Embed Size (px)
Citation preview
Composite Paper Structures
Program Objective:• Increase the value of pulp products by 50%
by identifying new composite paper product platforms that will dramatically improve existing sheet properties and develop new applications for pulp fibers.– Develop non-brittle synthetic fibrous fillers with the
ability to bond with fibers and fillers.– Applications include printing, packaging, food, and
sanitary products.
Composite Paper StructuresProgram Value:
Projected filler loading targets a 100% increase in current filler loading-levels, i.e., >35% for wood-free copy paper, >15% for newsprint, > 55% for SC, > 15% tissue and >15% for container board.
Proposed new fibril bonding fillers will cost ≤ $150/ton.
• Filler increase of 15% will save ≈ $25/ton fiber
• Reduced papermaking chemicals will save ≈ $10/ton
• Projected number average saving of ≈ $35/ton
Composite Paper StructuresComposite Paper StructuresMajor Research Deliverables:
A cost-performance analysis of new chemo-technologies for developing bonding fillers:
• Polymeric surface coated fillers (PCC >> clay)
• Preparation of new fillers using materials to control the growth and surface properties of manufactured fillers (i.e., PCC)
• Cationic, anionic, amphoteric polymers
• Charge neutral hydrogen bonding polymers
• MW & linear/cross-linked nature of polymer
Composite Paper Structures:
Approach 1. Surface Coated Fibrous Fillers
This study will be directed at developing economical polymeric coating (cationic, anionic, amphoteric, hydrogen bonding-charge neutral) technologies for PCC fillers that yield surface coated fillers having lignocellulosic fiber/filler bonding capabilities.
Approach 2. Novel Inorganic Fibril Bonding Fillers
Synthesizing new inorganic fillers in the presence of water-miscible polymers to control filler bonding capacity, structure, and particle geometry (i.e., aspect ratio). By this method, it is expected that polymeric additive molecules can be fixed into filler particles (i.e., PCC, silicate). The proposed polymer additives will have functional groups that will bond with wood fibers, thereby increasing the amount of filler that can be incorporated into the sheet structure.
Composite Paper Structures:
Experimental Considerations:
• Employ SW ECF kraft and TMP furnishes• Using IPST MBDT (Moving Belt Drainage Tester) and
Formette for handsheet making• Increased filler content handsheets to be tested for:
– Mechanical properties– Optical properties– Linting and dusting– Printing
Progress and AccomplishmentPolymer coated-filler
High aspect ratio filler
Different methods for making polymer-coated PCC
Crosslinking chemistry of starch in the presence of high filler content
Handsheet properties with treated PCC
High aspect ratio filler synthesis and characterization
Retention and its effect on paper properties
Progress and Accomplishment
Reference ECF Bleached 1:1 SW/HW Furnished Acquired
- Commercial Source
FQA Analysis
Length Weight Curl Curl Kink
Weight. Weight. Arithmetic Length Weigh. Index
1.363 2.353 0.10 0.11 1.64
Problem Analysis
Molecular level thickness
Traditional papermaking:cooked starch + filler + fiber
Retention aid + Fiber + Filler
Filler flocculation
Fiber flocculation
Does not contribute to strength development
significantly
Poor formation and reduced strength
Filler Treatment Using Starch
Filler
Starch adsorbed on filler
Filler
Starch coated on filler
StarchIn traditional papermaking Our approach
Approach Using Starch Coating
Filler aggregates with suitable sizes
Decrease contact area between fiber and filler
Increase mechanical retention
Filler aggregatesfully coated by starch Improve bonding
Soft contact and plastic deformation
Increase contact area
High turbulence Surface coatedenough starch
Starch forms a strong matrix
The matrix is deformable
The aggregate size is ~ 20-40 nm
Starch-coated PCC
Starch coated PCC
Fiber
Plastic deformation under pressure
Improve bonding and increase bonding area
Starch Cooked at Different Conditions
1 gm starch cooked in 10 ml water, then immersed in 90 ml water
1 gm starch cooked in 100 ml water
Cooking with small amount of water
Filler + Starch
Dispersing in adiluted pulp slurry
Starch swells, but still strongly crossliked.
Starch does not dissolve in water, and most fillers form aggregates with swollen gel.
PCC + raw starch
Cooking with medium amount of water
Filler + Starch
Dispersing in adiluted pulp slurry
Starch swells to form a partially crosslinkedsoft gel. The starch gel covers the fillers.
Starch does not dissolve in water, and the fillers are still covered by swollen gel.
PCC + raw starch
Cooking with a large amount of water
Filler + Starch
Dispersing in adiluted pulp slurry
Starch is fully swelled.
Starch will be washed out from PCC filler, and only small amount of starch remains on fillers surface
PCC + raw starch
Cooking with a large amount of water, then crosslinked
Filler + Starch
Dispersing in adiluted pulp slurry
Starch is fully swelled, but crosslinked by crosslinker.
