Transcript Paper strength increase by using polyelectrolytes as

Paper Strength Increase by Using Polyelectrolytes as
Promising Alternative to Fibre Beating
Stephan Daus (PTS)
Trabzon, Octobre 8th 2013
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Paper Strength
Fibre Modification Concepts
• Fibre beating common method to increase paper strength
 Increased density after beating – Loss of Bending Stiffness
 High Energy Consumption
 Alternative Methods Desired
Polyelectrolyte Modification (PEM):
Pulp
Cation.
Polyelectrolyt
Pulp
Pulp 1st layer
Filtrate 1
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Anion.
Polyelectrolyt
Pulp 2nd layer
Filtrate 2
3
Fibre Modification Concepts
Pump
Pump
Modification with Polyelectrolyt
Complexes
cationic
PE
anionic PE
PEC
pulp
4
5
6
7
3
2
1
11
4
8
3
9
2
5
6
7
8
9
1
10
Sheet
formation
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Uptake of Polyelectrolytes and Polyelectrolyte Complexes
PEM 1
PEM 2
PEM 3
PEC 1
PEC 2
PEC 3
Cat. / anionic
Starch
PAH /
PAA
PAAE/
CMC
Kat. / anionic
Starch
PAH /
PAA
PAAE /
CMC
[mg/g]
[mg/g]
[mg/g]
[mg/g]
[mg/g]
[mg/g]
BEKP
14.6 / 27.6
35 / 35
15 / 15
21
18
18
NBSK
9.7 / 18.4
30 / 30
10 / 5.1
21
18
18
1.5 %
10 %
1.5 %
Stock
10 %
Consistency
1.5 %
1.5 %
PEM 1 / PEC 1 – cationic and anionic starch
PEM 2 / PEC 2 – polyallylamin hydrochloride and polyacrylic acid
PEM 3 / PEC 3 – polyamidoamine-epichlorhydrin resin and carboxymethyl cellulose
• Uptake up to 2 % per g pulp
• Uptake of polyelectrolytes depends on fibre charge
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Increase of the Tensile Index after Polyelectrolyte Modification
BEKP
NBSK
Mass PEC/pulp [mg/g]
0
20
40
60
80
80
Mass PEC/pulp [mg/g]
100
80
40
20
0
60
80
80
refined pulp
100
80
refined pulp
PEM3
60
PEC3
PEM1
40
40
20
20
0
60
60
PEM1
PEC3
PEC1
40
40
20
20
0
0
20
40
60
80
100 120 140 160
Refining energie [kWh/t]
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0
0
0
20
40
60
80 100 120 140 160 180
Refining energie [kWh/t]
Tensile index [Nm/g]
PEC1
Tensile index [Nm/g]
PEM3
Tensile index [Nm/g]
Tensile index [Nm/g]
60
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Strength vs. Fibre Density
Tensile-Index
[Nm/g]
Index[Nm/g]
Tensile
70
60
LF_180 kWh/t
PEMBeschichtung
LF_150 kWh/t
50
KF_150 kWh/t
40
KF_100 kWh/t
Mahlung KF
KF_PEM1
KF_PEM2
KF_PEM3
Mahlung LF
LF_PEM1
LF_PEM2
LF_PEM3
KF02
30
LF0
20
10
0
0,50
0,55
0,60
0,65
Rohdichte[g/cm³]
[g/cm ]
Density
3
• reduced density after polyelectrolyte modification
• increased paper strength
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0,70
7
Cat. Starch [mg/g pulp]
Increase of Polyelectrolyte Uptake
20
18
16
14
12
10
8
6
4
2
0
Polyelectrolyte Uptake:
• is charge dependant
• can be increased CMC grafting
y = 0.4307x + 1.3916
R2 = 0.9944 Pulp
Pulp treatment
Surface Charge
[µeq/g]
0
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10
20
30
40
Surface Charge [µeq/g]
BSKP
PE-Modification (mg/g)
1 (CS)
2 (AS)
3 (CS)
50
No
19.6
9.4
8.8
9.6
BSKP
Unbeaten
Fine reduced
13.4
6.0
7.0
6.7
BSKP
CMC-treated
62.2
29
24
29
BHKP
No
32.1
14
11
14.5
BHKP
Unbeaten
Fine reduced
22.7
10.5
9.5
11
BHKP
CMC-treated
64.3
29
17
29
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Increase of the Storage Modulus
after Polyelectrolyt Modification
BSKP - unbeaten + CMC + PEM
BSKP + 100 kWh/t + PEM
BSKP - 100 kWh/t
BSKP - unbeaten + CMC + PEM + NFC
BSKP - 50 kWh/t
BSKP - unbeaten + PEM
BSKP - unbeaten
Beating
Polyelectrolytes
PEM + Beating
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0.0
1.0
2.0
3.0
4.0
Storage Modulus E' (GPa)
5.0
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Thank you for Listening.
Contact information:
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•
Dr. Stephan Daus, [email protected]
•
Dr. Nikita Polikarpov, [email protected]