Carolina Larsson - diva-portal.se5510/FULLTEXT01.pdfCarolina Larsson Sizing of different pulp...

Karlstads universitet 651 88 Karlstad Tfn 054-700 10 00 Fax 054-700 14 60 [email protected] www.kau.se

Faculty of Technology and Science

Chemical Engineering

Carolina Larsson

Sizing of different pulp qualities

Master thesis in Chemical Engineering specialised in Pulp

Technology, 30 credit points

Date: 2008-04-03

Supervisors: Ing-Marie Bernskiöld

Stora Enso Skoghall

Annki Karlsson

Stora Enso Research Centre

Lars Ödberg

Fiber- and Polymer

Technology, KTH

Examiner: Ulf Germgård

Karlstad University

Preface The work presented in this degree project was carried out between September 2007 and April 2008 at Stora Enso Research Centre in Karlstad, Sweden. This thesis concludes the M.Sc study in Chemical Engineering at Karlstad University.

First of all I would like to thank everyone at Stora Enso Research Centre and Skoghall Mill who has helped me during this project. Thank you for lending me your equipment and answering all my questions and also for making me feel welcome.

I am especially grateful to my supervisors Annki Karlsson and Ing-Marie Bernskiöld for your engagement and enthusiasm in this project.

I would also like to thank Professor Ulf Germgård at Karlstad University for being my examiner.

Finally I would like to thank Professor Lars Ödberg for your valuable knowledge and for contributing in designing this project as well as analysing the results.

Figure i. Pressurised edge wicking (0.15 bar) as a

function of STFI-Density for dual sized

sheets made with CTMP and kraft pulp

respectively. Red symbols (high freeness),

black and green symbols (medium freeness)

and blue symbols (low freeness) represent

CTMP. Pink and grey symbols represent the

kraft pulps. AKD and rosin size at three

different dosages (1, 2 and 4 kg/t of each

size) are shown with different signs. The

sheets were pressed at three different levels.

SummaryEdge wicking, i.e. in-plane wetting, is an important parameter for liquid packaging board products. Before filling of the products at the dairy the web is being sterilised with hydrogen peroxide (H2O2). A tube is shaped and cut into packages which mean that new surfaces are created. If a short stop occurs in the sterilising bath the raw edges exposed to H2O2 could absorb the liquid and when the package later is being filled this absorption could lead to tube burst. For the end products it is also important to prevent the liquid from penetrating the raw edges of the board in order to maintain the functionality and fresh look of the package.

To control edge wicking different kinds of internal hydrophobic sizing agents are used. Alkyl ketene dimer (AKD) is the most common size in neutral sizing and rosin in conjunction with alum is the traditional acidic sizing agent. AKD and rosin size are often used in combination (dual sizing) to make the board hydrophobic.

The objective of this work was to examine the effects of the sizing agents on different pulps in different dosages. The pulps used in the sheet preparation were unbleached kraft pulp as well as bleached and unbleached CTMP refined to different levels. Apart from varying the size dosages, the wet sheets were also pressed at different levels to vary the density. The major part of the study included dual sizing but a minor part also concerned mono sized sheets.

The parameters investigated on the laboratory sheets were STFI-Density, hydrogen peroxide edge wicking, pressurised edge wicking, lactic acid edge wicking (LA) and AKD and rosin size content.

In hydrogen peroxide edge wicking the amount of size was the central source of improved wick index. The retention was therefore of great significance for the results. The dual sized sheets were found to give least edge wicking, due to the synergy effect between AKD and alum rosin size.

The kraft pulps gave sheets with satisfactory edge wicking even at the lowest size dosage (1 kg/t) while CTMP required a dosage of 4 kg/t to reach the same wick index.

To achieve acceptable pressurised edge wicking values the most important parameter was found to be the density of the sheets. The kraft pulp sheets gave the lowest edge penetration while the high freeness CTMP sheets did not give satisfactory penetration resistant even at the highest size dosage (figure i).

The edge wicking of lactic acid could be prevented by sizing with AKD only. Sheets made from mono sized sheets containing rosin size did not manage to avoid a large in-plane wetting of the board structure. Hence, dual sizing to improve the edge wicking of lactic acid is not necessary. The density was found not to be an important parameter in lactic acid edge wicking, all the pulps got equal edge wicking regardless of density. Retention above 1 kg/t AKD in sheets was enough to prevent penetration. Retention above 1.5 kg/t AKD in sheet did not improve the edge wicking any further.

No significant difference in sizeability between unbleached and bleached CTMP was observed.

0

1

2

3

4

5

6

7

8

9

10

150 250 350 450 550 650 750 850

STFI-density [kg/m3]

0.1

5 b

ar

pre

ss

uri

se

d e

dg

e w

ick

ing

[k

g/m

2]

Unbl. CTMP, low CSF

Bl. CTMP, low CSF

Unbl. CTMP,medium1 CSF


Bl. CTMP, medium2' CSF

Unbl. CTMP, high CSF

Bl. CTMP, high CSF

Unbl. kraft pulp, low SR

Unbl. kraft pulp, high SR

1 kg/ton

2 kg/ton

4 kg/ton

CTMP

Kraft pulp

[Sizing of different pulp qualities]

Contents 1. Introduction ................................................................................................1

1.1. Theory ............................................................................................1

1.2. Scope..............................................................................................3

2. Materials .....................................................................................................4

2.1. Pulps...............................................................................................4

2.2. Chemicals.......................................................................................4

2.2.1. Chemicals used for sheet forming .....................................4

2.2.2. Chemicals used for edge wicking tests..............................4

3. Methods ......................................................................................................4

3.1. Sheet preparation ...........................................................................4

3.2. Fibermaster ....................................................................................6

3.3. Charge analyses .............................................................................6

3.4. STFI-Density..................................................................................7

3.5. Amount of size in paper .................................................................7

3.6. Edge wicking tests .........................................................................8

3.6.1. Hydrogen Peroxide edge wicking......................................8

3.6.2. Pressurised edge wicking ..................................................8

3.6.3. Lactic Acid edge wicking ..................................................8

3.7. Standard deviation .........................................................................9

4. Results and discussion.............................................................................10

4.1. Fibermaster ..................................................................................11

4.2. Retention ......................................................................................12

4.3. Dual sizing ...................................................................................14

4.3.1. Hydrogen peroxide edge wicking....................................14

4.3.2. Pressurised edge wicking ................................................16

4.3.3. Lactic acid edge wicking .................................................19

4.4. Mono sizing .................................................................................21

5. Conclusions ..............................................................................................24

6. Further Work ............................................................................................25

7. References ................................................................................................26


Appendices ....................................................................................................A

Appendix 1: Experimental plan and results .........................................A

Appendix 2: FiberMaster ..................................................................... E

Appendix 3: Charge analysis ................................................................F

Appendix 4: Retention .........................................................................G

Appendix 5: Hydrogen peroxide edge wicking ...................................H

Appendix 6: Pressurised edge wicking ................................................. J

Appendix 7: 24 h Lactic acid edge wicking......................................... L

Appendix 8. Standard deviation.......................................................... M

Appendix 9: Unbleached vs bleached CTMP......................................N

- 1 -


1. Introduction In-plane wetting, or edge wicking, is a very critical parameter for liquid packaging boards. It is necessary to control the penetration of aqueous liquids into the packaging board during filling in the filling machine to avoid tube breaks and at the raw edges in the end use products. Before filling of the products the reel of packaging material is sterilised in hydrogen peroxide (H2O2). The web is then formed into a tube before it is filled with the liquid product (juice etc.). Next the tube is shaped and cut into individual packages and if the raw edges in the sealings are damaged by the sterilising liquid the tube can break and the product leaks out. Figure 1 shows the filling machine principle.

Figure 1. Filling of packaging at a dairy [1].

At the raw edges created when the board is cut (for example when a juice container is being opened) the new surface is highly exposed to liquid. In order to control the wettability and absorbency of the board different kinds of sizing additives are used. When the sizing agent is added to the stock it is called internal sizing which is used for liquid packaging boards. The purpose with internal sizing is to modify the surface of the fibres to control penetration of aqueous liquids into the board [1; 2; 3].

1.1. Theory

The conditions of sizing can be acidic or neutral/alkaline pH. Alkyl ketene dimer (AKD) is a synthetic sizing agent that is used under neutral or slightly alkaline papermaking conditions. AKD dispersions consist of wax particles which are insoluble in water and are manufactured from acid chlorides, mostly stearic acid (C18) [2; 4]. The wax particle is surrounded by stabilisers which function is to prevent particles of AKD from colliding and sticking together. The most commonly used stabilisers for AKD include cationic starch products and cationic synthetic polyelectrolytes. The particle size of the dispersion is normally 0.5-2 µm in diameter. The idea of having cationic particles is that they are supposed to be deposited onto the negatively

- 2 -


Figure 3. Illustration of the

three step mechanism

of sizing with AKD

[2].

Figure 2. Hypothetical reaction between

AKD/water and fibre surfaces

[7].

charged fibre surfaces, heterocoagulation. Retention of AKD on the pulp fibres is the first step in the sizing process. In the second step AKD spread out over the available fibre surface as the web is being heated [2]. Sizing does not develop significantly until after the paper has become dry (solid content of about 80%). It has been suggested that the presence of liquid water blocks the spreading of sizing agents over the paper surface [5]. The sizing development may take place over a period as long as 10 days. The sizing reaction behaves as a first order reaction. The reaction rate is a function of temperature and pH. AKD and cellulose form a strong covalent compound via a β-ketoester bonding, a considerable proportion of the AKD dosage however remain on the fibers in an unreacted state. Reacted AKD is 2-3 times more efficient than unreacted AKD; the non bound AKD though contributes to sizing providing that reacted AKD also is present on the fibre surfaces [2; 5; 6]. Lindström et al. have revealed this synergistic effect between reacted and unreacted AKD [5]. Since AKD is a reactive size the degree of sizing depends on the extent of chemical reaction. The hypothetical reaction between AKD and the fibre surface can be seen in figure 2. The mechanism of sizing with AKD is shown in figure 3.

