1. TEXTILE SCIENCE

2. WEFT KNITTING
 Weft knitting is the simplest method
of converting a yarn into fabrics.
 Weft knitting is a method of forming a
fabric in which the loops are made in horizontal way from a
single yarn and intermeshing of loops take place in a
circular or flat form on a crosswise basis.
 In this method each weft thread is fed, more or less, at
right-angle to direction in which fabric is formed.

3. WEFT KNITTING – contd..
 Each course in a weft knit builds upon the previous
knitted course.
 Most of the weft knitting is of tubular form.
 It is possible to knit with only one thread or cone
of yarn, though production demands have resulted
in circular weft knitting machines being
manufactured with upto 192 threads (feeders).

4. Types of Weft Knitted Fabrics
Weft
Knitted
Fabrics
Plain
Knits
Purl
Knits
Interlock
Knits
Rib Knits

5. PLAIN KNIT
 If a weft knitted fabric has one side
consisting only of face stitches,
and the opposite side consisting of
back stitches, then it is described as a plain knitted fabric.
 It is also frequently referred to as a single jersey fabric
(single fabric). Plain knitted fabrics are produced by using
one linear array of needles.
 As such all the stitches are meshed in one direction.
 These fabrics tend to roll at their edges.
PLAIN KNIT

6. PLAIN KNIT – contd..
 They roll from their technical
back towards the technical front
at the top and lower edges.
 They also roll from their technical front towards the
technical back at their selvedges (the self-finished left and
right-hand edges of the fabric).
 The structure is extensible in both lateral and longitudinal
directions, but the lateral extension is approximately twice
that of the longitudinal extension.

7. PROPERTIES
 Single jersey is composed of a number of identical
loops, all pulled through the preceding loops from the
back of the face of the fabric.
 This stitch is mostly employed in single jersey weft
knitting machine.
 This stitch is the simplest one & the process is rapid.
 The fabric produced with this stitch have flat vertical
lines on the face of the fabric and the dominant
horizontal ribs on the back side.

8. PROPERTIES
 Plain knit can be unravelled from the course knitted
last. Here the height and width of loop is equal.
 This fabric has the maximum covering power and has a
potential recovery of 40% in width after stretching.
 This stitch is used for preparing ladies stockings,
banians, men's and ladies shirts.
 Its production rate is high because of stitch simplicity.
 Plain knit fabric tend to curl.

9. USES
 Sheets
 Sweaters
 Terry robes
 T-shirts
 Men's underwear
 Dresses
 Hosiery and pantyhose
 Fully fashion garments

10. PURL KNIT
 If on both sides of a relaxed weft knitted
fabric only reverse stitches are visible,
then this is defined as a purl knitted fabric.
 Purl fabrics are produced by meshing the stitches in
adjacent courses in opposite directions either by using
special latch needles with two needle hooks or by
transferring the fabric from bed to bed between each
knitting action.

11. PURL KNIT
 When the fabric is stretched lengthwise, then the face
stitches are visible.
 The fabric shrinks more in the direction of Wales, and once
it is released, it relaxes to hide the face stitches between the
courses.
 The interlooping of the stitches of adjacent courses in
opposite directions results in the courses of a purl knitted
structure closing up.
 The structure, therefore, has a large longitudinal
extensibility.

12. CHARACTERISTICS
 Slowest of the knitting machines
 Both side similar appearance
 More expensive
 Good stretch in all direction
 Stretches out of shape easily
 Crosswise stretch less than a jersey knit
 Thicker than jersey knits
 Does not curl
 Can be unrove from either end

13. USES
 Infant and children's wear
 Sweaters
 Scarves
 Fancy garment parts
PURL KNIT

14. INTERLOCK KNIT
 Interlock knitted structures could
be considered as a combination of two
rib knitted structures.
 The reverse stitches of one rib knitted structure are covered
by the face stitches of the second rib knitted structure.
 On both sides of the fabric, therefore, only face stitches are
visible, and it is difficult to detect the reverse stitches even
when the fabric is stretched widthwise.
 The geometry of the yarn path influences the stretch
behavior of the knitted fabrics.
INTERLOCK KNIT

15. INTERLOCK KNIT
 The change of direction of the meshing of the stitches in
adjacent wales results in the wales of a rib knitted fabric
closing up giving it better stretch properties widthwise as
opposed to other basic knitted structures.
 The combination of two rib knitted structures in the
interlock structure gives very little or no room at all for the
wales or courses to close up and therefore the interlock
fabrics shows relatively poor stretch properties in both
directions.

