No matter what type of weaving is being done, four major operations are performed in sequence
and are continuously repeated.
Shedding
In shedding, alternate warp yarns are raised to insert the filling yarn into the
warp to form a shed. Shedding is automatically performed by the harness on the
modern weaving looms. Harness is a rectangular frame to which a series of
wires, called heddles, are attached. As each warp yarn comes from the warp
beam, it passes through an opening in the heddle. The operation of drawing each warp yarn
through its appropriate heddle eye is known as drawing in.
Picking
As the warp yarns are raised through shedding, the weft yarn is inserted through the shed by a
carrier device. A single crossing of the filling from one side of the loom to the other is called a
pick. Different methods are used for carrying the filling yarn through the shed in different kinds
of looms. There are many types of looms including shuttle loom, shuttle less loom, and circular
loom.
Beating Up
This weaving operation is also called battening. In it, all warp yarns pass
through the heddle eyelets and through openings in another frame that looks like
a comb and is known as reed. With each picking operation, the reed pushes or
beats each weft yarn against the portion of the fabric that has already been
formed. It results in a firm and compact fabric construction.
Taking Up and Letting Off
As the shedding, picking and battening processes are being operated, the new
fabric is wound on the cloth beam. This is known as 'taking up'. At the same
time, the warp yarns are released from the warp beam which is known as 'letting
off'.
The pattern of the weave depends on the manner in which groups of warped yarns are raised by
the harnesses to allow the insertion of the weft yarn. These differences are responsible for
producing different types of fabric weaves. Weave patterns can create various degrees of
durability in fabrics apart from their utility and looks.