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CHARACTERIZATION OF PULPS FOR PAPERMAKING CHARACTERIZATION OF FOUR STOCKPILE PULPS
Project 2406
Report Seven
A Progress Report
to MEMBERS OF GROUP PROJECT 2406
March 8, 1967 r- 1 9 E P iiBXj 4 Cp I h--IIL L I THE INSTITUTE OF PAPER CHEMISTRY
Appleton, Wisconsin
CHARACTERIZATION OF PULPS FOR PAPERMAKING
CHARACTERIZATION OF FOUR STOCKPILE PULPS
Project 2406
Report Seven
A Progress Report
to
MEMBERS OF GROUP PROJECT 2406
March 8, 1967 MEMBERS OF GROUP PROJECT 2406
Albemarle Paper Company American Can Company Blandin Paper Company Brown Company The Chesapeake Corporation Consolidated Papers, Inc. Container Corporation of America Continental Can Company, Inc. Crossett Division, Georgia-Pacific Corporation Crown Zellerbach Corporation Eastman Kodak Company Fox River Paper Corporation Great Northern Paper Company Hammermill Paper Company Hoerner Waldorf Corporation International Paper Company Kimberly-Clark Corporation Knowlton Brothers The Mead Corporation Michigan Carton Company Mohawk Paper Mills, Inc. NVF Co. Nekoosa-Edwards Paper Company Oxford Paper Company Potlatch Forests, Inc. The Procter & Gamble Company Riegel Paper Corporation Riverside Paper Corporation Scott Paper Company Sonoco Products Company Tennessee River Pulp & Paper Company Thilmany Pulp & Paper Company Tileston & Hollingsworth Co. Union Camp Corporation Union Mills Paper Manufacturing Co. U.S. Plywood--Champion Papers Inc. S. D. Warren Company Wausau Paper Mills Company West Virginia Pulp and Paper Company Weyerhaeuser Company TABLE OF CONTENTS
Page
SUMMARY 1
INTRODUCTION 4
PULPS 8
PULP PREPARATION AND TESTING 10
THE GRAPHICAL PRESENTATION OF DATA 12
DRAINAGE PROPERTIES 27
FIBER DIMENSIONS 31
FIBER STRENGTH 38
BONDING 39
RELATIONSHIP OF MECHANICAL PROPERTIES OF HANDSHEETS TO PULP CHARACTERISTICS 46
The Effect of Fiber Length 46
The Effect of Fiber Strength 51
The Effect of Bonding 51
Drainage Characteristics 56
Relationships Among Tests 61
FUTURE USE OF DATA 64
ACKNOWLEDGMENTS 66
APPENDIX I. TABULATION OF DATA 67
APPENDIX II. FIBER LENGTH DISTRIBUTIONS 75
APPENDIX III. BAUER McNETT SCREEN ANALYSES 87
APPENDIX IV. LIST OF FIGURES AND TABLES 90 THE INSTITUTE OF PAPER CHEMISTRY
Appleton, Wisconsin
CHARACTERIZATION OF PULPS FOR PAPERMAKING
CHARACTERIZATION OF FOUR STOCKPILE PULPS
SUMMARY
This report presents the results of work done to characterize four dry-lap
market pulps. These four pulps were selected to represent a broad range of paper- making properties, and were stored to provide a stockpile for continuing use in the pulp characterization program. The pulps which were selected were a bleached western
softwood sulfite, an unbleached southern-pine kraft, a bleached northern hardwood kraft, and a bleached northern softwood kraft. Descriptive data supplied by the manu- facturers of each of these pulps are presented to allow the reader to compare these pulps to those with which he may be familiar.
In this initial characterization of these four pulps, the fiber dimensions, fiber strength, and bonding characteristics of each pulp were measured for samples which had been beaten up to sixty minutes in a Valley beater. These three pulp characteristics have been shown to have an important effect on the strength proper- ties of paper.
The fiber length distributions for each of the beaten pulps were measured.
Distinct differences in the "cutting" resistance of the four pulps were noted. The bleached sulfite pulp was the least resistant to cutting, and the unbleached southern pine kraft was the most resistant. The apparent coarseness values of the unbeaten pulp ranged from 18 mg./100 meters for the hardwood to a value of 53 mg./100 meters for the unbleached southern pine kraft.
The fiber strength was measured using the zero-span tensile test and was at approximately the same level for all four pulps. Page 2 Members of Group Project 2406 Report Seven Project 2406
The bonding characteristics were measured by an improved dynamic nitrogen- gas adsorption method, the measurement of optical scattering coefficient, and the perpendicular (Z) tensile test. Good correspondence was found between the scatter- ing coefficient and the gas adsorption area, but no correlation was found for the
(Z-) tensile test.
The filtration properties of the pulps were measured to characterize both their drainage rates and also to provide data on the more fundamental properties of hydrodynamic specific volume and hydrodynamic specific surface. The hydrodynamic specific volume of the pulp, calculated from the filtration resistance and the wet- mat compressibility, was used as an indication of the swelling of the pulp, its conformability, and hence its bonding capability. Data for the common Canadian and
Schopper-Riegler freeness tests are given to provide a relative comparison with data on similar pulps beaten by comparable means. An excellent general correlation was found between the Canadian Standard freeness and the filtration resistance measured at a single arbitrary pressure drop of fifty centimeters of water. The data for all four of the pulps fell on a common curve over the range of beating which was studied.
The Institute in-plane tear test was performed together with the more common breaking length, burst factor, and Elmendorf tear factor. The lack of direct correlation between the two tear tests was ascribed to the difference in mechanical conditions at the zone of tear. The in-plane tear energy increased twofold with beating for the unbleached southern-pine kraft, while over the same beating range the Elmendorf tear factor decreased to one-half its original value. The usefulness of each test depends, of course, on the actual mode of tear which occurs in a particular application.
Handsheet data are presented in this report as an arbitrary, though well- known, papermaking process to illustrate the interpretation of paper properties in Members of Group Project 2406 Page 3 Project 2406 Report Seven terms of fundamental characteristics. It is, of course, recognized that individuals in the member companies will want to extend this interpretation to their own exper- ience in commercial papermaking operations.
In addition to the graphical presentation of data and comments regarding the influence of each of the measured pulp characteristics on the paper properties, three possible uses for these data are reviewed. These three methods are: 1. statis- tical, 2. pragmatic, and 3. theoretical. The limitations of the statistical and direct theoretical approaches were pointed out, thus leaving the pragmatic approach, supplemented by the insights of the theoretical method, as the most practical present approach. Page 4 Members of Group Project 2406 Report Seven Project 2406
INTRODUCTION I
This report presents data obtained by a variety of techniques on four commercial pulps. This work was initiated for a number of reasons as discussed in the technical meeting in November, 1965 and in our letter of January 26, 1966.
In the past, the terms "reference" or "standard" pulps have suggested several interpretations and consequently various objectives and lines of attack. The different objectives are not necessarily contradictory and any given one may be highly desirable and justified for a specific company's needs, but not necessarily justified in a group-sponsored effort. For example, the correlation of "fundamental" characterizations of a pulp with its actual performance on the paper machine has been discussed but avoided (in the group-sponsored project) because of the numerous ramifications that would be required to make a significant correlation for the wide range of machines and grades of paper of interest to the sponsors.
On the other hand, there are benefits to be gained by some aspects of the reference pulp idea and we have adopted the concept of "stockpile pulps" for the following purposes.
1. To provide a stockpile of pulps which will be available for
use in all research in this general area whenever a commercial
pulp is suitable. This will provide a maximum of information
with minimum duplication and a better base for comparison of
future developments.
2. To provide a variety of pulp characteristics for periodic
attempts to test and illustrate developments of various
procedures by application to actual commercial pulps. Members of Group Project 2406 Page 5 Project 2406 Report Seven
3. To illustrate to the sponsors the application and potential
significance of these techniques to pulp types whose paper-
making performance can be recognized in at least a qualita-
tive sense by the sponsors of the program.
These pulps are not intended to represent a standard of performance against which other pulps are compared and therefore we have avoided the terms reference or standard pulp.
With these objectives in mind we solicited suggestions from the sponsors of the project and ultimately selected four stable, dry-lap market pulps as our basic stockpile to represent the following types:
A. (or 1) - West Coast Softwood Bleached Sulfite
B. (or 2) - Unbleached Southern Pine Kraft
C. (or 3) - Bleached Northern Hardwood Kraft
D. (or 4) - Bleached Northern Softwood Kraft
In order to identify the general performance characteristics of these pulps with your experience to the greatest practical extent, we have included all the information furnished by the supplier. In addition we have tested them by the conventional pulp testing procedures and have included these data in our report.
In addition to the conventional tests we. have also included those characterizations from the pulp evaluation program which appeared to us to have reached a stage of development where their application could be illustrated. This does not mean that any of these tests have reached the ultimate degree of refine- ment (and this will be obvious as you study this report) but we hope that these Page 6 Members of Group Project 2406 Report Seven Project 2406
tests will be of interest and stimulation in suggesting applications in your own I laboratories.
With all these data available, we have made a limited application of
crossplots and attempts to illustrate the significance of these tests. Where these
correlations involve handsheets, we recognize that the tests made in the laboratory
on handsheets are arbitrary tests (which the industry has found useful) but which
do not pretend to encompass the entire range of papermaking performance which might
be expected from these pulps.
The pulp characterization programs that preceded Project 2406 produced
a number of reports concerning the comparison of physical test data, their corre-
lation, and some application and interpretation of these data on a broad, integrated
front. Reports which have taken this 'approach were: under Project 1513: Reports
Five, Sixteen, Eighteen, Nineteen; under Project 2210: Report Sixteen; and under
Project 2211: Reports One, Three, Six, and Eight. Unfortunately, these studies
were not performed on pulp which could provide a stable stockpile to ensure contin-
uity and comparable results in future work.
This report draws together data which have been collected on the character-
istics of the stockpile pulps measured according to currently available techniques
and compares these characteristics with data on handsheets made from the same
sample. The data will form a base for further work using these pulps in the
improvement of tests for pulp characterization and also will help to show the appli-
cability of fundamental characteristics to the interpretation of paper properties.
In the present report, these interpretations are restricted to handsheets, but it
is assumed that the cooperators have information on the comparable machine perfor-
mance of similar pulps so you will be able to also interpret your commercial data
in terms of fundamental pulp properties.
- Members of Group Project 2406 Page 7 Project 2406 Report Seven
The tests used to characterize the pulps have been grouped into five main categories: 1. drainage properties, 2. fiber dimensions, 3. fiber strength, 4. bond- ing, and 5. the resultant handsheet properties. The tests which were made are listed in Table I.