Ödberg et al. [8] demonstrated formation of β-ketoester bonding, with and without the cationic stabilizer present using infrared spectroscopy. It has been shown that relatively small portions from 0.006 to 0.07 percent of bound AKD are needed to obtain hydrophobic paper [6].

To catalyse the reaction between AKD and cellulose, bicarbonate (NaHCO3) is often added to the stock. Lindström et al. suggested a mechanism involving a cyclic transition state, where a dual function of the HCO3

- ion is emphasised. This involves nucleophilic attachment to the hydrogen atom of cellulose hydroxyl groups as well as proton donation to the AKD [9].

Two benefits of neutral/alkaline sizing compared to acidic sizing are improved storage durability and that calcium carbonate can be used as filler. Other advantages are the improved paper strength and the lower amount of size needed [4; 10]. A disadvantage in neutral sizing is that high levels of disturbing substances in the wet end of the paper machine like

- 3 -


hemicelluloses and electrolytes can reverse the charge of the AKD particles and prevent attachment to the fibres [11].

In acidic sizing the most common sizing agent is rosin size in conjunction with alum (Al2 (SO4)3·XH2O). Alum is added to the system to aid anchoring of the rosin acids onto the fibre surfaces. Rosin is a component of the tall oil and is a mixture of closely related materials from the wood [10; 12; 13]. In rosin sizing the anchoring to the cellulosic surface is commonly believed to be achieved by electrostatic interactions between adsorbed alum and size which means that the sizing is developed immediately. AKD is often used in combination with alum rosin (dual sizing) [5].

A critical parameter in sizing is the retention of AKD and rosin size. To improve the retention during papermaking, retention aids such as cationic starch, micro particles and cationic synthetic resins of various types are added to the stock. Starch is a polysaccharide that resembles of cellulose and consists of two molecules; amylose and amylopectine. Starch exists in nature as granules in corn, potatoes and wheat. To separate the starch from the granules it has to be boiled [13].

Edge wicking is strongly affected by the board density. Beating of the fibres results in increased flexibility and thus smaller pores between the fibres which means higher density. Beating also increases the amount of fines. Sizing agents like AKD adsorb to a large extent on fines and the existence of fines consequently increases the amount of AKD necessary for good sizing [14].

To examine the internal sizing of the paperboard there are a number of tests which are performed in the laboratory before the product is transported to the customer. The edge wicking is an important parameter, not just for the end-product but also in the filling machine. Hydrogen peroxide is used to sterilise the web before filling and during this process liquid can penetrate the board at the raw edges. High edge wicking of the board can lead to tube burst during filling. The depth of the H2O2-bath corresponds to a pressure on the board of 0.15 bars, which is the reason for measuring pressurised edge

wicking.

The lactic acid edge wicking test is made to make sure that the packages (end-products) containing milk and juice are resistant to liquid penetration.

The edge wicking index is expressed in kg/m2 and corresponds to the amount of liquid absorbed by the edge of the board.

1.2. Scope

The primary objective of this project was to investigate the sizeability of different kinds of pulps (CTMP and softwood kraft pulp).

- 4 -


2. Materials

2.1. Pulps

Nine different pulps were used in the study; all taken from the Skoghall Mill, Stora Enso. Seven of them were chemi-thermomechanical pulps (CTMP) refined to different freeness values (CSF = Canadian Standard Freeness)1 (low, medium and high CSF), four unbleached and three bleached. The bleached CTMP had an ISO brightness of about 10 ISO units higher than the unbleached CTMP. Two different unbleached softwood kraft pulps with different Shopper Riegler (SR)2 numbers were used (low and high SR). The low freeness CTMP along with the kraft pulps were taken at the board machine after beating and dilution with white water where the pulp consistency was about 4%. The pulps were dewatered in the laboratory to a pulp consistency of about 20%. The unbleached medium1 and high freeness CTMP pulp samples were taken at the pulp mill having pulp consistencies of about 27%. The unbleached medium2 CTMP was taken just before bleaching in the pulp mill and the bleached medium2’ CTMP directly after bleaching (≈ 27%). The basic pulp parameters are found in appendix 2 (p. E) and 3 (p. F).

2.2. Chemicals

2.2.1. Chemicals used for sheet forming

Chemicals used in the sheet preparation were taken from the Skoghall Mill, Stora Enso. The sizing agents were alkyl ketene dimer (AKD) and cationic rosin in combination with alum. Bicarbonate was added to adjust pH and to catalyse the reaction between AKD and cellulose. Two different retention aids were used to improve the retention3.

2.2.2. Chemicals used for edge wicking tests

The edge wicking tests required Hydrogen Peroxide (35%, pH ≈ 1.5) and lactic acid (1%, pH ≈ 2.4).

3. Methods

3.1. Sheet preparation

The pulp was disintegrated and diluted with tap water to a consistency of 0.5%. The pH was adjusted in the range of 7.0 -7.4. The sheet forming chemicals was first added to a separate beaker containing the pulp suspension after which it was stirred for 15-30 s together with the pulp 1 Freeness is a measure of how quickly water is able to drain from a fibre furnish sample. More beaten CTMP has a lower freeness value, i.e. higher density. 2 Shopper Riegler is a measure of how quickly water is able to drain from a fibre furnish sample. Increased beating (higher density) of kraft pulps gives an increased SR number. 3 Retention is a general term for the process of keeping fine particles and fibre fines within the web of paper as it is being formed.

- 5 -


before the pulp was poured into the sheet former. Isotropic handsheets were produced in a PFI Sheet Former 25110, producing quadratic sheets of 200x200 mm with a target grammage of 100 g/m2. Table 1 illustrates the addition order and amount of chemicals used in the sheet formation. This schedule was followed for unbleached CTMP (medium1, low and high CSF) and bleached CTMP (low and high CSF) along with the unbleached softwood kraft pulps. All dosages are given as active chemicals.

Table 1. Table showing the dosage of chemicals during the sheet forming.

The letters C1 and C2 correspond to constant levels.

Exposure time [s] 90 75 60 60 45-15

Set nr. Bicarbonate AKD Rosin Alum Retention

aids Pressure

[active kg/t]

[active kg/t] [active kg/t] [kPa]

1 C1 1 1 2 C2 100

2 C1 1 1 2 C2 400

3 C1 1 1 2 C2 1200

4 C1 2 2 3 C2 100

5 C1 2 2 3 C2 400

6 C1 2 2 3 C2 1200

7 C1 4 4 5 C2 100

8 C1 4 4 5 C2 400

9 C1 4 4 5 C2 1200

To investigate the effects of AKD and alum rosin separately an experiment with unbleached low CSF CTMP according to table 2 was performed.

Table 2. AKD and alum rosin dosage.

Test

AKD

[active kg/t]

Alum

[active kg/t]

Rosin

[active kg/t]

1 0 3 2

2 0 5 4

3 2 0 0

4 4 0 0

To further examine the difference between unbleached and bleached CTMP an extra study was made with the same pulp before and after bleaching (medium2 and medium2’). Table 3 shows the size dosages.

- 6 -


Table 3. AKD and alum rosin dosage.

Test

AKD

[active kg/t]

Alum

[active kg/t]

Rosin

[active kg/t]

1 1 2 1

2 2 3 2

3 4 5 4

The sheets were pressed twice (5 + 2 min) in a laboratory press at 100, 400 and 1200 kPa, respectively. The sheets were then dried at 68°C for 1 hour on a drying drum. The sheets were thereafter cured at 60°C for 17-18 hours.

For analysis of size content the samples were stored in aluminium foil. Sheet samples for the other tests were conditioned at 23°C and 50% RH for at least 4 hours as paper has a time dependent response to moisture.

3.2. Fibermaster

The STFI Fibermaster is a tool for studying fibre dimensions such as fibre length, fibre width, coarseness and shape factor. The pulp is circulated in an internal measuring loop in the Fibermaster and the fibres passes a measuring cell where the fibres are illuminated and the image is registered on an image sensor. Two DSP–processors (Digital Signal Processor) in the camera handles the sensor and image analysis. The image is sent to a computer for further analysis.

Fibres are defined as particles with a length/width ratio greater than 4. The results are presented as average values and distributions.

3.3. Charge analyses

A System Zeta Potential SZP-06 (BTG Mütek GmbH, Herrsching, Germany) was used for measuring the zeta potential and conductivity of the nine different pulps (0.3%) before addition of chemicals. A Particle Charge Detector PCD-03 (BTG Mütek GmbH, Herrsching, Germany) was used for measuring cationic demand of the water phase.

The total acidic groups in the pulps, i.e. total charge, were analysed according to SCAN-CM 65:02, the carboxylic and sulphonic groups were determined by titration with sodium hydroxide and conductometric detection.

The surface charges of the pulps were determined with polyelectrolytic adsorption [22].

All results from charge analysis are found in appendix 3 (p. F).

- 7 -


3.4. STFI-Density

The thickness was measured using a TJT Thickness Tester M201 according to the internal method nr 295. This method yields the structural thickness, measured in a certain amount of points in the sheet of paper with two opposite micrometers. The structural thickness also gives the profile of the sheet as a standard deviation. The principle of the thickness tester is shown in figure 4.

Figure 4. Principle of measuring structural thickness. Structural thickness

is measured with two opposite micrometers.

3.5. Amount of size retained in the sheets

The total amount of AKD is given as the sum of non bound and bound AKD.

What is defined as non bound AKD was extracted from the samples with THF (tetrahydrofuran) for three hours at 180°C in autoclaves.

