PREPARATION OF FIBER FOR SPINNING--FORMATION OF “SLIVER”
The opening room where the fiber is made ready for the preparation
machinery is a reminder of the days when all rope-making processes were
hand work. The bales are first opened up. In the case of Manila this
means cutting away the straw matting put on to protect the fiber in
shipment. Then the hanks which are packed in various ways--sometimes
doubled, sometimes twisted--are taken out and straightened and the band
at the end of each hank removed.
No machinery has yet been perfected for doing the work just described,
but the first of the preparation processes, a short step beyond, tells
quite a different story. Here the hanks of such fibers as require a
special cleaning treatment are placed on fast-working hackling machines
which comb away most of the snarls, loose tow and dirt.
[Illustration: PREPARATION ROOM, NO. 3 MILL, PLYMOUTH CORDAGE COMPANY]
At this point hard fibers--Manila, Sisal and New Zealand--are usually
oiled to soften them and to make them more workable for the operations
that follow. The oil, furthermore, acts as a preservative. It is a
matter of importance to the buyer, however, that the fiber should not
be too heavily oiled, for that merely increases the weight and cost of
the rope without improving its quality. Our experts have determined
through long experience the amount of oil that should be used to best
serve the interests of both manufacturer and buyer, and have perfected
a process which insures a perfect distribution over all the fibers,
while frequent tests on each machine, in which definite quantities of
fiber are weighed before and after oiling, prevent any excess.
[Illustration: WHERE THE LUBRICATING OIL IS MIXED]
The quality of oil used is also important, for grades containing acids
have a harmful effect on all vegetable fiber. We compound our own oils
and we also take great care to prevent acids from entering our grounds
or factories and so coming in contact with our products.
Long ago the Plymouth Cordage Company learned that in the methods
employed in the preparation of fiber for spinning lay one of the
secrets of fine rope-making. To secure a more effective and special
treatment in this process, we have added to the regular machines many
improvements of our own. So highly perfected is the apparatus that
by machine work entirely the separate hanks of fiber are combed and
elongated into a soft, continuous sliver of any size desired and of
convenient length, glossy in appearance, perfectly clean, and with each
fiber lying as nearly as possible in the straight position which gives
it maximum strength. These operations, in which the entire character of
the comparatively short vegetable fiber changes seemingly, are wholly a
development of modern rope-making, since in the days of hand spinning
no sliver was necessary.
[Illustration: FORMATION OF SLIVER--FIRST BREAKER]
The machines are arranged in series, usually as follows: a first and
second breaker, a coarse and a fine spreader and a draw frame. The
treatment is varied to suit the particular requirements of different
hemps or ropes by a prolonging or shortening of the series and by the
adjusting of individual machines, but the method is always essentially
the same.
[Illustration: SECOND BREAKER
SPREADER
DRAW FRAME
REDUCING SIZE OF SLIVER FOR SPINNING]
The purpose of the first breaker is to form the primary sliver or
“roping” as it is sometimes called. The hanks of fiber--somewhat matted
if they have been oiled--are fed by hand into the machine, several at a
time. Steel pins fitted to a slowly revolving endless chain grasp the
mass while a second set of pins, moving more rapidly, draws out the
individual fibers and combs them into a continuous form.
[Illustration: GROUP OF DRAW FRAMES]
The operations which follow are very similar. A number of “ropings” are
allowed to feed together into a first, slowly revolving set of pins
and are drawn out again by a high-speed set into a smaller sliver, the
pins becoming finer on each succeeding machine until the draw frame is
reached. Here the fiber is pulled from a single set of pins between two
rapidly moving leather belts called aprons. On all of these machines
the fiber passes between rollers as it goes onto and leaves the pins
and the sliver is given its cylindrical form by being drawn through a
circular opening.
A finished sliver must conform to the special size desired for
spinning. Different sizes are secured by changing the number of
“ropings” which are allowed to feed into the fine spreader. When “rule
of thumb” standards of measurement were practiced the size of the
sliver was tested by the number of turns which could be clasped in the
hand between the ends of the thumb and forefinger. If the workman’s
hand chanced to be different from the official hand, he made allowances
accordingly. At best this was a rough and ready method, but through
long practice the men could become surprisingly expert. Mechanical
grips or clasps are now used because they are more convenient and
afford greater accuracy.
The wonder of modernism in rope-making is nowhere more striking than
in the preparation room. To pass from one end, where the raw hemp is
received just as it left the hands of the native Filipino laborer with
his crude methods, down through the long rows of machines to the draw
frames from which the sliver is delivered in a form that can be likened
to a stream of molten metal, is to cover decades of inventive genius
and mechanical development.
The mechanism performs its work so accurately that at first glance the
man feeding the fiber into the machine and all the other men, busy
about their various duties, would appear to be playing very minor parts
in modern rope-making. In reality, expert workmanship and watchfulness
are very important factors. Good rope depends no more upon scientific
machine processes than upon ceaseless attention to the little details.
And the attention paid to the details of the preparation room is
especially important.
A rope expert once said, “Any manufacturer can make rope--it is a
simple operation; but very few can make _good rope_ because few are
willing to devote the necessary amount of pains to each of the little
operations in the process.”
[Illustration: PLYMOUTH CORDAGE COMPANY FACTORY TODAY AND IN EARLY
DAYS]
[Illustration]