Understanding Jacquard Looms – India

In weaving,
the shed is the separation between the two layers of warp yarn to facilitate
weft insertion. The process of raising and lowering of the upper and lower warp
threads for interlacing of weft threads is shedding.
Depending on
the fabric to be woven, three shedding processes are available:
1. Dobby shedding
2. Tappet shedding
3. Jacquard shedding
A heald (also
called heddle) is a
looped wire or cord suspended from the shaft of a loom. It has an eye in the
centre through which a warp yarn is passed in a loom before going through the
reed to control its motion and to separate the threads for weft insertion. There are as many healds as there are threads. A set of
healds support a structure called as heald frame.
Dobby shedding:
·
It is a shedding mechanism placed on the top of the loom to create
patterns by using larger number of healds as compared to a tappet.
·
It is compact and electronically guided. Designs are more complex than a
tappet but production of tappet is greater.
·
Theoretically it can control up to 48 heald frames, but in practice it
uses 36 for woollen fibres and 24 for fibres like cotton.
·
Dobby looms usually provide geometric design or patterns.
Second-hand Rapier looms and Airjet
looms with Dobbies can be purchased at Vendaxo.
Tappet shedding:
·
The tappet works on the principle of rotary motion to produce
reciprocating motion in the followers and levers. The heald frame is operated
by this rotary motion. The followers are called anti-friction bowls while the
levers are formally known as the treadle arrangement.
·
The nature of the movement is such that the number of heald frames is
limited to 8. Any design requiring more than 8 heald frames needs a dobby loom.
·
Due to its simple and limited shedding mechanism, the design is
restricted to plain designs.
Jacquard Loom:
The Jacquard
machine is a device fitted to a power loom that can be used to produce
elaborate designs and patterns that cannot be easily accomplished by dobby and
tappet systems.
Salient
features:
·
A
jacquard shedding loom provides unlimited design options because each warp yarn
can be individually controlled.
·
It
has no heald frames, instead, a harness comprising of as many wires as there
are ends in the warp sheet connects each end individually to the loom. The
harness is used to lift and lower the warp thread.
·
The
loom can control up to 2000 ends per repeat/cycle.
·
The
only limit to the number of repeats is the cost and inconvenience of producing
a very complicated pattern chain.
·
Two
or more jacquard machines can work in conjunction if more independent lifts are
required.
·
It
can be operated electrically but also manually by skilled workers.
Advantages:
·
Any
kind of design is possible using a jacquard machine. The weave produce is very
intricate.
·
It
has a wide variety of customisations possible to suit the need of the owner.
·
It
can be used to weave specialised fabric such as terry towels, carpets and
damask.
Disadvantages:
·
Cost
of installation runs high because of the complex machinery.
·
They
need to be operated very carefully because they are prone to producing errors.
·
The
fabric produced is more expensive than dobby or tappet.
·
Production
is not as much as simple mechanism of the tappet.
Check out
high quality second-hand Jacquard looms here at Vendaxo.