The bound AKD was given by boiling the same extracted sample with alkaline ethanol for two hours. The pH was then adjusted to 5-6 before the sample was boiled for one hour with isooctane to get the hydrolysed AKD into the isooctane phase. Both extracts were analysed with GC-FID (gas-chromatography with flame ionization detector) and dotriacontane (C32H66) was used as an internal standard.

Extraction of rosin size from the sheets was made with acetone: water 9:1 with addition of KH2PO4. The extract was analysed with GC-FID and 14-methylpentadecanoic acid (C16:0 ai) as internal standard. The amount of rosin size was corrected for the resin acid content in the fibres.

All values of size in sheets are given as active amount in kg/t.

The retained amounts of size in the sheets were only analysed on the sheets pressed at 400 kPa for each dosage, i.e. three samples for each pulp. For unbleached (medium1) CTMP and unbleached softwood kraft pulp (high SR) all samples were analysed.

- 8 -


3.6. Edge wicking tests

3.6.1. Hydrogen Peroxide edge wicking

The face surfaces of the samples were sealed by adhesive tape and then cut into pieces of 75×25 mm. This leaves all edges open to allow for edge wicking. Five samples at the time were weighed and put into the hydrogen peroxide bath with rods holding them at place. The bath had a pH of about 1.5 and a temperature of 70°C (during a 10 minute period). Then the samples were placed between two blotting papers to remove non absorbed liquid. A brass roller was moved back and forth twice over the samples, without no extra pressure applied. The weight was then measured again. The Edge wicking index was calculated using:

lt

WWE

⋅

−=

)( 12

Where W1 is the weight of the five samples before the bath in mg, W2 is the weight after the bath in mg, t is the STFI-thickness in µm and l is the total edge-length of the five samples in m. At least three measurements were made for each test point, i.e. 3×5 pieces.

3.6.2. Pressurised edge wicking

Samples were cut into pieces of 62×50 mm. The samples were laminated and a hole was punched in the centre. In a chamber with distilled water (23°C) the samples were placed under a pressure of 0.15 bars during 20 seconds. Next the samples were put between blotting papers following the same procedure as for the hydrogen peroxide test. The edge wicking index was calculated using:

612

10)))(((

)(

⋅⋅⋅

−=

tnd

WWE

π

Where W1 is the weight of four sample pieces before the bath in mg, W2 is the weight after the bath in mg, d is the diameter of the hole (12 mm), n is the number of sample pieces and t is the STFI-thickness in µm. Two experiments were made for each test point, i.e. 2×4 pieces.

3.6.3. Lactic Acid edge wicking

The method is similar to the hydrogen peroxide edge wicking except for the exposure time (24 hours), temperature (23°C) and size of the sample pieces (50×150 mm). The tests were only carried out for the sheets pressed at 400 kPa. No duplicate sample was made.

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3.7. Standard deviation

To evaluate the credibility of the results the standard deviation was calculated according to:

)1(

)( 2

−

−∑n

xx

Where x is the sample mean average and n is the number of samples.

- 10 -


4. Results and discussion A colour and shape design according to table 4-5 has been chosen to illustrate the results in the following figures.

Table 4. Colour scheme used to illustrate the results. For example 1 kg/t

symbolised with a diamond means that 1 kg/t has been added of

each size.

Pulp Colour

Unbleached CTMP, low CSF

Bleached CTMP, low CSF

Unbleached CTMP, medium1 CSF

Unbleached CTMP,medium2 CSF

Bleached CTMP,medium2’ CSF

Unbleached CTMP, high CSF

Bleached CTMP, high CSF

Unbleached Kraft pulp, low SR

Unbleached Kraft pulp, high SR

Table 5. Symbols used to illustrate the dual size dosages.

Dosage Symbol

1 kg/t

2 kg/t

4 kg/t

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4.1. Fibermaster

In terms of fibre morphology, the bleached and unbleached CTMP did not show a significant difference. The major difference between chemical and mechanical pulp was the larger amount of fines found in CTMP. The softwood kraft pulps have slenderer fibres and more flexible fibre walls which gives a more dense structure of the sheets. As shown in figure 5 the percentage of fibres in the range 0.2-1.0 mm was larger in CTMP than in kraft pulp. The low freeness pulps had the highest amount of fines and the high freeness pulps the lowest of the mechanical pulps. The kraft pulps conversely have the greatest amount of fibres larger than 1.0 mm followed by the high freeness CTMP.

Figure 5. Percentage of length properties for different pulps. The kraft

pulp has less percentage of fibres in the range of 0-1.0 mm than

CTMP, after that point the proportions is the reverse.

The test results from Fibermaster in its entirety are found in appendix 2 (p. E).

0

5

10

15

20

25

30

35

40

45

01 <0.2

mm

02 0.2-0.5

mm

03 0.5-1.0

mm

04 1.0-1.5

mm

05 1.5-3.0

mm

06 >3 mm

1 - Unbl. CTMP, low CSF

8 - Bl. CTMP, low CSF

2 - Unbl. CTMP, medium1 CSF


7 - Bl. CTMP, medium2' CSF

3 - Unbl. CTMP, high CSF

4 - Bl. CTMP, high CSF

5 - Unbl. Kraft pulp, low SR

6 - Unbl. Kraft pulp, high SR

Property 04 FiMa kortfiberklasser, längdandel l/l (%)

Value

Level

Order

Sample

- 12 -


4.2. Retention

Figure 6 displays the correlation of bound and total AKD for the sheets made from the nine different pulps.

The analysed amount of total AKD was higher in sheets made from CTMP pulp than from kraft pulp, due to a larger specific area and more fines (chapter 4.1). The amount of bound AKD in sheets made from chemical pulp was not more than about 0.1-0.2 kg/t in contrast to the CTMP sheets which contained about 0.2-0.5 kg/t bound AKD. The low freeness CTMP retained more total AKD than CTMP with higher freeness. An explanation can be that low freeness pulp, which is more beaten, has a larger specific area due to a larger amount of fines and thus can attach a greater amount of AKD until the area is satisfied

Figure 6. The bound AKD in sheets plotted against the total AKD. The

solid line connects the CTMP values and the dashed line the

kraft pulps. The unfilled symbols represent the bleached pulps.

The amount of rosin size found in the samples was lower than the amount of AKD even though the dosages were the same in every case. One reason for this might be that AKD is added to the stock before rosin size. The kraft pulp tended to have better rosin size retention than CTMP. This relation is illustrated in figure 7.

0,0

0,1

0,2

0,3

0,4

0,5

0,6

0,0 0,5 1,0 1,5 2,0 2,5 3,0

Total AKD in sheets [kg/ton]

Bo

un

d A

KD

in

sh

ee

ts [

kg

/to

n]

Unbl. CTMP,low CSF

Bl. CTMP,low CSF

Unb. CTMP,medium1 CSF


Bl. CTMP, medium2'CSF

Unbl. CTMP,highCSF

Bl. CTMP,high CSF

Unbl. kraft pulp,lowSR

Unbl. kraft pulp,highSR

1 kg/ton

2 kg/ton

4 kg/ton

CTMP

Kraft pulp

- 13 -


Figure 7. The rosin in sheets plotted against the total AKD. The dotted

circle represents a size dosage of 1 kg/t, the dashed line shows

the points with the dosage of 2 kg/t and solid line is for the 4 kg/t

dosage.

A compilation of the retention in [%] of total AKD, bound AKD and rosin size for each pulp is found in appendix 4 (p. G)

0,0

0,5

1,0

1,5

2,0

2,5

3,0

0,0 0,5 1,0 1,5 2,0 2,5 3,0

Rosin in sheets [kg/ton]

To

tal

AK

D i

n s

he

ets

[k

g/t

on

]

Unbl. CTMP,low CSF

Bl. CTMP,low CSF

Unbl. CTMP,medium1CSF


Bl. CTMP,medium2' CSF

Unbl. CTMP,high CSF

Bl. CTMP,high CSF



1 kg/ton

2 kg/ton

4 kg/ton

- 14 -


4.3. Dual sizing

4.3.1. Hydrogen peroxide edge wicking

Figure 8 displays that an increased size dosage gave lower hydrogen peroxide edge wicking, i.e. less edge penetration, for the CTMP as well as for the kraftpulps. The goal is to get as low edge wicking as possible and the target point is varying between different board qualities. It was possible to reach acceptable hydrogen edge wicking values at the highest dosage (4 kg/t) for CTMP as well as for the kraft pulps. It was more difficult to reach low edge wicking with CTMP than kraft pulp, which is due to lower density and larger surface area.

Other differences between the pulps that can have an influence on the results are for example the amount of extractives and surface charges. The zeta-potential, total charge and surface charge however do not directly explain the results (appendix 3, p. F).

The standard deviation was in most cases larger at the small size dosages. Three test values were removed due to large standard deviation (appendix 8a, p. M)

Figure 8. H2O2 edge wicking as a function of STFI-Density. The dotted

circle represents a size dosage of 1 kg/t, the dashed circle shows

the points with the dosage of 2 kg/t and solid circle is for the 4

kg/t dosage. The pink and grey lines are representing the kraft

pulps.

