PAflRS
THE 'DEFIBZRING OF RSOLAflIED. ROPE CABLE
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P. 1. BairdS
tad. 0.
i:. Htubesk'
:
tntrodüotion,.
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to. determine the•
The purpose of this study
effectiveness and the' eoononitãe 'of various 60*134' and various
in 4e't'
prooesaing treitments, particularly of the rod
Beaterstflated.
It!atf
paper.
fibei?iug reclaised tope
ttber
from the oooperator' a Si].l'oóntained a. 1*11. 'aZount atbe'.
to.
bundles whioh had not 'been separated sliff iaieñtly .
formed into, a, ôtear sheet: of paper. A 'waterleaf 'hà$. Sheet'
•
from this beaten material is sho*a.as'sbeet No.
MaterialS .and. Procedure.'.
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fóllowIng equipment. was used in 'this study'%.
A horizontal cylindrical steel digester,, of the zag
charge of
•bQiler type1' of 325 gaflons...oapaoity. A
material, in 'this digeetéi is about 500 'pounds of wood 'chips
oVS5O pounds of the reolaimed. oablé' paper (air—dry basis).
The digester r.otateè' at 1 r.p.m. The.' charge is heated'
.
directly by'mea;s of steam introdnoed through one of the
truTmione. At the end ct the digestion the' pressure is 'relieved and the contetti are ooted thiffioieñtiy by admission
of coldwater, tG'permit the removal of the manhole oQver.
'The contents are then emptied. into, I shallow drainer provided.
• with a,perforated tile bottOm, where the pulp is washed. A
2. ''
photograph of the digester te shown In
.
sernicomrneroial rod mjtl'Shot in Figure .4
used. It is 3 feet in. diameter and 5 feet lông, 'inside
measure, and can be r .tated at. speeds varying from 1? 'to
28 r.p.m. Aoharge,of pulp equivalent to '25 pounds Qven
A
Forebt Products LabbtatorY,MadisOn,.Wi5.
%ssistant Chethist, 17.9. Forest Products Laboratory, Madison,
1Senior Chemist'1'
Tie.
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dry anc3. at consistences ranging from 4 to 8 per cent is the
proper charge for this mill. It can be run bOth COfltIflUOUSlY
and batchwise, and when operated continuously the material is
introduced by a screw feeding device through one trunnion of
the mill- (fig. 1), the milled pulp flowing out through the
Sufficient water is fed with the material
opposite trunion.
to form a pulp suspension of the desired consistence. When
operated batchwise, the material to be milled with water
sufficient to give the desired consistence is added through
a side manhole. At the completion of a batcb,wise operation
the manhole cover is removed and the mill contents dumped
into a shallow screened drainer where the pulp can be washed.
A 50—pound experimental Marx beater having a roll
of
24 inches in diameter with 18 inches face, and a bed plate
with
52
steel
the elbow type was used. The roll is fitted
fly bars, 3/8 inch thick, arranged in clusters of four. The
bed plate is fitted with 14 steel fly bars each 15/32 inch
thick at the base but bevelled at an angle of 25 degrees to
The maximum dead
an outer edge of about 1/16 inch thick.
load weight of the roll, without using the counterbalancing
The tub of the beater is of concrete
device, is 1800 pounds.
construction with a trough of special cross section designed
The roll is driven at
for rapid circulation of the stock.
peripheral
speed of 1950
which
corresponds
to
a
300
The
beater is
feet per minute, by a
roll
settings
and a power
equipped with a motion recorder for
3.
The beater is shown by Figure
meter.
Material
The reclaimed paper was composed of small multicolored bundles and sheets as well as short lengths of cotton
Occasionally small pieces of fine copper wire were
twine.
The moisture content of the paper as received was
found.
8.95 per cent on the wet basis. A sample of this paper in
the form of a hand sheet held together with animal glue containing a small amount of glycerin is shown as sheet No. 2.
Procedure
The plan of study embodied the cooking of the paper
to soften it to pulp and the processing of this pulp as well
as of the,raw paper in the rod mill or in the beater to determine the effectiveness of each in defibering the material.
