Engelmann spruce for pulp and paper products

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Title:
Engelmann spruce for pulp and paper products
Physical Description:
Mixed Material
Creator:
Schafer, E. R ( Earl R )
Forest Products Laboratory (U.S.)
Publisher:
U.S. Dept. of Agriculture, Forest Service, Forest Products Laboratory ( Madison, Wis )
Publication Date:

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Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 29175672
oclc - 231767495
System ID:
AA00020490:00001

Full Text


E G ENOELMAIN SPRUCE FOR PULP AJD PAPER PRODUCTS


By

E. R. SCHAFFR, Chemical Engineer

Forest Products Laboratory) Forest Service
~-S[.-. Department of Agriculture
s !


I I

r Introduction


This report summarizes work that has been conducted at the Forest Products
Laboratory since 19A1 on the suitability of Engelinann spruce (Picea
engelmanni) for pulp and paper manufacture.

Although the spruces are among the best and most used of woods employed by
the pulp and paper industry, Engelmann spruce has not been used in large
volume for this purpose. This is because it grows in the mountain ranges
of the western parts of the United States and Canada in heretofore rela-
tively inaccessible regions and at great distances from the present pulp and
papermaking areas. Until recent years the use of Engelmarmnn spruce for
papermaking has been mostly in one mill at Spokane, Wash.

Remoteness of markets and the unfavorable transportation position in general
to the Rocky Lountain area have acted as the major deterrents to development
of a pulp and paper industry. However, increasing demand for paner in the
United States and throughout the world and the diminishing supplies of the
or desirable pulping species in papennrmaking centers have prompted interest
in untapped wood resources in undeveloped regions. Since l?3' Envelmann
spruce has been shipped into the Lake States in growing volume, and efforts
are being made to establish pulp and paper mills for the use of this wood
in the Rocky Mountain States.

Bark-beetle infestations in Colorado have killed several billion feet of
Engelmann spruce timber in recent years. Occurrence of a similar infesta-
tion in the snruce forests of Western Montana and Northern Idaho is
presently causing lumbermen and the Forest Service much concern,

Dead Engelmann spruce trees are satisfactory for papermaking if salvaged
before they are extensively decayed. That decay is not a serious problem
from this standooinrit, however, is shown by the fact that samples received
at the Forest Products Laboratory for pulping tests have been nractically


Maintained at Madison, Wis., in cooperation with the University of
Wisconsin.


Rept. No. RlU9-2


-1-


Arriculture-Madison






free of decay, although some of the spruce had been standing dead for 20
years or more, Likewise, bug-infested trees that are logged promptly will
produce exactly the same quality of lumber or pulp as uninfested green trees.


Properties of Engelmann Spruce


The principal properties of Engelmann spruce that make it highly regarded
for papermaking, are its relatively light color, indicating an absence of
tinctorial and resinous substances that are troublesome to remove in pulp-
ing, its long slender fibers (about 3 mm.), and moderately low density.
Because of these properties it can be pulped easily by the sulfite, sulfate,
and groundwood processes and made into a wide variety of papers.

Engelmann spruce has the lightest weight of the spruces, ranging from about
19 to about 22 pounds per cubic foot (moisture-free weight, green volume),
White and black spruce weigh from 22 to 26 pounds per cubic foot. The
lower density of Engelmann spruce is offset to a considerable extent by the
relatively high solid volume of wood per cord, resulting from its thin bark
and straightness. Consequently, the weight of wood and yield of pulp on
the cord basis are comparable to those of other spruces. The yield and
quality of pulp obtained from Engelmann spruce depend on density, rate of
growth, straightness, size, soundness, and other characteristics. The
source of the wood is not an important factor, except as environment may
affect these properties and characteristics. For example, the density of
Engelmann spruce in the northern part of its area of growth tends to be
higher than in the southern part. Beetle-killed trees that have been stand-
ing for some years have a lower moisture content than live trees, and
present certain technological problems, -ihich, however, are not difficult
to solve if given proper consideration.

Some of the properties and the chemical analysis of several samples of
Engelmann spruce received for pulping tests are given in table 1.