TABLE I
TESTS PERFORMED ON STOCKPILE PULPS
Drainage Properties
Canadian Standard Freeness Schopper-Riegler Freeness Filtration Resistance (Research Model) Filtration Resistance (Commercial D.R.A.) Hydrodynamic Surface and Volume (calculated from filtration resistance and wet-pad compressibility)
Fiber Dimensions
Fiber-Length Distribution (projection) Grid-Count Fiber Length (for a few samples) Number and Weighted Average Length (calculated from distribution) Coarseness (for unbeaten pulps)
Fiber Strength
Zero-span Tensile Strength
Bonding
Unbonded Area of Handsheets (by dynamic gas adsorption) Specific Scattering Coefficient Perpendicular (Z) Tensile Strength Area of Water-Dried, Unbonded Fibers
Handsheet Properties
Breaking Length Burst Factor Elmendorf Tear Factor Institute In-Plane Tear Energy Stretch Tensile Energy Absorption Sheet Moisture Basis Weight Thickness Ovendry Density Page 8 Members of Group Project 2406 Report Seven Project 2406
PULPS
Each pulp was procured in a one-ton lot taken from standard production of a market pulp mill. The bales were opened, the contents sampled in a representative manner, and repackaged in smaller quantities. To minimize subsequent changes, each pulp was allowed to age for several months before testing.
The following descriptions of each pulp are based on information supplied by the manufacturer.
Pulp "A" (or No. 1)- West Coast Softwood Bleached Sulfite.
This pulp was chosen to duplicate, as nearly as possible in a current
market pulp, the wet-lap pulp which had been used in a major part
of the previous work in the pulp evaluation program. (From prev-
ious reports it will be obvious that this is a Weyerhaeuser pulp.)
This pulp is made from Western Hemlock by a bond paper type of cook
and fully bleached in a three-stage system consisting of chlorine,
caustic extraction, and buffered hypochlorite. In the early pulp
evaluation program, this grade was known as "Standard" but today
is labeled "W." The following information was also furnished by
the supplier:
Air dry 88.8 G.E. tab 90.2 G.E. TAPPI 91.0 Dirt count 55 Appearance 24 Shives 1 Viscosity 222 Physical tests at 250 cc. C.S. Burst 60.7 Tear 77.0 Fold 1180 Break 8000 Time 64 Members of Group Project 2406 Page 9 Project 2406 Report Seven
Pulp "B" (or No. 2) - Unbleached Southern Pine Kraft Pulp.
This was defined by the supplier as a paper-grade southern pine
kraft, intermediate between bleachable and liner grade pulp.
The wood species was described as mixed southern pine with over
50% being loblolly. Pulp was cooked by the kraft process in a
Kamyr digester, flash-dried and compressed to a density of
50 lb./cu. ft.
Pulp "C" (or No. 3) - Northern Hardwood Bleached Kraft Pulp.
The following information was released by the manufacturer.
Approximate Wood Species Distribution
55% maple (red and some sugar) 20% birch (yellow and white) 15% beech 10% elm, oak, ash
Cooking
Batch digesters - 3000 ft.3 Direct steaming, with circulation 17% active alkali based on o.d. wood = liquor/wood = approx. 3.3/1 30% sulfidity, 81% activity liquor
Cooking time = 0.75 hour to plus 1.50 hr. at 167°C. K No. = 10.5 - 11.5
Bleaching
Four stage C-E-H-D to 86 - 88 G.E. C = chlorination (chlorine water) E = extraction (sodium hydroxide) H = sodium hypochlorite D = chlorine dioxide
Pulp "D" (or No. 4) - Northern Bleached Kraft.
This is 100% jack pine. Page 10 Members of Group Project 2406 Report Seven Project 2406
PULP PREPARATION AND TESTING I
Each stockpile pulp was beaten in a well-calibrated Valley beater over the same range of beating time. The samples were conditioned at standard tempera- ture and humidity (70°F. and 50% R.H.) before weighing each beater charge, and the sample was soaked overnight in deionized water before dispersing with a Williams disk and beating. The beating order of the pulps and the run times were carefully randomized to prevent any spurious results due to the possible changing conditions of the Valley beater, and each beater run was made in duplicate. Because of the large number of tests to be performed on each sample, it was not practical to make a single standard beater run to obtain the necessary beaten pulp at each interval.
Instead the pulps were beaten to a given time and the entire beater charge was dumped. Such tests as could be made immediately, such as handsheets, freeness, and other measurements, were made and then a sample was stored in a cold room at
40 C. at beater consistency to be used for the further tests. The remaining tests were performed within a few weeks after the beater runs. Other work here at the
Institute has shown that storage in the cold room at beater consistency produces very little change in the physical properties of pulps.
Each test was performed according to the applicable TAPPI or Institute standard procedure with proper attention to the necessary details in each case.
Handsheets were made on a standard British mold and in all cases, except for zero- span breaking length and z-tensile strength, were of the standard 1.2-gram weight.
Zero-span sheets were 1.0 g.; z-tensile, 2.4 g. Experimental data derived from these tests are shown in Appendix I.
The first column in Appendix I shows the code number of a particular beaten pulp. The first number signifies the pulp itself (1, 2, 3, or 4 being A, A
B, C, or D) and the second two digits signifying the number of minutes that Members of Group Project 2406 Page 11 Project 2406 Report Seven particular pulp was beaten before being dumped. The columns are arranged according to test number or test code and the test code is given in the table at the beginning of Appendix I (for example, Column 2 is Canadian Standard Freeness). These data are the averages of the two duplicate beater runs.
J Page 12 Members of Group Project 2406 Report Seven Project 2406
THE GRAPHICAL PRESENTATION OF DATA
It is very difficult to judge the relative trends in data from a direct
tabulation of the numbers. In recognition of this fact, frequent use has been made
in this report of the graphical presentation of data. Reference can be made to the
detailed tabulation for specific data values, but, for the most part, the relative
values as plotted on a graph have been used. The excellent facilities of the
Institute's Computing Center have been used to produce the graphs and figures,
together with the appropriate legends and symbols, directly from the data table
using a digital computer and an on-line digital plotter. The speed with which these
graphs can be produced greatly compensates for the fact that some of these graphs I lack the "finish" of hand-drawn and lettered figures. It is entirely practical to
select a particular pair of tests and have the computer plot the data for all four
pulps, together with proper identification, at a rate of two minutes per graph.
If an abbreviated form of the axis identification is permissible, the plotting
time can be reduced to approximately twenty seconds. As will be evident from the
following sections, a great deal of use has been made of this fast and convenient
method of scanning the data, investigating correlations, and illustrating particular
relationships.
All the data in Appendix I has been plotted in Fig. 1-23 on the following thir- teen pages to show the relative trends of the test values with beating time. The
same symbols are used in all the graphs in this report to identify each pulp, and
with a little use, they will become familiar. The symbols used are as shown in
Table II (p. 26).
A Members of Group Project 2406 Project 2406 Page 13 Report Seven
a,
0 0~ C3
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(n Ca
0
(ncz
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LLJ,
U-0 0-Y
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Figure 1. Canadian Standard Freeness Versus Beating Time for Four Stockpile Pulps Page 14F Members of Group Project 2~406 Report Seven Project 2~406
4N
4k
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Figure 2. Schopper-Riegler Freeness Versus Beating Time I0 & 0 10 a~~~~~~~~S
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00
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Acw 2 10.00 A0.0Oa 30.00 'WOOM 50. 00 60.00o .00, T 10.00 20.00 30.00 '40.00 5 0.00 60.00 o 0 BEATIING TIMELMIN) BEP ING TIME [MIN) 0t o, Figure 5. Hydrodynamic Surface Versus Beating Figure 6.. Hydrodynamic Volume Versus Beating Time Time
- ~~ ~~~~~~~A 0 a A * h
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;:4 -L r r - - - I-i * I .00 10.00 M0.0 30.00 '40.00 50.00 60.00 310.0CI +0.00 so.0Go 06.00 .00 10.0 20.00 BEAUING TIME (MIN) (D( BEATING~ TIME (MIN) Figure 7. Number-Average Fiber Length Figure 8. Weighted-Average Fiber Length (D I- Versus Beating Time Versus Beating Time V~~~~~wV ~~~~~~4 A6 .4
UO0T:djospV SP-Ua20J;TN OTWUi~ua Xq paanspaW sdTnd ~TTd)P0ozS anol0 (.0 (0 sP s~at4sPux2H jo PaaV papuoqun 'j-T aan2-uj aio; q42uor 2UTNf2~Jq updS-oaaZ ,6 Oaan2TJ
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IN
(0~ L, 0 r- " 2-o *I~~~~~~~~~~~~~~' L.)q A-o (DH Li C-) Figure12. Perpendicular(Z) Tensile Test~~~~~~~~~~r
U- VersusTime~~~~~~~~~~~~~1Beating
I- LUg (n. 0 C -
0 ,
C - I,
0 410.00 50.00 fi0.00 ..10 1,0.00 20.00o 30.00 BERTING TIME (MIN) Figure 11. Specific Scattering Coefficient Versus Beating Time for Four Stockpile Pulps O(D
0 0 Cn C' CD
0
C,
(D LI (D
10
Zad 0
Nx 0
00
0 0 I 0 *: .1 o-JLJ .cc 10.0 20.00 30.00 '40.0 50.00 60.00 .00 10.00 ZO.00 SEPTIIG UVE COtINfl Figure 14~. Breaking Length as a Function of of Unbonded, Water-Dried Fibers Figure 13. Area Beating Time for the Four Stock- by Dynamic Nitrogen-Gas as Measured pile Pulps Adsorption
p Y i .I
'J(DW
0Cm 0 = cm In -- g N)0 Cm I CD M G) Cm -t- 0 r-) cm 'a cm 0m
cM
cm CM
cm Cm (C, cm Uto6 C4
a-cm 9-
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LI-
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(II 1.0 0 zD t-5 fI .00 10 00 a.00c 30.00o 'O. w 50. 00 610.00 30.00 4W.00 50.00 60.00 .0CID0.00 20.00o BEPTING TIME (MIN] BEATING' TIME [MIN) (D (D Figure 15. Burst Factor for Four Stockpile Figure 16. Elmendorf Tear Factor Versus (D N) Pulps as a Function of Beating Time Beating Time 0(D
CfD
0
Ca- -t
*-
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A p - 4 ~~~~~~~~~~~~~~~I
li-iZo 6~
6 (2 0E
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.00 10.00 ZO.00 10 2 0 30.00 '+.0 50.00 50.00 II I -- -- BEATING TIME (NIN1) .0 10.00 20.00 30.00O 40. 00 so. 00 60.00 BEARTING TIME (MIN) Figure 19. Tensile Energy Absorption Versus Figure 20. Moisture (D ( Beating Time Content of Standard Handsheets (D N-)
j1 (D PJ 0 (D C., rt N)
0 U (D (D
C; 0 C~
0
0 C C -
0 0
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0 I - 9 0 - -- -- O w-
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0
0 G')
00
0 .00 - .1 0 00 2.00 50.00 '+0.00 50.00 60.00 '.00 10.00 20.0co 30.0 '~0. 00 50.00 0. 00 0 0 *.BEATING TIME [MIN) BEATING TIME (MIN)
Figure 21. Basis Weight of Handsheets Figure 22. Thickness of British Standard Hand- sheets Versus Beating Time
I s~aaqspupH pappui2;S go 1;Tsuaa LapuaAQ -C GJfl2TI
(NIW) MWI 9NIlb]3R 00o.9 DaaOs 00,ti ODOOG WOOO 00oo 00' i ~I I Ia
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UaAGS ;~joda~ goig ;o~a SZ~p 9ObZ joa[oid dnoaE) 40 sla~qtua Page 26 Members of Group Project 2406 Report Seven Project 2406
TABLE II
SYMBOLS FOR SAMPLE IDENTIFICATION
Symbol Letter Number Description
A 1 Western softwood bleached sulfite
0 B 2 Southern softwood unbleached kraft C 3 Northern hardwood bleached kraft i ~b ~D 4 Northern softwood bleached kraft
Some of the tests, such as the Bauer McNett analysis or the complete fiber length distribution, do not yield a single number. These results could not be plotted in the summary graphs but are discussed in the later sections of this report. Members of Group Project 2406 Page 27 Project 2406 Report Seven
DRAINAGE PROPERTIES
The large increase in the filtration resistance and the corresponding
drop in the Canadian and Schopper-Riegler freeness show clearly the large decrease
in "drainability" of these pulps as they are beaten. There is quite a good correla-
tion between the filtration resistance, at a pressure drop of 50 centimeters of
water, and Canadian Standard freeness for all four of the stockpile pulps over the
beating range employed. This relationship is shown in Fig. 24. This might not
apply for pulps which were considerably easier to drain or for those which had been
beaten far beyond this range. The increase in drainage resistance is almost com-
pletely due to the large increase in specific surface of these samples. This shows
up in the fiber length distribution as an increase in the number of shorter fibers
and fines and also in the actual measurement of the hydrodynamic specific surface
by filtration analysis. The relative importance of specific surface and specific
volume in determining the drainage resistance can be seen in Fig. 25 and 26. The
specific volume has little effect on the filtration resistance, while the specific
surface has an overpowering effect on the filtration resistance or freeness. The
specific volume measures the swelling and fibrillation of the pulp, which in turn
has an immediate positive influence on the bonding of the pulp fibers in the sheet.
