To convert textile fibers into fabrics
some type of fiber arrangement is required.Probably the most common method is
to convert fibers into yarns, which are then constructed into fabrics. Yarns
are essential for knitted, woven or knotted structures and for many braided
ones.
‘Yarn’ is defined by the American
Society for Testing and Materials (ASTM) as “A generic
term for a continuous
strand of textile fiber, filament, or material suitable for knitting, weaving
to form a textile fabric. Yarn occurs in the following forms.
(a) A number of fibers twisted
together.
(b) A number of filaments laid
together without twist.
(c) A number of filaments laid
together with more or less twist.
(d) A single mono filament. e.g. Silk
Yarns can be made either from short
staple length fibers or from filament fibers.
There are two types of yarns, i.e.,
spun yarns and filamentous yarns.
If filaments are used to make yarns they may be either multifilament or
monofilament
Mono filaments are filament yarns Multi filaments are composed of many
composed of one single filament. Filaments
Characteristics
of Spun Yarns and Filament Yarns
a.
Balanced Yarns:
a.
Unbalanced Yarns:
Crepe and textured surface may be
created from unbalanced yarns.
DIRECTION OF TWIST:
In addition to the amount of twist in
a yarn, the direction of the twist
is also designated. There are two
types of yarn twist S and Z.
Single, Ply and Cord
Yarns
Yarn Numbering
System:
Yarn numbering systems are therefore
used to express a relationship between a
unit length and weight of yarns. There
are two main numbering system in use.
