/
Issued June 11, 1912.
U. S. DEPARTMENT OF AGRICULTURE,
FOREST SERVICE.
HENRY S. GRAVES, Forester.
FOREST PRODUCTS LABORATORY SERIES.
EXPERIMENTS WITH
JACK PINE AND HEMLOCK FOR
MECHANICAL PULP.
BY
J. H. THICKENS, . ?snr y
Chemical Engineer in Forest Products.
WASHINGTON:
GOVERNMENT 'PRINTING OFFICE.
1912.
Rwsest ef*Ic5* W^S.^Ifi.cf AgriooJture jVlechanical Pulp
PLATE I.
FIG. 1 .MOTOR GENERATOR SET AND SWITCHBOARD.
FIG. 2. -GRINDER AND WET-MACHINE ROOM.
Issued June il,
U. S. DEPARTMENT OF AGRICULTURE,
FOREST SERVICE.
HENRY S. GRAVES, Forester.
FOREST PRODUCTS LABORATORY SERIES.
EXPERIMENTS WITH
JACK PINE AND HEMLOCK FOR
MECHANICAL PULP.
BY
J. H. THICKENS,
//
Chemical Engineer in Forest Products.
WASHINGTON:
GOVERNMENT PRINTING OFFICE.
1912.
LETTER OF TRANSMITTAL
UNITED STATES DEPARTMENT OF AGRICULTURE,
FOREST SERVICE,
Washington, D. 0., December 13, 1911.
SIR: I have the honor to transmit herewith a manuscript entitled
" Experiments with Jack Pine and Hemlock for Mechanical Pulp,"
by J. H. Thickens, chemical engineer in forest products, and to
recommend its publication.
Respectfully, HENRY S. GRAVES,
Forester.
Hon. JAMES WILSON,
Secretary of Agriculture.
2
CONTENTS.
Page.
Need of a substitute for spruce pulp wood 5
Results of experiments 6
Why jack pine and hemlock have not been used for pulp 7
Equipment used in the experiments 8
Electrical equipment 8
Pulp machinery and auxiliary equipment 8
Methods employed .* 10
Qualitative and quantitative tests 10
Commercial tests 10
Treatment of the wood before grinding 10
Grinding 11
Losses in grinding 12
Fiber study 12
Calculation of results 12
Comparison of yields 13
Factors which influence quality and production 15
Speed and pressure 15
Surface of stone 16
Temperature 18
Undetermined factors 18
Microscopic comparison of experimental pulps and commercial standards 18
Standard pulps 18
Jack pine pulp 20
Hemlock pulp 21
Mixed pulps 21
Samples of paper produced 22
Summary of data 23
3
477631
L LUSTRATIONS.
PLATES.
Page.
PLATE I. Fig. 1. Motor generator set and switchboard. Fig. 2. Grinder and
wet-machine room Frontispiece.
II. Fig. 1. Natural surface of stone (jack pine run No. 2). Fig. 2. Ten
to the inch solid, straight-cut burr (hemlock run No. 0). Fig. 3.
Eight to the inch solid, spiral burr (hemlock run No. 43) 8
III. Fig. 1. Three to the inch solid, straight-cut burr (hemlock run No.
46). Fig. 2. Three to the inch solid, straight-cut burr, cut over
with 12 to the inch solid, spiral burr (hemlock run No. 51). Fig.
3. Six to the inch diamond-point burr (jack pine run No. 17-1) . . 8
IV. Fig. 1. Spruce sulphite standard. Fig. 2. Spruce ground wood,
No. 1 standard 16
V. Fig. 1. Spruce ground wood, No. 2 standard. Fig. 2. Spruce
ground wood, No. 3 standard, coarse ground 16
VI. Fig. 1. Spruce ground wood, No. 4 standard, medium ground.
Fig. 2. Spruce ground wood, No. 5 standard, fine ground 16
VII. Comparison of hemlock pulps ground at different speeds. Fig. 1.
100 revolutions per minute (run No. 35). Fig. 2. 150 revolutions
per minute (run No. 36). Fig. 3. 200 revolutions per minute
(run No. 37) 16
VIII. Comparison of jack pine pulps ground at different speeds. Fig. 1.
152 revolutions per minute (run No. 19). Fig. 2. 205 revolu-
tions per minute (run No. 20-1) 16
IX. Fig. 1. Jack pine ground wood (run No. 14-1). Fig. 2. Jack pine
ground wood (run No. 13-1) '. . ' 16
X. Fig. 1. Jack pine ground wood (run No. 7-1). Fig. 2. Jack pine
ground wood (commercial run No. 24) :V 16
XI. Fig. 1. Hemlock ground wood (run No. 41). Fig. 2. Hemlock
ground wood (commercial run No. 14-1) 16
XII. Fig. 1. Hemlock ground wood (commercial run No. 8). Fig. 2.
Hemlock ground wood (run No. 2) 16
XIII. Fig. 1. Hemlock ground wood (commercial run No. 30). Fig. 2.
Hemlock ground wood (commercial run No. 50). (Used in accom-
panying paper sample) 16
XIV. Fig. 1. Ground-wood pulp, one-third spruce, two-thirds hemlock
(run No. 46a). Fig. 2. Ground-wood pulp, all hemlock (run No.
466). Fig. 3. Ground-wood pulp, all spruce (run No. 46c) 16
XV. Mixed ground-wood pulps (used in accompanying paper samples).
Fig. 1. One-third spruce, two- thirds hemlock (commercial run
No. 46a). Fig. 2. One-third hemlock, one-third jack pine, one-
third spruce (commercial run No. 51). Fig. 3. One-third jack
pine, two-thirds hemlock (commercial run No. 52) 16
TEXT FIGURE.
FIG. 1. Portion of a chart from a recording wattmeter, showing decreased power
consumption after removal of load from pocket and pocket binding. . . 14
4
EXPERIMENTS WITH JACK PINE AND HEMLOCK FOR
MECHANICAL PULP.
NEED OF A SUBSTITUTE FOB SPRUCE PULPWOOD.
Few well-established industries have expanded as rapidly as has the
pulp and paper industry. In less than a decade the amount of raw
material used annually has more than doubled. During 1900 l
there were consumed in the United States 1,986,310 cords of pulp-
wood. The ground-wood process used 598,229 cords of domestic
spruce, 120,820 cords of imported spruce, and 67,791 cords of other
woods, such as hemlock, jack pine, poplar, and balsam, or a total of
786,840 cords. During 1909 2 the amount of wood used in all proc-
esses was 4,001,607 cords, the ground-wood process using a total of
1,246,121 cords, which consisted of 806,282 cords of domestic spruce,
317,289 cords of imported spruce, and 122,550 cords of other miscel-
laneous woods.
Thus the increase in the total amount of pulpwood used during this
period was 101 per cent, while the amount of pulpwood of all kinds
used for ground wood increased 58J per cent. The domestic spruce
consumption for this purpose increased 35 per cent and the con-
sumption of miscellaneous woods 80.5 per cent. But the largest
increase was in the use of imported spruce, the consumption of which
increased 162 per cent.
The price of spruce has increased at a very rapid rate. In 1900 the
average cost of spruce used in all processes in the United States was
$4.83 per cord for domestic spruce and $6.50 for imported, while in
1909 the average price of domestic spruce was $9.32 and of imported
$11.34 per cord.
This increase has been reflected in the cost of ground-wood pulp.
The manufacturing cost of pulp, as determined by the Tariff Board, 3
increased from $10.84 per ton in 1900 to $16.58 in 1909, 93 per cent of
this increase being accounted for by the greater cost of the wood used.
Manifestly, therefore, it is almost essential, if the ground-wood
i Twelfth Census of the United States.
a " Pulpwood consumption, 1909," Bureau of the Census.
3 Report by the Tariff Board relative to pulp and news print paper industry, Senate Document No. 31,
Sixty-second Congress, first session.
5
8 JACK PINE AND HEMLOCK FOR MECHANICAL PULP.
industry is to centime, that substitutes be found for spruce pulp,
especially in the manufacture of news, wrapping, and other of the
cheaper grades of paper. To determine whether there are not other
domestic species which will produce a commercial grade of ground
wood suitable for the purpose, etc., the Forest Service, in cooperation
with the American Pulp and Paper Association, began an extensive
series of tests on several of the woods which occur in large quantities
in the United States, particularly in the Lake States. The woods
which have been tried up to the present are hemlock and jack pine,
together with a small amount of spruce, for the purpose of comparison.
The experiments were conducted at Wausau, Wis., under the
general supervision of the director and assistant director of the
Forest Products Laboratory, and an advisory committee of the
American Pulp and Paper Association, composed of Messrs. G. F.
Steele, chairman Nekoosa-Edwards- Paper Co.; W. G. McNaughton,
secretary Nekoosa-Ed wards Paper Co. ; D. C. Everest, Marathon
Paper Mills Co.; W. L. Edmonds, Wausau Paper Mills Co.; A. M.
Pride, Tomahawk Paper Co. ; and Wm. Eibel, Rhinelander Paper Co.
RESULTS OF EXPERIMENTS.
Not only have very promising sheets of pulp been obtained from
both the hemlock and jack pine, but paper has been made from
them on commercial machines, operating at high speed, and under
all other conditions of actual commercial practice, which has the
strength, finish, and appearance of standard news paper. The
production per grinder, the horsepower consumption per ton, and
the yield per cord approximate the averages which obtain in the
grinding of spruce. Again, pulps composed of mixtures of hemlock,
spruce, and jack pine in different proportions have been obtained,
which compare very favorably with the ordinary spruce ground wood.
Hemlock ground wood has a decided reddish tinge, though this is
not very noticeable, even in an all-hemlock sheet of news paper.
Jack pine pulp is also slightly off in color, but is not nearly as dark
as hemlock pulp. Careful study by experts should make it possible
to bring the color of the paper produced from these pulps more
nearly to the usual white. As it is, the sheets of news paper which
have been secured are only slightly off color, though they are the
result in each case of but a single attempt to secure the standard
degree of whiteness.
Since the experiments on hemlock have brought out a number of
points in favor of the grinding of that wood, two paper-mill com-
panies have signified their intention of using it in their cheaper grades
of paper. One of these mills has already begun to do so, and is well
satisfied with the pulp obtained.
