patterns
◦ Known for comfort and ease of fit
◦ Bulky = good insulation and warmer
◦ Wrinkle recovery superior
◦ Problem with stretching out
x Should be folded not hung
x Sagging at stress points (knees, elbows)
◦ Shrink more than wovens
Knit v. Woven
y
WOVEN
◦ More expensive to produce
◦ Can use lower-quality yarns
◦ More difficult to change pattern on loom
◦ Looms use more energy/louder than knitting machines
◦ More rigid/less able to conform to body
◦ Superior resistance to wind
◦ Can be set with sharper pleats and creases
◦ Do not stretch out/can be hung
◦ Less tendency to hang
◦ Less tendency to shrink than knits
Knitting Terminology
y
y
y
y
y
Stitch
◦ The loop of yarn formed by the knitting process
Knit
◦ Basic knitting stitch
Purl
◦ Horizontal rows
Wales
◦ Loops form Vertical ribs/columns – parallel to selvage
Gage or Gauge
◦ the density of knitting machine needles, and the
number of knitting needles per inch (approx. 2.54cm).
The smaller the figure, the coarser the stitch, and vice
versa
Gauge example
Knitting Terminology
y
y
y
Courses
◦ A series of successive loops laying crosswise in the
fabric
Face/Back
◦ Just like a woven fabric, there is a face and a back to
the knitted fabric
Cut
◦ The fineness of weft knits made on a circular knitting
machine
The higher the gauge or cut number, the finer the fabric
Components of Knit Construction
Variables in Knitted Construction
y
A great deal of variety may be created by
manipulating the following:
◦
◦
◦
◦
◦
Fiber content
Yarn type and twist
Fabric count
Coloration
Finishes
4 stitches make us all knit fabrics
Weft Knits
◦ Can be made by hand knitting, or a circular or
flat bed machine
◦ Made with one continuous yarn that travels
around the fabric on a circular knitting
machine and across the fabric on a flatbed
machine.
◦ Common weft knits:
x jersey knits
x rib knits,
x purl knits
Wales on front – vertical
y Courses on back - horizontal
y
Weft knit–vertical wales on face
Weft knit–horizontal
courses on back
Weft Knit Stitch Variations
y
Miss or Float Stitch
◦ Used to create patterns or change colors
◦ Reduce the stretch of the fabric
◦ Prone to snagging
y
Tuck Stitch
◦ Used to create pattern and textured effects
◦ Identified by open lacy areas, bubbles, puckers
◦ Reduce the stretch of the fabric
y
Open, Transfer or Spread Stitch
◦ Fashion marks
x Shaped to fit during the knitting process
Weft Knit Stitch Variations
y
Open, Transfer or Spread Stitch
◦ Create texture
◦ Fashion marks
x Occur when transfer stitches change the number
and position of the yarns
x Shaped to fit during the knitting process
◦ Mock-fashion marks
x Do not shape the garment
Float stitch knit–face
Float stitch knit–back
Tuck stitch knit–face
Tuck stitch knit–back
Full-fashion marks
Mock full-fashion marks
Common Weft Knits
y
Jersey knits
◦ Also called single knits
◦ Economical to produce
◦ Knit stitches on front/ Purl stitches on back
y
Rib knits
◦ Knit and purl wales alternate across width
y
Purl knits
◦ Alternate courses of knit and purl stitches on
both sides of the fabric
Characteristics of Jersey Knits
y
Stretch crosswise and lengthwise
◦ Stretches more in the crosswise
Tend to run or ladder if stitch breaks
y Produced under tension
y
◦ Fabric less stable and curls when cut
y
Special finishes
◦ Counteract curling and improve stability
End Uses of Jersey Knits
Sheets
y Sweaters
y T-shirts
y Men’s underwear
y Dresses
y Hosiery
y
Jersey Knit Variations (pg 142-143)
Fleece #101
y Intarsia
y Jacquard knits #97
y Knitted terry #102
y Knitted velour #111
y Lisle
y Plaited knits
y Silver-pile knits
y
Characteristics of Rib Knits
Swatch #100
Reversible
y More elastic than jersey knits
y More stretch crosswise than lengthwise
y Edges do not curl
y Running and laddering still a problem
y More expensive to produce
y
Rib Knit Diagram
End Uses of Rib Knits
Collars
y Necklines
y Cuffs
y Bottom edges of sweaters
y Knit hats
y Men’s hosiery
y
Rib Knit Diagram
2x2 rib knit–face or back
1x1 rib knit–face or back
Rib Knit Variations
y