To achieve low edge penetration in the hydrogen peroxide bath the amount of size retained was the major requirement. To illustrate the dual size effect the total size amount was plotted against the H2O2 edge wicking (figure 9). The results showed that the kraft pulp sheets got satisfying edge wicking even at the low size dosage (~1 kg/t retained size). The CTMP pulp sheets needed a dosage of at least 4 kg/t AKD + 4 kg/t rosin size (3-4 kg/t retained size) to obtain acceptable edge wicking. CTMP sheets prepared from

0

1

2

3

4

5

6

7

8

9

150 250 350 450 550 650 750 850 950

STFI-Density [kg/m3]

H2O

2 E

dg

e w

ick

ing

[k

g/m

2]

Unbl. CTMP, low CSF

Bl. CTMP, low CSF





Bl. CTMP, high CSF

Unbl. kraft pulp,low SR

Unbl. kraft pulp,high SR

1 kg/ton

2 kg/ton

4 kg/ton

- 15 -


medium freeness pulps resulted in higher edge wicking compared to the high and low freeness pulps, which got lower and approximately equal values. The low freeness pulps have a larger specific area due to the beating and should be able to carry more AKD particles but on the other hand the larger area to cover means larger amount of AKD needed to achieve a hydrophobic surface. The higher values for the medium freeness pulps are surprising and no explanation has been found.

Difference in sizeability between unbleached and bleached CTMP can not be concluded from the results. The edge wicking values differed at different size dosages, sometimes the bleached CTMP got lower edge penetration and sometimes the results were reversed. More results from comparison of unbleached and bleached CTMP can be seen in appendix 9a (p. N).

The amount of total AKD, bound AKD and rosin size found in the sheets are plotted against the measured H2O2 edge wicking values in appendix 5 (p. H). The edge wicking index improved (lower values) at larger amounts of AKD. As the sheets besides AKD contains rosin size (dual sized) the effect is also dependent on the rosin retention.

The test values all refers to sheets pressed at 400 kPa.

Figure 9. H2O2 edge wicking versus the total size found in sheets

pressed at 400 kPa. The dotted circle represents a size

dosage of 1 kg/t, the dashed circle shows the points with the

dosage of 2 kg/t and solid circle is for the 4 kg/t dosage. The

pink and grey lines are representing the kraft pulps.

0

1

2

3

4

5

6

7

8

9

0 0,5 1 1,5 2 2,5 3 3,5 4 4,5

Total size in sheets [kg/ton]

H2O

2 e

dg

e w

ickin

g [

kg

/m2]

Unbl. CTMP, low CSF

Bl. CTMP, low CSF





Bl. CTMP, high CSF

Unbl. Kraft pulp,low SR

Unbl. Kraft pulp, high SR

1 kg/ton

2 kg/ton

4 kg/ton

- 16 -


4.3.2. Pressurised edge wicking

The pressurised edge wicking tests established that a higher density reduces the in plane wetting. It was difficult, even at the higher size dosages, to get acceptable edge wicking for CTMP. It was necessary to have CTMP-sheets with densities above 300 kg/m3 and high size dosages to get reasonable edge wicking values. At low densities the sheet structure is more open which makes it easier for the liquid to penetrate into the sheet. For the kraft pulp sheets a density of approximately 600 kg/m3 was enough to improve the edge wicking into satisfactory levels. Figure 10 shows the relation between pressurised edge wicking and STFI-density.

A comparison between unbleached and bleached CTMP according to pressurised edge wicking is found in appendix 9b (p. N).

Four test values were removed due to large standard deviation (appendix 8b, p. M).

Figure 10. Pressurised edge wicking as a function of STFI-Density.

Figure 11 shows the pressurised edge wicking plotted against the total amount of size found in the sheets. At the same size retention the kraft pulps resisted edge penetration much better than the CTMP pulps. The CTMP fibre is more stiff and rigid compared to the more slender and flexible kraft fibre, which gives sheets with lower density. The low freeness CTMP pulps (more refined) were easier to size to give good pressurised edge wicking than the high freeness CTMP pulp. Pulp with a lower freeness has more flexible fibres which are more easily bound to other fibres. Sheets made from highly refined fibres (lower freeness) are stronger and denser and contains more fines. The pores between the fibres become smaller as the fibres are closer to each other.

The influence of retained size was relative insignificant to pressurised edge wicking compared to hydrogen peroxide edge wicking (see also appendix 5-6, pp. H-K). The higher amount of size in sheets did not improve the edge

0

1

2

3

4

5

6

7

8

9

10

150 250 350 450 550 650 750 850


0.1

5 b

ar

pre

ssu

rise

d e

dg

e w

ick

ing

[kg

/m2]

Unbl. CTMP, low CSF

Bl. CTMP, low CSF





Bl. CTMP, high CSF



1 kg/ton

2 kg/ton

4 kg/ton

CTMP

Kraft pulp

- 17 -


wicking at the lower density levels, i.e. higher density sheets were more positively effected by the size content.

The amount of total AKD, bound AKD and rosin size found in sheets were plotted against the measured pressurised edge wicking values in appendix 6 (p. J).

The test values refer to sheets pressed at 400 kPa.

Figure 11. Pressurised edge wicking versus total size in sheets pressed

at 400 kPa. The dotted circle represents a size dosage of 1

kg/t, the dashed circle shows the points with the dosage of 2

kg/t and solid circle is for the 4 kg/t dosage. The pink and

grey lines are representing the kraft pulps.

Hydrogen peroxide edge wicking plotted against pressurised edge wicking at a dosage of 4 kg/t is shown in figure 12. A difference between hydrogen peroxide edge wicking and pressurised edge wicking was the impact of density and size amount. In hydrogen peroxide edge wicking the most critical parameter was the amount of size retained in the sheets. In pressurised edge wicking the most important parameter was the density; a higher density generally lowered the edge wicking. When the samples were exposed to pressure the high freeness CTMP pulps did not stand up to the edge penetration, due to the open structure.

0

1

2

3

4

5

6

7

8

9

0 0,5 1 1,5 2 2,5 3 3,5 4 4,5

Total size in sheet [kg/ton]

Pre

ssu

ris

ed

ed

ge

wic

kin

g [

kg

/m2]

Unbl. CTMP low

Bl. CTMP low

Unbl. CTMP standard1

Unbl. CTMP standard2

Bl. CTMP standard2'

Unbl. CTMP high

Bl. CTMP high

Unbl. Kraftpulp, SR=17

Unbl. Kraftpulp, SR=34

1 kg/ton

2 kg/ton

4 kg/ton

- 18 -


Figure 12. The hydrogen peroxide edge wicking as a function of

pressurised edge wicking at a size dosage of 4 kg/t.

0

1

2

3

4

5

6

7

8

0 1 2 3 4 5 6 7 8

Pressurised edge wicking [kg/m2]

H2O

2 e

dg

e w

ick

ing

[kg

/m2]

Unbl. CTMP, low CSF

Bl. CTMP, low CSF



Bl. CTMP, high CSF



Increasing density

Target point

- 19 -


4.3.3. Lactic acid edge wicking

Figure 13 shows the lactic acid edge wicking value versus the STFI-Density. The density was shown not to be an important parameter in lactic acid edge wicking. A dosage of 2 kg/t AKD (plus 2 kg/t rosin size) was enough to prevent the in plane wetting. The test values all refers to sheets pressed at 400 kPa.

Figure 13. Lactic acid edge wicking as a function of density. The dashed

lines represent the bleached pulps.

Figure 14 shows the lactic acid edge wicking as a function of the total amount of AKD in sheets. As rosin size not improves LA edge wicking (chapter 4.4) the results were only affected by the AKD retention. The retained amount of total AKD in sheets needed to be above 1.25 kg/t. A higher retention did not further improve the edge wicking.

0

1

2

3

4

5

6

7

8

9

150 250 350 450 550 650 750 850


24

h L

ac

tic

ac

id e

dg

e w

ick

ing

[kg

/m2]

Unbl. CTMP,low CSF

Bl. CTMP,low CSF

Unbl. CTMP, medium1CSF

Unbl. CTMP,high CSF

Bl. CTMP,high CSF



1 kg/ton

2 kg/ton

4 kg/ton

- 20 -


Figure 14. Lactic acid edge wicking as a function of total AKD in the

dual sized sheets. The dashed lines represent the bleached

pulps.

The 24 hour lactic acid edge wicking plotted against bound and non bound AKD in sheets is found in appendix 7 (p. L)

0

1

2

3

4

5

6

7

8

9

10

0 0,5 1 1,5 2 2,5 3

Total AKD in sheet [kg/ton]

24

h L

ac

tic

acid

ed

ge

wic

kin

g [

kg

/m2]

Unbl. CTMP,low CSF

Bl. CTMP,low CSF


Unbl. CTMP,high CSF

Bl. CTMP,high CSF

Unbl. Kraft pulp,low SR

Unbl. Kraft pulp,high SR

1 kg/ton

2 kg/ton

4 kg/ton

- 21 -


4.4. Mono sizing

Unbleached CTMP refined to a low freeness was sized with only AKD or Rosin size. The pH during sheet forming was the same as in the dual sizing (7.0-7.4) which is not optimal for the sizing agents alone. For comparison, the results from the dual sizing are also given in the graphs.

H2O2 edge wicking plotted against the total size content in sheets is shown in figure 15. The values at the test points in the graph (2 and 4 kg/t) refer to the added amounts of AKD and rosin size.

Compared to mono sized sheets, the dual sized sheets resulted in the best hydrogen peroxide edge wicking index which confirmed the synergy effect taking place between AKD and rosin. Rosin alone tended to give lower edge penetration than AKD at same size amount retained in the sheets. An explanation can be the non bound AKD that during normal conditions together with the bound AKD gives a hydrophobic surface. However, when the sheet is exposed to heat (from the 70°C polar hydrogen peroxide bath) there is a theory that the non bound AKD reorient (turn-over-effect) with the hydrophilic part turning towards the polar liquid instead of the reverse, or alternatively to turn into emulsion droplets [15]. The rosin size is not as temperature sensitive, due to the interaction with alum.

Figure 15. H2O2 edge wicking (70°C, 10 min) versus the amount of total

size in sheets (unbleached low CSF, 400 kPa). The standard

deviation was at the most 0.07 and therefore negligible.