JACK PINE AND HEMLOCK FOR MECHANICAL PULP. 7
WHY JACK PINE AND HEMLOCK HAVE NOT FEEN USED.
There is much doubt as to exactly why the pulp industry has
neglected to use hemlock and jack pine for the cheaper grades of
paper. It seems to be the general impression that hemlock grinds
so fine and short that there is a great loss in conversion. It has been
said that the yield obtained is in many instances only three-fifths of
that from an equal amount of spruce. This loss in grinding hemlock
has not been in evidence during the tests.
The pitch in jack pine is undoubtedly responsible for the lack of
attention paid to that wood. This, however, can be removed by
steaming or soaking, and such treatments will be taken up in future
experiments.
In all the experiments the yields secured from the different woods
were in direct proportion to their bone-dry weight per cubic foot.
It is therefore to be expected that the yields from jack pine and
hemlock will be less per unit of volume than those from spruce, since
the two first woods are considerably lighter in weight. On the basis
of weight, however, there appears to be relatively little more loss in
converting hemlock or jack pine into pulp than in converting spruce.
The fiber obtained from the ground hemlock and jack pine has
been considered unsatisfactory on account of its shortness. Yet it
has been found long enough for use in cheap papers. .
One who is accustomed to handling spruce ground wood will not
be favorably impressed with the appearance of either hemlock or
jack pine pulp. This is particularly true of the hemlock sheet.
Both pulps are somewhat softer in texture than spruce, and, alto-
gether, are not as pleasing in appearance as the present commercial
product.
Another point which may account for the lack of attention paid
to hemlock and jack pine is the care which must be exercised in
grinding them. It is possible to obtain a grade of pulp from spruce
which is suitable for most purposes without using a great deal of
care in the preparation of the surface of the pulp stones. In the
grinding of jack pine and hemlock, especially hemlock, on the other
hand, great care must be exercised in bringing the stone to the correct
degree of sharpness, since these woods will grind to powder if the
surface is as sharp as the one ordinarily employed in grinding spruce.
Yet notwithstanding certain shortcomings the fact remains that
it is possible to obtain hemlock and jack pine pulps commercially
which are suitable for the cheaper grades of paper.
8 JACK PINE AND HEMLOCK FOR MECHANICAL PULP.
EQUIPMENT USED IN THE EXPERIMENTS.
ELECTRICAL EQUIPMENT.
To study accurately the fundamental variables of grinding it was
necessary to install an elaborate electrical drive and apparatus for
control and manipulation. There has also been provided a system
of recording instruments for the determination of speed, pressure,
and load fluctuation. The electrical apparatus consists of a motor-
generator set and a direct-current variable-speed motor. The
variable-speed motor, direct connected to the pulp grinder, is rated
at 225 horsepower at 100 revolutions per minute and 500 horsepower
at 300 revolutions per minute, with a 50 per cent overload capacity
at all speeds. However, it is possible to obtain about 25 per cent
more capacity than the rating. Variation in speed is obtained by
variation of voltage applied to the motor armature, and by means
of a rheostat in the field circuit of the generator it is possible to
maintain this voltage at any point desired, thus giving a very con-
stant speed.
The efficiency of the grinder motor has been determined for all
values of speed and load throughout the range of usage. Conse-
quently, the power applied to the grinder at any value of peripheral
speed or at any pressure on the cylinders can be calculated.
Individual motor drives have also been installed for the various
other pieces of pulp-making machinery and their auxiliary apparatus.
The machines for wood preparation and the wet-machine vacuum
pump are the only ones which are not direct connected to indi-
vidual motors. In several cases variable-speed motors have been
installed to permit adjustment of speed to the most effective value.
PULP MACHINERY AND AUXILIARY EQUIPMENT.
The pulp-making machinery, machines for wood preparation, and
the auxiliary pieces of apparatus are all of standard commercial
types and were loaned by the following manufacturers or others
interested in the work of the laboratory:
Grinder Friction Pulley and Machine Works.
Wet machine Improved Paper Machinery Co.
Flat screen Harmon Machine Co.
Ruth centrifugal screen H. L. Orrman & Co.
5 by 8 inch triplex pump Goulds Manufacturing Co.
4 by 6 inch triplex pump Do.
5-inch centrifugal pump Do .
4-inch centrifugal pump Do.
Storage tank Valley Iron Works.
Barker. . . .'..... Green Bay Foundry and Machine Works.
Forest Service, U. S. Dept of Agriculture Mechanical Pulp.
PLATE II.
FIG. 1. NATURAL SURFACE OF STONE. (JACK PINE RUN No. 2.)
FIG. 2. TEN TO THE INCH SOLID; STRAIGHT-CUT BURR. (HEMLOCK RUN No. 0.)
FIG. 3. EIGHT TO THE INCH SOLID; SPIRAL BURR. (HEMLOCK RUN No. 43.;
Forest Service, U. S. Dept. of Agriculture Mechanical Pulp. PLATE III.
FIG. 1. THREE TO THE INCH SOLID; STRAIGHT-CUT BURR. (HEMLOCK RUN No. 46.)
FIG. 2. THREE TO THE INCH SOLID; STRAIGHT-CUT BURR. CUT OVER WITH TWELVE
TO THE INCH SOLID; SPIRAL BURR. (HEMLOCK RUN NO. 51.)
FIG. 3. Six TO THE INCH DIAMOND POINT BURR. (JACK PINE RUN No. 17-1.)
JACK PINE AND HEMLOCK FOR MECHANICAL PULP. 9
Swing cut-off saw American Pulp and Paper Association.
3-ton scale Paper (Inc.).
2 Ash ton relief valves Do.
1 pulp truck W. A. Lounsberry & Co.
1 wood truck Do.
1 54 by 27 inch pulp stone Manufacturers' Paper Co.
12 42-inch screen plates Union Screen Plate Co.
1 wet-machine felt Albany Felt Co.
1 wet-machine felt Appleton Woolen Mills.
1 set barker knives Dowd Knife Works.
1 set sectional and solid burrs. .Ticonderoga Machine Works.
Plate I shows a portion of the pulp-making equipment. The
grinder (PL I, fig. 2) has three pockets, the cylinders are 14 inches
in diameter, and it is designed for a 54 by 27 inch pulp stone. Each
of the grinder cylinders is equipped with a pressure gauge, and the
pressure line between the triplex pumps and the grinder is provided
with Ashton relief valves, which make it possible to obtain very
uniform pressures up to 100 pounds per square inch.
A recording thermometer gives a record of the temperature in the
grinder pit. From the grinder pit the pulp is passed through a
mechanically agitated sliver screen, then pumped to a storage tank
by means of a 6-inch centrifugal pump, and from there pumped to a
centrifugal screen. A variable-speed motor direct connected to the
screen makes it possible to obtain speeds of rotation from 400 to 600
revolutions per minute. Throughout the tests, however, the speed
was maintained at 500 revolutions per minute. The plate in the
centrifugal screen is perforated with holes 0.065 inch in diameter.
The tailings from it are led by gravity to a 12-plate horizontal dia-
phragm screen, the plates of which are the Union Screen Plate Go's,
type B, cut with 0.012-inch slots.
The good pulps from the centrifugal and the plate screens are
united in the vat of the wet machine, which is direct connected to a
variable-speed motor giving felt speeds ranging from 75 to 115 feet
per minute. The wet machine is provided with a small triplex pump
by which the cylinders connected to the press rolls are operated, the
dryness of the pulp being determined by the pressure applied to the
cylinders. A vacuum of from 10 to 15 inches, produced by a rotary
suction pump, is maintained on the felt, and this, too, assists in
obtaining the desired dryness of the pulp. The white water from
the wet-machine vat is pumped back to the grinder sliver screen by a
4-inch centrifugal pump. White water from the felts is run directly
to the sewer, as is also the white water from the felt suction. Plate
I, figure 2, gives an idea of the general arrangement of the pulp-
making machinery. A 40-inch swing cut-off saw and a Green Bay
wood barker are used to prepare the wood.
10 JACK PINE AND HEMLOCK FOR MECHANICAL PULP.
METHODS EMPLOYED.
QUALITATIVE AND QUANTITATIVE TESTS.
In order to cover the field in a reasonable length of time, short tests
ranging up to two hours in length were run. In these tests no attempt
was made to cover every point, the object being to touch only such
as were thought to have a marked effect on the quality of the product.
The surface of the stone, the pressure on the grinder cylinder, and
the peripheral speed of the stone were the variables which received
most attention. No especial attention was given to economic con-
siderations.
Tests were made with pressures of from 20 to 75 pounds per square
inch on the cylinder, corresponding to from 8.2 to 30.8 pounds per
square inch of pocket area. The speed of rotation of the stone was
varied from 84 to 225 revolutions per minute, corresponding to a
range in peripheral speed of from 1,173 to 3,150 feet per minute.
In studying the effect of the surface condition of the stone it was
necessary to utilize burrs of many different types and designs.
These ranged in fineness of cut from 12 to the inch to 3 to the inch.
The style of cut differed also, spiral cut, diamond points, and straight
cut being employed. The power applied to the grinder ranged from
87.3 to 520 horsepower, while the rate of production of bone-dry
pulp varied from 1 ton to 7.3 tons in 24 hours. It should be under-
stood that neither the two minimum nor the two maximum values
were necessarily obtained from the same test. When the power
applied to the grinder was 87.3 horsepower, for instance, it does not
necessarily follow that the production was 1 ton per day. The horse-
power consumption per ton under the given conditions was found to
vary from 68.3 to 196 in 24 hours.
The samples of pulp obtained during the qualitative and quanti-
tative tests were examined and commented upon by members of the
advisory committee of the American Pulp and Paper Association, and
those runs considered most promising were duplicated later in
commercial tests.
COMMERCIAL TESTS.
TREATMENT OF THE WOOD BEFORE GRINDING.