The fines and shorter fibers, on the contrary, increase the hydrodynamic surface and thus the filtration resistance, and produce a pulp which drains more slowly, but does not necessarily have an improved strength. It is important to be able to distinguish between these two characteristics, and it is possible, as in high-consistency refin- ing, to process a pulp in such a way as to change primarily one characteristic, in this case specific volume, while having a small effect on the other. In the case of
HCR one often obtains a strong sheet at freeness levels considerably above expecta- tion because there is less unnecessary production of fine particles and increased hydrodynamic surface in this refining process.
J Page 28 Members of Group Project 2'406 Report Seven Project 21406
0
03-
0 0I 0- J
I
-J +
Li 0i 0 + z CC UI-
C3l
a: a:0, Lc= I0l
('4
0=- IL
03 I I ~~~~~I II .00 10.00 20.00 30.00 '40.00 .50o.00 I50.00 FILTRATION R9ESISTRNCE-50 t1 lO8CM/GM]~
Figure 214. The Correlation Between Filtration Resistance and Canadian Standard Freeness v *
10 c~ -
0 0 0 = (D( 0 1
N) 0
C - 0
0
LA- P-i c-f
U0 C06
ONl - LAM-
LI) zo U-. C-iz a:8 LU 2i-, Li DCr a:- LA - H P- CD-- a:
A 0( -j 6-
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LA- I+ ones (D 0. 0 0 I _-F- I - - F _ -r - - . 6 .00 1.00 2.00 B.00 '4.00 S. 00 6.00 - I -- -- I I- cc I20.00 '40.00 60.00 B0.00 100.00 IZO.Or ~I- HYRO!DOYNAMIC VOLUME (CNM(3/GN) HYDRODYNAMIC SURFACE C10+3 CNNN2/GN) Figure 25. Scatter Diagram of Filtration Figure 26. The Relationship Between Filtration (D N) Resistance and Hydrodynamic Volume Resistance and Hydrodynamic Surface :nJLo Page 30 Members of Group Project 2406 Report Seven Project 2406
The separation of these two concepts of hydrodynamic surface and hydro- dynamic volume should be a part of any attempt to interpret beating or refining of pulps. It might be interesting to see, for example, what the relative increases are in surface and volume for pulps beaten in refiners with sintered-metal tackle.
Professor J. Chiaverina, University of Grenoble, France, has reported a 40% increase in burst at the same energy input or a 30% decrease in power requirement at the same value of burst factor for this type of refiner. These results were reported at the 11th Annual Pulp and Paper Conference, Western Michigan University, January
20, 1967. These refining methods show an indication of producing stronger paper more efficiently, and an analysis of the pulp characteristics would help one under- stand and control the process. Members of Group Project 2406 Page 31 Project 2406 Report Seven
FIBER DIMENSIONS
The complete fiber length distributions for each of the beating intervals
are presented in Appendix II. These graphs show the distribution of fiber length
for each of the pulps at each of the beating intervals. The general effect of beating on fiber length distribution is summarized in Fig. 27-30, which compare the
fiber length distribution for the last beating interval for each pulp with that for only five minutes of beating. These particular graphs give a qualitative indication of the resistance of each of the pulps to shortening or the generation of finer materials.
The Bauer McNett analyses for the same fiber or pulp sample are listed in
Appendix III. Because of the lack of accuracy in measuring the consistency of these pulp samples, however, the most valid interpretation of these curves should be based perhaps only on the relative percent of material greater than 200 mesh and not too great a significance should be attached to the apparent percent of fines, which was calculated by difference. Since there were some untraced difficulties in the apparatus or procedures, average values were not computed, and the raw data are presented.
For four samples covering a rather wide range in pulp properties and beating intervals the grid-count fiber length was also measured and a comparison of the grid-count number-average fiber length and number-average fiber length calculated from the projection results is shown in Table III. These results show clearly the great difference in fiber length distribution for these samples. The large proportion of long fibers in the southern-pine kraft and the western softwood is in contrast to the large proportion of shorter fibers in the hardwood sample.
The "cutting" behavior of these particular pulps, as shown in Fig. 27-30, is also Page 32 Members of Group Project 2406 Report Seven Project 2406
2406-8 Fl 5 __'2406-8 I1 60
Id
z.Uc
duN. 4
a:1*O
U,' LLJM2.. 1
M 9;
5.00 6.00 7.00
Figure 27. Fiber Length Distributions for Bleached Western Softwood Sulfite at 5 and 60 Minutes Beating Members of Group Project 2406 Page 33 Project 2406 Report Seven
2406-8 B 1 5 -32406-8 81 60
>- UO0
Z9oro 6.
Figure 28. Fiber Length Distributions for Unbleached Southern Pine Kraft at 5 and 60 Minutes of Beating Page 34 Members of Group Project 2406 Report Seven Project 2406 It.
t
0 L3
0 2'406-8 C2 5 1J1 J24f06-8--. C2 30
0 0
WC L. Um
I ~-
CLU
(JO 4
a:Li U- 0
C -
0 I I I . .00 1.00 2.00 3.00 40 S. 00 5.00 .7.00 RVERRGE LENGTH (MM.)
Figure 29. Fiber Length Distributions for Bleached Northern Hardwood Kraft at 5 and 30 Minutes of Beating Members of Group Project 2406 Page 35 Project 2406 Report Seven
2406-8 Dl 5 _ 62406-8 Dl 60
1.00 5.00 6.00 7.00
Figure 30. Fiber Length Distributions for Bleached Northern Softwood Kraft at 5 and 60 Minutes of Beating Page 36 Members of Group Project 2406 Report Seven Project 2406 interesting in that certain pulps show a much greater tendency than others to have their fiber length reduced by the Valley beater. The one case being most marked is that of Sample A which can be seen from Fig. 27 to cut very readily and to yield a high proportion of material of fiber length less than 1 millimeter. Other pulps, such as B or D, cut much less severelyand tend to retain their fiber length for much longer periods in the Valley beater.
TABLE III
COMPARISON OF FIBER LENGTH MEASUREMENTS
Projection, Average Fiber Length, number millimeters Grid Count average
C05-1 0.60a CO5-2 0.78 C05 (av.) 0.69 0.71
C30-1 0.77 C30-2 0.71 C30 (av.) 0.74 0.59
DO5-1 1.71 DO5-2 1.76 DO5 (av.) 1.74 1.89
D60-1 1.72 D60-2 1.38 D60 (av.) 1.55 1.41
a Average of four counts, 250 to 800 fibers per count.
Another significant factor in characterizing fiber dimensions is the coarseness, or average weight per unit length of fiber. The measured coarseness for the unbeaten pulps is shown in Table IV. The apparent values of coarseness for pulps with mixed species, such as the unbleached southern pine.(B) and the mixed northern hardwood (C), represent an average coarseness which is a function of both the coarseness of the individual species and the percentage mix of species in the pulp. Such averages should be used in only a qualitative manner. Members of Group Project 2406 Page 37 Project 2406 Report Seven
TABLE IV
COARSENESS OF STOCKPILE PULPS ^-
Coarseness, rg./100 m. Pulp Max. Min. Av.a
A-00 30.4 25.1 28.3 -
B-00 57.1 50.6 53.1
C-00 19.9 17.5 18.3 C,
D-00 31.0 29.5 30.2 -
a Of 4 determinations.
The large differences in the coarseness of these samples are still evident, however, from the data; and these differences may help to explain some of the differences in the mechanical properties of sheets made from these pulps.
A few preliminary measurements of coarseness on the beaten samples showed that the coarseness of the softwood bleached sulfite (A) stayed practically constant for at least fifty minutes in the Valley beater. The apparent coarseness of Pulps
B and C decreased somewhat, and the measured coarseness of Pulp D decreased very strongly. Further measurements would be needed to check these results and see if this is a real, reproducible effect which can help our understanding of the beating and refining behavior of these pulps. The preliminary data showed 20 to 30% decrease in apparent coarseness for Pulps B and C, and a 50% decrease for Pulp D. This is a large change which does not seem to be corroborated by any parallel change in the fiber length distributions or the handsheet properties, so these initial figures should be used with caution until verified by further work. Page 38 Members of Group Project 2406 Report Seven Project 2406
FIBER STRENGTH
The zero-span tensile test has been shown by previous work to be a reliable and relatively direct measure of the intrinsic fiber strength. The zero- span tensile results as a function of beating time are shown in Fig. 9. The actual level and the trends of this test can be seen by inspection of that graph. To be noted especially are the increases in zero-span breaking strength as a function of beating time. It was thought for some time that this apparent increase in zero-span breaking length as a function of beating time was due simply to better bonding of the fibers and was not actually an increase in fiber strength. Recent results to be reported elsewhere on Project 2406 have shown that there is an actual and real increase in the strength of individual fibers as they are beaten. Further informa- tion on the z-tensile test and its comparison with the individual fiber tests can be found in Reports One and Three; the effect of beating is shown in Report Five,
Project 2406.