The results from the pressurised edge wicking is shown in figure 16. As discussed in chapter 4.3.2, a density above 300 kg/m3 is needed in order to get a response from the added size. This is also observed in figure 16 where increased size retention decreases edge penetration for samples having a density of 304-322 kg/m3. At same size amount retained in the sheets, rosin size tended to give lower edge penetration.

The values at the test points in the graph (2 and 4 kg/t) refer to the added amounts of AKD and rosin size respectively.

AKD = 2 kg/t

AKD = 4 kg/t

Rosin = 2 kg/t

Rosin = 4 kg/t

AKD=2,Rosin=2 kg/t

AKD=4,Rosin= 4kg/t

0

2

4

6

8

10

12

0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0

Retained size content [kg/ton]

H2O

2 e

dg

e w

ickin

g [

kg

/m2]

- 22 -


Figure 16. Pressurised edge wicking versus amount of total size in

sheets (unbleached low CSF CTMP, 400 kPa). The standard

deviation is drawn as intervals.

Figure 17 display the lactic acid edge wicking plotted against the retained size content. Rosin sizing was shown to work poorly for lactic acid edge wicking because the lactic acid splits the bonds between alum and rosin. The AKD sized sheets had an edge wicking value of 14 units lower than the rosin sized sheets. The dual sized samples did not give any better edge wicking values. Consequently, to achieve acceptable lactic acid edge wicking it is enough to use AKD only as sizing agent.

The values at the test points in the graph (2 and 4 kg/t) refer to the added amounts of AKD and rosin size respectively.

AKD=2 kg/t

322 kg/m3

AKD= 4 kg/t

317 kg/m3

Rosin= 2 kg/t

307 kg/m3

Rosin=4 kg/t

311 kg/m3

AKD=2,Rosin=2 kg/t

304 kg/m3 AKD=4,Rosin=4 kg/t

322 kg/m3

0

1

2

3

4

5

6

7

8

9

0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0


0.1

5 b

ar

pre

ss

uri

sed

ed

ge w

ickin

g [

kg

/m2]

- 23 -


Figure 17. 24 h lactic acid edge wicking versus the amount of total size in

sheets (unbleached low CSF CTMP, 400 kPa). Each point

represents one test value.

AKD 2 kg/t

AKD 4 kg/t

Rosin 2 kg/t

Rosin 4 kg/t

AKD=2,Rosin=2 kg/t

AKD=4,Rosin=4 kg/t

0

2

4

6

8

10

12

14

16

18

20

0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0


24 h

lac

tic

acid

ed

ge

wic

kin

g [

kg

/m2]

- 24 -


5. Conclusions • Using kraft pulp instead of CTMP made it easier to achieve low

edge penetration according to both the pressurised and hydrogen peroxide edge wicking tests. The H2O2 edge wicking depended on the size dosage while in the pressurised edge wicking the structure was more important due to its density dependency (figure 8-12).

• In hydrogen peroxide edge wicking rosin size worked better than AKD alone, however the dual sized sheets was shown to give the lowest edge penetration (figure 15). Comparing kraft pulp and CTMP, kraft sheets got satisfying edge wicking even at the low size dosage (1 kg/t) while CTMP sheets needed 3-4 kg/t retained size to obtain acceptable edge wicking (figure 9).

• The results from the pressurised edge wicking showed that a density above 300 kg/m3 and high size dosage was necessary to obtain acceptable wick index for CTMP. The kraft pulps achieved low edge wicking even at a density of 600 kg/m3 and the standard pressure (400 kPa) was enough to produce sheets with excellent edge wicking (figure 10).

• It was possible to obtain acceptable lactic acid edge wicking with AKD size in relatively low dosages, approximately 1.25 kg/t retained AKD (figure 14). The lactic acid edge wicking was density independent. CTMP and kraft pulp got equal amounts of edge penetration (figure 13).

• There was a tendency that the retention of AKD was greater for the CTMP pulp while the rosin size retention was higher in kraft pulp sheets (figure 7).

• The kraft pulp could bind a smaller amount of AKD (0.1-0.2 kg/t) than CTMP (0.2-0.5 kg/t), due to a smaller specific area and less fines (figure 6).

• The low freeness CTMP retained more total AKD than CTMP with higher freeness. An explanation can be that low freeness pulp, which is more beaten, has a larger specific area due to a larger amount of fines and thus can attach a greater amount of AKD until the area is satisfied (figure 6).

• There was no significant difference in sizeability between unbleached and bleached CTMP.

- 25 -


6. Further Work Follow-up to this research could be a study using only AKD or Rosin size to observe the difference in retention between chemical pulps and CTMP.

Another field of interest would be to make sheets from a mixture of CTMP and softwood kraft pulp in respect to investigate the selectivity among each pulp.

Change the dosage order of AKD and rosin size could be done as an attempt to optimise the sizing. The pH could also be optimised along with the dosage ratio AKD: Rosin.

Evaluate strength properties of the sheets to further investigate the impact of sizing agents.

The retention aid system is also an object of improvement (optimisation).

- 26 -


7. References

1. Fellers, C; Girlanda, O. (2005): Assessment of Critical Converting

Elements for the Paperboard Demonstrators, Report no 103, STFI-Packforsk, Stockholm, Sweden.

2. Neimo, L. (1999): Papermaking Chemistry, Papermaking Science and Technology, Book 4, Fapet Oy, Helsinki, Finland, pp.151-197. ISBN: 952-5216-04-7.

3. Roberts, J. (1992): Neutral Sizing, Pira reviews of Pulp and Paper Technology, Pira International. ISBN: 0 902799 83 5.

4. Bajpai, P. (2005): Emerging Technologies in Sizing, Pira International Ltd, Surrey, UK. ISBN: 185802 983 X.

5. Lindström, T; Söderberg G. (1986): On the mechanism of sizing

with alkylketene dimers, Nordic Pulp and Paper Research Journal, no.1, part 1, pp. 26-42.

6. Åvitsland, G.A. (2005): Edgewise liquid penetration in paper –

Influence of surface chemistry and paper structure, Licentiate Thesis in Fiber and Polymer Technology, Royal Institute of Technology, Stockholm, Sweden.

7. http://www4.ncsu.edu/~hubbe/AKD.htm

8. Ödberg, L; Lindström, T. (1987): Evidence for β-ketoester

formation during the sizing of paper with alkylketene dimers, Tappi Journal April 1987, pp. 135-139.


with alkylketene dimers, Nordic Pulp and Paper Research Journal, no. 1, part 3, pp. 31-38.

- 27 -


10. Gess, J.M; Rodriques, J.M. (2005): The Sizing of Paper, Third edition, Papermaking Additives Committee, TAPPI Press, Atlanta, USA.

11. Mattsson, R. (2002): AKD Sizing – Dispersion Colloidal Stability

Spreading and Sizing with Pre-flocculated Dispersion, Licentiate Thesis, Luleå University of Technology, Luleå, Sweden. Trita-FPT 2002:07.

12. Hubbe, M.A. (2004): Acidic and Alkaline sizings for Printing,

Writing and Drawing Paper, The Book and Paper Group Annual 23, North Carolina State University, USA, pp. 139-151.

13. Renberg, J. (2001): Undersökning av mäldkemiska samband på en

kartongmaskin, Examensarbete, Institutionen för Kemi och Metallurgi, Luleå Tekniska Universitet.

14. Karlsson, H. (2001 ): The effect of beating, sizing, wet pressing and

calendaring on edge wicking studied by pressurised and

atmospheric edge wicking techniques, Master thesis, Luleå University of Technology, Luleå, Sweden

15. Packaging R&D Stora Enso, Internal report.

16. Aksberg, R; Lindström, T; Tufvesson, H. (2007): A test apparatus

for evaluating edge wicking in sized paperboard suitable for

retortable packaging, Nordic Pulp and Paper Research Journal, vol 22 no 2, pp. 194-199.

17. Crouse, B.W; Warner, C.L; Eastman Kodak Co. (1986): Mechanistic Aspects of Edge Wicking, TAPPI Papermakers Conference, Notes 7-15, New Orleans, USA, April 14-16.

- 28 -


18. Ekdahl, G. (2003): Sizing of liquid packaging board, Scientific and Technical Advances in Internal and Surface Sizing of Paper and Board, Paper 18, Graz, Austria, Dec 11-12.

19. Hubbe, M.A. (2006): Paper’s resistance to wetting – A review of

internal sizing chemicals and their effects, BioResources 2(1), Department of Forest Biomaterilas Science and Engineering, North Carolina State University, USA, pp. 106-145.

20. Jopson, N. (2007): Sizing, structure and surface, A guide to how

sizing is used to control wettability and absorbency, Pulp & Paper International, vol 49, no 5, pp. 26-28.

21. Karademir, A. (2002): Quantitative Determination of Alkyl Ketene

Dimer (AKD) Retention in Paper Made on a Pilot Paper Machine, Turkish Journal of Agriculture and Forestry, Department of Forest Product Engineering, KSÜ Faculty of Forestry, Kahramanmaras, Turkey.

22. Lindström, T; O’Brian, H. (1986): On the mechanism of sizing

with alkylketene dimers, Nordic Pulp and Paper Research Journal, no.1, part 2, pp. 34-42.


with alkylketene dimers, Nordic Pulp and Paper Research Journal, no. 2, part 4, pp. 39-45.

24. Lindström, T; Tufvesson, H. (2007): The effect of sizing and paper

structure on paperboard for retortable packaging, Nordic Pulp and Paper Research Journal, vol 22 no 2, pp. 200-209.

25. Loeb, H. (2005): Development of edge wicking resistance during the

converting process of liquid packaging board, Final Thesis, Royal Institution of Technology, Lund, Sweden.