Filler and starch still strongly bond together.
PCC + raw starch
water
PCC + raw starch + water
Squeezed to starch:PCC:waterabout 1:10:10
Typical Cooking Process Used in This Study
Cooked at 90 oC
Break into small andstrong aggregates
20-40 µm; coated by starch. The coated starch is water-insoluble.
Different Methods for PCC Treatment Using Starch
• Starch-PCC blend: PCC was milled with cooked starch at high solid content (paste-like)
• Starch-coated PCC: PCC and raw starch were cooked together at high solid content (paste-like)
• (Starch-PCC blend)-coated: PCC was first milled with cooked starch, then was cooked at high solid content (paste-like) with addition of raw starch
PCC and raw starch were cooked together in limited amount of water, then dispersed in a large amount of water.
Characterization of Starch-Coated PCC
PCC was mixed with cookedstarch, then dispersed in a large amount of water.
Optical Microscope Image
Characterization of Starch-Coated PCC
Using Electronic Microscope (TEM and SEM) was unsuccessful because techniques require dry samples.
Optical Microscope Image
Characterization of Starch-Coated PCC
Blended using a food process blender at “Hi-beat” setting with 3.6% starch-coated PCC
Ratio ofstarch: PCC : waterin cooking
Stirring time(min)
Average particlesize (µm)
1:10:11 8 3.971:10:9 55 7.81:10:6.2 91 8.2
Dissolution of Coated Starch in Water
0
10
20
30
40
0 20 40 60 80 100 120
Blending time (min)
Diss
olve
d st
arch
(wt%
)
00.20.40.60.811.21.41.61.82
Diss
olve
d st
arch
co
ncen
trat
ion
(g/L
)
Starch dissolved wt% Concentration
32.7 g starch-coated PCC in 898.1 g water wasblended at a speed of "Hi-beat" in blender.The starch that dissolved in water was measured.
Evaluation of HandsheetEvaluation of HandsheetFiller suspensionFiller suspension
Measure particle size then add to pulpMeasure particle size then add to pulp
0.4 wt% pulp suspension with filler0.4 wt% pulp suspension with fillerAdd 2ppm retention, Add 2ppm retention, stir 20s at 1000 rpmstir 20s at 1000 rpm
HandsheetHandsheetMBDTMBDTPressure at 50 psi for 5 minPressure at 50 psi for 5 min
Dry at ca. 105 Dry at ca. 105 ooC for 30 minC for 30 minCondition room overnightCondition room overnight
Physical property Physical property measurement measurement
Laser Laser scatteringscatteringMalvern Malvern 26002600
50% hardwood + 50% softwood; Target basis weight: 80g/m2
Effect of Filler Content on Tensile Strength(Based on basis weight)
14
16
18
20
22
24
9 11 13 15 17 19 21
PCC content (WT%)
Tens
ile (N
m/g
)
PCC coated by starch PCC + cooked starchPCC blended by starch PCC blended and coated by starchPCC blended and coated by milled starch
PCC: Starch =86.6:13.4; Pulp: 0.4 wt% ; Percol 175: 2 ppm
Effect of Filler Content on Tensile Strength(based on fiber weight)
15
19
23
27
9 11 13 15 17 19
PCC content (WT%)
Tens
ile (N
m/g
)
PCC coated by starch PCC + cooked starchPCC blended by starch PCC blended and coated by starchPCC blended and coated by milled starch
Effect of Filler on Tensile Strength at High PCC Content
(Based on basis weight)
5
10
15
20
17 22 27 32 37 42 47 52
PCC content (wt%)
Tens
ilte
(Nm
/g)
PCC coated by starch PCC + Cooked starchPCC blended and coated by starch PCC blended and coated by milled starch
Effect of Filler on Tensile Strength at High PCC Content(based on fiber weight)
10
15
20
25
30
17 22 27 32 37 42 47 52
PCC content (wt%)
Tens
ilt (N
m/g
)
PCC coated by starch PCC + Cooked starchPCC blended and coated by starch PCC blended and coated by milled starch
Effect of Filler Content on Folding (based on basis weight)
0
2
4
6
8
10
9 11 13 15 17 19
PCC content (wt%)
Fold
ing
(Num
ber/b
ase
fiber
wei
ght)
PCC + cooked starch PCC coated by starchPCC blended and coated by starch PCC blended and coated by milled starchPCC blended by starch
Effect of Filler on Folding at Low PCC Content
(based on fiber weight)
0
1
2
3
4
5
6
7
8
9 11 13 15 17 19
PCC content (wt%)
Fold
ing
(Num
ber/b
ase
wei
ght)
PCC + cooked starch PCC coated by starchPCC blended and coated by starch PCC blended and coated by milled starchPCC blended by starch
Effect of Filler on Folding at High PCC Content
(based on basis weight)
0
1
2
3
4
17 22 27 32 37 42 47 52
PCC content (wt%)
Folding (Number/...
