Hemp Hurds as Paper-Making Material | Page 8

the desired kind or kinds of fiber in the proper proportion and
amount and the adding of such loading and sizing agents as may be
necessary. As shown in the record of results, the furnish in these tests
consisted of hurd stock alone and of various proportions of hurds,
sulphite fiber, and soda fiber. The percentages to be given in the record
of the furnishes refer to the percentage of the total fiber furnish, and
this likewise applies to the loading and sizing agents. In case sulphite
or soda fiber was used, the commercial product in the dry state was
charged into the beating engine and disintegrated, after which the hurd
stock was added in the wet condition.

Beating.--Beating is that operation concerning which the paper makers
often say "there is where the paper is really made," and although the
statement may not be literally true it contains a great deal of truth. It is
the operation whereby the fibers are separated from each other, reduced
to the proper lengths, and put in such a physical or chemical condition
that they felt properly and form into a satisfactory sheet. It is probable
that the quality of the sheet depends more upon the proper beater action
than upon any other single operation. The action consists in drawing a
water suspension of the fiber between two sets of rather blunt knives,
one set being located in the bottom of a circulating trough and the other
set on the periphery of a roll revolving just above the former set of
knives. It is during this operation that the loading and sizing agents are
incorporated and the whole furnish is tinted either to produce a
satisfactory white or the desired color.
The term "paper making," as used in this publication, means the
operation of forming the finished sheet of paper from stock which has
been furnished and prepared in the beater. In these tests a 30-inch
Fourdrinier machine of regular construction was used, a machine which
often is used for the production of paper for filling regular commercial
orders. The machine is designed to cause the water suspension of fibers
to flow on to a traveling wire cloth, whereby the water drains away.
More water is removed by passing the wet sheet through a series of
press rolls, after which the sheet is dried on steam-heated drums and
passed through polished iron rolls, which impart a finish to the sheet. A
Jordan refining machine was employed in conjunction with the
machine to improve further the quality of the fiber, and a pulp screen
was used in order to remove coarse and extraneous materials from the
fiber.
=DESCRIPTION OF TESTS.=
The nature of each complete paper test and the dependence of each
operation on the others were such that it does not seem advisable to
submit the results of the seven tests in tabular form. The numerous
cooks, however, which furnished the pulp for the paper tests are
presented in Table I in all essential detail.

TABLE I.--Data on cooking hemp hurds.
------+-----------+------------+----------+--------------------+----------- | | | | |
| | | | Cooking | Yield of | Caustic |Strength of | | | bone-dry | soda used
|caustic soda|Causticity+--------+-----------+ fiber Cook |(percentage|
(grams per | of soda | | |(percentage No. |of bone-dry| liter). | solution.|
Time |Temperature|of bone-dry | hurds). | | |(hours).| (°C.) | unsieved | | |
| | | hurds).
------+-----------+------------+----------+--------+-----------+----------- 293 |
20.6| 100 | 75.3| 3| 166| 294 | 21 | 100 | 75.3| 3| 166| 295 | 21.6| 100 |
75.3| 3| 166| 296 | 20.3| 100 | 75.3| 3| 166| 301 | 21.9| 100 | 82.5| 4| 166|
[3] 302 | 24.4| 100 | 82.5| 4| 166| 303 | 24.2| 100 | 84.3| 4| 166| 44.1 304 |
25 | 100 | 84.3| 4| 170| 39.5 305 | 25 | 100 | 84.3| 5| 170| 39.4 306 | 27.8|
107.5| 84.3| 4| 166| 36.5 307 | 26.7| 107 | 84.4| 5| 170| 38.1 308 | 26 |
107 | 84.4| 5| 170|\_ 37.3 309 | 27.3| 107 | 84.4| 5| 170|/ 310 | 27.1| 107 |
84.4| 6| 170| 37.0 311 | 27.2| 107 | 84.4| 6| 170| 36.8 312 | 28.3| 116.5|
85.5| 5| 170| 35.9 313 | 29.1| 113.1| 84.9| 5| 170|\_ 35.2 314 | 29.1| 109 |
83.9| 5| 170|/ 315 | 29.4| 109 | 83.9| 5| 170| 34.9 316 | 30 | 109.5| 84.9| 5|
170| 37.2 317 | 29.6| 109.5| 84.9| 5| 170| 37.0 318 | 29.6| 107 | 84.8| 5|
170| 37.7 319 | 29.4| 107.5| 84.2| 5| 170|\_ 35.4 320 | 29.3| 107.5| 84.2|
5| 170|/
------+-----------+------------+----------+--------+-----------+-----------
[Footnote 3: Stock not used; dirty.]
Discussion of the various cooks will be given in connection with the
descriptions of those paper tests in which