Hemp Hurds as Paper-Making Material eBook

This eBook from the Gutenberg Project consists of approximately 36 pages of information about Hemp Hurds as Paper-Making Material.

Hemp Hurds as Paper-Making Material eBook

This eBook from the Gutenberg Project consists of approximately 36 pages of information about Hemp Hurds as Paper-Making Material.

As to beating cost, in the last two and most satisfactory tests the total washing and beating time was three hours, which may be about an hour more than ordinarily is used in making papers of this grade, although the practice varies to a considerable extent.

In regard to furnish, there is such a diversity of practice that it is difficult to make a comparison, but if the hurd stock can be produced as cheaply as soda-poplar stock, the furnish used in these last two tests should be regarded as satisfactory to the book and printing paper manufacturer.

The finish of the paper was not all that might be desired, but that was due almost entirely to the calender stack available for the work, which was composed of nine light rolls, many of which were about 6 inches in diameter and which had not been reground for some time.  From a small test on a large calender stack it was readily shown that the paper produced is capable of taking a satisfactory finish.

This comparison, satisfactory in many respects, develops two factors which are decidedly unfavorable to hemp hurds, namely, raw-material storage and digester capacity, and they must be taken into full account in considering the paper-making value of this material, although it should be recognized that investigation may result in the material improvement of these conditions.  Moreover, it is not at all improbable that further investigation would develop more satisfactory treating conditions and more suitable furnish compositions, and the belief in this possibility is strengthened by the fact that material progress was being made at the conclusion of this preliminary work.

Calculations on the raw material and acreage for a permanent supply for a pulp mill producing 25 tons of fiber a day for 300 days per annum, or 7,500 tons per annum, give the comparison between hurds and wood shown in Table II.

TABLE II.—­Comparison between wood and hemp hurds.

-----------+-------------+--------------+-----------+--
------------------ | | | | Acres required for | | | | sustained supply. | | | |---------+---------- | | Raw material | Annual | | Material. | Pulp yield. | required per | growth | For | For 1 ton | | year. | per acre. | 25-ton | of fiber | | | | mill. | per year. -----------+-------------+--------------+-----------+-------
--+---------- Wood | Two cords | 15,000 cords | 0.37 cord | 40,500 | 5.4 | yield 1 ton | | (about | | | of fiber. | | 0.55 ton).| | | | | | | Hemp hurds | One ton | 25,000 tons | 2.5 tons | 10,000 | 1.33 | yields 600 | | | | | pounds | | | | | of fiber. | | | |
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