- 29 -


26. Packaging R&D Stora Enso, Internal report2.

27. Tufvesson, H. (2006): The Mechanisms of Edge Wicking in

Retortable Paperboard, Licentiate Thesis in Fibre and Polymer Technology, Royal Institute of Technology, Stockholm, Sweden. Trita-FPT 2006:28. ISBN: 1652-2443.

28. Wågberg, L; Åvitsland, G.A; Ödberg,L. (2006): AKD sizing of

TCF and ECF bleached birch pulp characterized by peroxide edge

wicking index, Nordic Pulp and Paper Research Journal, vol 21 no 2, pp. 237-244.

29. Wågberg, L; Ödberg, L. (1989): Charge determination of porous

substrates by polyelectrolyte adsorption, Nordic Pulp and Paper Research Journal, no 2, pp. 71-79.

- A -

Appendices

Appendix 1: Experimental plan and results

AK

D

(ac

tive

) R

os

in

(ac

tive

) A

lum

(a

cti

ve

) P

res

su

re

ST

FI-

thic

kn

es

s

ST

FI-

D

en

sit

y

Pre

ss

-W

ick

0

,15

ba

r H

2O

2-

Wic

k

LA

-Wic

k

24

h

AK

D

(ac

tive

) to

tal

AK

D

(ac

tive

) b

ou

nd

AK

D

(ac

tive

) n

on

b

ou

nd

R

os

in

(ac

tive

)

AK

D

tota

l re

ten

tio

n

AK

D

bo

un

d

rete

nti

on

R

os

in

rete

nti

on

[k

g/t

] [k

g/t

] [k

g/t

] [k

Pa

] [µ

m]

[kg

/m3]

[kg

/m2]

[kg

/m2]

[kg

/m2]

[kg

/t]

[kg

/t]

[kg

/t]

[kg

/t]

[%]

[%]

[%]

1

1

2

10

0

38

9

28

3

5.6

5

.4

1

1

2

40

0

32

7

33

3

7.2

6

.4

4.9

0

.6

0.2

0

.4

0.3

6

0

17

2

6

1

1

2

12

00

3

09

3

60

6

.6

10

.2

2

2

3

10

0

43

6

25

4

5.6

2

.5

2

2

3

40

0

36

1

30

4

5.6

2

.8

2.3

1

.1

0.3

0

.9

0.7

5

6

13

3

3

2

2

3

12

00

3

11

3

53

2

.7

3.4

4

4

5

10

0

44

0

25

4

5.2

1

.3

4

4

5

40

0

34

6

32

2

4.6

1

.9

1.9

2

.2

0.4

1

.8

1.3

5

6

10

3

2

Unbleached CTMP

Low CSF

4

4

5

12

00

3

23

3

56

2

.2

2.0

1

1

2

10

0

38

1

27

9

7.3

8

.1

1

1

2

40

0

33

0

32

9

5.7

8

.5

7.4

0

.7

0.2

0

.5

0.2

7

2

20

2

4

1

1

2

12

00

2

87

3

82

5

.7

6.6

2

2

3

10

0

41

6

26

0

6.0

1

.9

2

2

3

40

0

34

3

32

6

2.7

2

.3

2.4

1

.3

0.3

1

.0

0.6

6

4

15

3

0

2

2

3

12

00

3

11

3

60

1

.7

2.5

4

4

5

10

0

42

8

26

1

5.5

0

.9

Bleached CTMP

Low CSF

4

4

5

40

0

34

8

32

1

4.1

1

.1

1.9

2

.6

0.5

2

.1

1.5

6

5

12

3

7

Appendix 1a. E

xper

imen

tal

pla

n a

nd r

esult

s fo

r: U

nble

ach

ed a

nd b

lea

ched

low

fre

enes

s C

TM

P.

- B -

AK

D

(acti

ve)

Ro

sin

(a

cti

ve)

Alu

m

(acti

ve)

Pre

ssu

re

ST

FI-

thic

kn

ess

ST

FI-

D

en

sit

y

Pre

ss-

Wic

k

0.1

5

bar

H2O

2-

Wic

k

LA

-W

ick

24 h

AK

D

(acti

ve)

tota

l

AK

D

(acti

ve)

bo

un

d

AK

D

(acti

ve)

no

n

bo

un

d

Ro

sin

(a

cti

ve)

AK

D

tota

l re

ten

tio

n

AK

D

bo

un

d

rete

nti

on

R

osin

re

ten

tio

n

kg/t

kg/t

kg/t

kP

a

[µm

] [k

g/m

3]

[kg/m

2]

[kg/m

2]

[kg/m

2]

kg/t

kg/t

kg/t

kg/t

[%]

[%]

[%]

1

1

2

100

481

233

5.1

6.2

0.7

0.2

0.4

0.4

68

23

41

1

1

2

400

397

277

5.1

7.3

6.3

0.7

0.2

0.4

0.2

68

24

21

1

1

2

1200

374

292

5.5

7.4

0.6

0.2

0.4

0.2

61

23

17

2

2

3

100

514

216

4.6

4.1

1.4

0.5

0.9

0.7

68

23

34

2

2

3

400

422

266

4.9

4.6

2.3

1.4

0.4

1.0

0.6

71

19

31

2

2

3

1200

365

313

3.2

4.4

1.3

0.3

1.0

0.6

67

15

32

4

4

5

100

556

203

5.0

2.4

2.6

0.6

2.0

1.0

64

14

24

4

4

5

400

389

285

3.5

2.7

2.1

2.5

0.5

1.9

1.4

62

13

34

Unbleached CTMP

Medium1 CSF

4

4

5

1200

342

333

1.9

2.5

2.9

0.8

2.1

1.3

71

19

33

1

1

2

400

402

278

7.1

8.5

0.8

0.2

0.6

0.4

78

20

37

2

2

3

400

430

265

7.1

6.1

1.5

0.3

1.2

0.8

76

15

40

Unbl.

CTMP

Med2

CSF

4

4

5

400

397

292

6.4

3.7

2.0

0.5

1.5

1.6

51

13

41

1

1

2

400

355

304

11.1

7.6

0.4

0.1

0.3

0.2

43

10

22

2

2

3

400

359

299

7.8

6.7

1.0

0.3

0.7

0.6

51

13

31

Bl.

CTMP

Med2'

CSF

4

4

5

400

374

294

5.8

1.8

2.3

0.5

1.8

1.7

58

12

44

1

1

2

100

554

198

7.1

5.6

1

1

2

400

418

259

8.0

7.1

6.5

0.9

0.2

0.7

0.1

86

21

15

1

1

2

1200

392

269

7.8

8.1

2

2

3

100

570

198

6.5

2.6

2

2

3

400

457

236

6.1

2.8

2.4

1.1

0.3

0.8

0.6

56

16

30

2

2

3

1200

422

274

5.5

2.9

4

4

5

100

527

203

7.0

1.0

4

4

5

400

438

247

7.4

1.2

1.9

1.7

0.5

1.2

1.3

42

12

32

Unbleached CTMP

High CSF

4

4

5

1200

372

283

6.2

1.5

Appendix 1b. E

xper

imen

tal

pla

n a

nd r

esult

s fo

r: U

nble

ach

ed m

ediu

m1 C

TM

P, unble

ach

ed/b

lea

ched

med

ium

2-2

’ C

TM

P a

nd u

nble

ach

ed h

igh

free

nes

s C

TM

P.

- C -

AK

D

(ac

tive

) R

os

in

(ac

tive

) A

lum

(a

cti

ve

) P

res

su

re

ST

FI-

thic

kn

es

s

ST

FI-

D

en

sit

y

Pre

ss

-W

ick

0

.15

ba

r H

2O

2-

Wic

k

LA

-Wic

k

24

h

AK

D

(ac

tive

) to

tal

AK

D

(ac

tive

) b

ou

nd

AK

D

(ac

tive

) u

nb

ou

nd

R

os

in

(ac

tive

)

AK

D

tota

l re

ten

tio

n

AK

D

bo

un

d

rete

nti

on

R

os

in

rete

nti

on

kg

/t

kg

/t

kg

/t

kP

a

[µm

] [k

g/m

3]

[kg

/m2]

[kg

/m2]

[kg

/m2]

kg

/t

kg

/t

kg

/t

kg

/t

[%]

[%]

[%]