I I I Members of Group Project 2406 Page 39 Project 2406 Report Seven
BONDING
Three measures of bonding were obtained in this study. The first of these,
scattering coefficient, has been used frequently in the past to measure the relative
level of bonded area in a sheet. The second method, that of dynamic gas adsorption,
is a measure of the unbonded area available to adsorption by nitrogen gas at very
low temperatures. This dynamic procedure, which was originally proposed by Stone
and Scallon as a convenient replacement for the laborious gas adsorption method used
by Haselton, was further developed under an Institute project and has been used in
this study to measure the unbonded area of the handsheets.
Unbonded, water-dried fibers from the same beaten pulps were produced by
taking a small amount of well-dispersed fiber, drying it on the Institute web-former,
and carefully doctoring it off the barely warm first yankee cylinder. The fibers
were in a very dilute, closed, recirculating system so that most of the fines and
finer particles were also collected with the fibers. The final collection of dried
fibers has a very small proportion of fibers bonded to each other. This tow of un-
bonded water-dried fibers was then tested for its surface area in the same manner
as the handsheets. The difference of these two data gives a reasonable indication
of the bonded area in the handsheets.
A third measure of bonding was the perpendicular (z) tensile test which
is a measure of the force necessary to separate the sheet along a region parallel
to its surfaces. This test has been subjected to further investigation under a
different project and the results of the test evaluations were reported at the
1967 TAPPI meeting in New York.
Figure 31 shows the well-known relationship between scattering coeffic-
ient and the unbonded area of the handsheets. For the four widely different pulps, 10 0 D
(D
d - 0
0
0 0 M4
0 0
0
9 a3
A- 0
0 xa N.3 A A
I.- z co= Li + L)9- L- Laj +0e C-) (D 300 X:_
-U'- (D Li 0D1 In I-- L-g C1) U., (09 0
2a 00
C I,, - 00 c-r--
CD 0 0 03 O*I. O.J .00 .to ..40 .60 .,Bo I'.00I M .00 .zo .'40 .60 .60 1.00 1.20 UNBONOEO AiREA OF HANOSHEET-(NM-'/GM) ,UN INWWAR OF MA~NIJSHEET (M-'2/GN) Figure 31. Increase in Optical Scattering Figure 32. Effect of Hydrodynamic Volume on Coefficient with Unbonded Area Unbonded Area Members of Group Project 2406 Page 41 Project 2406 Report Seven
the data points seem to fall within a common range but there is no unique curve
common to all four pulps. There was no evident correlation between the area of
unbonded fibers or the hydrodynamic surface and the scattering coefficient of the
dried handsheet.
Figure 32 shows a distinct decrease in the unbonded area of a handsheet
with an increase in hydrodynamic volume. This is as would be expected since the
increase in hydrodynamic volume would indicate a more deformable, more easily
bonded pulp and, when formed into a sheet and dried, this same sample would yield
a lower unbonded area. The scatter diagrams of hydrodynamic surface and the area
of the unbonded water-dried fibers versus the unbonded area of the handsheets as
measured by gas adsorption did not show any evident correlation.
The relationship between surface area of the unbonded water-dried fibers
and the hydrodynamic surface area as measured by filtration resistance is shown in
Fig. 33. The large increase in hydrodynamic surface with only a small increase in
the area of the unbonded fibers can be rationalized by considering either the loss of fines in the web-former procedure, the attachment of these fines and subsequent drying on the parent fibers, or the collapse of fibrillar material and its adhesion to the water-dried fibers. It is likely that, in some measure, all three of these phenomena occur. Two pulps, however, which seem to show somewhat differing be- havior are the unbleached southern pine kraft (B) and the northern pine bleached kraft (D). The northern pine material (D) tends to retain a larger amount of its unbonded area when it is dried.
One would expect that the z-tensile test value would increase as the un- bonded area of the handsheet decreases. For any one pulp there is a trend but each pulp is at a different level, as shown in Fig. 34. The theory of the z-tensile (D Pi 0 (D
rtj C9- a U) Nfl
C2
..-o
N A+
C3. X.3 ri z I+ + Xi- -
-C
~0 L3 M: I-O
Li z Li (D Cr +e (D
I-S
N-.3 ;Cc 0 N-
GC) I-i 0
00
LiJ. L-i.
a ------I I - I I I (D (D .00 20.0W 0.W0 s0.00 80.0 100.00 120 '.00 .20O .'40 60 . 30 LWO (00 HYDROYNAMIC SURFA1CE (10+3 EMN""Z/GM) UNBONDED fiRER F 10¶dSHEETE M)-2/GM3 Figure 33. Scatter Diagram of Hydrodynamic Figure 34. Scatter Diagram of Perpendicular o) 0 Surface and Area of Unbonded, (z) Tensile and Unbonded Area CY)C) Water-Dried Fibers
II Members of Group Project 2406 Page 43 Project 2406 Report Seven
test and the most recent developments in its use were discussed by Wilmer Wink at the 1967 TAPPI meeting. In quoting an abstract from Mr. Wink's paper, "One can safely infer that microscopic stress concentration is an inherent effect in all current bonding strength test procedures." These stress concentration effects make it very difficult, if not impossible, to measure the absolute bonding strength of a given interfiber bond and the final result depends very strongly upon the homogeneity or formation of the sheet and on other physical factors in the test.
Figure 35 does, however, show a general increase in the z-tensile test as a function of hydrodynamic volume; this again is an indication of the greater wet conformability of the fibers and their ability to conform to one another and thus bond. A further discussion of bonding as measured by these various methods and their relationship to empirical tests such as tensile, burst, and tear are included in one of the sections to follow.
Table V shows the absolute bonded area of each of the samples calculated from the unbonded area of the handsheet and the area of the water-dried fibers.
The values for relative bonded area for the hardwood pulp (C) are obviously too low. This is attributable to the loss of the very small hardwood fibers and particles in the fiber-drying procedure. An approximate calculation of the error to be expected from the loss of fines in the fiber-drying procedure showed that the error was always negative, and its magnitude increased from a value approximately proportional to the percent loss, to a value of 100 percent error when half of the potential dry-fiber area was lost in the web-former drying process. That is, the relative bonded area calculated from the above data is probably somewhat less than the actual relative bonded area for the long-fibered pulps and is considerably less than the actual value for the very short-fibered hardwood pulp. The expected error for a handsheet with a true bonded area of 50% was calculated to be -1% for 1% fiber Page 414 Members of Group Project 21406 Report Seven Proj ect 2406
0
0
20
0
0.3
0 A +
e4-
Crn
LJ- o+
Li
AI WC=. (D
'I I I V T .00 1.00 Z. 00 5.0co '4.00 5.0Go 6. H-YDO(OYNAMIC VOLUME (CM""3/GM3 EK
Figure 35. Effect of Hydrodynamic Volume on the (z) Tensile Test Members of Group Project 2406 Page 45 Project 2406 Report Seven
loss, -11% for 10% fiber loss, and -100% for 50% fiber loss. That is, if half the
fiber area is lost in forming the unbonded, water-dried fibers and none is lost in
forming the handsheets, the calculated bonded area will be zero. This apparently
happened for one of the hardwood pulps.
TABLE V
ABSOLUTE AND RELATIVE BONDED AREAS
Unbonded Area Unbonded Area Absolute Relative of Handsheet, of Aiber,BondeArea, Bonded Area, Sample m. /g. m. /g. m. /g. %
A05 0.632 0.781 0.149 19 A10 0.601 0.836 0.235 28 A20 0.580 0.809 0.229 28 A40 0.518 0.935 0.417 45 A60 0.441 0.889 0.448 50
B05 0.519 0.728 0.209 29 B10 0.471 0.791 0.320 40 B20 0.445 0.763 0.318 42 B40 0.410 0.779 0.369 47 B60 0.370 0.810 0.440 54
C05 0.737 0.907 0.170 19-- / C10 (0.850) 0.816 C20 0.760 0.827 0.067 8 C30 0.580 0.792 0.212 2.7
D05 0.496 0.886 0.390 44 D10 0.590 0.918 0.328 36 D20 0.534 0.889 0.355 40 D40 0.532 0.995 0.463 47 D60 0.385 1.093 0.708 65
Certain improvements could be made in the fiber drying procedure to decrease the possibility of loss of fines, but such changes would require major changes in the present web-former or the construction of a separate apparatus.
At the present time, it appears that the use of the web-former to produce unbonded, water-dried fibers is most useful for long-fibered, moderately beaten pulps and it should be used with caution on any pulp which has a large proportion of small fibers or fines. Page 46 Members of Group Project 2406 Report Seven Project 2406
RELATIONSHIP OF MECHANICAL PROPERTIES OF HANDSHEETS TO PULP CHARACTERISTICS
This section treats the influence of the pulp characteristics of fiber length, fiber strength, bonding, and drainage properties on the dependent properties of tensile strength, burst factor, tear factor, and in-plane tear energy. The first three of these tests are well known. The fourth, the Institute in-plane tear energy, is a newer test which is described below in the section on the effect of fiber length.
For purposes of illustration, it was necessary to choose one test out of each of the pulp-characteristic groupings. The tests which were chosen to give a valid indica- tion of each of these characteristics were as follows: fiber length, the weighted- average fiber length calculated from the fiber-length distribution; fiber strength, the zero-span tensile test; bonding, the unbonded area of the handsheet as measured by dynamic gas adsorption; and drainage, the filtration resistance measured on the research-model filtration resistance apparatus. In some cases, such as fiber strength measured by zero-span, the techniques have been developed by hard work over the years to a point where they are immediately useful. Other methods are less well-developed and obviously in need of further work.
THE EFFECT OF FIBER LENGTH
The effect of fiber length on the dependent physical properties of the handsheets is shown in Fig. 36-39. The scattered data on Fig. 36 and 37 show that other factors than fiber length are more important in determining the level of break- ing length and burst factor. The next two figures show very clearly, however, the strong influence of fiber length on both the standard Elmendorf tear factor and the newer in-plane tear-energy test. Since the Institute in-plane tear test may not be familiar, the following comments have been added. O 0 F
rFU.
C) a 4H-
0 0) 8 40
LO- O 0
0 a It,. a2 - A + 0 0 I- A XU .0 -J z~ln AL 0 Cr IL 0
03 N
CD 0
H-0
CI S. 00 6.0Go I I ~I 1 .0 2.00 3.00 4.00c S..Do 4..0 - .00 IiM~ Z.0Go 3.00 4.00 'IGHTEO-AVERRGE FIBER~ LENGTH (MM) (D -P7 WF-TGHTErJ-AVEFRgGE FIBER~ LENGTH (MN) :: 0
Figure 36. Scatter Diagram of Breaking Length Figure 37. Scatter Diagram of Burst Factor and Fiber Length and Fiber Length (D W 0 (D
C/) en 0 (D
CD
a'
0 09 a.