All of the wood used in the tests was cut either in Wisconsin or
Michigan and was representative of the species. In some cases the
wood was secured directly from the forest, while in others it was
shipped to the laboratory from near-by mills. Upon arrival at the
laboratory the logs were closely piled on skids. An attempt was made
to keep the material green by painting the ends with paraffin, but this
proved unsatisfactory, because the paraffin peeled off. The wood
tested was taken directly from the piles for all tests up to and includ-
JACK PINE AND HEMLOCK FOB MECHANICAL PULP. 11
ing run No. 52 of the hemlock series, with the exception of runs Nos.
49, 50, and 51, the wood for which was soaked in the pond for approxi-
mately two months before being used. The only jack pine soaked
was that used in the commercial test on seasoned wood of that spe-
cies run 14. The jack pine and spruce used in tests on mixed pulps
were in all cases dry before grinding. The wood for the tests was
prepared approximately 2 cords at a time, sawed into 2-foot lengths,
barked, weighed, and piled up for the grinding process.
To determine accurately the yield, the bone-dry weight per cubic
foot of wood, as well as the percentage of moisture present, was
determined in each commercial test. All weighings were made in
500 or 1,000 pound lots, and the wood was used as soon as ground.
No attempt was made to remove knots or punky portions of the
wood. In fact, all of the tests were carried on in accordance with
the usual commercial practice.
GRINDING.
Before commencing the grinding tests an impression of the surface
of the stone which had been selected was taken by means of a piece
of carbon paper and a sheet of coated paper. This impression was
later photographed, as shown in Plates II and III. In these the
black dots represent projecting points and the white portions
between them depressions in the stone. The surface shown in Plate
III, figure 2, is particularly interesting, since it is the result of dressing
with two different kinds of burrs.
Before starting the tests the recording thermometer and all of the
other recording instruments were placed in operation. The pockets
of the grinder were filled, the pressure adjusted to the proper value,
and the grinder started.
For the purpose of check and control, regular readings were taken
of the various switchboard instruments, the indicating tachometer,
the pressure gauges, and the recording thermometer. On short tests
up to 2 hours in length these readings were recorded at 5-minute
intervals, but on longer tests the interval was increased to 15 minutes.
The speed, pressure, and other variables were maintained as nearly
constant as possible. For instance, when one of the grinder pistons
was raised the speed was brought back to the desired value by
manipulation of the rheostat controlling the motor armature voltage.
During the qualitative and quantitative tests the pulp stone did not
have an opportunity to heat up, and, in consequence, some of the
data on power consumption and production may be more or less
questionable. In the commercial tests, however, all of which were
made under the hot-grinding process, the stone was brought up to a
high temperature, which was maintained throughout the run; con-
sequently these more nearly approximate commercial conditions.
12 JACK PINE AND HEMLOCK FOR MECHANICAL PULP.
LOSSES IN GRINDING.
To determine approximately the losses occurring in the conversion
of wood to pulp, the bone-dry weight of screenings obtained from a
known amount of bone-dry wood was determined. The loss in the
white water was then taken as the difference between the bone-dry
weight of the wood ground and the bone-dry weight of the pulp
secured plus the screenings.
FIBER STUDY.
During each test the character of fiber obtained was examined by
means of an apparatus for microscopic study. This consists of an
ordinary stereopticon provided with a specially constructed carrier
for microscopic slides. Samples of wet pulp were taken from the
wet-machine vat and slides were made by first removing the water
by drying, then staining with Bismarck brown, and moistening with
glycerine. The mixture of glycerine and fiber was teased out to
cover the area of an ordinary microscopic cover glass, which was
placed over the mixture. Evaporation or leakage was prevented by
means of a thin strip of shellac around the edge of the cover glass.
With this apparatus it was also possible to compare different
samples of pulp with the commercial standards used, the latter being
selected from a large number of samples submitted by American
manufacturers of ground- wood pulp.
CALCULATION OF RESULTS.
To give a clear understanding of the method employed in calcu-
lating the various items in connection with a test, all the calculations
for a representative run, No. 50, Table 4, are given here. Consid-
erable data taken during the tests have been eliminated from the
compilation, since they have no direct bearing on the study.
The test mentioned required 3.42 hours to complete, and during
that time 3,388 pounds of hemlock wood were ground. For com-
parison all of the figures on weight of wood were brought to a
bone-dry basis. The bone-dry weight of wood was secured by
drying a known volume of wood to constant weight and calculating
the weight per cubic foot. By calculating the bone-dry weight of a
log of measured volume and subtracting this amount from the actual
weight of the log, the' moisture content of the wood was determined.
The bone-dry weight of this wood, per cubic foot, was 24.84 pounds,
and the moisture content was 46.5 per cent; consequently the amount
of bone-dry wood ground was 53.5 per cent of 3,388, or 1,810 pounds.
This is equivalent to 72.9 cubic feet of solid wood ground during the
JACK PINE AND HEMLOCK FOR MECHANICAL PULP. 13
given period; or, in other words, the grinding was carried on at the
rate of 512 cubic feet of solid wood in 24 hours.
The amount of wet pulp obtained during the test was 3,795 pounds,
and this upon analysis was found to have a moisture content of 60.22
per cent. Consequently, 1,507 pounds of bone-dry pulp were
obtained during the period of test, corresponding to a production of
or 5 - 3 tons * n 24 hours. To grind the wood and pro-
duce this pulp it was necessary to apply to the grinder motor power
which averaged 338 kilowatts. This value was obtained by dividing
the total number of kilowatt hours used, as given by a watt-hour
meter, by the length of the test in hours. Figure 1 shows a section of
a wattmeter record obtained during this test, and illustrates how the
power used by the grinder varied upon the removal of the load from
one of the grinder pockets. The entire recording wattmeter curve
was averaged by means of a planimeter, in order to check the value
of power consumed as given by the watt-hour meter.
By using curves which show the losses in the motor it was found
that 15.3 kilowatts were required to supply the heat losses in the
grinder-motor armature and 7.1 kilowatts to supply the stray power
losses, making a total of 22.4 kilowatts lost in converting the power
from electrical to mechanical. This amount subtracted from 338
kilowatts gives 315.6 kilowatts which were furnished to the grinder
pulpstone, and 315.6 divided by 0.746 1 gives the value of 422J horse-
power applied to the grinder. In order, then, to obtain 5.3 tons of
bone-dry pulp in 24 hours it was necessary to apply to the grinder
over that period 422 J horsepower, or the horsepower consumption
per ton was 422J divided by 5.3, or 79.7 horsepower per ton in 24
hours.
The yield from 100 cubic feet of solid wood was obtained by dividing
the amount of pulp produced during 24 hours, 5.3 tons or 10,600
pounds, by the number of hundreds of cubic feet of wood ground in
24 hours, viz, 5.12. The result is 2,070 pounds.
The average temperature of grinding was determined by reading
the recording thermometer every five minutes, adding these values,
and dividing by the total number of readings.
COMPARISON OF YIELDS.
Much importance is attached to the amount of pulp obtained
from a cord of wood, because this represents the efficiency of con-
version. Commercial practice in the manufacture of spruce ground
wood requires a yield of approximately 2,300 pounds per cord of
i A horsepower is equivalent to 0.-746 kilowatt.
14
JACK PINE AND HEMLOCK FOR MECHANICAL PULP,
rossed wood, or 1,800 pounds per cord of rough wood. The average
yields which have been obtained for hemlock and jack pine, together
KILOWATTS.
FIG. 1. Portion of chart from recording wattmeter, showing decreased power consumption after removal
of load frojuti pocket and pocket binding.
with those obtained for two different shipments of spruce, are given
in Table 1.
JACK PINE AND HEMLOCK FOR MECHANICAL PULP.
TABLE 1. Average yields from spruce, hemlock, and jack pine.
15
Species.
Weight per
100 cu. ft.
bone-dry.
Yield per
100 cu. ft.
of solid
wood.
Efficiency
of
conversion.
Spruce
Pounds.
2,840
Pounds.
2 480
Per cent.
87 3
Do
2,270
2,000
88 2
Hemlock
2,480
2 100
84 8
Jack pine
2 540
2 200
86 7
One hundred cubic feet of solid wood was selected as the basis of
yield, since it eliminates the variable loss in barking, and represents
fairly well the amount of solid wood in a rossed cord. The yield, as
will be seen, is directly proportional to the bone-dry weight of the
wood. The loss in conversion has been found to range between 12
and 15 per cent of the original weight of the bone-dry wood. Ap-
proximately 6 per cent can be accounted for in the white water and 1
per cent in screenings. The manner in which the remaining losses
occur has not been determined, but will be studied in future tests.
The storage capacity for white water in the laboratory was very
limited, and this may to some extent account for the low yields.
The continuous use of the white water and the use of save-alls would
undoubtedly tend to increase the yields and result in saving a great
deal of fine pulp.
The loss in barking jack pine and hemlock, so far as has been
determined up to the present time, is practically the same as the loss
in the barking of spruce. There are a great many knots in both
hemlock and jack pine, and it is possible that this may cause a some-
what greater loss in barking these species. However, on account of
the small amounts of the various woods used, no reliable data on loss
were obtained.
FACTORS WHICH INFLUENCE QUALITY AND PRODUCTION.
SPEED AND PRESSURE.
The effect of speed on the quality of pulp can best be illustrated
by the magnified fibers shown in Plates VII and VIII. In grinding
these pulps the pressure and surface of the stone were maintained
constant, and the speeds were, respectively, 100, 150, and 200 revolu-
tions per minute for the hemlock, and 152 and 205 revolutions for
the jack pine. There is little difference in the fibers ground under
these different conditions of speed; especially those run at 150 and
200 revolutions per minute. Speed probably has very little effect
on the quality of pulp. With satisfactory pressure and curface of
stone, it is possible to obtain good grades of pulp at any speeds within
reasonable limits. Commercially, it is practically impossible to main-
16 JACK PINE AND HEMLOCK FOR MECHANICAL PULP.
tain the speed constant at all times. When the pressure on a pocket
is removed the speed is bound to rise considerably, especially when
the water wheels or turbines are operated without a governor.
