Woven Fabrics - Fairchild Books

Over 4,000 years ago, man created fabric through
the use of a crude wood-framed loom. Typically
this weaving device held yarns in an upright position as
they were interlaced with one another by hand. Primeval
man used this to make fabric to clothe and protect.
As civilization began to develop, some woven fabric was
used to indicate standing within the community. Eventually,
royalty and religious figures used ornately woven
fabric to indicate their stature. Looms were also used to
depict stories in woven fabric, some of which are now
highly valued (e.g., tapestry). Centuries later, as looms
became more sophisticated and yarns smoother and
finer, looms were used to create some of the world’s most
intricate woven fabrics.
Woven fabrics are made by interlacing two sets
of yarns at right angles to each other. The length-wise
yarns are known as warp yarns, or ends, and the widthwise
yarns are known as filling yarns, or picks. The
length-wise edges of the fabric are the selvages. The selvage
is usually easily distinguishable from the rest of the
material. (See p. 93.)
Grain indicates a direction parallel to either the
warp or filling yarns. The term on grain is used if a
fabric has been cut parallel to either the warp or filling
yarns. A direction not parallel to either of these yarns is
called off grain, or bias. Fabric cut off grain results in a
skewed portion of the textile product (e.g., pants leg or
drapery). Woven fabrics elongates most in a direction
that is 45° to both sets of yarns. The reason for this is
that there is maximum yarn bending and shifting from
the pulling force being exerted. Pulling that is on grain
results in only a slight yarn extension, with the least
amount usually in the warp direction.
Woven fabrics also have their best drape in a bias
direction. This is the result of the bending and shifting
of the yarns from the fabric weight. Some garments are
cut on the bias (i.e., the bias direction is vertical in the
garment) to obtain maximum drapability, as shown in
Figure 5.1. A problem that can occur, however, is the
garment may grow (i.e., increase in length) and become
uneven in length when worn.
Bias bindings are narrow strips of fabric cut in the
bias direction used to finish the edges of seams in sewn
products. This binding elongates to conform to the
shape of curved seams, thus eliminating the puckering
or small wrinkles that would occur if the binding were
cut on grain.
FABRIC SCIENCE
A 90 F
Figure 5.1
Sketch of a garment cut on the bias.
The Loom
Woven fabric is produced on a loom (Figure 5.2). The
following is a simplified explanation of the process utilized
to produce woven fabric:
u The warp beam, located at the back of the loom is
a large roller on which all the warp yarns to be used
for the fabric are wound parallel to each other.
u The warp yarns pass through the harnesses, which
look like picture frames holding many thin vertical
wires called heddles, each with a hole in the middle.
Each warp yarn is threaded through the hole of
a heddle and thus is controlled by that harness.