0n
9 0. a-
m
a 0 a 0
C-, 0
L.) A0 0- 0 A 0~
0 Ze IL 9-. CD m - ( 0 (D pq C') 0 U: G) % AJ 0 0j
2- 00
a A&/N 0 0 ---~ -- I - T'- - - I I .00 1.00d 200 3.007 'LOU0 5.0o 5.00o .00 1.00 2.0 300 41.00 S.00c 6.00 WEIGHTED-RVERRGE FIBER LENGTH (MM) WEIGHTED VERRGEIFIBER 3LENGTH (MM1) N) N) Figure 38. Effect of Fiber Length on the Figure 39. Effect of Fiber' Length on the :-p _-P CQ 0 Elmendorf Tear Factor In-Plane Tear Energy 0.90Y)
b Members of Group Project 2406 Page 49 Project 2406 Report Seven
There are two basic ways, or modes, in which a sheet can be torn. If one
takes a sheet of paper and starts a small tear in it, he can continue the tear by
two methods. The first way would be to move his hands perpendicular to the sheet
of paper and simultaneously bend, and tear the sheet into two pieces. This is the
mechanical mode of action which is used in the Elmendorf tear tester. The alternate
mode of tearing, the in-plane mode, can be illustrated by our subject moving his
hands apart parallel to, or in the same plane, as the sheet. This mode of tear
can also be demonstrated by tearing the sheet while it is lying flat on a desk top.
Now if we consider the immediate zone of the tear we can see that the two processes
are mechanically quite different. The perpendicular tearing mode introduces consider-
able bending and peeling action in the immediate region of the tear, while the action
in the in-plane tearing zone is mainly one of direct progressive tension. Which test
is the most useful or pertinent to a given end-use evaluation would, of course,
depend on which mode of tearing was most common in actual failure or use. The
progressive failure of a bag in a drop-test, for example, might be much closer in
the in-plane mode of tear than the perpendicular mode.
The in-plane tear energy was determined on an Instron tensile tester using
a special set of skewed jaws. A more convenient device designed specifically for
this test is under development.
I Figure 40 shows the zero-span breaking length as a function of the fiber
length. This was included as a test to see whether the fibers contained in the
hardwood sample were short enough to markedly influence the measurement of zero-span
breaking length. It is evident that the fibers were not so short as to give a
spuriously low value.
Figure 41 is a cross-plot of the Elmendorf tear factor and the Institute
in-plane tear energy. There seems to be no direct, consistent correlation between 0 (D
a 0 CD C 0 N_ (0 (D C,
a Ca C
o2 I 0 0
AL a-9 0 0D
0 0 :-J C7
C0
I- za-) 6-u 0 a:a:U6 a: w AL cr .i - Z-j 0r IL (0 (0 5' La- 01 (D
0
00
I-S.tj or_
0 0 I . I I T _ I I F I I - .00 I.00 2.00 3.00 4.00 5.00o 6.a .0I 0 1I0 . 00 20.00 30.00 40.00a so.00 650.00 WEIGHTEd-rPVERAGE rOFlER LENGTH (MM) TEAR FACTOR9 (X1O' ) o c' Figure Ot r) 40. Check of the Influence of Average Figure '41. Scatter Diagram of Tear Factor Fiber Length on Zero-Span Tensile and In-Plane Tear Energy Strength Members of Group Project 2406 Page 51 Project 2406 Report Seven the two tests. This is not, however, surprising since the mechanism of tearing is different in the two tests. The true value of either test and its useful correla- tion with end-use performance would depend on which mode of tear were most common for a specific application. In either mode of tear, however, the length of the fibers has a very strong influence on the final result as shown in Fig. 38-39.
THE EFFECT OF FIBER STRENGTH
The influence of the intrinsic fiber strength is clearly shown in Fig. 42-45 which give the breaking length, burst, tear factor, and in-plane tear energy as a function of zero-span breaking length. The strong and consistent increases in breaking length and burst factor with intrinsic fiber strength are clearly shown in the first two graphs. Figure 44 shows that if any correlation exists for tear it is perhaps negative; that is, as the intrinsic fiber strength increases, the Elmendorf tear factor decreases. Figure 45 shows that the in-plane tear energy for some of the pulps increases as the fiber strength increases; but the increase is not as uniform, nor as consistent, as in the case of the tensile properties or the burst test. This interesting inversion between the ordinary Elmendorf tear test and the
Institute in-plane tear test is indicative of the basic difference between the mode of tearing for each test.
THE EFFECT OF BONDING
The effect of an increase in bonded area of the handsheets on the mechanical properties is shown in Fig. 46-49. It should be kept in mind that what is plotted in the graphs is the unbonded area of the handsheet as measured by nitrogen gas adsorp- tion. As the bonding in a particular handsheet increases,this number will decrease; that is, a higher unbonded area as plotted means a lower bonded area in the sheet and less bonding. Although there seems to be a fair degree of scatter in the data, some c-f CY1
N)
(D (D
30 Ca-
C; 0
C - 2-
0
Ca- C -
C, (D+ I- 9
a -N C + 0 + + 0 a = - C - 0)+ e '-a CD C) (D d-J 0 U (D) I--J -0 t-, 0
0 I-h 0 03-
10I'
0 I 0 0 L-J. LiJ. 9 C- (4- (D (D 0 0
N)j N) a2 4p -p - I 12.00 16.00 20.00 zq 00 00 C . T_ -- - 8.00 .00 4. 211 OC ZERO-SPAN BREPKING LENGTH tM)~? ZEIRO-SFPN BREAKING LENGTH (KM] on the Figure '42. Effect of Fiber Strength on the Figure '43. Effect of Fiber Strength Breaking Length Burst Factor 0
(D (D
O 0 i CD-
a Oa M
N)0 2- _p " a3 CD 9 a
a ,I)
a F0 a_ 00 a_
I,, &9 9 0 M
Ma
a C) 0) a, C) O It a:1 MO L.J- =L-a A + + a:m a.-- cc:
*-C.- LJ_ A +' LNG ~_C-
a C; 4t C- in (D 10 I O '.60 '1.00 0.00 I .co 16.00 020Po0 q.00 .4.00 '1. 00 B.2 2'Z.00 10s.00 20.00 i4'.00 ZER~O-SPAN BREPKING LENGTHr. (KM) ZERO-SFPN BREAKING LENGTH (KM) (D (D Figure 44.t Scatter Diagram of Fiber Strength Figure 45. Scatter Diagram of Fiber Strength and Tear Factor and In-Plane Tear Energy (D Qi 0 (D
0 0 Ul) C!- (D C - CD
0 0 9-
-~ a + C_ +
0 0 0D
0 0 03
@4 C2 + a I
C!-
0D 0 A 0)16 a: z 6= 9-
0 3: C-' -a: :Ca A (D Li 0 U9 a: A CO 0 0 AL CG) 0
0, C. 00 a~ LU. L.-J (DCD 0 0 060 AUO AO .'60 .'80 1.00 .1. za .00 .0 .40 .60- .8 I.00 1.20 . UNBONDED AREA OF HAPNDSHEET (rM'2/Cm] UMDNOEO -PIRSA OF HRNOStIEET (NK0IUGMI rN) N) Figure '46. Effect of Bonding on Breaking Figure '47. Effect of Bonding on Burst Factor CD 0 Length a) 0') -9
t-D (
O S
2- 0 t C~u
riIn 0 01 N)0 O CD 0 a r_ N)
C 0 0)
0 051 0b N~)
C, 0 0 o I 0 0 C9 UIC
Ca U, 09 al'&
i.3 0 + A A Li~ CC 0D L~j, IL Cr 0 + zM Cr'-
I2-.
+A aI:* ()C M wa,- = -
0; ~0
O II (D( I I I I I .00 . ZO .4.0 .60 .80 1.00 1.zo '.0 .Zo .'40 .sa .800 1. 0 I.zr CD L UNBONOEO PREA OF HRNDSIIEET (I9-2~/GM) UNBJNDED AR~EA OF MPNOSHIEET rrmwZ/GM) Figure 4+8. Scatter Diagram of Tear Factor Figure '49. Effect-of Bonding on In-Plane and Unbonded Area of Handsheets Tear Energy Page 56 Members of Group Project 2406 Report Seven Project 2406 general trends are evident. For example, for a particular pulp, the breaking length increases as the degree of bonding increases. Although there is more scatter in the burst data, the same trend is evident. The test which scatters most, and for which no conclusion can be drawn, is that of Elmendorf tear factor.
The last of the four graphs shows a very unexpected trend in that the tear energy measured by the in-plane method shows a distinct increase with bonded area, or, in terms of the graph, a decrease with an increase in unbonded area. According to previous interpretations of the tearing process one would expect that as the sheet becomes more lightly bonded the fibers would pull out rather than breaking.
The pulling-out of a fiber requires considerably more energy than breaking it, so one would have expected the more lightly bonded sheet to absorb more energy and produce a higher value of in-plane tear energy. Such a behavior was not observed, and the more highly-bonded pulps yielded higher in-plane tear energies. This was especially evident for the unbleached southern-pine kraft pulp (B).
The following reasonable explanation for this behavior was suggested by
Dr. Van den Akker. When a fiber is strong, an increase in bonding should initially increase the tear energy due to the increased bonding and frictional effect involved in pulling the fibers from their original positions. If the bonding is further increased, however, a point should be reached where the fiber is no longer strong enough to resist breaking and the tear energy should fall. The frictional effect, combined with a high fiber strength, may explain the behavior of Pulp B.
DRAINAGE CHARACTERISTICS
The last of the four areas in which an attempt was made to-correlate the mechanical properties was that of the drainage characteristics. The next eight figures (50-57) show clearly why in statistical terms such cross-plots of one ) V 4 1
.1 1, , L-J. tj-
0 I
I 0 F
U, - r 0 0 (D a 0 to a- + +
0 0 0-J. 0 +0 a O I. . O9
. 1 0~ +
+ O +D * 11 0D U, + IT. 0 011 a AL 0
MI- L)m
=0- II a6- LO
a
!2-
,cI:(D g !2 0 T - I I .0~0 110.00 Z0.0GO 30.00 F40-00 50.00 60.00 '.0 0.00a 20.00c 30. cc0 0. cc0 50.00 60. 00 FILTRAPTION RESISTANCE-SO CM (10-5 CN/GN)- FILT~RTICN RESISTRNCE-SC CM EiC-8 CM/GM) Figure 50. Parallel Changes in Breaking Length Figure 51. Parallel Changes in Burst Factor (D (D and Filtration Resistance with and Filtration Resistance with Beating Beating $ % - - f .0 I p
C - 0 2,-
0 F 0~
K)0 C - (-r=-h 0 a) 0 + r-) 09
0, 0)
0! 0)+
C;
li- + 0 C.) C - Li 0) + 0) C)' IL 0 IL 0-
0 0 0 C, !: I .-O cn- C) A LnS 0. cc 0) A
02 0.