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The first, using a chemical
Three cooks were made.
ratio of 3 per cent of caustic soda and a 5.6 to 1 ratio of
water to fiber, was cooked for 1 hour at a temperature
126° 0.; the second, using 3 per cent o± caustic soda at a
2.23 to 1 ratio of water to fiber, was cooked-for 4 hours at
a temperature of 116° 0.; and the third, without chemical but
with a 5.6 to 1 ratio of water to fiber, was cooked for 1—3/4
hours at a temperature of 121° 0. The exact weights of the
materials used- and the cooking conditions are shown in
Table 1.
Table 1.--Cooking data
Materials
Cook;
:
:Diges—:
:
.
No. :Paper :Water
Conditions
:
:Oaustic:Temper—: ter
ature :pres—
sod-a
:
:
:
:
Time :Water—fiber
ratio
:
:sure
————:
: Lbs--
:
:
—
:
Los.
:
Lbs.
:
83
:
00.
:
126
:
227.5, 1267
3
227.5:
508.0:
6.83
:
116
:
4003: 227.5: 1267,0:
None
;
121
:
4001:
4002:
2:
Lbs.—:.dours—:
.
1
:
5.6 to
20
:
4
:
2.23 to 1
25
:
1—3/4: 5.6 to 1
weight which is equivalent to 250 pounds as received.
2.
—Air pressure was relieved shortly before the desired temperature was reached.
the time the digester reached the desired. temperature
until the pressure was relieved.
relief line prevented air pressure relief.
The processings in the rod mill consisted of milling
both the raw paper and cook No. 4001 with plugged steel pipe
pounds and with solid
rods having a total weight of
bronze rods having a total weight o± 3566 pounds. With the
pipe rods the operation was carried. out batchwise at a consistence of o.0 per cent. At various intervals the mill was
sampled, and hand- sheets were made to show the degree of deRepresentative hand, sheets as well as others mentioned form a part of this report.
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Using the heavy rods the operation was carried ouM
continuously to simulate full mill—scale conditions. An
attempt was made to add material at the rate of 25 pounds
(oven-dry baéis) per hour but some difficulty was.enoountered
at times due to the long strings of paper becoming wrapped
'arojad. the edges of the screw in the .feeditg device and ahok—,
ing the feed. The consistence was held as closely as possible
to 6.0 per cent but this varied somewhat due to the 'additional
water required to help free the screw. At the end of '.1 hour
of. continuous operation a sample of discharged pulp was taken
and formed into haM sheet!.
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portion of cook No 4001 taken from the discharge
at this time was passed through a 9—cut screen and formed
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into hand sheets.
The rod mill conditions are shown in detail in
Table 2.
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The processings in the beatèi consisted of brushing
4003, each at a
the raw paper, cook No. 4001 and cook
consistence of 3.25 per cent with, the roll raised 0.054-inch'
above the bed plate. The temperature was matntained. at about
At the end of 40 minutes samples
38° 0. during the treatment.
were taken for hand sheets to sho! defibering. The brushing
of the raw paper and cook No. 4001 was stopped at the end of
40 minutes, but cook No. 4003 was processed for an additional
just bleared. the
60 adnutes with the roll lowered 'so that
bed plate.
it
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Sheet No. 3
Sheet
No. 4
Sheet No. 5
Sheet
Sheet
Sheet No. 8
Sheet No. 9
Sheet No. 10
No. 7
Rod
Milled Cable Papers
No. B
conditions
Table 2.
Rods
Rod
:
mill:
Size
Cook
Kind
No.
:
run:
No.
Plugged
steel pipe
:Inches:Inches:
:
:
:
:
paper;
:
:
1+001
Solid
.
:
:
3.0
bronze
:
14.5
:
:
23
:
:
12
:
2.5
59
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:
I
:
:
23
12
2021+
151+2
25
:
:
225
:
.
20214. :
151+2
.
25
:
.
:
50
0
6.0
3—10
i.ncl
25
:
11
60
:
12
6o .
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13
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No.
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6
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sample
ence
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:Consist—:Time:Sheet
—25
:
:
:
Lbs. :Per cent:Min.:
:
:
2.5
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.
Lbs.
k5
2 37
Raw
Solid
bronze
:
:
:
:
-:
1+6
:
paper:steel pipe: 2.37
:
:
:
:
:
:
Material
added
:Number: Total:
:weight:Paper :Water
fliam—:Length:
eter
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equivalent.
at
r.p.m.
at 26 r.p.m.