Pulping of Engelmann Spruce


Sulfite pulps made from spruce, true firs, and hemlock are used for making
newsprint, bond, book, writing, wrapping, and tissue papers, a wide variety
of special papers and boards, and rayon and other cellulose derivatives.
Experiments and mill production with Engelmann spruce, both live-cut and
insect killed, show it to have practically the same sulfite pulping charac-
teristics as eastern white and black spruce, and its pulps have papermaking
properties falling in the normal range of those for these eastern spruces,
the usual standards for comparison. However, the Forest Products Labora-
tory tests indicated that pulping conditions for the dry insect-killed wood
may need to be slightly modified (that is, by rewetting of chips by steaming
and by use of soluble-base cooking acid and a low-temperature, long-time
cooking schedule) in order to obtain the most satisfactory pulping and the
strongest pulps. Laboratory and mill experience have also indicated that


Rept. No. R1944-2


-2-






the lower-density samples of Engelmann spruce tend to give pulps having
tearing strengths in the low portion of the normal range, a result that
while not generally desirable, is probably not critical in most situations.


With the exception of resistance to tearing, the stronvnst pulps are made
from spruce, balsam fir, and hemlock by the sulfate process. Hi-h tearing
resistance is a characteristic of sulfate pulps made from the coarser-
fibered southern pines and Douglas-fir. Spruce sulfate pulps are prized
for the manufacture of the highest-quality specialty papers, wrapping and
bag papers, and for blending 1rith other pulps to impart strength in a wide
variety of paper and board products. Experiments with live-cut and insect-
killed Engelmann spruce show that this wood digests with the facility of the
best quality softwoods used for sulfate pulping and that its pulps range in
papermaking properties with the highest quality of softwood sulfate pulps,
with the exception that bleachable pulps made from lower-density wood tend
to have higher bursting and lower tearinr strengths than usuil. Specifically,
the Engelmann spruce pulps, whether of the kraft or bleachable grades, are
equal or superior (with the exception noted above) to those made from
lodgepole pine or those made from jack nine, which among eastern Softwoods
is the most used for sulfate pulping.

High-quality groundwood pulp can be made from Engelmann spruce. Experi-
ments on live-cut and beetle-killed wood showed it to be comparable to
eastern spruces in energy consumption and other grinding characteristics,
and that the pulp can be used for all the purposes for which groundwood is
employed.

Table 2 gives the yield of pulp that can be expected from Enrelmann spruce
by the various processes.


Newsprint Paper from Engnlmann Spruce


Newsprint papers were made in experiments with both live-cut and insect-
killed Engelmann spruce. Acceptable-quality paper was made by conventional
groundwood and sulfate pulping and papermaking procedures. The strength
and brightness of the papers were above average.

Table 3 shows a comparison of the properties of a typical experimental
newsprint paper made from EnFelmann spruce and average values for
commercial newsprint.


Rept. No. R1944-2


June 1953







Table I.-.Physical characteristics and chemical analysis of Engelmann spruce
used in pulping experiments

tLive-cutsLive-cuttLive-cut i Beetle- iBeetle-
t wood : wood s and t killed killed
t from : from t beetle- i wood : wood
:Montana : Oregon : killed t from : from
I I t wood :Colorado: Utah
I t % from t s
S Coloradol-; I
-- --------------------.----------- - .-.- ........ -.. ....-C......d..


t 0
Shipment No......................: 1509 s
0
2 *
Physical characteristics-


Diameter...**............inches...
Age........................years.
Rings per inch..... ........ ...
Density........lb. per cu. ft.l.:


11.4
88
15.5
22.4


Chemical analysis


Lignin.................*.percent..:
Holocellulose..........percent..:.
Alpha cellulose.........percent..:
Total pentosans........percent..o
Solubility in:
Alcohol benzene.......percent..:
Ether.................percent..:
1 percent caustic soda.percent.:
Hot water.............percent..:


27.9

42.4
12.1

1.3
0.5
8.0
1.7


2
2659 t
*
*


9.3
145
31.5
22.5



26.3
67.9
44.3
9.2

2.8
1.4
12.2
3.7


s
2466 S
a


10.8
68
12.5
19.2


* 0
*
* ....*....*
o 0
o *g.gg*oog.