PCC + cooked starch PCC coated by starchPCC blended and coated by starch PCC blended and coated by milled starch
Effect of Filler on Folding at High PCC Content
(based on fiber weight)
0
1
2
3
4
15 20 25 30 35 40 45 50
PCC content (wt%)PCC + cooked starch PCC coated by starchPCC blended and coated by satrch PCC blended and coated by milled starch
Effect of Filler Content on ZDT (based on fiber weight)
180
220
260
300
340
9 11 13 15 17 19
PCC content （wt%）
ZDT
(kPa
)
PCC + cooked starch PCC coated by starch
PCC blended and coated by starch PCC blended and coated by milled starch
Effect of Filler on ZDT at High PCC Content
(based on basis weight)
100
150
200
250
300
350
17 22 27 32 37 42 47 52
PCC content (w t%)
ZDT
(kPa
)
PCC coated by strach PCC blended and coated by starchPCC blended and coated by milled starch PCC + cooked starch
Summary• Starch can coat to filler surface by cooking them
together at high concentration conditions• Starch : water ratio is very important for
controlling the starch coating layer strength and coating efficiency
• Starch-coated filler showed positive trend for paper strength improvement
• Adding small amount of cooked starch in PCC-raw starch cooking process can further improve paper physical properties
Other Coating Approaches That Have Been Tested
• The ratio of starch : filler : water has been explored.
• Using crosslinker to further increase coating layer strength were explored. More study need to be done
• Chemistry of synthesizing high aspect ratio PCC was studied
• Similar results were obtained using gum and chitin to substitute starch
Other Coating Approaches That Are Currently Being Evaluated
• Nano-silica gel coating approach has been considered.
• Copolymers of styrene and maleic acid salt with different change densities were used to coat filler surface. The work is ongoing in our lab
High aspect ratio PCC
Improve mechanical retention
Change the filler distribution in paper sheet so the physical properties
Improving Filler Retention Using High Aspect Ratio PCC
• PCC with different aspect ratios (~5, 10, 20) and length (3-130 µm) were synthesized. Chrysanthemum-like PCC was also synthesized
• The PCC with an aspect ratio of 10 and a average length of 14 µm was used in this study
Effect of PCC Shape on Retention (without retention aid)
0
10
20
30
40
50
60
70
80
0 5 10 15 20 25 30 35
PCC addition level, %
PCC
rete
ntio
n, %
Albacar HO
Needle PCC
PCC retention: Total filler in the handsheets (MBDT was used for handsheet making)
Effect of PCC Shape on Formation (without retention aid)
3
3.5
4
4.5
5
5 8 11 14 17 20
PCC percentage in paper, %
Form
atio
n In
dex,
%
Albacar HONeedle PCC
Retention of Albacar HO® and Needle PCC in Responding to CPAM Single Retention System
0
10
20
30
40
50
60
70
80
90
100
0 0.02 0.04 0.06 0.08 0.1 0.12
CPAM used, %
PCC
rete
ntio
n, %
Niddle PCC
Albacar HO
Retention of Albacar HO® and Needle PCC in Responding to CPAM Microparticle Retention System
0
10
20
30
40
50
60
70
80
90
100
0 0.02 0.04 0.06 0.08 0.1 0.12
CPAM used, %
PCC
rete
ntio
n, %
Needle PCC
Albacar HO
Effect of PCC Shape on Opacity
Effect of PCC shape on folding endurance
0
5
10
15
20
25
0 5 10 15 20
PCC in paper
Dou
ble
fold
s, ti
mes
Normal PCCNeedle PCCLow aspect ratio niddle
Effect of PCC Shape on Density
0.315
0.32
0.325
0.33
0.335
0.34
0.345
0.35
0.355
0.36
0 5 10 15 20
PCC in paper, %
Den
sity
, g/c
m3
Albacar HONeedle PCC
Effect of PCC Shape on Tensile Strength
0
5
10
15
20
25
0 5 10 15 20
PCC in paper, %
Tens
ile in
dex,
Nm
/g
Albacar HO
Needle PCC
Effect of PCC Shape on Folding Endurance
0
2
4
6
8
10
12
14
16
18
20
0 5 10 15 20PCC in paper
Dou
ble
fold
s, ti
mes
Albacar HO
Needle PCC
Summary of High Aspect Ratio Approach
• PCC with different aspect ratios and sizes can be synthesized
• Mechanical retention of high aspect ratio PCC with a length of ~15 µm is higher than commercial PCC with a size of 1-3 µm