When hemlock wood was ground at low speed and low pressure
it was impossible to obtain anything more than a powder. Also when
this wood was ground at low pressure and high speed the product was
extremely short, but the pressures at which these results were obtained
are considerably lower than those ordinarily employed commercially,
and the results have little significance. If the stone is what is ordi-
narily called sharp, it is necessary to use a lower pressure, and when
dull, a higher one, but it is impossible to obtain the same quality of
pulp under both conditions. Speed and pressure affect quantity
rather than quality, and by the proper adjustment of both the maxi-
mum efficiency of grinding is attained. If a certain speed is selected
there must be a corresponding pressure which will yield the greatest
amount of pulp in 24 hours with the least consumption of power.
By the term " constant pressure/' wherever used in this report, is
meant constant pressure on the grinder cylinders. The pressure per
square inch of wood in contact with the grinding surface varies con-
siderably, chiefly with the size of wood ground and the area of the
pocket. Again, the length of the wood is not at all a constant quantity,
and this, too, can only result in a variable pressure per square inch of
wood. The pressure of the wood on the stone varies throughout
certain limits with any pressure on the grinder cylinder, and the
ranges of pressure of the wood on the stone are raised or lowered by
raising or lowering the cylinder pressure. This pressure variation,
however, can hardly be controlled commercially, and therefore has
not been considered in the test's discussed in this report. There is
also more or less pressure variation due to binding of wood in the
pockets, and this, too, is difficult, if not impossible, to control.
Figure 1 shows a measure of the power applied to the grinder. The
effect of pocket binding and the withdrawal of pressure from one of
the pockets will be noted. At one end of this chart the power con-
sumed is approximately 360 kilowatts, falling off gradually to 280
kilowatts, due to pocket binding. After raising the pistons and read-
justing the wood in the different pockets, the power to the grinder
motor had to be increased to 350 kilowatts on account of the added
load produced by eliminating the pocket binding.
SURFACE OF STONE.
The most efficient grinding condition is one where there is a maxi-
mum amount of grinding surface, and still a sufficient amount of
depression in the stone to allow for the carrying away of the ground
wood, or, as this is commonly called, for the clearing of the stone.
Forest Service, U. S. Dept. of Agriculture Mechanical Pulp.
PLATE IV.
FIG. 1. -SPRUCE SULPHITE STANDARD.
'-.^^m^^stm
FIG. 2. SPRUCE GROUND WOOD, No. 1 STANDARD.
Forest Service, U. S. Dept. of Agriculture Mechanical Pulp.
PLATE V.
. :. \
FIQ. 1. SPRUCE GROUND WOOD, No. 2 STANDARD.
FIG. 2. SPRUCE GROUND WOOD, No. 3 STANDARD, COARSE GROUND.
Forest Service, U. S. Dept. of Agriculture Mechanical Pulp.
PLATE VI.
FIG. 1. SPRUCE GROUND WOOD, No. 4 STANDARD, MEDIUM GROUND.
m
FIG. 2. SPRUCE GROUND WOOD, No.- 5 STANDARD, FINE GROUND.
Forest Service, U. S. Dept. of Agriculture- Mechanical Pulp.
PLATE VII.
FIG. 1.-100 R. P. M. (RUN No. 35.)
FIG. 2. 150 R. P. M. (RUN No. 36.)
- *. , - "-
FlQ. 3.-200 R. P. M. (RUN No. 37.)
COMPARISON OF HEMLOCK PULPS GROUND AT DIFFERENT SPEEDS.
Forest Service, U. S Dept. of Agriculture Mechanical Pulp.
PLATE VIII.
fflnBi 3IP4,
^XM^^mMm
FIG. 1.-152 R. P. M. (RUN No. 19.)
FIG. 2. 205 R. P. M. (RUN No. 20-1.)
COMPARISON OF JACK PINE PULPS GROUND AT DIFFERENT SPEEDS.
Forest Service, U. S. Dept. of Agriculture Mechanical Pulp.
PLATE IX.
FIG. 1. JACK PINE GROUND WOOD. (RUN No. 14-1.)
FIG. 2. JACK PINE GROUND WOOD. (RUN No. 13-1.)
Forest Service U. S. Dept. of Agriculture Mechanical Pulp.
PLATE X.
mm
i - I * \r .' ,\>
FIG. 1. JACK PINE GROUND WOOD. (RUN No. 7-1.)
FIG. 2. JACK PINE GROUND WOOD. (COMMERCIAL RUN No. 24.)
Forest Service, U. S. Dept. of Agriculture Mechanical Pulp.
PLATE XI.
FIQ. 1. HEMLOCK GROUND WOOD. (RUN No. 41.)
'-'--'-^^ - , -^., - " '>--*. 'l*- -'
FIG. 2. HEMLOCK GROUND WOOD. (COMMERCIAL RUN No. 14-1.)
Forest Service, U. S. Dept. of Agriculture Mechanical Pulp.
PLATE XII.
.: J^fegj
FIG. 1. HEMLOCK GROUND WOOD. (COMMERCIAL RUN No. 8.)
FIG. 2. HEMLOCK GROUND WOOD. (RUN No. 2.)
Forest Service, U. S. Dept. of Agriculture Mechanical Pulp.
PLATE XIII.
'
FIG. 1. HEMLOCK GROUND WOOD. (COMMERCIAL RUN No. 30 )
FIQ. 2. HEMLOCK GROUND WOOD. (COMMERCIAL RUN No. 50.) USED IN ACCOMPANYING
PAPER SAMPLE.
Forest Service, U. S. Dept. of Agriculture Mechanical Pulp.
PLATE XIV.
FIG. 1 .GROUND-WOOD PULP, ONE-THIRD SPRUCE, TWO-THIRDS HEMLOCK. (RUN
No. 46 A.)
FIG. 2. GROUND-WOOD PULP, ALL HEMLOCK. (RUN No. 46e.)
/. "%,
IMfei^
^^/^ - /
(^^* ^i ~y-
FIG. 3. GROUND-WOOD PULP, ALL SPRUCE. (RUN No. 46c.)
Forest Service, U. S. Dept. of Agriculture Mechanical Pulp.
PLATE XV.
FIG. 1. ONE-THIRD SPRUCE, TWO-THIRDS HEMLOCK. (COMMERCIAL RUN No. 46A.)
*V3
FIG. 2. ONE-THIRD HEMLOCK, ONE-THIRD JACK PINE, ONE-THIRD SPRUCE. (COMMERCIAL
RUN No. 51.)
^Ti&^i? ^A--. '?;* -. .vvt- '^ i-^ .-m .-^JW,-- '** -v
t :: J '^ V^SI S W:^^'
s>^^ -<, ; v- .*;-,' :v'..jf3^r/> iV-^k r v >.
FIG. 3. ONE-THIRD JACK PINE, TWO-THIRDS HEMLOCK. (COMMERCIAL RUN No. 52.)
MIXED GROUND-WOOD PULPS USED IN ACCOMPANYING PAPER
SAMPLES.
JACK PINE AND HEMLOCK FOR MECHANICAL PULP. 17
Throughout the experiments, particularly the commercial tests, it
was found that the pulp of same appearance as regards fiber and of
the same apparent strength can be obtained by using burrs of
different design and fineness of cut, provided the grit of the stv, is
in each case the same. For example, during the commercial tests
the stone was burred at different times with different types of burrs,
and the grinding in each case was found to require the consumption
of the same amount of power. The production per day was the same
also, provided the grit was brought to the same condition of sharpness
and the other variables were kept constant.
During some of the preliminary tests the surface of stone was
dulled with a fire brick, as is often done in mills. This appears to
have been unnecessary ; in fact, the result is detrimental rather than
beneficial.
Better pulp was obtained and the production was increased slightly
by crushing the tops of the ridges formed in burring by means of a
solid, smooth bush roll. This method does not smooth off the indi-
vidual particles of sand on the stone as duUing with the brick does,
but rather sharpens them . During the tests conducted on mixed woods
a surface obtained by the use of a three- to- the- inch straight-cut solid
burr and a 12-cut spiral burr was used. The stone was first dressed
with a three-to-the-inch burr, forming grooves in the stone approxi-
mately one thirty-second inch deep; then the portion of the stone
between these depressions was roughed with a 12-cut spiral burr.
This caused the grit to stand out and gave a maximum of useful
grinding surface. The pulp obtained with this surface was almost
entirely free from shives, and the fibers were long and fine. The sur-
face of stone used during these tests is shown in Plate III, figure 2.
A great deal of experimentation still remains to be done, not only
with burrs of different cut and design, but more especially with stones
of different grits, since it appears that the grit is more responsible
for the quality of pulp obtained than any other variable feature in its
production.
Where the pulp stone is deep burred, however, the grit is not so
important a factor of quality. When the power consumed in making
a ton of bone-dry pulp is as low as 50 to 60 horsepower, the added
production which must be secured to bring the power to this low
value is obtained through the action of the ridges on the stone and
not through the grit. When it is desired to manufacture a pulp of
high quality, however, it is the grit of the stone and the manner of
raising it which must be considered. The type of burr used and the
depth of dressing both influence production, but it is only the latter
that influences the quality. When the pulp stone has been dressed
so as to provide just sufficient depression to carry away the ground
23688 12 2
18 JACK PINE AND HEMLOCK FOR MECHANICAL PULP.
wood a high-grade pulp will be produced, providing the grit of the
stone is suitable, irrespective of the style of the burr and within
~vable limits of the pressure used. It is not impossible to con-
jf an artificial stone which could be used continually without
n, Jig, which would clear itself without having depressions or
ridges, and which would have the correct size and kind of grit to give
the maximum production and best quality.
TEMPERATURE.
The temperature of grinding, it is said, has much to do with the
quality and quantity of pulp obtained, and many manufacturers
insist that it is impossible to secure a tough, strong fiber with anything
but the hot grinding process. It was noted in the experiments that
the rate of production was not nearly as great at a low temperature
as it was after a high one was reached. However, it was impossible
to detect microscopically any difference in the fibers themselves. As
has been said, the only observations made on cold grinding were
while the stone was warming up, and on this account it is impossible
to say definitely what particular advantages or disadvantages, if any,
lie in the hot grinding process.
UNDETERMINED FACTORS.