(D '0 0 I-j IF I I 00 210.00 'W O 0.00 .0 80.00 I 100.00 120.no .0I2 2 20.00 '20.00 50.00u BO.0go 00.00 120.00 CANADIAN SIFANDRRD FREENESS~ tMLI Cxio' CRNRDIRN STRNDRRD FREENESS [ML) 1XI0 1 ) 0(0 Figure 514. Scatter Diagram of Breaking Length Figure 55. Scatter Diagram of Burst Factor and Canadian Standard Freeness and Canadian Standard Freeness (D PI 0(D
0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~CD
0~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0(
0
o -0
o
0 o 0
o L
Cr,
oo, cr o ~~~~~~~~~~~~~~~~~~LiO
C)0C.
0 Li~~~~~~~~~~~~~~~~~~~~~~~~~~~
A. -J . CD~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~J
00
.00 20.00 410.00o 60.00 80.00 100.00 120.00.2.0 4.0 00 o 1000 100 tr CANADIAN~ STANDA ~ ~ ~ X0IrNAANSNARFENSS()~ FREENESS~ ~ (ML)~ NOIN TRORD EXIO'
Figure 56. Scatter Diagram of Tear Factor Figure 57. Scatter Diagram of In-Plane Tear .p7 p and Canadian Standard Freeness Energy and Canadian Standard Freeness ' )
b i Members of Group Project 2406 Page 61 Project 2406 Report Seven
result versus another are called scatter diagrams. There seems to be no general
relationship between the physical properties of the handsheets and the gross drain-
age properties as measured by either freeness or filtration resistance.. There is
some trend evident within a given test for a given pulp but this is, of course,
a simple concomitant increase or decrease with the beating process and is not a
causal effect. The overpowering influence of fines on the drainage resistance and
on the freeness measurement was mentioned earlier in this report and is the reason
why no better correlation between the drainage properties and the mechanical
properties was observed.
One interesting conclusion, however, can be reached from these data if
one looks at, for example, the plot of breaking length as a function of filtration
resistance. It is evident that over an initial portion of the curve the tensile
strength rises very quickly with only a small increase in the filtration resistance.
The curve then breaks over and the filtration resistance begins to increase with a
relatively small increase in tensile strength. This, of course, is a break-even
point where the stock, which becomes slower and slower draining as the filtration
resistance increases due to the increase in fines, shows very little accompanying
increase in either burst or tensile. It is evident that some economical compromise
situation, perhaps near the breakpoint or knee in the curve, could be selected for practical operations.
RELATIONSHIPS AMONG TESTS
The final section in the description and comparison of the physical test data concerns the comparison of one test versus another. This can be informative concerning the real meaning of the test which has been performed. Most of the relationships described herein have been previously noted in the literature or in previous reports. I Page 62 Members of Group Project 2406 Report Seven Project 2406
Figure 58 shows the very good correlation between tensile energy absorp- tion and the measured burst factor. The theoretical analysis of the burst test and the physical factors involved have been described previously by Dr. Van den Akker in the literature.
A number of graphs which were not reproduced in this report showed a.random scatter when plotting tensile properties such as breaking length and tensile energy absorption versus in-plane or Elmendorf tear test. Likewise there was no evident correlation between the burst factor and any of the tear tests, nor would any be expected. Evidently, the localized rupturing mechanism which occurs in the tear test has little relationship to the tensile energy absorption which is the overall energy absorbed in stretching and eventually rupturing a sheet of paper under tension.
This might be expected but is further amplified by the data shown in this report.
The tensile energy absorbed for these samples is roughly one-half the product of the stretch or elongation at break and the breaking length so that an increase in either the stretch or the breaking length will produce a proportional increase in the tensile energy absorbed and an increase in the burst factor.
_ _ I~~~~~~~~~~~~~~~~~~~~~~~~~~~ Members of Group Project 2~406 Page 63 Project 2'406 Report Seven
0
0
0 0 0 +0
0
crd +
Cr)- AO +D 0 9'
I=
C)
M0
00I 4+0.0I CC 80.00 IZ1Z-0b 160.00I 200.00 240.01. TENSILE ENERGY A~BSORPTION1 [GM-CM/CM"'N2)
Figure 58. Correlation Between Burst Factor and Tensile Energy Absorption Page 64 Members of Group Project 2406 Report Seven Project 2406
FUTURE USE OF DATA
There are three main uses that could be made of the data included in this report.
1. One could use the statistical-correlational approach which
would arrive at unbiased, quantitative estimates of multiple
effects and thus be able to separate, or more clearly define, I the actual effect of two or more of the variables at the same
time. Such an approach would be more exact and perhaps yield
more useful results than the simple qualitative observational
approach which has been taken in this report. An example of
this approach is that taken by Dr. Thode in Project 2211,
Reports Three and Six.
2. One could apply seimiempirical models of the beating process and
the processes of fiber swelling and fragmentation. The effects I on sheet properties could be developed along the lines given
by M. W. Kane or J. d'A. Clark. Such approaches depend very
heavily upon practical empirical tests of secondary quantities
which are related in some way to the fundamental properties of
bonding, fiber strength, and fiber length.
3. One could follow the direct theoretical approach based upon the
fiber length distribution, individual fiber strengths, and the
properties of individual bonds in tension and torsion. A sound
foundation has been laid in this area by Dr. Van den Akker and
further progress should be evident in the years to come. Members of Group Project 2406 Page 65 Project 2406 Report Seven
There are difficulties, of course, in applying Method 1, the statistical approach, in the general field of pulp characterization. Very often the results which are obtained are specific to a given pulp and processing condition. Uncon- trolled or unrecognized factors also may enter into the result, and it is very difficult and very dangerous to generalize or extrapolate such data.
Method 3, the direct theoretical approach, although potentially very powerful and fruitful in the long run, is as yet only in its infancy and the practical.applications which are possible from the theoretical approach are as yet limited. The primary usefulness of the theory is in defining and illustrating the fundamental concepts of paper structure in idealized situations to help us understand better the processing behavior and end-use performance of paper.
The second approach seems presently the most practical for an industrial laboratory provided it is based on an understanding of the fundamental character- istics of pulp and how these characteristics are related to the empirical tests which are performed. The further step of correlating these empirical tests to the sheet properties of both machine-made paper and handsheets would, of course, be the function of each particular laboratory.
Although these three approaches are useful in their specific areas the primary use of the data in this report is to gain insight into the processing and paper properties of specific pulps and to interpret these properties in terms of generally applicable fundamental pulp characteristics. Page 66 Members of Group Project 2406 Report'Seven Project 2406 F
ACKNOWLEDGMENTS
v It is obvious that the data contained in this report represent the combined effort of many persons on the Institute staff. Robert Fumal, Albert van Beuningen,
Donald Fird, and Robert Gertz are to be commended on their cooperation and diligence in performing various phases of the pulp preparation and handsheet testing. Lester
Nett was especially helpful in the performance of the dynamic gas adsorption experi- ments and in other ways also. Larry Leporte carried the main responsibility for the I work on the commercial drainage resistance analyzer, and Bruce Andrews supervised the research filtration resistance analysis work done by James Tierney. As always, I
Marguerite Davis did a fine job in determining the fiber length distribution for these many samples.
The possibility of drawing on so many and varied talents has been a real help, and is, of course, one of the primary advantages of a central research insti- tute in a study which covers such diverse areas.
Thanks are also due to Dr. T. Alfred Howells for his assistance and guid- ance from the beginning to the final reporting of this phase of Project 2406.
THE INSTITUTE OF PAPER CHEMISTRY
Robert A. Holm, Research Fellow Special Processes Group Technology Section Members of Group Project 2406 Page 67 Project 2406 Report Seven
APPENDIX I
TABULATION OF DATA
TABLE VIA
TEST CODE IDENTIFICATION
1 Beating time (min.)
2 Canadian Standard freeness (ml.)
I 3 Schopper-Riegler freeness (ml.)
4 Bauer McNett analysis
5 Fiber length distribution
6 Number-average fiber length (mm.)
7 Weighted-average fiber length (mm.)
8 Grid-count fiber length (mm.)
9 Basis weight (g./m. )
10 Thickness (microns)
11 Ovendry density (g./cm. )
12 Breaking length (km.)
13 Stretch (%)
I 14 Burst factor
15 Tear factor
16 Tensile energy absorption (g.-cm./cm.2 )
17 In-plane tear energy (g.-cm./43 mm.)
18 Zero-span breaking length (km.)
19 Sheet moisture (%)
20 z-tensile strength (kg./cm. )
21 Scattering coefficient (cm. 2/g.)
22 Unbonded area of handsheet (m.2/g.) Page 68 Members of Group Project 2406' Report Seven Project 2406
TABLE VIA (Continued)
TEST CODE IDENTIFICATION
23 Area of unbonded fibers (m.2/g.)
24 Hydrodynamic volume (cm.3/g.)
25 Hydrodynamic surface (10+3 cm.2/g.)
26 Filtration resistance
27 Filtration resistance-50 cm. (10 8 cm./g.) I 28 DRA filtration resistance at 50 cm. (10 8 cm./g.) Members of Group Project 240O6 Page 69 Project 2'406 Report Seven
TABLE VIB
EXPERIMENTAL DATA
Test Codeb 1 2 -3-- -5 -c
100 0 . 0 . 0 . 0 . 0 . 10 5 5 . 6 65 . 8 60. 0 . 0 . 1 10 10. 5 15 . 0 . 0. 1 20 20. 49 0 .- 0 . 0 . 14.0 4.0. 0 . 0. 16 0 6 0. 9 0. 3 60 . 0 . 0 .
2 00 0 . 0 . 0 . 0 . 0. 20 5 5 . 7142 . 0 . 0., 2 10 10. 7 2 0. 8 70 . 0 . 0. 22 0 2 0. 65 0. 8 50 . 0 . 0. 0 24 0 140. 4522. 0 . 0.4 26 0 60. 2 27 . 5 17 . 0 . 0.