16. INTERLOCK KNIT

17. CHARACTERISTICS
 Reversible
 It does not curl
 Firmer fabric
 Costlier fabric
 Better insulator
 Less extensible as compared to other jersey fabrics
 Heavier and thicker as compare to rib
 It unrove from the course knitted the last

18. USES
 Outwear fabric
 Dress wear
 Skirt
 Blouses
 T-shirts

19. RIB KNIT
 Rib, also called ‘Double-knit’ is the second family of knit
structures.
 Rib requires two sets of needles operating in between each
other so that wales of face stitches and wales of back
stitches are knitted on each side of the fabric.
 Rib fabrics are knitted on machines with two sets of
needles.
 Rib knits have a very high degree of elasticity in the
crosswise direction.

20. RIB KNIT – contd..

21. RIB KNIT – contd..
 To produce rib stitch, it requires two sets of needles
operating in between each other in a knitting machine. A
rib structure is also known as double jersey structure.
 Rib knit fabrics have alternating lengthwise rows of plain
and purl stitches constructed so that the face and back of
the fabric appear alike.
 This may be produced either on a flat rib machine or a
circular rib machine.

22. RIB KNIT – contd..
 In both machines, one set of needles pulls the loops to the
front and the other set pulls the loops to the back of the
fabric.
 Each set of needles alternately draws loops in its own
direction, depending upon the width of the rib desired.
 For example, rib stitches can be 1x1, 2x2, 2x1, 3x1, and so on.

23. PROPERTIES
 It is a reversible fabric that means it has the same
appearance on face and back of the fabric, both sides
showing face loops only.
 The back loops can be seen only if the fabric is
stretched width way.
 It has the excellent widthwise extensibility.
 As there are face loops and the back loops side by side,
the fabric does not curl at the edges.

24. PROPERTIES
 Wale lines on ribs run lengthwise on both sides can be
seen prominently. No course lines are seen.
 It is not ready to unravel the structure from start. It
only unravels from the end knitted last.
 Rib knits are warm.
 Rib is expensive than plain and it is a heavier structure.
 Output is less. Rib knitted fabrics are costlier.

25. USES
 Collars and cuffs
 Necklines
 Bottom edges of sweaters
 Double knits jackets
 Knit hats
 Men's hosiery
 Rib knits are usually found on the lower edges of sweaters, sleeves of
the wrist line and at neck line, cuffs, stockings, socks, etc.

27. PLAIN FABRIC & MACHINE RIB FABRIC & MACHINE
1. Face side and Back side of fabric are
different
1. Face side and Backside of fabric are
same.
2. Less expensive 2. Expensive
3. Lighter fabric 3. Heavier fabric.
4. Produce by S/J m/c. 4. Produce by Double Jersey m/c.
5. The m/c. contains no Dial. 5. The m/c. contains Dial.
6. The m/c. contains Sinker 6. The m/c. contains no Sinker

28. PLAIN FABRIC & MACHINE RIB FABRIC & MACHINE
7. The m/c. contains one set of needles 7. The m/c. contains two set of needles
8. Extensibility:
a) Length wise – 10 to 20%
b) Width wise – 30 to 40%
8. Extensibility:
c) Length wise – 50 to 80% (for 1´1 rib)
d) Width wise – 30 to 45% (for 1´1 rib)
9. Thickness & Warmth: Thicker and
wormier than plain woven made from
same yarn.
9. Thickness & Warmth: Much thicker
and wormier than plain woven made
from same yarn.
10. Curling: Tendency to curl 10. Curling: No tendency to curl
11. End use: Ladies stocking, fine
cardigan, men and ladies’ dresses,
sweater etc.
11. End use: Socks, cuffs, warm
outerwear, under wear etc.