Since the experimental work on hemlock, jack pine, and spruce
was started a number of factors which more or less influence the
quality and the rate of production of pulp have made themselves
evident. These are the rate of growth of the wood, moisture content
of the wood, size of wood ground, temperature of grinding, the thick-
ness of stock in the grinder pit, and the grit of the pulp stone, the
last undoubtedly being the most important. All of these variables
will be studied in future experiments, though the grit of the pulp
stone is the one which will probably receive the greatest attention.
It is doubtful whether this very important item in the production of
ground wood has been given sufficient consideration by manufacturers.
MICROSCOPIC COMPARISON OF EXPERIMENTAL PULPS AND
COMMERCIAL STANDARDS.
STANDARD PULPS.
Since it was necessary to have some means of comparing the
experimental pulps produced with commercial products, portions of
the samples obtained from manufacturers were photographed, in an
endeavor to classify the fibers according to their quality. It was
found that there is a more or less regular grading of the material
from long, fine fiber to pulp which is almost a powder. It is probable
JACK PINE AND HEMLOCK FOR MECHANICAL PULP.
19
thai/ each of the various grades of pulp has its particular use in cer-
tain qualities of paper, though no attempt has been made to classify
them according to uses. The standards selected are shown . ites
IV, V, and VI; in each case the fibers are enlarged 15 time For
the purpose of comparison the spruce sulphite standard fiber is shown
in Plate IV, figure 1, and the No. 1 spruce ground- wood standard in
figure 2. It is indeed very seldom that a sample of pulp is obtained
which corresponds to the No. 1 spruce ground- wood standard. As
will be noted, the fibers are very similar to the sulphite fibers, although
there is a certain amount of short material and coarse fiber present
which does not occur in the sulphite pulp.
Plate V shows the No. 2 ground- wood standard and No. 3 coarse
ground- wood standard. The No. 2 differs from the No. 1 standard
only in the amount of short fiber and coarse fiber present, the No. 2
having larger amounts of these two kinds. The coarse standard
needs no description. It is a kind of fiber often made by mills during
their low-water periods in order to maintain production with less
power consumption.
The No. 4, medium ground-wood standard, and the No. 5, fine
ground-wood standard, seem to follow in logical sequence those pre-
viously given. The No. 4 standard has the appearance of being a
mixture of No. 3 and No. 5. The No. 5, as will be noted, contains an
extremely small amount of fiber and is composed largely of dust and
short-fiber particles.
Table 2 gives the data furnished by the manufacturers of the
various pulp samples selected as standards. These data, for the
most part, are only approximate, but they will serve to give some
idea of the conditions under which the material was produced.
TABLE 2. Conditions of manufacture of spruce ground-wood standards.
Number of stand-
ard.
Make of grinder.
1
Size of cylinders.
&
*
o
i" 3
35
40
45
60
90
Equivalent pres-
sure on 14-inch
cylinder.
Kind of stone.
Kind of burr.
Size of
stone.
Number o
ets.
3
~<v
5
54
54
54
54
54
Pm
1
2
3
4
5
Friction Pulley & Machine
Works.
Carthage Machine Co
3
3
3
3
3
16
16
18
14
10
45.7
52.2
74.4
60.0
45.9
Lombard
Washers
27
26
27
251
181
Lombard and
Manufacturers'
Lombard
Empire
Solid spiral cut 8
to 1 inch.
Diamond point
cut 6 to 1 inch.
Straight cut 7 to 1-
inch.
Diamond point 7
to 1-inch and 5
to 1-inch.
Dayton Globe Iron Works
Carthage Machine Co
Friction Pulley & Machine
Works.
Greeley, New
Castle.
20 JACK PINE AND HEMLOCK FOR MECHANICAL PULP.
TAB^E 2. Conditions of manufacture of spruce ground-wood standards Continued.
R
i
I
"3
1
"S-c
1*
Make of grinder.
rotations
nute of s
ii
,
I 1
sf
&4&0
"o
Grade of paper.
r-t
& 5
s
o
M
s
*
P3
H;
g
s
1
Friction Pulley & Machine Works
180
2,545
90
160
.012
Do not make paper.
f 190
2,686
1
2
Carthage Machine Co
\ to
to
\ 75
175
.012
Poster
1 200
2,827
!
3
Dayton Globe Iron Works
145
2,050
i 300
.010
News
4
Carthage Machine Co
270
3 817
100
075
Do
5
Friction Pulley & Machine Works
220
3,110
70
Cold.
.011
Specialties. Some
coated, requiring
a soft and fine
pulp.
1 To grinder.
JACK PINE PULP.
Plates VIII, IX, and X show six samples of ground-wood fiber
obtained from jack pine. The data taken during these tests are given
in Table 4. There is a very striking likeness between the fiber
obtained from jack pine and that from spruce. Especially is this
true of the fiber secured by using the natural grit of the pulp stone
without any burring. Tests Nos. 7-1, 19, and 13-1 were run by
using an excessive amount of power and by sacrificing the rate of
production. This wood was ground, however, in the dry state, and
unquestionably the same quality of fiber could be obtained with
increased production and lower horsepower consumption per ton if
it was soaked or steamed. The fibers obtained in tests Nos. 20-1,
commercial run No. 14-1, and commercial run No. 24 compare favor-
ably with the No. 4 standard, and the production and power con-
sumption are more nearly those obtained commercially. There is
more short material than is found in the No. 1 or No. 2 standards, but
still the fiber is long and fine, and appears to have considerable
strength. The illustrations show some of the better fibers obtained.
Of course pulp has been made in the laboratory which was fully as
fine as that shown as the No. 5 standard. Some has been made also
which is fully as coarse as the No. 3. However, this is rather the
exception than the rule.
The jack pine fiber shown in Plate X (run No. 7-1) was the most
pleasing in appearance when in the pulp lap, and was generally con-
sidered to possess the best quality. The rate of production, however,
was so very low, and the horsepower consumption so high, that it has
no commercial importance.
JACK PINE, AND HEMLOCK FOR MECHANICAL PULP. 21
HEMLOCK PULP.
Plates XI, XII, and XIII show hemlock fibers which were o v ' i ,d
during the tests. Undoubtedly the most notable feature is * ge
amount of fine material present as compared with the jack pin- .cim-
ples. Hemlock grinds short and fine to a far greater extent than
either spruce or jack pine. While there are a great many long fibers
present, they are not sufficient in number to give a strong and tough
pulp. A certain amount of short material is necessary, however, for
news paper, and it is this material which gives a good finish. The
finish on the paper made from the hemlock pulp, commercial run No.
8, was exceedingly good; in fact, the superintendent of the mill where
the sample was run pronounced it better than the standard news. It
will be seen that there is a regular gradation in the length of fibers
from the long to the almost powder form. On certain of the illustra-
tions of hemlock fiber black spots composed of a great deal of fine
fiber will be noticed. These are the result of drying the pulp before
making slides, it being impossible entirely to beat out the fiber after
drying. When the material was in the form of pulp laps there was
no marked difference in the pulps. However, as with the jack-pine
samples, only the better grades of pulp obtained are shown. The
sample of pulp illustrated in Plate XIII, figure 2 (commercial run No.
50), is fairly representative of the pulp which it is possible to make
from hemlock under the conditions described.
MIXED PULPS.
Plate XIV shows three photomicrographs of fibers obtained under
exactly the same conditions of pressure, speed, and surface of stone.
The temperature and other minor variables were also kept as nearly
alike as possible.
Figure 1 shows fibers obtained by grinding hemlock in two of the
grinder pockets and spruce in the third (run 46a) . Upon determina-
tion it was found that the pulp contained 34 per cent spruce and 66
per cent hemlock. Figure 2 shows hemlock fiber obtained under the
same conditions (run 46&) as the first test, and figure 3 shows a number
of spruce fibers (run No. 46c). The hemlock fiber is considerably
shorter than the spruce and there are more shives present. In the
composite sample the hemlock is decidedly in evidence.
Plate XV shows three fibers obtained by grinding different woods
in different pockets of the pulp grinder. Commercial run No. 46a is
composed of a mixture one-third spruce and two-thirds hemlock;
commercial run No. 51 is composed of one- third jack pine, one-third
spruce, and one-third hemlock; commercial run No. 52 of one-third
jack pine and two-thirds hemlock. All of these pulps when in the
22 JACK PINE AND HEMLOCK FOR MECHANICAL PULP.
lap appeared to be a very good quality; in fact, it will be seen that the
fiber of which they are composed is of good length and that there is
no as much short material present as there is in the samples
of pulp.
Coi aorcially it would be possible to obtain better mixed pulps by
grinding the different woods in separate grinders and preparing the
stones so as to obtain the best quality of pulp from each wood.
It has been found, by comparing the samples submitted by Amer-
ican manufacturers with the standards chosen, that 5 per cent can
be classed as No. 1 pulp, 12 per cent as No. 2 pulp, 12 per cent as No.
3 pulp, 61 per cent as No. 4, and 10 per cent as No. 5. Comparison
of the experimental pulps with the commercial standards shows that
mixed pulps particularly compare well with the No. 4 standard, for
which there is evidently the greatest demand.
SAMPLES OF PAPER, PRODUCED.
In order to determine the adaptability of the pulps obtained in the
experiments to the manufacture of paper, a number of test paper runs
were made with the pulps which gave greatest promise. Samples of
the paper obtained accompany this report. All of the sheets of news
paper were made on a machine in the Port Edwards mill of the
Nekoosa-Edwards Paper Co. This machine is 116 inches wide, and
the sheet produced, trimmed, was 109 inches. The machine was
operated at a speed of 465 feet per minute, and no changes were made
in weight of sheet or speed after the beginning of the test; in fact,
throughout the runs the conditions were maintained as nearly con-
stant as possible. The finish on the paper was obtained by passing
the sheet nine times through a 12-roll calender stack. In each case
three 1,500-pound beaters of stock were run into sheet in order to
have the test continuous over sufficient time to give an idea of its
operation on the paper machine. It was intended to by-pass the
Jordan engine, but this being impossible, the stock was passed
through the engine and the roll set up only slightly.
Running changes were made in each test, and no difference was
found with any of the sheets excepting jack pine. This material
was somewhat pitchy, and after an hour's run it was necessary to
remove the dandy, since it began to pick up stock. All of the papers
were free on the wire and caused no trouble whatever.
