Hemp Hurds as Paper-Making MaterialDewey, Lyster H. (Lyster Hoxie)
Science
Hemp Hurds as Paper-Making Material
Dewey, Lyster H. (Lyster Hoxie)
Fiber plants; Hemp; Paper industry
The fiber is sometimes broken from dry hemp stalks without retting. The
hurds thus produced contain a small percentage of soluble gums, chiefly
of the pectose series. Comparatively little hemp is prepared in this
manner in America.
Process retting by means of weak solutions of chemicals or oils in hot
water is practiced to a limited extent. The hurds from these processes
may contain traces of the chemicals or oils and also soluble gums in
greater degree than those of the dew-retted or water-retted hemp.
=PROPORTION OF HURDS TO FIBER AND YIELD PER ACRE.=
[Illustration: FIG. 1.--Hemp-breaking machine. The stalks are fed
sidewise in a continuous layer 2 to 3 inches thick, turning out about
4,000 pounds of clean fiber per day and five times as much hurds.]
The yield of hemp fiber varies from 400 to 2,500 pounds per acre,
averaging 1,000 pounds under favorable conditions. The weight of hurds
is about five times that of the fiber, or somewhat greater from hemp
grown on peaty soils. A yield of 2-1/2 tons of hurds per acre may be taken
as a fair average.
=HURDS AVAILABLE FROM MACHINE-BROKEN HEMP.=
Hemp hurds are available only from hemp which is broken by machines,
when the hurds may be collected in quantity in one place (figs. 1 and
2). Most of the hemp in Kentucky is still broken by hand brakes. These
small brakes are moved from shock to shock, so that the hurds are
scattered all over the field in small piles of less than 50 pounds each,
and it is the common practice to set fire to them as soon as the brake
is moved. It would be difficult to collect them at a cost which would
permit their use for paper stock.
Where machine brakes are used, the hemp stalks are brought to the
machine as grain is brought to a thrashing machine, and the hurds
accumulate in large piles, being blown from the machine by wind
stackers.
Machine brakes are used in Wisconsin, Indiana, Ohio, and California, but
to only a limited extent in Kentucky. Five different kinds of machine
brakes are now in actual use in this country, and still others are used
in Europe. All of the best hemp in Italy, commanding the highest market
price paid for any hemp, is broken by machines. The better machine
brakes now in use in this country prepare the fiber better and much more
rapidly than the hand brakes, and they will undoubtedly be used in all
localities where hemp raising is introduced as a new industry. They may
also be used in Kentucky when their cost is reduced to more reasonable
rates, so that they may compete with the hand brake. Hemp-breaking
machines are being improved and their use is increasing. The
hemp-growing industry can increase in this country only as machine
brakes are developed to prepare the fiber. A profitable use for the
hurds will add an incentive to the use of the machine brake.
[Illustration: FIG. 2.--Machine brake and hemp hurds. Hemp hurds from
machine brakes quickly accumulate in large piles.]
=PRESENT USES OF HEMP HURDS.=
Public-domain text, read in full here on John Shaqi.
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