* 0
* ..........
* 0
* 0
* 0
o 0

o 0
12 00


S
3049 a
a
0
0
0
0
13.6
162 a
24.8 $
20.8
a
9
0
2
28.2 a
67.3 2
45.2 ,
7.4

1.7 t
1.1 a
11.6 "
1.8 t
**


3030



12.7
223
33.7
19.0



27.4
70.7
45.4
8.4

3.5
1.4
10.4
1.3


I
-Average sample from 5 live-cut and 25 beetle-killed trees.
2
-Average of logs in the shipment.
3
-Moisture-free weight, green volume.
4
Moisture-free material.


Rept. No. R1944-2







Table 2,--Typical yields obtained 1n pulping EnEelmann spruce


Density of wood (moisture-free weight/green
volume).,..................................pounds per cubic foot,.: 20


Weight of moisture-free wood in 1I cord of
rough wood.........,. ..... .. .... ..... .*. .* ......pounds...
I
Sulfate pulping !
a
Kraft-type pulp:
Yield unbleached pulp per 100 pounds of wood ........pounds...:
Yield unbleached pulp cord- ...2... .....pounds. :
*
Bleachable type
Yield unbleached pulp per 100 pounds of wood- .........pounds...:
Yield unbleached pulp per cord.......................pounds...
Yield bleached pulp per 100 pounds of woodI.- ..........pounds...:
Yield bleached pulp per 1rd-0 ppodds
*
Sulfite pulping

Strong type:
Yield unbleached pulp per 100 ounds of woodI .....,.pounds., :
Yield unbleached pulp per cord-. ... ... ..pounds.
I
Bleachable type: a
Yield unbleached pulp per 100 pounds of wood .........pounds...,
Yield unbleached pulp per cord-.....................pounds..,:
Yield bleached pulp per 100 pounds of woodI.. .. pounds..
2
Yield bleached pulp per .... .. ....

Groundwood pulpinR

Yield pulp per 100 pounds of wood....................pounds,..
Yield pulp per cord-7. ..........*........ .....,....pounds...
UU


1,950


46-50
940-1,020


44
900
42
855




48-50
980-1,020


48
980
45
920


95
1,970


1
-Moisture-free basis.
2
-Air-dry pulp. Losses of wood in barking, sawing, and chipping and of fiber
in mill effluent, totaling about 6 percent, are included in this estimate.

!Air-dry pulp equivalent. Losses of wood in barking and sawing and of fiber
in mill effluent, totaling about 4.5 percent, are included in this estimate.


Rept. No. R1944-2




UNIVERSITY OF FLORIDA
II 1111111111111111111 1111111 Nlii IIIIIIII1III 1111111IIII1
3 1262 08924 0997
Table 3.--Properties of experimental newsprint paper mau Lu.V. .........
spruoe

Experimental i Commercial
newsprint t newsprint1
- ----------------------------------------------------I-----------


2Pulp furnish
Pulp furnish;-


Seinibleached sulfate...............percent..:
Grcundwood... ..... ...,, ,.., ...percent.,

Tests on paper!

Ream weight (25 x 40 500)2.........pounds..:
Thickness.... .... .. .. ............... .mils..:
Density............ .. .. .......gm. per cc..:
Bursting strength......pts. per lb, per rm,.
Tearing strength ..... ,.gm. per lb, per rm..:
Tensile strength .......... lb, per sq. in..:
Castor-oil penetration. .............. sec..:
Size No .. ........... ......... ...... ...... .
Gloss............... . . .. ... . .percent..
Porosity, . . . . . .. . . . ............... sec...
Opacitye ......... .. ..... .. .. .. ..percent.
Brightness, ......... ...... .. a ....... percent..:


40
3.8
0.58
0.42
0.64
3,780
126
0.58
33
98
90
59


38
3.3
0.64
0.25
0.54
2,537
50
41

49
92
52


1
-Average of 56 commercial newsprint papers,
2
Other ingredients: 1/2 percent rosin size and 1 percent alum.


0o convert to newsprint
0.864.
4
-To convert to newsprint


trade ream basis (24 x 36 500) multiply by

trade ream basis multiply by 1.157.


Rept. No. R1944-2


I
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....Sa S0 41