The samples of paper containing spruce were made up for the pur-
pose of comparison. It will be seen that, with the exception of color,
the sheets differ little, and it is reasonable to suppose that the color
could be improved. Allowance should be made for the appearance
of the sheets as regards brown shives, these being due to the hem-
lock sulphite used, and not to the ground wood. Data on the beater
''furnish" for the various papers are given in Table 10. Table 3
gives a comparison of strength of the various sheets.
JACK PINE AND HEMLOCK FOR MECHANICAL PULP.
The samples of butcher's manila and No. 2 white manila given were
made by the Nekoosa-Ed wards Paper Co., the furnish being sho^ :T I
Table 10. These samples are meant merely to give an idea of
can be obtained when mixtures of hemlock and spruce are usea.
The strength of all of the sheets, with the exception of the one made
up of hemlock sulphite and jack-pine ground wood, compares well with
standard news paper. The paper from run No. 24 has another decid-
edly objectionable feature, and that is the loss of finish occasioned by
rubbing the sheet with the hand. The fibers under this treatment
fuzz up, and considerable powder and short fiber fall off. Several of
the other sheets have this same peculiarity, but if more size were
added this trouble would probably be eliminated.
The experimental papers have not yet been tested on high-speed
presses, and this must be done before accurate knowledge of the value
of the several sheets can be had.
However, after having obtained news paper of the quality of the
attached samples from hemlock, jack pine, and mixtures of these
woods without changing in any way present commercial practice, it
seems beyond doubt that these woods may be advantageously used
either singly or in various combinations, at least in the cheaper grades
of paper.
TABLE 3. Strength, weight, and thickness tests on experimental papers.
i
Mullen test.
Schopper test.
,d
' d
i
1
1
||
S
Lengthwise.
Crosswise.
^
Q
^
o o
,rj
fS
T3
^
g .s
OT
a
Is
d >>
i
d s>>
i
1
mlock sulpr
uce ground
^S
1
I
0.
ight per rea
24 by 36
erage thicki
p
fl
o
1
"&
erage stretc]
erage load o
trip 18 b
.65 cm.
!!
<3 d
erage stretc
erage load o
trips 18 b
.65 cm.
p
03 fcjQ
g
o>
<D
^>
r3
B
>
> Wl-<
>-~
!>
> WH
* ' r-l
O
w
00
w
^
5
M
CQ
<J
<5
<t
<
A
<1
P.ct.
P. c/i.
P. c.
P.ct.
Lbs.
Inches.
i6s.
P.ct.
Kilos.
Meters.
P.ct.
Kilos.
Met's.
1(T
5
95
32
0. 0033
11
0.344
0.8
2.95
3,687
1.4
1.765
2,254
1
25
75
33
.0035
13.2
.400
.95
3.49
4,043
1.22
.780
2,150
94
25
75
33
.0038
8.2
.249
.95
2.53
3,251
1.08
.305
690
46
25
25
50
33
.0037
11.4
.345
1.05
3.495
3,907
1.42
.755
,987
50
25
75
34
.0035
10.2
.300
1.11
3 615
4 111
1 17
555
819
51
25
25
25
25
32
.0035
9.7
.303
.95
2.855
3,495
1.24
.410
,692
52
25
50
25
33
.004
9.9
.300
.98
3.005
3,606
1.43
.330
,640
All of the above are averages of 10 determinations.
SUMMARY OF DATA.
Tables 4, 5, 6, 7, 8, and 9 show compilations of the data secured
during tests on hemlock, jack pine, and mixtures of these two woods
with spruce. The results of tests under many different conditions of
speed, pressure, and surface of stone are given. In a number of cases
the data on production and power consumption do not agree with that
taken at another time and under the same conditions of pressure,
JACK PINE AND HEMLOCK FOE MECHANICAL PULP.
speed, and type of burr. In all of these instances the differing values
onii N> accounted for by the fact that although the same kind of burr
)d, the stones were of different sharpness.
s been found difficult to duplicate in one test the surface of
si^ , used in another under the same conditions and obtain the same
production with the same power consumption. In fact, the pro-
duction factors vary greatly over short periods as a result of the vary-
ing attention given by the grinder man. On this account the power
and production data in the tables can be applied to commercial plants
only approximately. If a grinder is operating under the conditions
of any of the commercial tests shown in Tables 5, 6, and 7, however,
the data given will closely approximate the actual working conditions.
TABLE 4. Qualitative and quantitative tests on jack pine Power consumption and
production.
Kind of
stone.
Run number.
Kind of burr.
Pressure on 14-inch
cylinder.
Pressure per square
inch, pocket area.
Revolutions per
minute.
Peripheral speed
per minute.
Average horsepower
to grinder.
Bone-dry pulp in 24
hours.
Horse power per ton
bone-dry pulp in
24 hours.
Bone-dry pulp per
100 cubic feet borie-
dry wood.
Weight per cubic
foot bone-dry
wood.
Average tem pera-
ture'bf grinding.
Size of screen slots.
Manufac-
turers'.
Do
1
2
Natural sur-
face,
do
Lbs.
20.0
30.0
Lbs.
8.20
12.30
151.
151.0
Feet.
2,100
2,100
Tons.
Lbs
Lbs.
JK
140.0
147.0
Inch.
(i)
Do
3
do
39
10.00
150
2,090
176.
(i)
Do
3-1
do ..
39.3
16. 10
151.0
2,100
176.0
(i)
Do
4
do
50
20.50
150.6
2,100
196.
(i)
Do
5
do ...
60.0
24.65
151.0
2, 100
199.
(i)
Do
6
do
60
24. 65
171.0
2,380
196.0
(i)
Do
6-1
do
60.0
24.65
171.0
2,370
201.0
(i)
Do
7
do
50
20.50
171.0
2,370
199.0
C 1 )
Do
7-1
do
50.0
20.50
172.0
2.380
256.0
1.305
196.2
1,820
25.27
197.0
0. 012
Do
7-2
do
50.0
20.50
172
2,380
245
1.263
193. 6
2, 150
25. 57
183.0
.012
Do
8
do
60
24 65
203
2,810
198.0
(i)
Do
8-1
do
60.0
24. 65
203.
2,810
191.0
(i)
Do
9
do
50
20. 50
202
2,800
205.0
(i)
Do
10
do....
75.0
30.80
202.0
2,800
185.0
(i)
Do
Do
11
11-1
Diamond
point, 6 to
the inch,
do
60.0
60.0
24. 65
24. 65
152. 5
154.0
2,100
2,100
380.5
360. 5
6.075
59.3
148.0
146.0
.012
.012
Do
do
50
20 50
152 5
2 100
350
5 225
67
145.0
.012
Do
12-1
do!!! '!!....
50.0
20.50
154.0
2,100
359.0
7.030
51.0
179.0
.012
Do
13
do. .
40.0
16.40
152.5
2,100
260.
3.028
85.9
138. 2
.012
Do. ..
Do
13-1
14
do
do
40.0
50.0
16. 40
20.50
153. 5
173.0
2,100
2,380
299.0
324.0
2. 670
4.7K
112.0
68.8
195.0
154.0
.012
.012
Do
14-1
do
50.0
20. .50
174.0
2,380
398.0
5. 046
78.8
166.0
.012
Do
15
do
60.0
24.65
173.
2,380
395. 5
6.290
61.8
138.
.012
Do
15-1
do. .
60.0
24. 65
174.0
2,380
461.0
5.500
83.8
158.0
.012
Do. ..
Do. ..
Do
16
16-1
17
do
do
do
40.0
40. (
40.0
16.40
16. 40
16. 40
203. 5
205.
173.0
2,800
2.800
2.380
362. 5
375.0
289.
5.450
5. 360
3.834
66.4
70.0
75.5
147.0
200.0
143.
.012
.012
.012
Do
17-1
. do
40.0
16.40
174.0
2,380
332.0
4. 350
76.3
178.0
.012
Do
18
do .
50.0
20. -50
204.0
2,800
407.5
6.910
59.0
143.0
.012
Do
18-1
...do....
50.0
20.50
205.0
2,800
414.0
6.360
65.0
193 t O
.012
Do
19
do
30
12 30
15 5
2 100
201
2.045
98 3
149.0
.012
Do
20
do
30.0
12.30
205.0
2,800
313.0
5 320
58.8
178.0
.012
Do
Do.
20-1
21
do
do....
30.0
30.0
12.30
12.30
205.
174.0
2,800
2,380
304.0
269. 5
3.620
4.810
83.8
56.0
2,370
24.90
198.0
172.0
.012
.012
Do
22
do
60.0
21. 64
205.
2,800
481.0
7.320
65.8
1S5.
.012
Do
Lombard
23
24
do
40.0
{ 40.1
16. 40
16.40
205.0
J175.
2,800
2,445
249.0
395.
4.110
4.305
84.9
91.8
2,220
25.60
206.
176.3
.012
.012
\ 45.
18. 46
/
1 Unscreened.
JACK PINE AND HEMLOCK FOR MECHANICAL PULP.
25
TABLE 5. Qualitative and quantitative tests on hemlock Power consumption and
production.
Kind of
stone.
m number.
Kind of burr.
essure on 14-inch
cylinder.
essure per square
ich, pocket area.
evolutions per
minute.
ripheral speed
per minute.
^erage horsepower
to grinder.
>ne-dry pulp in 24
hours.
C fl
!*
a=
E
111
o
M
P
| d
t
m
1!
*!
HI
to
&o
0> p
v
jo
C
1
g
o
o>
tf
Pi
(2
<
PQ
W
<J
CQ
Straight cut,
Lbs.
50
Lbs.
20.50
170.0
Feet.
2,380
288.0
Tons.
Lbs.
Lbs.
F.
131.
Inch.
(i)
turers'.
Do
1
10 to the
inch,
do
30
12.30
100.0
1,400
1.54.0
126.0
C 1 )
"Do
2
do
30
12 30
150
2 100
202
143.0
( 2 )
Do
3
do
30
12.30
200.0
2,800
275.
150.0
2 )
Do
4
do
30
12 30
25
3 150
301
155.0
M
Do
5
do
20
8.20
150.0
2,100
169. 5
1.011
167.7
159.0
2 )
Do
6
do
20
8 20
175
2 450
210
1 380
152
170 C
2)
Do
7
do
20
8.20
225.0
3,150
223.0
1.295
172.
