How Are Pirns Wound? - Trim Engineering Services

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Pirns are rods onto which weft thread is wound
for use in weaving. While they sound similar to
bobbins, but they are different in that they are
fixed in place and the thread is delivered off
the end, rather than from the center. They are
not wound evenly from end to end in order to
ensure snag-free thread delivery. Pirns are
generally made of plastic or wood, and are
slightly tapered for most of the length, tapering
at the end. Pirns are generally used with power
looms that have automatic changing mechanisms,
which remove the used pirn from the shuttle and
replace it with a fresh one, thus allowing
uninterrupted weaving.
Having enough pirns in hand can help make your
weaving time more effective and free of time
wastage. Also, by pre-loading pirns, you can
change colours and transition projects more
easily and quickly. Thus, it is advised to have a
good number of pirns in stock before commencing
your project. You can approach Trim Engineering
Services, one of the renowned pirn manufacturers
in India, to get the best quality pirns for any
kind of project. Pirns are basically of three
types, namely plain tapered, full-base, and
partly-formed-base pirns. All these pirns are
long and thin, but the dimension of each of these
pirns is controlled by the dimension of the
shuttle it needs to be placed in. Whatever the
kind and size of pirn, the winding process is
same for all. Pirn winding is generally done on
special automatic pirn winding machines
consisting of spindles. In case of regular
winding, the cross-wound package results in
tension variation during weaving, while the
parallel-wound package results in instability.
This is why winding of pirn involves overlapping
short cross-wound sections in conical patterns.
The winding process begins from the conical base
of the pirn, and slowly advances towards the
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tip. Instead of travelling back and forth along
the package, the yarn that is transferred from
the larger package to the smaller pirn is wound
on one part of the package at a time. This
mechanism maintains uniform tension of the thread
on the pirn and reduces ballooning effects that
are seen in bobbins, which reduces the
possibility of slough-off. This winding
mechanism also cleans the pirns from any kinds of
slubs or other faults during weaving itself,
which is why no additional yarn cleaning
operation is required while winding pirns. When
a pirn is filled, the machine automatically
removes it from the spindle and replaces it with
an empty pirn to be filled again, thus allowing
uninterrupted weaving. All kinds of silk,
cotton, woolen, synthetic fiber, and terrycot
yarns can be wound in this way. When a ready
pirn is used to weave, it is put into a shuttle
that travels back and forth across the width of
the shuttle loom. This movement unwinds the yarn
from the pirn through the eye or slot of the
shuttle. This is how simple the winding and
weaving mechanism of a pirn is. But, isnt it
interesting to know how pirns and bobbins are so
different from each other, while they perform the
same task! For more information, visit
http//www.trimengineering.in/