Introduction to flat knitting

1. FLAT KNITTING TECHNOLOGY
INTRODUCTION :
 The fabric which is produced by the machine is
usuallyweft knitted fabric.
 Flat fabric will be produced.
 In the flat knitting machine needles are kept
stationary and the cam will me move along the width
of the machine ( vice versa to circularknitting
machine).
 It was first invented in 1865.
TYPES OF MACHINES:
Basicallytwo types
 V-Bed rib machine
 Flat bed purl machine
In a V-Bed machines needle beds are kept
diagonallyat the angle of 90 to 104 degrees.latch
needles are commonly used.
In a flat bed machines both beds are parallelto
each other and doublehook latch needle will be used.
MACHINE COMPONENTS :
Needle bed:
 The needle bed is a metal plate in which precisely
measured slots ( tricks ) are milled.

2.  The needles are inserted in these tricks and are
forced to slide backwards and forwards to form the
knitting sequence.
 The distance between the tricks and thickness of the
needles determine the thickness of yarn can be
processed by the machine.
 There are front and rear bed present in the flat
knitting machine.
CAM BOXES :
 To activate the needles and force them to slide up
and down in the tricks , the protruding butts are
made to follow the cam track.

3.  The cam track of a manuallyoperated knitting
machine have three types of cams ,
1. Raising cams :
The needle butts are forced upwards
on contact with these cams and the needles are driven
from their resting position to perform knitting sequence.
2. Lowering cams :
These force the needles butts
downward to knockover and to form a loops.
3. Fixed cams :
These are used to complete the smooth
shape of the cam track.

4. From the above cam structure , the dotted line indicate
the needle path which form knit stitch.
How can we introduce miss stitches ?
There is lever connected outside the cam box , the
cam ( metal piece) connected to the lever . if we don’t
need the cam , simply it will be withdrawn by the lifting
of lever.
If withdrawing the raising cam obviouslymiss stitch
will be produced.
How can introduce tuck stitch ?
There is a two type of raising cam present in the cam
box . Those were primary raising cam and secondary
raising cam. If withdrawing the secondary raising cam all
the needles will produce tuck stitch . For producing miss
stitch only primary cam will be withdrawn. For
producing knit stitch both the primary and secondary
cams will be inserted .

5. How can selectively introduce knit , tuck and miss
stitches ?
There is a one more positionof cam in between
fully inserted and fully withdrawn is partiallywithdrawn
of cam. Using high butt and low butt needle we can
selectively introduce knit , tuck and miss stitches.
If the cam in the fully inserted position, all the
high butt and low butt needles will introduce tuck
stitches .
If the cam in the partiallyinserted position , all
the high butt needles will produce knit stitches and all
the low butt needles will produce miss stitches.
If the cam in the fully withdrawn position, all the
high and low butt needles will produce miss stitches.
The simple logic is when we withdrawn the cams
partiallyonly the high butt needles will follow the cam
track. But the low butt needles will miss the cam track.
Conclusionabout cam box :
 Only we introduce two stitches simultaneouslyin the
knitting machine . but may be the next course we can
change the cam box arrangement.
 Different stitches can be achievedby positioningof
cams in the cam boxes ( two beds have separate cam
box )
Primary cam
position
Secondary cam
position
Results

6. Fully
inserted position
Fully inserted HBN knit , LBN
knit
Partially
withdrawn
HBN knit , LBN
tuck
Fully withdrawn HBN Tuck , LBN
tuck
Partially
withdrawn
Fully inserted HBN knit , LBN
miss
Partially
withdrawn
HBN knit , LBN
miss
Fully withdrawn HBN tuck , LBD
miss
Fully withdrawn Fully inserted HBN & LBN miss
Partially
withdrawn
HBN & LBN miss
Fully withdrawn HBN & LBN miss
HBN → High Butt Needles
LBN →Low Butt Needles
Racking of needle bed :
During the process of loop formation ,
one of the needle beds can be driven sideways a short
distance to change the relative positionof the needles is
called racking . it is measured by needle spaces .

7. Loop transfer can be achieved by
racking of needle bed and then transfer the loop from
one needle another needle ( spring loadedneedle ).
Is it possible to produce two separate fabrics
simultaneouslyin a flat knitting machine ( V-bed
machine ) ?
Yes , we can produce two separate fabrics
simultaneouslyin a V-bed machine . keep one set of
needles will be stationaryfor the two courses using one
feeder . then again for the two courses keep another set
of needles will be stationary using other different
feeder .The design will be like follow picture
Notationof above picture is

8. For a 5 th and 6 th course one set of needles will
knit , at the same time other set of needles will miss the
yarn from the first feeder.
For a 7 th and 8 th course one set of needles will
miss ( which is knit the yarn previoustwo courses) and
other set of needles will knit ( which is miss the yarn
previoustwo courses) the yarn from the second feeder.
So that four courses will be needed for
completing the design of producing two separate
fabrics.
The cams should be arranged by the followingimage

9. Is it possible to produce tubularfabric in flat knitting
machine ? ( V-bed machine )
Yes , we can produce tubularfabric in the flat
knitting machine. The same procedure followed for
producing two separate fabrics . The production of
tubularfabric using only one feeder will be enough

10. instead of using two feeders in the productionof two
separate fabrics.
So that two courses will be a repeat of design
to produce a tubularfabric . The design will be like the
following image.
For the productionof 5 th course one set of needles will
knit and other set of needles will miss the yarn from one
feeder .
For the productionof 6 th course vice versa to previous
course from the same feeder
The arrangement of cams for producing tubularfabric
will be like the following image :

11. Where the shaded part will be indicatethat cam will be
active
The biggest advantage of producing two separate fabrics
and tubularfabric:
a) We can produce a weft knitted fabric with a knitted
pocket . so that no need for stitching a pocket in a
knitted fabric.

12. b) We can produce a protective garment ( the body is a
separated fabrics and the edges will rib fabric) . we
can insert the metallic plate inside the fabric for
protection .
Advantages of flat knitting :
 Very suitable for high cost raw material due to the
zero percentage wastage.
 Due to the loop transfer , the yarns are not float
under the fabric , so that fabric weight will be less.
 Intersia fabric can be easily produce in a flat knitting
machine .
 The shifting of wale line can be achieved in the case
of flat knitting , so that we can reduce the width of
fabric during knitting.
Disadvantages of flat knitting :
 Very high cost of machine.