Woven Fabrics - Fairchild Books

weight of the yarn is indirectly proportional to the
yarn-count number. Cotton yarn, for example, which is
used for sheer voile fabrics, may be as fine as 100 count,
whereas thicker yarns used in many poplin fabrics may
be a 30 count. Heavy cotton duck fabric used for truck
tarps may be made of 5-count yarn.
How Spun Yarn Count Is Expressed
The method of expressing yarn size of spun yarns differs
by the fiber content. Yarns spun on the cotton count
system, for cotton and cotton blends, are designated
as c.c. for cotton count. They may also be specified as
Ne for Number English and cc could be replace with
Nec. Cotton and cotton-blend yarns are expressed by
two numbers: The first is the yarn size and the second
indicates the yarn ply. For example, 50/1 means a size-
50 single yarn. (In oral communication, it is called a
“fifty single” or “fifties yarn”.) A 70/1 is a size-70 single
yarn or 70 s; 60/2 yarn is called a 60 two-ply or 60 s two.
Worsted, worsted blends, and acrylic fibers are spun
on the worsted count system and are designated by
w.c. or New. These yarns are indicated in the reverse
order from the cotton count system. For example, 1/50
(referred to as one 50 or singles 50) is a singles yarn of
50-count size. A 2/40 yarn is two size-40 yarns plied
together. This yarn is called a two-40 s yarn.
Woolen and woolen blends yarns are designated by
the term run, or Nar such as 4-run yarn. They are rarely
plied and are single yarns unless otherwise indicated.
Linen yarns are expressed by the term lea, or NeL,
which is used for flax, jute, hemp, and ramie fibers. They
are almost never plied because the fiber length is so long
that plying does not improve the yarn measurably. Thus,
they are considered single yarns unless otherwise indicated.
Yarns as fine as 400-lea are used to make fine lace.
Spun yarns can also be expressed in the metric system.
The yarn size is indicated using the term metric.
For example, a 50-count metric yarn would be designated
as a 50 s metric. The metric yarn-count system
expresses the number of kilometers of yarn per kilogram
of weight. The system is used for all spun yarns and is
an indirect count method. It may be indicated by Nm
and is frequently used in international markets for any
spun yarn except spun cotton, which is indicated by Ne.
Several classifications are used for determining
yarn counts. These classifications are called yarn-count
standards and are different for each fiber-spinning system.
The yarn-count standard represents the number of
yards in one pound of a number 1 count of that specific
yarn. The following standards are in general use:
FABRIC SCIENCE
A 82 F
Cotton and cotton blends 840
Spun silk and all spun 100 percent
manufactured fiber yarns except acrylic 840
Worsted, worsted blends, and acrylic 560
Woolen and woolen blends (run) 1,600
Linen (lea) 300
All spun yarns (metric) 496.055
A number-1-count cotton has 840 yards in one
pound (768 meters per 453.6 grams) of the yarn, and
a number-1-count worsted has 560 yards in one pound
(512 meters per 453.6 grams) of the yarn. Both are called
number-1 yarns, yet each is of different weight per unit
of length. Thus a 20 cotton count would be finer than
a 20 worsted count because the former has 16,800 yards
per pound (15,362 meters per 453.6 grams) and the
latter has 11,200 yards per pound (10,214 meters per
453.6 grams).
Table 4.2 provides typical yarn number and denier
comparisons. When using this table, remember that a
200-denier filament yarn is of equal weight per unit of
length (and approximate thickness) to a 40-count worsted
yarn, a 27-count cotton yarn, a 14-count woolen
(run) yarn, a 74-count linen (lea) yarn, and a 45-count
metric.
There are many other variations of yarn numbers
used outside the United States.
Ply Yarn Counts and Singles Equivalent
Spun yarns that are plied are expressed as, for example,
40/2 (cotton type). This means that two yarns of 40/1
each have been twisted together. The thickness of the
resulting ply yarn is about twice that of the original 40/1
yarn, or about the same thickness as 20/1 yarn because
this is an inverse proportion system. The singles equivalent
of a 50/2 is 25 count, and of a 45/3 is 15 count.
Filament yarns are rarely plied because they gain
little by being plied. When they are, the usual method
of expressing such a yarn would be, for example, two-ply
40 denier. The singles equivalent of such a yarn would
be 80 denier.
Ply yarns and single-yarn equivalents are illustrated
in Figure 4.15.
The Tex System
The tex system is intended to replace all the existing
count and denier systems with a single system for