169.0
2)
Do
2-1
do
30
12.30
150.0
2,100
254.0
1.965
129.0
167. C
2)
Do
g
do
40
16.40
175.0
2,450
328.0
3.055
107.3
166.0
2)
Do
9
do
60
21 65
175
2 450
430
4 730
91
168
2)
Do
10
Spiral cut, 10
20
8.20
100.0
1 393
87.3
129,0
(1)
Do
11
to the inch,
do
40
16.40
175.
2.440
259.0
1.430
181.0
170.0
( 2 )
Do
12
do
50
20. 50
225.
3,150
368.
2.475
149.
178.
(*)
Do
13
do .
60
24.65
225.
3.150
475
3. 595
132.0
171.0
(2)
Do
14
do
50
20 50
175
2 440
358
3 395
105 6
166.
H
Do
15
do ..
60
24.65
175.0
2,440
397.0
4.044
98.4
131.5
(2)
Do
16
do
30
12 30
175
2 44(
243
148. 5
(2)
Do
do .
30
12.30
200.
2,790
297.0
146.0
M
Do
18
do
30
12 30
100
1 390
162 8
158.0
(2)
Do
19
do ..
50
20.50
100
1,390
261.
2. 470
105. 7
157.
(2)
Do
20
do
40
16 40
200
2 790
377
3 780
99 7
!>
(2)
Do
21
do ..
(50
24.65
100.6
1,100
281.0
2. 810
100.0
160.0
2
Do
22
do
50
20 50
150
? 090
366
3 815
96
161 5
w
Do
23
D i a m o n d-
40
16.40
175.0
2,440
347.0
3. 360
103.2
159.0
M
Do
24
pointcut, 10
to the inch,
do
50
20 50
175
2,440
394.0
5.065
77 7
157.
( 2 )
Do....
Do
25
26
do
do
60
30
24. 65
12 30
100.0
200
1,390
2,782
291.5
315.0
3.312
2 945
88.0
107
156.0
163.0
Do
27
do
50
2J. 50
200.0
2,782
432.0
5.400
80.0
160.5
M
Do
28
do
60
24. 65
101
1,408
290.0
168.0
(2)
Do
Do
29
30
do
Straight cut:
4 to the inch.
50
1 40
20.50
16. 40
175.
175.0
2,435
2,435
372.0
319.0
3.900
81.8
187.0
145.
0)
(2)
Do
31
10 to the inch
do
f
60
24 65
100
1 390
269
3 330
80 9
145
(2)
Do
Do
3?
33
do
do
6(
50
24. 65
20 50
100
175
1,390
2, 435
298.0
376
3. 120
4 000
95.5
94
155.0
163.0
( 2 )
( 2 )'
Do
Do
34
35
Spiral cut, 8 to
the inch,
do
60
60
24.65
24 65
100.0
100
1,390
1 390
297.0
284
4.35C
2 915
68.3
97 5
135.0
147
( 2 )
(2)
Do.. ..
36
do .
60
24.65
150.0
2,090
417.0
5. 130
81.4
152.
(2)
Do
37
do
60
24 65
200
2 782
50
6 890
75 5
154
(2)
Do
38
do
50
20.50
84.3
1,173
212.0
2.660
79.7
154.0
M
Do
39
do
60
24 65
85
1 183
271
2 955
91 8
150
M
Do
40
do
50
20.50
100.0
1,390
285.
3 0?5
94 3
156.0
( 2 )
Do
41
do
50
20 50
150
2 090
379
4 450
85 2
155
()
Do
42
do..
50
20.50
175.
2,435
429.0
5.295
81.1
155.0
(2)
Do
43
do
50
90 50
200
2 782
439
5 4^5
80 9
145
(2)
Do
Lombard . .
Do....
44
45
47
do
Straight cat,
3 to the inch,
do
40
40
55
16. -10
16.40
22.60
175.0
200.0
200
2, 435
2..800
2,800
359.0
340.0
516.0
4.225
2. 91f
5.370
85.0
116.5
96.2
158.0
159.0
161.0
H
(2)
Do
48
. . .do
50
20.50
225.0
3,145
510.
6.235
81.8
164.0
Do......
50
Straight cut, 3
to the inch;
spiral cut, 12
to the inch.
50
20. 50
175.0
2,445
422.5
5.300
79.7
2.070
24.84
170.6
( 2 )
1 Unscreened.
2 Size of screen slots, 0.065 and 0.012.
26
JACK PINE AND HEMLOCK FOR MECHANICAL PULP.
TABLE 6. Commercial tests on jack pine Power consumption and production.
GREEN MATERIAL.
|
S,
i
1
i
<N
a fl
3- 1
^
J
^
Si
2
Kind ol
stone.
mercia
numL
Kind of burr.
4 .
^%
CTS
o a
If
s 2
S 1 *
tH <U
1*
ff>f$
olutions
minute.
pheral sp
per minute.
rage horsepo^
to grinder.
e-dry pulp ir
hours.
sepower per
ne-dry pulp
hours.
o!
S i
"S
&.g
S'S
v, C
I
&o
f,r
t,
&!
3 2 ^
'.Q >
%
"3
S
<8
G
>
g
0^^
-
S
S 3
&
H O'D
I
o
fi
P4" 1
X
P-i
4
m
w
m
4
CO
CO
Lbs.
Lbs.
Feet.
Tons.
Lbs.
Lbs.
op
Lbs.
Incli.
Manufac-
14
D i a m o n d-
50
20.5
169
2,380
435
5.380
80.9
2,200
24.9
153
(i)
turers'.
point cut, 6
to the inch.
Do
14
.. do....
50
20.5
171
2,400
458
G. 650
68.9
2 070
24.9
150
(i)
Do
14
do
50
20.
171
2,400
430
6. 850
62.7
2, 130
24. 9
145
H
Do
14
.. do...
50
20.
171
2,400
416
7.040
69. 1
24.9
149
m
Do...
14
do. ..
50
20.
171
2,400
430
6. 610
65.
24.9
149
Do....
14
.. do....
50
20.
171
2,400
4 ''7
7. 070
60.4
2,190
25.8
150
( c)
Do
14
do
50
20.
171
2,400
447
7. 550
59.2
25. 8
150
Do
14
.. do
50
20.
171
2,400
df\C
8.300
55.3
25.8
147
n
Do
14
do
50
20.
171
2,400
441
7.700
57.3
2,190
25.1
147
i
Do
14
.. do
50
20.
171
2,400
jor
7.420
58.0
2,075
25. 1
151
i)
Do
11
do
50
20
171
2 400
4^1
4 960
85
2 025
25 1
154
ll
Do. . .
14
.. do
50
20.
171
2,400
6.035
76.0
2,180
25. 1
162
i)
Do
14
50
20
1 7 1
2 400
446
6 635
67 3
2 200
25 1
150
Do... .
14
. do....
50
20.
2,400
445
7. 135
62 5
2, 190
25.1
147
t <
Do
14
do ..
50
20
171
2,400
462
7 440
62 2
2 160
25 4
143
j\
Do
14
.. do
50
20.
171
2,400
6,860
66.0
2,153
25.4
14S
(1)
Do
14
do.
50
20.
171
2,400
484
7 560
64
2,155
25 4
142
Do
14
do
50
20.
171
2,400
467
7.335
63.7
2,235
25.4
137
0)
Weighted av-
436
7.030
2.170
148
erages.
Size of screen slots, 0.065 and 0.012.
SEASONED MATERIAL.
Manufac-
14
Diamond
50
20.5
171
2,400
457
5.140
89.0
2,125
25.4
147
/0.065
1 019
turers'.
point, cut 6
1 . Ul^S
to the inch.
Do
14
do
50
20.5
171
2,400
451
5.570
81.0
2,170
25.6
142
' . 065
i .012
Do
14
do
50
20.5
171
2,400
468
6.780
69.0
2,210
25.6
140
/ .065
i .012
Do
14
do
50
20.5
171
2,400
455
7.050
64.5
2,260
25.6
136
/ .065
\ .012
Do
14
do .
50
20.5
171
2,400
460
7. 365
62.4
2,233
25.6
142
.065
.012
Do
14
do....
50
20.5
171
2,400
490
6.160
79.5
2,150
25.6
154
.065
.012
Do
14
. do
50
20.5
171
2,400
3S6
3.995
96.6
2,095
25.6
152
. 065
.012
Do
14
do
50
20.5
171
2,400
421
6.240
67.6
2,225
25.6
144
.065
.012
Do
14
do
50
20.5
171
2,400
444
6.340
70.0
2,320
25.6
152
.065
.012
Do
14
do
50
20.5
171
2,400
417
5,990
69.7
25.6
146
.065
\ .012
Weighted' av-
447
6. 2SO
72.7
2,210
145
erages.
SEASONED MATERIAL.
Lombard .
24
Straight cut, 3
to the inch;
40
16.4
175
2,445
385
4.190
91.9
2,220
25.6
169.4
10.065
\ .012
spiral cut, 12
to the inch.
{/u>e
Do
24
do
45
IS. 46
175
2,445
404
4. 100
91.8
2,220
25.6
182.0
.012
Weighted av-
395
4. 305
91. 8
2,220
25.6
176.3
14.9
erages.
T\OK PINE AND HEMLOCK FOR MECHANICAL PULP.
27
TABLE 7. Quantitative and commercial test on mixtures of spruw, jack pine, and hemlock
Power consumption and production.
^
.
g
4
.2
4
3
f
i
.a
1
4
3
a
i
Ig
^
I
2
Kind of stone.
rcial run num
Kind of burr.
4
g
e per square
pocket area.
tions per mini
?ral speed per i
W SH
p
ry pulp in 24 1
ower per ton
pulp in 24 hot
ry pulp per 1(X
bone-dry woe
per cubic fool
dry wood.
II
Qgs per 100 cut
bone-dry wooc
screen slots.
a
a
1
I
|
i
i
s
ra
II
o
1*"
i
M
O
t>
!
"3
3
i!
PH
PS
PH
<
PQ
n
PQ
F
J
&
w
$ spruce; hem-
lock:
Lbs.