300 0 . 0 . 0 . 0 . 0 . 30 5 5 . 5 07 . 8 02 . 0 . 0 . 4~5 0 -. 310 10 . 0 . 0 . 0 . 32 0 2 0. 2 70.: 0 . 3306 30. 1 60 . 0 . 640. 0). 0 . 0 . 0 4.00 . 0 . 64.0. 0 . 40 5 5 . 0 . 4.10 10 . jib. 0 . 1.20 2 0. p147 . 822 . 0 . 0. 441.0 4.0. 395. 0 . 0 . 1.60 6 0. 2 52 . 0 . 0 . 0 . 0 0 . 0 . 0 . 0 . 0 5 . 100 . 100 . 0 .
a Pulps identified by pulp number and minutes of beating b For list of test codes, see p. 67-68. c Zero (0.) entries represent no data. Page 70 Members of Group Project 2406 Report Seven Project 21406
TABLE: VIB (Continued)
EXPERIMENTAL DATA
rest Codeb pulpa 6 7 8c 9 10
100 1.5 1 2 .3 5 0 . 0.0 0. 0 10 5 1 .7 2 2 . 49 0 . 61 . 14 105. 5 1 10 1 .52 2 .2 8 0 . 6 1.5 9 9. 2 1 20 1. 13 1 .9 1 0 . 6 0. 8 9 1 .4 14 0 1 .0 2 1 .63 0 . 6 2 .2 8 7. 0 160 1 .03 1 .66 0 . 5 9 .7 7 9 .3
2 00 1 . 95 2 . 62 0 . 0.0 0 .0 20 5 2 .06 2 .7 2 0. 6 0.2 1 2 5.5 21 0 2 .14 2 .7 6 0 . 6 1 .3 1 17 .2 22 0 2 .13 2 .7 2 0. 6 1 .1 1 07 .2 2 .68 6 0 . It 9 9 .1 24 0 1 .97 0 . 26 0 1 .98 2 .63 6 1.1I 9 7. 1 0 . 0. 0 0.0 30 0 .6 5 .78 0 . 30 5 .71 .87 5 9 .5 1 04. 0 0. 9 6. 5 3 10 . 62 .7 6 0 . 5 9. 4 8 7 .0 3 20 . 60 .72 0 . 33 0 .59 .70 8 3 .8 0 . I 0 .0 I 400 1 .67 2 .2 8 0. 0. 0 2. 49 5 9. 1 9 5 .2 405 1 .8 9 0 . 4110 1 .5 6 2 .12 5 9 .8 9 3.3 0 . .87 .6 42 0 1 .53 2 .03 0 . 5 9. 4 6 0 .1 8 5 .0 440 1 .45 1 .98 0 . 46 0 1 .41 1 .99 6 0. 2 82 .5 0 . 0 0.0 0 0. 00 0.0 0 .0 0 . 0 .50 .50 1 0 .0 20. 0
a Pulps identified by pulp number and minutes of beating. b For list of test codes, see p. 67-68. c Zero (0.) entries represent no data. Members of Group Project 2406 Page 71 Project 2406 Report Seven
TABLE VIB (Continued)
EXPERIMENTAL DATA
Test Code 11 12 13 14 15
100 0. 000 0.00 0.00 0.0 0.0 105 .606 3.28 1.87 17.0 187.0 110 .620 4.f67 2.32 27.1 132.0 I 120 .665 6.19 2.55 38.6 94.5 140 .716 7.71 2.52 147.9 80.3 160 .752 8.31 2.55 51.7 65.4
200 0.000 0.00 0.00 0.0 0.0 205 .479 3.140 2.20 22.3 300.5 210 .523 5.15 2.75 34.8 280.0 220 .570 6.64 2.87 53.0 205.5 240 . 610 8.74 3.47 65.7 168.5 260 .629 9.55 3.40 72.0 155.5
300 0.000 0.00 0.0 0.0 305 .572 1.67 S 5.3^ 63.0 310 .606 2.25 \22 .8. 70.7 320 .683 6.68 3.05 37.6 75.5 330 .718 7.41 3.15 44.9 73.0
400 0.000 0.00 0.00 0.0 405 .620 6. 1 7 2.60 143.9 150.0 410 8.02 2.92 56.0 130.0 I I420 .678 9.64 3.10 67.2 101.5 440 .706 10.85 3.05 80.0 92.2 460 .730 11.52 2.97 82.3 82.1 .6.7 067 8 .73 0 0 0.000 n.nn0.00 0.00 0.0 0.0 0 .100 2.00 .50 10.0 50.0
a Pulps identified by pulp number and minutes of beating. b For list of test codes, see p. 67-68. c Zero (0.) entries represent no data. Page 72 Members of Group Project 2406 Report Seven Project 2406
TABLE VIB (Continued)
EXPERIMENTAL DATA
Test Codeb Pulp a 16 17 18 19. 20
100 O.0 c 0.0 0.00 0.00 0.00 105 31.5 379.5 13.25 7.60 4.58 110 54.0 450.0 14.05 7.60 7.10 120 76.7 466.0 14.75. 7.65 9.97 140 93.2 414.5 15.25 7.70 12.20 160 97.6 324.5 14.75 7.85 12.30 I 200 0.0 0.0 0.00 0.00 0.00 i 205 33.6 455.0 1'4 . 50 8.50 3.78 210 63.3 598.5 15.25 8.60 5.01 220 83.7 688.5 15.95 8.55 7.60 240 126.0 735.5 16.70 8.60 10.06 260 136.7 753.0 16.95 8.65 10.35
300 -:o0,o 0.0 0.00 0.00 0.00 305 27.0. 119.0 14.00 7.55 5.34 310 . 163.5 1 4.55 7.55 8.03 320 8.2 214.0 15.15 7.65 14.00 330 101.9 238.0 141.85 7.70 17.30
400 0.0 0.0 0.00 0.00 0.00 405 69.8 503.0 16.50 7.80 5.57 i 410 100.0 512.0 16.75 7.75 7.40 420 118.8 1476.0 18.10 7.85 10.65 440 133.4 418.0 18.05 7.85 12.80 460 138.9 391.0 18.25 7.95 13.35
0 0.0 0.0 0.00 0.00 0.00 0 20.0 100.0 2.00 1.00 2.00
a Pulps identified by pulp number and minutes of beating. b For list of test codes, see p. 67-68. c Zero (0.) entries represent no data. Members of Group Project 2406 Page 73 Project 2~406 Report Seven
TABLE VIB (Continued)
EXPERIMENTAL DATA
Test Codeb- Pulpa 2 1 22 23 214 25
100 0.n00 0. 000 0.00 0 0.0 0 0 10 5 . 63 2 .781 2.75 0 10. 3 00 11 0 2 68.0 . 6 n1 .836 2.5 70 1 2 .600 1 20 2140. 0 . 58 0 * 809 2.70 0 1 7 .800 114 0 208.0) . 51 8 .935 2.8 70 33 . 400 160 1 76.0 .414 1 . 899 2. 910 5 2. 1400
2 00 0.0n 0.000 0. 000 20 5 -212.5 5 19 .728 7 .300 2 10 1914.5 . 47 1 * 791 2.8 60 9. 200 2 2 0 17 3.5 .14145 .763 2.9 60 11 . 7 00 24 0 15 3.5 . 1410 .779 3. 0140( 19 . 9 00 26 0 1143.5 .370 .810 3 145 0 314. 100
3 00 0. 0 0. 000 0.000 0. 00 0 0.000n 3 05 14314 .5 . 73 7 .907 2. 146 0 1 6. 140 0 3 10 1403 *5 . 85 0 .816 2.5 60 20 * 1400 32 0 314 5.5 . 76 0 .827 3 0. 6 0 0 33 0 3014. 5 .58 0 .792 143 . 600 r 0 8000
1400 0 .0 0.000 0. 00 0 0. 000( 1405 2 77 .5 . 1496 .886 2. 800 1.1. 8 00 141 0 2 6 1 .0 . 59 0 .918 2.77 0 13 . 1400 142 0 22 8. 0 . 5314 .889 2.8 90 144 0 2 08. 0 . 53 2 .995 3.100 2-2 .3 00 146 0 .38 5 1.093 3.07 0 30O 5.00
0 50. 0 0. 000 0.000 0 .0 04. '0. 00 0 0 . 1on . 2 00 . 500 :10. 0 0:0
a Pulps identified by pulp number and minutes of beating. b For list of test codes, see p. 67-68. C Zero (0.) entries represent no data. Page 74 Members of Group Project 2406 Report Seven Project 2406
TABLE VIB (Continued)
EXPERIMENTAL DATA
Test Codeb Pulpa 26 27 28 29 30
100 0. 0.000 0.000 O.C O.c 105 0. 1.000 1.409 0. 0. 110 0. 1.520 1.964 0. 0. 120 0. 3.100 3.532 0. 0. 140 0. 12.960 8.120 0. 0. 160 0. 32.880 17.101 0. 0.
200 0. 0.000 0.000 0. 0. 205 0. .400 .549 0. 0. 210 0. .600 .796 0. 0. 220 0. 1.180 1.491 0. 0. 240 0. 3.740 3.377 0. 0. 260 0. 12.640 7.362 0. 0.
300 0. 0.000 0.000 0. 0. 305 0. 2.650 2.859 0. 0. 310 0. 3.780 3.855 0. 0. 320 0. 8.680 7.988 n. 0. 330 0. 23.930 15.594 0. 0. i
400 0. 0.000 0.000 0. 0. 405 0. 1.180 1.775 0. 0. 410 0. 1.510 2.048 0. 0. 420 0. 2.120 2.768 0. 0. 440 0. 4.620 5.196 0. 0. 460 0. 10. 880 8.951 0. 0.
0 0. 0.000 0.000 0. 0. 0 0. 5.000 2.000 0. 0.
a Pulps identified by pulp number and minutes of beating. b For list of test codes, see p. 67-68. I c i Zero (0.) entries represent no data. I I ,-IIII~ m---u 4W 4.
0 03 C±
U, 2L406-8 R1 2LfO6-8 Ai 5 HI F-i
t.1 Z I- HI
L.O HI P. LF'i z 0 L(JO: A z:. I.,U, L0~ z.9 u.jtrI Lu) ci
a C! 0
0 U, (D 10 0J
0) (W 1.00 Z.00o 3-00 4.00 S.00o .00 1.00 2.00 1.00 4.00 5.00 6.007. ~C/J, AVEIRAGE LENGTH (MM.) - rmvorir~~~r I cKirTua r~Am Figure 59. Fiber Length.Distribution for Bleached Western Figure 60. Pulp A Beaten for 5 Minutes Softwood Sulfite (Stockpile Pulp A - Unbeaten) j r
CD P
0
03.
02 0 Iv, 24f06-8 R1 10 2'406-8 R1 20
0(D
(D 0 M.-
z z
a-.JO Lda 1.. a- Ui.
0iv.
01
C3 CD 0, Ui 00
00
00 1.00 2.00 3.00 4.00 1.00 2. 00 3.00 40 S.00u 6.00 cnZ: AVERAGE LENGTH (MM.) RVERAGE LENGTH (MM.)
