Warp knitting is a family of knitting methods in which the yarn zigzags along the length of the fabric, i.e., following adjacent columns ("wales") of knitting, rather than a single row ("course"). For comparison, knitting across the width of the fabric is called weft knitting

1. 1
Warp Knitting
Md.Azmeri Latif Beg
M.Sc in Textile Engineering
Daffodil International University

2. TOPICS NAME
Advanced_ Warp_ Knitting
Technique

3. WARP KNITTING
By Solayman Masud, ID: 142-32-260

4. What is Warp knitting?
• Warp knitting is a family of knitting methods in which the yarn
zigzags along the length of the fabric, i.e., following adjacent
columns ("wales") of knitting, rather than a single row ("course").
For comparison, knitting across the width of the fabric is called
weft knitting

5. Flow Chart of Warp Knitting
Beam
↓
Guide bar
↓
Needle
↓
Fabric
↓
Take-up
↓
Roll off

6. Types WARP KNITTING
Raschel, made with latch needles,
Tricot, using bearded needles.

7. WARP-KNITTING
When producing warp-knits, a yarn sheet is linked
by stitches in longitudinal direction.
Thus, each individual thread in the sheet (warp)
forms a wale

8. Main products
• Nets
• Curtains
• Technical fabrics
• Covers
• Covering sheets
WARP KNITTING

9. • Warp sheet
• Loops development with the help of needles
• Loops insertion with the help of needles
• Needle movement controls mechanically and
electronically
WORKING PRINCIPLE

10. • More stable than knitted
• Big and small holes are possible
• Many designs are possible
• Highly course yarn can be used
• Technical fabric can be produced
PROPERTIES OF WARP KNITTED FABRIC

11. • use to fulfill technical demands, like, filters,
seat covers etc
• used as curtains, table covers
• used as chadar in some countries
• not used for clothing
USE OF WARP KNITTED FABRIC
6/13/2015

12. WARP KNITTING
In this process;
• yarn sheet is developed (warp sheet)
• and then with the help of needles stitches
are formed by,
• insertion new loop into old loop

13. THE PROPERTIES OF WARP KNITTED
STRUCTURES
6/13/2015
Warp knitting offers:
• Higher production rates than for weaving.
• A wide variety of fabric constructions.
• Large working widths.
• A low stress rate on the yarn that facilitates careful
handling of fibres such as glass, aramide and carbon
(particularly when using weft-insertion techniques).
• Conventional warp knitted structures that can be
directionally structured.
• Three-dimensional structures that can be knitted on
double needle bar raschels.

14. WARP KNITTING MACHINE

15. WARP KNITTED FABRIC

16. WARP KNITTING TECHNOLOGY
• Warp knitting machines--needles are
mounted collectively and rigidly in a
horizontal metal bar (the needle bar that
runs the full knitting width of the machine).
• Equally the yarn guides are also set rigidly
into a horizontal metal bar (the guide bar
that runs the full width of the machine).

17. TRICOT KNITTING
Function of different parts of M/C:
1. Compound needle: In Tricot warp knitting m/c
compound needle is used. To form loop and produce the
fabric is the main function of the needle.
2. Needle bar: A needle bar is used in this m/c. The main
function of it is to hold the needles together and helps
the needles to move unison while loop forming.
3. Guide bar: Guide bar is used in this m/c to guide the
yarn properly to the needle. It feeds the yarn around the
needle and controls the rate of warp feed from the warp
beam by making lapping movement.

18. TRICOT KNITTING
Function of different parts of M/C:
4. Sinker and Sinker bar: In the tricot warp knitting m/c tricot
sinker is used to hold down the loops produced by the needles.
The sinker bar keeps the sinkers together to move unison while
knitting. The main function of the sinker is to hold down, knock
over and supporting the fabric loops.
5. Sliding latch: In warp knitting m/c compound needles
are used. A sliding latch is used here to close the hook
while knitting.
6. Sliding latch bar: In warp knitting m/c the sliding
latches remain unison. The latch bar keeps the latches
together and helps it to move unison while knitting.
7. Cloth roller: The produced fabric is wound on the cloth
roller.

19. TRICOT KNITTING
Function of different parts of M/C:
8. Lubrication: The m/c has automatic lubrication
system.
9. Controlling unit: The controlling unit is used to control
the m/c easily. It has a digital control unit.
10. Toothed belt: In this m/c the toothed belts are used
to transfer motion without any slippage.

20. Knitting Element Displacements
The diagram
summarizes the
somewhat
confusing
displacements
made by the guide
bar. The front of the
machine lies to the
right of the
diagram.

21. Knitting Element Displacements
The diagram shows
the individual yarn
guides set in a solid
bar. The front-to-back
movements are called
swings. The first
swing from front to
back is followed by a
lateral shog: the
overlap, which wraps
the yarn in the needle
hook

22. Knitting Element Displacements
The next movement is
a swing from back to
front followed by the
underlap that may be
from 0 to 8 needle
spaces depending on
the fabric structure
being knitted.

23. TRICOT KNITTING
In diagram (1.3 a & b)
the guide bar swings
from the front of the
machine (on the right
hand side of the
diagram) to the back
of the machine taking
the yarn through the
gap between two
adjacent needles.

24. TRICOT KNITTING
Diagram (1.4 c) shows the
guide bar moving laterally
towards the observer.
This is known as a shog
movement, specifically the
overlap that wraps the yarn
around the beard of the
needle.
Diagram (1.4 d) shows the
second swing in the cycle
taking the yarn between
adjacent needles back to the
front of the machine.
At this time the needle bar
moves upwards to place the
overlap below the open
beard on the shank of the
needle.

25. Diagram (1.5 e) shows
the presser bar moving
forward to close all the
needles and in (1.5 f)
the closed needle
passes down through
the old loop and the
sinkers move backwards
to release the old loops
so that knock-over can
take place.
TRICOT KNITTING

26. TRICOT KNITTING
In figure (1.6 g) the sinker
bar moves forward to
secure the fabric prior to
the needle rising in the
next cycle and at this
stage the guide bar makes
a second shog, this time
an overlap which may be
of 0 to 8 needle spaces
depending on the
structure being knitted.