The internationally well-known and most important shrinking process
today dates back more than 70 years. Though the correct expression for
this process is Controlled Compressive Shrinkage, the average
person knows it as SANFORIZED. The process is a purely mechanical
treatment without any addition of chemicals.
The word SANFORIZED is derived from the first name of the inventor of
the compressive shrinkage process, Mr. Sanford L.
Cluett.
The Sanforized Company, a division of Cluett Peabody & Co., Inc., New
York, USA, is sole owner of the registered trademarks
Sanforized,
Sanfor and Sanforizado.
The Sanforized label means dimensional stability for garments
made up of Sanforized labeled fabrics.
The purpose of the process is to shrink fabrics in such a way that
textiles made up of these fabrics do not shrink during washing.
The amount of potential wash shrinkage must be determined prior
to shrinking. A full width sample is wash-tested according to the test
method. After the lengthwise and widthwise shrinkage has been
determined, the compressive shrinkage machine can be adjusted
accordingly.
The process can be described by the following schematic:
Fabric (F) passes through the skyer (S) or other moistening
device and is moistened by water and/or steam. This will lubricate
the fibers and promote shrinkability within the fabric. Normally, a
fabric must be moistened in such a way that every single thread
achieves a moisture content of approximately 15%. This allows
compression of the fabric with very little resistance.
When the fabric passes through the clip expander (C), we obtain
the required width. The clip expander also transports the fabric
to the most important part of the machine: the rubber belt unit
(indicated by arrows in above figure). In the close-up of fig. 1,
we see the endless rubber belt (R). By squeezing rubber belt (R) between pressure roll (P) and rubber belt cylinder (RB),
we obtain an elastical stretching of the rubber belt surface. The more we
squeeze the rubber belt, the more the surface is stretched. This point
of squeezing is known as the pressure zone, or the nip point.
Fabric (F) is now fed into the pressure zone. When leaving the
pressure zone, the rubber belt recovers itself and the surface
returns to its original length carrying the fabric with it. The
effect of this action is a shorting of the warp yarn which packs the
filling yarns closer together. At this actual moment, shrinkage
occurs.
After compaction within the rubber belt unit, the fabric enters the
dryer (D). Here the fibers are locked in their shrunken state
by removing the moisture from the fabric.
After the compressive shrinkage process is completed, another sample
of the fabric is taken. This sample is also wash-tested. The final
result of this test must meet the Sanforized Standard, in length and
width before it may carry the Sanforized label.
All Sanforized Licensees are contractually obligated to follow
the required test method and meet the standards set forth by The
Sanforized Company
Ref:
Courtesy: rauf.com
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