Figure 61. Pulp A Beaten for 10 Minutes Figure 62. Pulp A Beaten for 20 Minutes
F ~~~~~~~~~~~~~~~~~~~~4,9, ) 4i
D C 0=
0 0 0~I 0, N0 nC, 2'406-8 Al LtO 24t06-8 RI 60 en, 0')G 0
C0
Ui 0 9Li
'0 0 m_:
CD-
1.00 Z.00 3.00 4.00 1.00 2. 00 3.00 4.00 S. 00 6.00a AVERAGE LENGTH (MM.) AVERAGE LENGTH (MM.) Figure 63. Pulp A Beaten for 40 Minutes Figure 64. Pulp A Beaten for 60 Minutes 0 C2 0t
2'406-8 81 2'406-8 81 5
a
C2 n,, C) C~
LfJ. z Ljao LUo 'Cr h'i CLa
D -
Li 0 (D 0 CD (D
I-j
CD 0 0 G-i 0
-r- 0 0 1.00 2.00 3.00 4.00 L-J. LJ. 2.00 . 1.00 4.00 5. 00 6. 00 7.00 (D (D AVERAGE LENGTH (MM.) RVERAGE LENGTH (MM.) 0 0
Figure 65. Fiber Length Distribution for Unbleached Figure 66. Pulp B Beaten for 5 Minutes N)N Southern Softwood Sulfate (Stockpile 00Q Pulp B - Unbeaten)
e ) ) .-,.~~~~~~~~~~~~~~~~~~~~~~~ U~~~ 2
CDS(D
0 E
0 (D. 0 t LH.
CD 0 0 0 r-1 2406-8 61 10 21406-8 61 .20 10 10)
0
0=.
Un,.
I--
LJO 0O
(D
a)
1.00 2.00 3.00 4.00 S.00a 6.00 .7.00 1.0CM 2.00 3.00 4.00 S. 00 6.00 (DC RVERRGE LENGTH (MM.) RVERiRGE LENGTH (MM.) CD -
Figure 67. Pulp B Beaten for 10 MinutesFiue Figure 68.6. PulpPl BBBatnfr2 Beaten for 20 MinutesMnts CY 0 0~ 03. zr
C~
0
24f06-8 61 '40 C3 2'406-8 61 60
0
C, C2-
C - C m
U,.
I- I6.
Q- ~C3 tE - C3
CJ 0= 0~ (D 0;. tJ' (D
C3
U, 0
-J 00 1.0 I00 2.00 5.00 4.00 S.00a 8.0Oa 7.0 1.00 2.00 3.00 4.00 S.00o S. 00 RVERRGE LtNGTH (MM.) RVE~RGE LENGTH (MM.) T. i.'7 Li. (D (D 0 0 rt r± Figure 70. Pulp B Beaten for 60 Minutes Figure 69. Pulp B Beaten for 40 Minutes ND N o)-P7 o. a.)O3)
c v W, 4 % I
fJ (D
0) 0: 09 0t
Eit CD 0 N0 CD 2Lf06-8 Cl 2406-8 C2 5 0 r- 10 M. M, 0)
z.
L.ju a_ (D 0
CDC
C - Li0 F i ueM1
2.00 3.00 '4.00 1.00 2. 0 .00 4.00 S. 00 AVERAGE LENGTH (MM.) AVERAGE LENGTH (MM.)
Fiber Length Distribution for Bleached Northern Figure 72. Pulp C Beaten for 5 Minutes (DW Hardwood Sulfate (Stockpile Pulp C - Unbeaten) (D OJ How
(D
(D 0 0 0
2'406-8 C2 10 2406-8 C2 20
3D
O'- 0
00 OW 00
00
.00 1.00 2.00. 3.00 it.00 AVERAGE LENGTH (MM.)
Figure 73. Pulp C Beaten for 10 Minutes Figure 74+. Pulp C Beaten for 20 Minutes
4 2 4 ------* - -- V~, IV I % - 7
a N)O0 0! 0
:I0 0~. C)0
0
0 0 r-i 0, 0 10
(-j. 2Lf06-8 C2 30 2q0.6-8 (D D1 0 -F- rt 0 03 ND In 0 . mv 0 CY)
;2
:z LJO
I N LLU 7 z.-
LUJ cr 0~C 0
0 U.'
0: (D I- - I I I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~i1 -I * 00 1. 00 2.00 . 300 4.00 S. 001 6.00 7.00 --r 0 2.0go .00 4.00 5.00 5.00 7.00 1-3 AVERAGE LENGTH (MM.] AVERAGE LENGTH (MM.)
Figure 75. Pulp C Beaten for 30 Minutes (D (D Figure 76. Fiber Length Distribution for Bleached C.) Northern Softwood Sulfate (Stockpile Pulp D - Unbeaten) 2406-8 0l 5 I2406-8 D1 10
0 0 0 In - C4
a- a-
zj~. L.J3 a:uJ 0- S0 (D 0.
0 U,- 0
00
00 00 2.00 3. 00 4.00 S. 00 5. 00 .00 1.00 2.00o 3.00 4.00 S.0co RVERAGE LENGTH (MM.) RVEIRAGE LENGTH (MM.)3 Figure 77. Pulp D Beaten for 5 Minutes Figure 78. Pulp D Beaten for 10 Minutes
N) N) 0m o)0
) ;01~~~ la%,- Id 9 1~~ b
(DCDD
0=
01- rtCa N0
C) 2L406-~8 01 20 24f06-8 D1 '40 0
z L c3
L'i ZI
00 CL rt0 0 (DC
CD CY)
CD 03 0 C0 LA
00 1.00 2.00 3.00 5. 00 7.00 1.0O 2I.00 . 3.00 4..00 5.00 6.00 AVERAGE LENGTH AVERAGE LENGTH (MM.) Figure 79. Pulp D Beaten for 20 Minutes Figure 80. Pulp D Beaten for '40 Minutes
j Page 86 Members of Group Project 24+06 Report Seven Project 2~406
b
C, 03- ±I
0 C, U, - 2'406-8 D1 60
C3
z LJO UC, cc" bi I-)
z. L'JIA
La_ U-
0-
Cn C, Ui
d1
.00 .00 2Z.00 3.00 4'.00 S. 00 '.00o 7.00 RVER9RGE LENGTH (MM.)
Project 81. Pulp D Beaten for 60 Minutes i Members of Group Project 2406 Page 87 Project 2406 Report Seven APPENDIX III
BAUER McNETT SCREEN ANALYSES
TABLE VIIA
BAUER McNETT SCREEN ANALYSES FOR BLEACHED WESTERN SOFTWOOD SULFITE
Pulp Screen Fraction, % by weight Sample on 20 on 355 on 65 on 150 Remainder
A05-la 59.6 18.5 10.7 4.5 6.7 a _2 64.5 26.3 0.3 b 4.0 4.9
A10-1 56.7 19.5 12.3 5.4 6.1 -2 61.9 25.7 0.7b 2.3 9.4
A20-1 47.8 20.1 14.3 6.8 11.0 -2 51.5 33.2 0.7 6.8 7.8
A40-1 34.5 20.9 18.2 9.8 16.6 -2 39.5 36.3 0.7b 8.6 14.9
A60-1 29.3 19.8 20.2 13.3 17.4 -2 28.8 38.9 0.6 b 12.7 19.0
a Duplicate beater runs. Projection fiber-length distributions for duplicate runs were practically identical. b Some untraced difficulty with apparatus or procedure.
j Page 88 Members of Group Project 2406 Report Seven Project 2406
TABLE VIIB
BAUER McNETT SCREEN ANALYSES FOR UNBLEACHED SOUTHERN PINE KRAFT i
Pulp Screen Fraction, % by weight Sample on 20 on 35 I on 65 on 150 Remainder
B05-1 61.2 16.3 6.5 1.8 14.2 -2 67.1 17.6 6.3 1.9 7.1
B10-1 61.9 15.3 6.1 1.5 15.2 -2 71.0 17.0 6.8 1.7 3.5
B20-1 68.5 15.6 6.8 1.9 7.2 -2 70.1 16.8 6.6 1.7 4.8
14.2 B40-1 64.4 13.9 5.7 1.8 ,. -2 69.3 21.6 0.2 2.4 6.5
B60-1 58.5 13.7 6.3 2.7 18.8 -2 63.5 14.7 7.2 1.4 13.2
TABLE VIIC
BAUER McNETT SCREEN ANALYSES FOR BLEACHED NORTHERN HARDWOOD KRAFT
Pulp Screen Fraction, % by weight Sample on 20 on 35 on 65 on 150 Remainder
C05-1 0.1 48.3 25.7 12.4 13.5 -2 0.0 42.2 25.8 15.4 16.6
C10-1 0.0 42.2 23.8 12.3 21.7 -2 0.0 28.7 42.2 11.2 17.9
C20-1 0.3 41.4 21.2 13.0 24.1 -2 0.0 26.9 41.1 11.8 20.2
C30-1 0.2 40.4 22.5 16.2 20.7 -2 0.6 34.1 24.4 16.3 24.6 Members of Group Project 2406 Page 89 Project 2406 Report Seven
TABLE VIID
BAUER McNETT SCREEN ANALYSES FOR BLEACHED NORTHERN SOFTWOOD KRAFT
Pulp D05-1 69.4 18.2 7.4 2.9 2.1 -2 75.1 19.3 8.0 2.3 a a D10-1 72.2 18.6 8.3 2.4 -2 -70.6 18.2 9.9 2.8 a I)20-1 69.3 16.9 8.5 2.4 2.9 -2 74.6 16.5 9.3 2.6 _a I)40-1 62.2 20.5 10.1 3.0 4.2 -2 65.4 18.8 11.6 3.5 a r)60-1 57.5 21.8 10.1 4.0 6.6 -2 53.5 21.6 10.4 3.8 10.7 c Total greater than 100%. Probably due to differences in oven drying of sample cloths and pulps. Page 90 Members of Group Project 2406 Report Seven Project 2406 * APPENDIX IV LIST OF FIGURES AND TABLE! Figure Horizontal Axis Vertical Axis 1-23 Beating time All test data 24 Filtration resistance CS freeness 25 Hydrodynamic volume Filtration resistance 26 Hydrodynamic surface Filtration resistance 27-30 Fiber length distributions (First and last interval) 31 Unbonded area Scattering coefficient ,A*') 32 Unbonded area Hydrodynamic volume 33 Hydrodynamic surface Unbonded fiber area 34 Unbonded area z-Tensile strength 35 Hydrodynamic volume z-Tensile strength 36-39 Average fiber length Tensile, burst, tear, in-plane 40 Average fiber length Zero-span 41 Tear factor In-plane tear 42-45 Zero-span Tensile, burst, tear, in-plane 46-49 Unbonded area Tensile, burst, tear, in-plane 9 50-53 Filtration resistance Tensile, burst, tear, in-plane 54-57 CS freeness Tensile, burst, tear, in-plane 58 Tensile energy absorption Burst factor Tables I Tests performed on stockpile pulps II Symbols for sample identification III Comparison of fiber length measurements IV Coarseness of stockpile pulps V Absolute and relative bonded areas