1

1

2

10

0

45

3

23

3

7.4

6

.4

1

1

2

40

0

40

3

28

0

8.1

6

.4

9.2

0

.4

0.2

0

.3

0.2

4

4

17

2

0

1

1

2

12

00

3

49

3

12

7.4

2

2

3

10

0

44

8

23

7

7.4

2

.2

2

2

3

40

0

40

1

26

5

5.8

3

.2

2.4

0

.9

0.2

0

.7

0.6

4

7

11

3

0

2

2

3

12

00

3

69

3

07

9

.1

7.7

4

4

5

10

0

46

9

24

4

7.6

1

.0

4

4

5

40

0

38

2

29

4

7.1

1

.7

2.2

1

.6

0.5

1

.1

1.5

4

0

12

3

7

Bleached CTMP High CSF

4

4

5

12

00

3

66

3

09

5

.1

1.0

1

1

2

10

0

19

5

63

0

0.9

1

.2

0

.7

0.2

0

.5

0.3

7

2

20

2

9

1

1

2

40

0

15

5

72

9

0.6

1

.0

3.9

0

.7

0.1

0

.6

0.4

7

3

12

4

3

1

1

2

12

00

1

38

8

41

0

.4

0.8

0.7

0

.1

0.6

0

.3

71

9

3

3

2

2

3

10

0

19

3

61

1

0.8

0

.6

1

.2

0.2

1

.0

0.9

5

8

9

43

2

2

3

40

0

15

1

75

0

0.5

0

.6

2.8

1

.2

0.2

1

.0

0.8

5

8

8

40

2

2

3

12

00

1

39

8

12

0

.4

0.6

0.9

0

.1

0.8

0

.7

47

6

3

6

4

4

5

10

0

20

8

58

3

0.6

0

.5

2

.0

0.2

1

.7

1.6

4

9

5

41

4

4

5

40

0

15

9

74

4

0.4

0

.5

2.2

2

.1

0.2

1

.9

1.8

5

2

5

45

Unbleached softwood

kraft High SR

4

4

5

12

00

1

41

8

09

0

.5

0.4

1.8

0

.2

1.6

1

.6

45

5

4

0

1

1

2

10

0

24

4

45

0

3.7

2

.3

0

0

0

1

1

2

40

0

19

2

59

8

1.8

1

.5

5.0

0

.5

0.1

0

.4

0.3

5

4

12

2

5

1

1

2

12

00

1

54

7

27

0

.9

0.8

2

2

3

10

0

24

6

46

4

3.4

1

.2

0

0

0

2

2

3

40

0

19

1

60

3

1.2

0

.8

2.5

1

.0

0.2

0

.8

0.6

4

9

8

29

2

2

3

12

00

1

56

7

19

0

.9

0.6

0

0

0

4

4

5

10

0

25

8

45

3

3.7

0

.8

0

0

0

4

4

5

40

0

18

6

62

8

1.1

0

.7

1.9

1

.9

0.3

1

.7

1.7

4

8

6

44

Unbleached softwood

kraft Low SR

4

4

5

12

00

1

57

7

41

0

.2

0.5

0

0

0

Appendix 1c.

Exp

erim

enta

l pla

n a

nd r

esult

s fo

r: B

leach

ed h

igh f

reen

ess

CT

MP

, unble

ach

ed k

raft

pulp

s (l

ow

and h

igh S

R).

- D -

AK

D

(ac

tive

) R

os

in

(ac

tive

) A

lum

(a

cti

ve

) P

res

su

re

ST

FI-

thic

kn

es

s

ST

FI-

D

en

sit

y

Pre

ss

-W

ick

0

.15

ba

r H

2O

2-

Wic

k

LA

-Wic

k

24

h

AK

D

(ac

tive

) to

tal

AK

D

(ac

tive

) b

ou

nd

AK

D

(ac

tive

) u

nb

ou

nd

R

os

in

(ac

tive

)

AK

D

tota

l re

ten

tio

n

AK

D

bo

un

d

rete

nti

on

Ro

sin

re

ten

tio

n

kg

/t

kg

/t

kg

/t

kP

a

[µm

] [k

g/m

3]

[kg

/m2]

[kg

/m2]

[kg

/m2]

kg

/t

kg

/t

kg

/t

kg

/t

[%]

[%]

[%]

0

2

3

40

0

36

2

30

7

7.2

9

.7

17

.9

0.0

0

.0

0.0

0

.9

0

0

47

0

4

5

40

0

35

9

31

1

4.8

5

.6

16

.6

0.0

0

.0

0.0

2

.1

0

0

53

2

0

0

40

0

34

9

32

2

5.8

9

.5

3.9

2

.0

0.3

1

.7

0.0

1

00

1

3

0

Unbleached

CTMP Low

CSF

4

0

0

40

0

35

0

31

7

5.0

3

.9

1.2

2

.7

0.4

2

.3

0.0

6

7

9

0

Appendix 1d. E

xper

imen

tal

pla

n a

nd r

esult

s fo

r: U

nble

ach

ed l

ow

fre

enes

s C

TM

P.

- E -

Appendix 2: FiberMaster

Unbleached CTMP Unbleached

kraft pulp Bleached CTMP

Freeness low med1 med2 high low med2’ high

SR low high

Fibre length FiMa l/l [mm] 1.15 1.31 1.29 1.57 2.21 2.10 1.21 1.28 1.56

Sd 0.021 0.001 0.007 0.026 0.009 0.021 0.032 0.022 0.006

Fibre width FiMa w/l [µm] 29.70 30.65 30.10 32.55 28.45 28.10 29.75 29.95 32.25

Sd 0.280 0.210 0.140 0.310 0.070 0.010 0.260 0.210 0.070

Shape factor FiMa s/l [%] 90.2 90.2 90.2 90.4 87.9 86.9 90.1 90.2 90.1

Coarseness FiMa [µg/m] 340.8 349.0 347.9 374.3 185.0 181.0 346.1 348.1 370.1

Fibre length ISO FiMa l/l >0.20 mm [mm] 1.64 1.83 1.84 2.12 2.44 2.37 1.73 1.82 2.12

Sd 0.031 0.005 0.009 0.026 0.005 0.004 0.038 0.028 0.007

Fibre width ISO FiMa w/l >0.20 mm [µm] 36.1 36.9 36.4 38.3 29.7 29.7 36.0 36.1 38.1

Sd 0.35 0.21 0.21 0.10 0.00 0.14 0.32 0.21 0.14

Shape factor ISO FiMa s/l >0.20 mm [%] 90.1 90.2 90.0 90.4 87.5 86.3 90.0 90.0 90.1

Sd 0.01 0.08 0.08 0.26 0.21 0.00 0.08 0.08 0.06

Fibre length FiMa l/n [mm] 0.23 0.24 0.23 0.27 0.63 0.53 0.23 0.23 0.26

Sd 0.001 0.001 0.001 0.012 0.007 0.018 0.005 0.001 0.001

Appendix 2a. Results from Fibermaster.

Appendix 2b. Length distribution chart.

0

2

4

6

8

10

12

14

16

18

20

01 0

.0-0

.1 m

m02 0

.1-0

.2 m

m03 0

.2-0

.3 m

m04 0

.3-0

.4 m

m05 0

.4-0

.5 m

m06 0

.5-0

.6 m

m07 0

.6-0

.7 m

m08 0

.7-0

.8 m

m09 0

.8-0

.9 m

m10 0

.9-1

.0 m

m11 1

.0-1

.1 m

m12 1

.1-1

.2 m

m13 1

.2-1

.3 m

m14 1

.3-1

.4 m

m15 1

.4-1

.5 m

m16 1

.5-1

.6 m

m17 1

.6-1

.7 m

m18 1

.7-1

.8 m

m19 1

.8-1

.9 m

m20 1

.9-2

.0 m

m21 2

.0-2

.1 m

m22 2

.1-2

.2 m

m23 2

.2-2

.3 m

m24 2

.3-2

.4 m

m25 2

.4-2

.5 m

m26 2

.5-2

.6 m

m27 2

.6-2

.7 m

m28 2

.7-2

.8 m

m29 2

.8-2

.9 m

m30 2

.9-3

.0 m

m31 3

.0-3

.1 m

m32 3

.1-3

.2 m

m33 3

.2-3

.3 m

m34 3

.3-3

.4 m

m35 3

.4-3

.5 m

m36 3

.5-3

.6 m

m37 3

.6-3

.7 m

m38 3

.7-3

.8 m

m39 3

.8-3

.9 m

m40 3

.9-4

.0 m

m41 4

.0-4

.1 m

m42 4

.1-4

.2 m

m43 4

.2-4

.3 m

m44 4

.3-4

.4 m

m45 4

.4-4

.5 m

m46 4

.5-4

.6 m

m47 4

.6-4

.7 m

m48 4

.7-4

.8 m

m49 4

.8-4

.9 m

m50 4

.9-5

.0 m

m

1 - Unbl. CTMP, low CSF

8 - Bl. CTMP, low CSF



7 - Bl. CTMP, medium2' CSF

3 - Unbl. CTMP, high CSF

4 - Bl. CTMP, high CSF

5 - Unbl. Kraft pulp, low SR

6 - Unbl. Kraft pulp, high SR

Property 01 FiMa längdfördelningskurva l/l (%)

Value

Level

Order

Sample

- F -

Appendix 3: Charge analysis

Pulp

Total Charge

[mmol/kg]

Surface charge

[mekv/kg] Zeta-pot

[mV]

Cationic demand [µeq/L]

Conductivity [mS/m]

Unbl. CTMP low freeness 132 13 -55 -17 0.20

Bl. CTMP low freeness 164 15 -59 -23 0.18

Unbl. CTMP medium1 119 13 -28 -20 0.29

Unbl. CTMP medium2 122 12 -37 -25 0.21

Bl. CTMP medium2’ 158 15 -54 -33 0.20

Unbl. CTMP high freeness 109 9 -61 -16 0.16

Bl. CTMP high freeness 193 13 -69 -21 0.17

Unbl. Kraft pulp, low SR 100 8 -87 -54 0.24

Unbl. Kraft pulp, high SR 99 13 -43 -26 0.21

Appendix 3. Total charge, surface charge, zeta potential (concentration of 0.3%),

colloidal charge (water phase) and conductivity of the nine different

pulps before addition of chemicals.

- G -

Appendix 4: Retention

Appendix 4. The retention in [%] of total AKD, bound AKD and rosin size for

each pulp.

0

10

20

30

40

50

60

70

80

90

100

Rete

nti

on

[%

]

Total AKD retention Bound AKD retention Rosin retention

Unbl. CTMP

Low CSF

Unbl. Kraft

pulp,Low SR

Bl. CTMP

High CSF

Unbl. CTMP

High CSF

Unbl. CTMP

Medium1 CSF

Bl. CTMP

Low CSF

Unbl. Kraft

pulp,High SR

- H -

Appendix 5: Hydrogen peroxide edge wicking

Appendix 5a. H2O2 edge wicking versus the amount of total AKD in the dual sized

sheets. The dotted circle represents a size dosage of 1 kg/t, the dashed

circle shows the points with the dosage of 2 kg/t and solid circle is for

the 4 kg/t dosage. The pink and grey lines are representing the kraft

pulps.