Double knits #104 & #105
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◦
y
Sometimes called double jerseys
Thicker than jersey knits
Two-way stretch
Very stable – will not ladder
Apparel and Upholstery used
Interlock knits #103
◦
◦
◦
◦
Specialized 1x1 rib knit
More stable and smoother than regular rib knits
Will ladder
Underwear, blouses and dresses
Interlock Diagram
Purl Knits
y
Produced on links and links machines
◦ Slowest of the knitting machines
◦ More expensive
y
Good stretch in all direction
◦ Stretches out of shape easily
y
y
y
Crosswise stretch less than a jersey knit
Thicker than jersey knits
Does not curl
Purl knit–face or back
End Uses for Purl Knits
Infant and children’s wear
y Sweaters
y Scarves
y
Warp Knits – see Fig. 9-8
Second major category of knit fabrics
y Characterized by vertical loops
y More resistant to laddering than weft
knits
y Usually done on flat knitting machine
y
◦ Two main types of warp knitting machine
(name = machine and fabric name)
x Tricot #106
x Raschel #107
x Minor warp knit – Simplex
Characteristics of Tricot Knits
Good elasticity
y Best of warp knits
y Inexpensive and quick to produce
y Curls along crosswise edge
y Good air and water permeability
y Soft
y Crease resistant
y Good drapeability
y
End Uses for Tricot Knits
Lingerie
y Nightwear
y Blouses
y Dresses
y Used as a backing fabric in multicomponent structures
y Limited interior uses because of high
elongation
y
Tricot Knit Variations
Brushed tricot
y Satin tricot
y Tricot-net fabrics
y Tricot upholstery
y Tulle
y
Raschel Knits
Swatch #107
Similar to Tricot Knits
y Greater diversity in design
y Differences between Raschel and Tricot
Knits
y
◦ Raschel has:
x More texture
x Open spaces
x Made from heavier yarns
Diagram of Simple Raschel Crochet Knit
Variations and End Uses of Raschel Knits
y
y
y
y
y
y
y
Warp knitted
Fine laces and nets
Heavy carpets
Thermal underwear with a waffle effect
Power-net fabrics for swimsuits and foundations
Heavy blankets
May resemble hand crocheted fabrics
Weft Insertion Knits
y
Insertion warp knits:
◦ Extra yarns may be inserted in the warp or in the
filling direction of warp yarns
y
Inlay Yarns:
◦ If yarns are inserted in warp direction
y
Power-net fabric:
◦ Raschel knit with inlaid spandex yarns.
Weft Insertion Characteristics
y
y
y
y
Fabric Appearance
◦ Extra set of yarns laid in
◦ Typically novelty yarns
◦ Other yarns may be laid in to add strength or stretch
Help add warmth or strength
Can be single or double knit
May also be warp knit
Diagram of Knitted Net
Care and Performance
y
Dimensional Stability = poor
◦ Stretch contributes to comfort but also to
poor dimensional stability
◦ Prone to shrinkage, stretching, and distortion
◦ Finishes
x Shrinkage control
x Heat setting of synthetics
x Resin finishes
Air drying and dry cleaning and help minimize
shrinkage
y
Pilling
Care and Performance
y
Pilling
◦ Made from fibers and yarns that are likely to
pill – wool and synthetic fibers
y
Snagging
◦ Looped structure of knit fabric increases the
possibility that snags occur
x If yarn has not been broken it is possible to work
back into the fabric
Handling in garment construction
y
y
y
Pattern
◦ Seam allowances vary on patterns, the 1/4" (6 mm)
seam allowance is the easiest to use.
Layout
◦ Knits have shading and pattern pieces should be cut in
one direction and be placed with the greatest degree
of stretch around the body.
Marking and Cutting
◦ Use weights to hold pattern pieces in place. A rotary
cutter works very well with knits, just be sure to use
a matt to protect your cutting table.
Handling in garment construction
y
Lining
◦ Interfacing is used to reinforce closures, add shaping to collars,
cuffs and plackets and stabilize areas such as shoulder seams and
some necklines. The best interfacing is a 100% polyester fusible
lightweight knit interfacing.
y
Stitching
◦ Sew the seam using an overlock stitch. This stitch sews and
overcast in one step. It is not necessary to stretch the fabric
while sewing as stretch is built in.
y
Fasteners