Lbs.
Ft.
Tows.
Tb<t
ibs
7T
Lbs.
In.
Lombard
46A
/Straight cut, \ r ft
\ Stothainch. 1 Ol
20.5
175
2,450
392.0
4.275
91.7
152.5
(0.065
\ .012
Hemlock:
Lombard
46 B
rln
50
20.5
175
2,450
413.0
4.885
84.6
175.5
/ .065
\ .012
Spruce:
Lombard
46C
do
50
20.5
175
2,450
407.0
4.878
83.5
160.0
/ .065
\ .012
J spruce; hem-
lock:
Lombard
49A
Straight cut,
3 to the inch;
40
16.4
175
2,445
360.4
4.880
73.8
155.0
/ .065
\ .012
spiral cut, 12
to the inch.
Hemlock:
Lombard
49B
do
40
16.4
175
2,445
370.0
4.885
75.7
168 3
f .065
\.012
COMMERCIAL RUNS.
spruce; ^hem-
lock: '
Lombard
Do
46A
46A
(Straight cut,
1 3 to the inch;
| spiral cut, 12
[ to the inch.
do
|,
50
50
20.5
20.5
20.5
175
175
175
2,445
2,445
2,445
426.0
425.0
432.0
5. 660
5. 135
4.905
75.3
82.7
88.0
149.0
173
10.065
\ .012
/ .065
\ .012
( .065
\ .012
- . T
/ .065
\ .012
/ .065
t .012
Do
46A
do
176 3
^ jack pine;
spruce; |
hemlock:
Lombard
Do
51
51
Weighted
averages.
[Straight cut,
1 3 to the inch;
| spiral cut, 12
I to the inch.
do
16.3
t
427.2
""
442.0
444.0
5.175
5.705
5.420
83.0
77.5
81.9
2,030
f24. 8 \
\23. 76f
-
169.0
167.6
/
175
175
2,445
2,445
I-
50
20.5
20.5
175.0
i jack pine;
hemlock:
Lombard
Do
52
52
52
Weighted
averages.
("Straight cut,
1 3 to the inch;
| spiral cut, 12
1. to the inch,
do
\
443.0
_ "
398.0
425.0
406.5
5.575
- '_.
4.550
4.350
3.950
79.4
:==
87.5
97.7
103.0
2,232
'_!-
(25. 6 }
i 24 - 7 t
l29.ll)
-..-..-
171.0
160.0
17.4
" -^*
f .065
\ .012
/ .065
\.012
/ .065
(.012
}
20.5
20.5
20.5
175
175
175
1"
50
50
2,445
2,445
2,445
185.4
179 4
....
Do
do
Weighted
averages.
17.6
I
414.0
4.310
96.3
2,230
f25. 2 \
\26. 75/
177.7
/"
28 JACK PINE AND HEMLOCK FOR MECHANIC
8. Commercial tests on hemlock Power consumptic .7 prodi
Kind of stone.
Commercial run number.
Kind of burr.
Pressure on 14-inch cylinder.
Pressure per square inch,
pocket area.
Revolutions per minute.
Peripheral speed per minute.
Average horsepower to
grinder.
Bone-dry pulp in 24 hours.
Horsepower per ton bone-
dry pulp in 24 hours.
Bone-dry pulp per 100 cubic
feet bone-dry wood.
Weight per cubic foot bone-
dry wood.
Average temperature of
grinding.
Screenings per 100 cubic feet
bone-dry wood.
Size of screen slots.
Manufacturers' . .
Do
14
14
/Spiral cut, 10
\ to the inch.
do
Lbs.
}50
50
50
Lbs.
20.5
20.5
20.5
175
175
175
Ft.
2,435
2,435
2,435
331.0
356.0
353.0
Tons.
2.855
3.795
3.425
116.0
94.0
103.0
Lbs.
1,955
2,030
2,122
Lbs.
24.8
24.8
24.8
F.
173.5
168.0
173.0
Lbs.
.10. C
In.
(0 065
( .C12
1 .065
1 .012
/ .065
\ .012
Do
14
do .
Manufacturers' ..
Do
M-l
14-1
Weighted
averages.
(Spiral cut, 10
\ to the inch.
do
349.0
363.0
371.5
3.417
103.1
2,048
i -
2,070
2,080
24.8
171.4
2,432
2,432
}50
50
20.5
20.5
175
175
4.195
4.068
86.5
91.4
24.8
24.8
165.5
108.
18.6
18.5
f .065
\ .012
/ .065
\ .012
Manufacturers'...
Do
8
8
Weighted
averages.
{Straight cut,
10 to the
inch.
do
368.2
4.115
89.5
87.7
84.2
97.5
2,077
24.8
167.0
165.5
159.0
177.6
f .065
\ .012
/ .065
\ .012
/ .065
V .012
F
40
40
16.4
16.4
16.4
176
176
176
2,450
2,450
2,450
346.0
287.0
270.0
306.0
3.945
3.410
2.772
2,118
2,085
2,038
24.8
24.8
24.8
24.8
15.5
18.6
Do
8
do
Manufacturers'. . .
Do
23
?3
Weighted
averages.
{Diamond
point, cut 10
to the inch.
do
3.435
89.7
109.5
87.5
83.9
2,083
2,040
2,125
2,130
24.8
24.8
24.8
24.8
168.4
}.
40
40
16.4
16.4
16.4
176
176
176
2,440
2,440
2,432
300.0
318.0
281.0
2.740
3.635
3.350
186.5
172.0
162.0
13.7
32.7
20.3
/ .065
\ .012
f .065
\ .012
f .065
\ .012
Do
?3
do
Lombard
30
"W
Weighted
averages.
{Straight cut,
4 to the inch;
spiral cut, 10
to the inch.
do
301.0
3.300
92.4
2,105
24.8
172.8
< .065
\ .012
f .065
\ .012
40
40
16.4
16.4
176
176
2,432
2,432
340.0
315.0
4.075
3. ,170
83.5
99.4
2,080
2,140
24.8
24.8
24.8
25.2
25.2
24.84
176.0
179.5
16.5
17.8
Do
Lombard
50
r .O
Weighted
averages.
(Straight cut,
3 to the inch;
spiral cut, 12
to the inch.
do
331.0
417.0
417.0
422.5
418.0
3.725
_--
4.05
3.815
5.300
89.5
2,102
177.0
184.5
185.0
170.6
175
175
175
1"
60
50
20.5
20.5
20.5
2,445
2,445
2,445
103.0
109.2
79.7
2,195
2,19
2,070
11.2
11.2
( .065
\ .012
/ .065
\ .012
/ .065
\ .012
Do
Do
50
do...
Weighted
averages.
4.370
97.5
2,160
25.1
180.3
.1ATK PINE AND HEMLOCK FOE
A.L PULP.
TABLE 9. Quantitative and commercial tests on spruce Power consumption and
production.
A
g
|
%
fc.
c5
a a
5<6
3>-
g
C3
a,
&
>
3
CM 3
3
-H^
+2
S-S
'I
ftjg
k
a
s$
wl?
P
ll
I
i
Kind of
stone.
un numbei
Kind of burr.
f
If
evolutions
ute
il
|a
ft
i
11
if
>
|1
i
orsepower
bone-dry
24 hours.
1!
r eight per c
bone-dry
G) So
C3 o
P
1!|
g >
5
g
PH
PH
PH
PH
PH
<!
cq
W
PH
P
^
CO
CQ
Lbs.
Lbs.
Ft.
lows.
L6s.
Z6.
k
Lfts.
In.
Lombard . .
1
Straight cut,
3 to the inch;
40
16.4
2 445
403
4 988
80.8
171.0
fO.065
spiral cut, 12
50
20.5
\0. 012
to the inch.
Do
do
1 40
16.4
Il75
2 445
399
4 525
88 1
175 5
10.065
\ 50
20.5
f
\0. 012
Weigh ted
401
4 810
83 5
2 480
28 4
172 6
17 2
averages.
Do
2
Straight cut,
40
16.4
200
2,795
398
4.245
93.8
164.3
3 to the inch;
spiralcut, 12
to the inch.
Do
9.
do
40
16.4
200
2,795
408
3.995
102.0
171. S
Do
2
do
40
16 4
>oo
2 795
394
4 175
94 4
166 7
Weigh ted
402
4 120
97 5
2 012
22 72
168.0
13 75
averages.
Straight cut
20
8 2
175
2 445
101
1 215
157.0
2,300
27.66
163.0
9.82
3 to the inch;
spiral cut, 12
to the inch.
4
do..
40
16.4
175
2,445
333
3.025
110.0
2,408
27.66
166.5
17.8
5
....do.
60
24.65
1 75
2, 445
454
5.255
86.4
2,415
27.66
152.2
18.6
TABLE 10. Furnish to beater on basis of 1,000 pounds of stock Experimental and
commercial papers.
EXPERIMENTAL PAPER.
1
1
a
a
1
PH
<i
1
P
ft
S
a
ffi
W)
O
3
bo .
"d
bo .
' rt 08
s
T3 .
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Run.
X
0) O
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a p
C3
3
d
a
tf
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g
3 ^
^
ft^
T3 *
.2
S
g
bo
a
3
a
o>
h
a
S
ti
3
jr
,a
3
03
3
P
&
w
CO
w
CO
^
o
PH
CO
P
O
r,fc,
'Lint.
Lbs
Lfefc
Lbs
Lbs.
Lbs.
02.
0?,
02.
02.
0^.
Commercial
1 A
50
950
8
8
20
067
3.33
Do
250
750
8
8
20
067
3 33
Do
24
750
8
8
20
3.6
0.15
Do
46
250
250
500
8
8
20
4
15
Do
50
250
750
8
8
20
3 7
20
Do
51
250
250
250
250
8
8
20
4 1
15
Do
500
250
8
8
20
4.3
.15
COMMERCIAL PAPER.
No 2 white manila
210
395
395
8
s
2 8
Butchers manila
<>10
263
527
>n
^0
26.7
2.75
0.83
O
UNIVERSITY OF CALIFORNIA LIBRARY
UNIVERSITY OF CALIFORNIA LIBRARY
BERKELEY
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