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as nearly
attempt was made to hold the
as possible to Gper cent but when the screw feeding
device clogged, a large quantity of water had to be
added to wash it free.
was added at a rate of about 25 pounds per hour.
Due to the strips winding around and clogging the
screw feeding device, this rate varied considerably
at times.
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Sheet No. 11
Sheet No. 15
Sheet No. 12
Sheet No. 13
Sheet No. 16
Rod
Sheet No. 17
Milled Cable Papers
Sheet No.14
Sheet No. 18
The beating conditions are shown in detail in
Table 3.
Table
.:
Beater:
run
No.
143
144
:
:
:
Cook:
145
:
:
Lbs. :Per cent:
:
:
4001: 50
:
50
.
:
1222
:
3.25
1531
:
3.25
S
:
Roll : Time: Sheet
:sample
ature :above :
:
:
:
:
:
:
: Consist—: Temper—:
:
:
4003: 50
•
:
:
No. :Pulp: Water: ence
:Raw
:paper:
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Materials
:
bed
:
:
No.
:
15
plate:
:Inches:Iin,:
:
C.
:
:
:
38
:
:
38
:
0.054: 40
16
40
,054
S
'z
1292
.
or
38
S
054
to 0.00: 60
S
S
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1?
;
18
S
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equivalent.
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a-Beater was run the spme as for runs Nos. 143 and 144 for
40 minutes; then the roll was lowered until it just cleared
the
decided
bed plate.
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From a casual examination of cook No. 4002,
not to make any processing studies on it.
it
was
Hand sheet papers were made from the variously
processed materials to show the degree of defibering obtained
under the different conditions. These sheets were made to
thickness as possible to give sn exact comparison
as
of residual fiber bundles or paper pieces.
Discussion of Results
The pulp from cook No. 4001 proved to be superior
This pulp
the others processed for defibering
when compared with the raw paper was very effectively de—.
fibered. in the rod mill using heavy rods as shown when sheet
Likewise the response
No. 13 is compared with sheet No. 12.
of this pulp as compared with that of. cook No, 4003 and. of
the raw paper to the action of the beater is best shown by
observing sheets i'Ios. 15, 16, and 17.
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The action of the ro& mill was studied
the type of rod..
oonsistenoeof 6.0 per cent and by
fibers
The light pipe rods were ineffeotive in separating
on the pupfoa:000k
even after so minutes of millin?
Nos. .5 to 10 inclusive. A. would
Nb. 40Q1 as Shot by
rods on the raw paper was.
be expqoted the action of ..the
25 mi;utes. At.
iilling.period.óf
hardly notioea'b:Ie
tea
strips wete
papet.
thia time, as shown by sheet No. 11, the
still
contS4ned..a
oonaidqrably ,reduoed. in size but the:.ptlp:
.
largeprQportion
of the fiber
bundles.
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operating the ,mill
Treatment with the heavy
lore effective in defibering the
continuously was.
raw paper than the treatment with light. rods. With the pulp
from. cook No. 4001 :however; the heavy rods qaused a very
by sheet No.. 13. 4thcnjgh
high degree of defibering as
there was a sinaflproportion of' fiber bundles yet reaqining
in the pulp,. :thtse. *erb .readfly. removed passing the mil1e4
pulp throufl:.a 9rou4 Doreen4 the .te2atin absëncO of.fiber.
•howi by sh!et 116. .14..
bundles
the
use
of
rodS
cast from bronzS4..
One
its
small
pieOes
of.the metal
Due to their. brittle bharaoter
throughout
the pulp. flit
were ,broken off exit deposite4
to
metallic impurity would be highly
the
:propet
slope:
be reconverted into. cable paper but with
would bC no
tion .of milling Slement metals there
H.
from this source.
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in this
diffiotltl arose
difficulty
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brushing action of the beater was very effective
when the paper hadbeeü previously eoftenedby cooking with
caustic soda as in cook No. 4Q01, The pulp from this. treat—
ment. is shown by sheet No. 15. Paper cooked without chemioal
.
as in cook No. 4003 was insufficientLy, softened tO. be
This.is shown by Sheet
pletely difibSrized in.the beater.
No. 1?. Raw paper as such would require so muoh beating 'that
the fiber would be tOo greatly h*drated and cut before
.pletedefibering.
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