SRRC engineers
soon improved their invention by adding two inexpensive attachmentsthe
aerodynamic cleaner and airbrush doffer. The aerodynamic cleaner increased by
one-third the capacity of the opener-cleaner. Together, they removed up to 45
percent of the trash from lint cotton, compared to 30 percent for conventional
cleaners. Just as important to mill owners, the SRRC inventions cleaned out
much of the so-called pepper trash--tiny bits of leaves and bark that had
previously resisted removal.
The next big SRRC invention in aid of cotton
processing was the granular card, patented in 1959. Simple and relatively
inexpensive, it was the first major change in the cotton carding machine since
its invention 200 years earlier. Like the machine it was designed to replace,
its purpose was to brush, clean, disentangle, and straighten the cotton fibers
before spinning them into yarn. The granular card replaced a carding machine
that had an elaborate assembly of brushes and other moving parts. The new
carding machine has a rough, granular surface on the underside of a fixed
cover. As the cotton passes over this rough surface, pushed along by air
currents, its matted fibers are disentangled and smoothed for subsequent
spinning into yarn.
Use of SRRC's granular card cut cotton waste
in half. Since it was a sealed unit, it also eliminated a major source of
cotton dust in textile mills. The machine was an instant success. One
technologist remembers his first look at the new card: The cotton came
out as light as a cloud and just as white. It seemed to float. Within 6
years after its invention, 24 firms had been licensed to manufacture it and
2,500 cards had been installed.
The industry was also quick to adopt a small
inexpensive SRRC invention called the pre-opener roll. Its function was to
remove the large unopened lumps of cotton from the card and return them to an
earlier stage of processing so that they could be reprocessed. Developed at a
low cost, some 4,000 pre-opener rolls were installed within 6 years.
The year 1963 saw the invention of the fiber
retriever, another inexpensive device that increased the efficiency of the
cleaning section of the card by as much as 40 percent. It also removed a high
percentage of short cotton fibers and decreased the loss of spinnable fibers,
thus improving yarn strength and uniformity. II was also welcomed by industry;
more than 20,000 retrievers were in use within 3 years.
Many of the most useful inventions developed
in New Orleans were instruments and procedures for testing cotton fibers. New
varieties of cotton and new methods of harvesting and ginning caused wider
variations in cotton quality than ever before. Also, faster spinning speeds in
textile mills and other changes made it more important than ever for mills to
know the significant properties of cotton in each bale before blending it with
others.
One new testing instrument SRRC scientists
named the nepotometer; it predicts the neppiness of cottons. Neps are the small
knots of tangled fibers that form during processing. They are tough to remove
and one of the many causes of poor fabric quality.
Another tester developed in the 1950's under
SRRC contract was the stelometer, which measures the strength and
stretchability of bundles of cotton fibers. Yet another was the digital
fibrograph to measure fiber length and length distribution with speed and
economy.
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