Appendix 5b. H2O2 edge wicking versus the amount of bound AKD in the dual

sized sheets. The dotted circle represents a size dosage of 1 kg/t, the

dashed circle shows the points with the dosage of 2 kg/t and solid

circle is for the 4 kg/t dosage. The pink and grey lines are

representing the kraft pulps.

0

1

2

3

4

5

6

7

8

9

0,0 0,5 1,0 1,5 2,0 2,5 3,0


H2O

2 e

dg

e w

ickin

g [

kg

/m2]

Unbl. CTMP,low CSF

Bl. CTMP,low CSF




Unbl. CTMP,high CSF

Bl. CTMP,high CSF



1 kg/ton

2 kg/ton

4 kg/ton

0

1

2

3

4

5

6

7

8

9

0,0 0,1 0,2 0,3 0,4 0,5 0,6

Bound AKD in sheets [kg/ton]

H2O

2 E

dg

e w

ick

ing

[k

g/m

2]

Unbl. CTMP,low CSF

Bl. CTMP,low CSF




Unbl. CTMP,high CSF

Bl. CTMP,high CSF



1 kg/ton

2 kg/ton

4 kg/ton

- I -

0

1

2

3

4

5

6

7

8

9

0,0 0,5 1,0 1,5 2,0 2,5Rosin in sheets [kg/ton]

H2O

2 e

dg

e w

ick

ing

[kg

/m2]

Unbl. CTMP,lowvCSF

Bl. CTMP,low CSF



Bl. CTMP,medium2'CSF

Unbl. CTMP,high CSF

Bl. CTMP,high CSF


Unbl. kraft pulp,highSR

1 kg/ton

2 kg/ton

4 kg/ton

Appendix 5c. H2O2 edge wicking versus the rosin part of the dual sized sheets. The

dotted circle represents a size dosage of 1 kg/t, the dashed circle

shows the points with the dosage of 2 kg/t and solid circle is for the 4

kg/t dosage. The pink and grey lines are representing the kraft pulps.

- J -

Appendix 6: Pressurised edge wicking

Appendix 6a. Pressurised edge wicking versus the amount of total AKD in the dual





Appendix 6b. Pressurised edge wicking versus the amount of bound AKD in the dual





0

1

2

3

4

5

6

7

8

9

0,0 0,5 1,0 1,5 2,0 2,5


Pre

ss

uri

se

d e

dg

e w

ickin

g [

kg

/m2]

Unbl. CTMP 309 mlCSF

Bl. CTMP 326 ml CSF



Bl. CTMP 388 ml CSF


Bl. CTMP 557 ml CSF

Unbl. kraftpulp, SR=17


1 kg/ton

2 kg/ton

4 kg/ton

0

1

2

3

4

5

6

7

8

9

0,0 0,1 0,2 0,3 0,4 0,5 0,6


Pre

ssu

rised

Ed

ge w

ickin

g [

kg

/m2]


Bl. CTMP 326 ml CSF



Bl. CTMP 388 ml CSF


Bl. CTMP 557 ml CSF



1 kg/ton

2 kg/ton

4 kg/ton

- K -

Appendix 6c. Pressurised edge wicking versus the rosin part of the dual sized

sheets. The dotted circle represents a size dosage of 1 kg/t, the


circle is for the 4 kg/t dosage The pink and grey lines are


0

1

2

3

4

5

6

7

8

9

0,0 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6 1,8 2,0

Rosin in sheets [kg/ton]

Pre

ss

uri

se

d e

dg

e w

ick

ing

[k

g/m

2]


Bl. CTMP 326 ml CSF



Bl. CTMP 388 ml CSF


Bl. CTMP 557 ml CSF



1 kg/ton

2 kg/ton

4 kg/ton

- L -

Appendix 7: 24 h Lactic acid edge wicking

Appendix 7a. Lactic acid edge wicking as a function of bound AKD in sheets.

Appendix 7b. Lactic acid edge wicking as a function of non bound AKD in sheets.

1

2

3

4

5

6

7

8

9

10

0,0 0,1 0,2 0,3 0,4 0,5 0,6


24 h

Lacti

c a

cid

ed

ge

wic

kin

g [

kg

/m2]

Unbl. CTMP,low CSF

Bl. CTMP,low CSF


Unbl. CTMP,high CSF

Bl. CTMP,high CSF



1 kg/ton

2 kg/ton

4 kg/ton

0

1

2

3

4

5

6

7

8

9

10

0,0 0,5 1,0 1,5 2,0 2,5

Non bound AKD in sheets [kg/ton]

24

h l

ac

tic

ac

id e

dg

e w

ickin

g [

kg

/m2]

Unbl. CTMP,low CSF

Bl. CTMP,low CSF


Unbl. CTMP,high CSF

Bl. CTMP,high CSF



1 kg/ton

2 kg/ton

4 kg/ton

- M -

Appendix 8. Standard deviation

H2O2 edge wicking

Unbl. CTMP

Low CSF Bl. CTMP Low CSF

Unbl. CTMP Med1 CSF

Unbl. CTMP Med2 CSF

Bl. CTMP Med2’ CSF

Unbl. CTMP High CSF

Bl. CTMP High CSF

Unbl. Kraftpulp Low SR

Unbl. Kraftpulp HighSR

MV S MV S MV S MV S MV S MV S MV S MV S MV S

1 5.4 0.2 8.1 0.2 6.7 0.6 5.6 0.1 6.4 0.4 2.3 0.1 1.2 0.3

2 6.4 0.8 8.5 0.4 8.0 0.6 8.5 0.5 7.6 0.1 7.1 0.1 6.4 0.5 1.5 0.1 1.0 0.01

3 9.1 1.6 6.6 0.1 7.8 0.4 8.1 0.5 7.4 1.2 0.8 0.1 0.8 0.01

4 2.5 0.2 1.9 0.1 4.5 0.01 2.6 0.04 2.2 0.4 1.2 0.1 0.6 0.04

5 2.8 0.3 2.3 0.03 5.2 0.2 6.1 0.2 6.7 0.4 2.8 0.04 3.2 0.5 0.8 0.05 0.6 0.06

6 3.4 0.1 2.5 0.09 4.8 0.1 2.9 0.1 7.7 1.0 0.6 0.03 0.6 0.03

7 1.3 0.2 0.9 0.01 2.4 0.4 1.0 0.03 1.0 0.1 0.8 0.2 0.5 0.02

8 1.9 0.4 1.1 0.1 3.0 0.5 3.7 0.8 1.8 0.2 1.2 0.1 1.7 0.1 0.7 0.1 0.5 0.03

9 2.0 0.1 1.2 0.1 2.8 0.2 1.5 0.02 1.0 0.04 0.5 0.04 0.4 0.01

Appendix 8a. Mean value (MV) and standard deviation (S) designating H2O2 edge

wicking. The yellow marked values symbolise the test results

removed due to large standard deviation.

Pressurised edge wicking

Unbl. CTMP

Low CSF

Bl. CTMP Low CSF

Unbl. CTMP Med1 CSF

Unbl. CTMP Med2 CSF

Bl. CTMP Med2’CSF

Unbl. CTMP High CSF

Bl. CTMP High CSF

Unbl. Kraftpulp Low SR

Unbl. Kraftpulp High SR

MV S MV S MV S MV S MV S MV S MV S MV S MV S

1 5.6 0.7 7.3 1.2 5.4 0.05 7.1 0.3 7.4 0.6 3.7 0.01 0.9 0.04

2 7.2 0.1 5.7 0.3 5.6 0.3 7.1 0.4 11.1 0.2 8.0 0.3 8.1 0.6 1.8 0.30 0.6 0.03

3 6.6 0.2 5.7 0.2 5.9 0.1 7.8 0.8 0.9 0.05 0.4 0.01

4 5.6 0.5 6.0 0.3 4.8 0.2 6.5 2.4 7.4 0.5 3.4 0.25 0.8 0.04

5 5.6 0.01 2.7 0.1 5.3 1.0 7.1 0.1 7.8 1.1 6.1 0.5 5.8 1.3 1.2 0.08 0.5 0.08

6 2.7 0.6 1.7 0.3 3.5 0.2 5.5 0.7 9.1 0.2 0.9 0.04 0.4 0.09

7 5.2 0.4 5.5 0.1 4.7 0.2 7.0 0.4 7.6 0.1 3.7 0.33 0.6 0.02

8 4.6 0.1 4.1 0.5 3.7 0.01 6.4 0.1 5.8 0.6 7.4 0.2 7.1 0.2 1.1 0.02 0.4 0.04

9 2.2 0.4 1.8 0.1 2.2 0.3 6.2 0.4 5.1 0.02 0.2 0.11 0.5 0.01

Appendix 8b. Mean value (MV) and standard deviation (S) designating pressurised

edge wicking. The yellow marked values symbolise the test results

removed due to large standard deviation.

- N -

Appendix 9: Unbleached vs bleached CTMP

Appendix 9a. Hydrogen peroxide edge wicking as a function of STFI-density for

unbleached/bleached CTMP with a size dosage of 2 and 4 kg/t AKD

+ rosin size.

Appendix 9b. Pressurised edge wicking as function of STFI-density for

unbleached/bleached CTMP with a size dosage of 2 and 4 kg/t AKD

+ rosin size.

0

1

2

3

4

5

6

7

170 220 270 320 370 420


H2O

2 E

dg

e W

ick

ing

[k

g/m

2]

Unbl. CTMP, low CSF

Bl. CTMP, low CSF




Bl. CTMP, high CSF

2 kg/ton

4 kg/ton

1

2

3

4

5

6

7

8

9

10

170 220 270 320 370 420


Pre

ss

uri

se

d e

dg

e w

ick

ing

[kg

/m2]

Unbl. CTMP, low CSF

Bl. CTMP, low CSF




Bl. CTMP, high CSF

2 kg/ton

4 kg/ton

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