u www.tugraz.at

Determination of Latex and Starch

Penetration via Serial Sectioning in

Combination with Fluorescence

Microscopy

Karin Hofer1, Bernhard Seidl2, Martin Kozich2, Wolfgang Bauer1

17.11.2015

EFPRO European Paper Week 2015

1

1 Institute of Paper, Pulp and Fiber Technology, Graz University of Technology, AUSTRIA

2 Agrana Research and Innovation Center, Tulln, AUSTRIA

Presentation Overview

Binder Penetration/Migration

Establishment of a New Method to Analyze Binder

Penetration

Serial Sectioning in combination with Fluorescence Microscopy

(SSFM)

Results

The Influence of Base Paper Properties on Latex Penetration

The Influence of Solids Content on Starch Penetration

Double-staining to localize Starch and Latex

Evaluation of SSFM via CLSM

Conclusion and Outlook

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Binder Penetration/Migration

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EFPRO European Paper Week 2015

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Binder migration

Binder follows the evaporated

water phase to the surface

Binder penetration

Binder follows the water into the

paper substrate

Binder

2

1

Whalen-Shaw, 1993

Localization of Binder

after the Coating Process

Establishment of a New Method to analyze

Binder Penetration

Starch

Reactive staining with 5-([4,6-Dichlorotriazin-2-

yl]amino)fluorescein

Latex

Staining by adsorption into the latex particle

with Rhodamine B

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Staining the

binder

Coating

Embedding

Image

Processing

3D Data

Calculations

Serial

Sectioning

Staining the

binder

Fluorescein

Dichlorotriazin

Reactive group Covalent bond

8mm

25mm

Establishment of a New Method to analyze

Binder Penetration

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EFPRO European Paper Week 2015

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Staining the

binder

Coating

Embedding

Serial

Sectioning

Image

Processing

3D Data

Calculations

Paper sample Microscope view

Cutting process

Filter cubes

Lenses

10/20/50x

Diamond knife Microscope unit Microtome unit

Rotary microtome

Sample holder

Serial

Sectioning

Establishment of a New Method to analyze

Binder Penetration

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Staining the

binder

Coating

Embedding

Image

Processing

3D Data

Calculations

Serial

Sectioning

Output SSFM VIS

UV

Coating layer

thickness

Fluorescent layer

thickness

Binder

Penetration Depth

Establishment of a New Method to analyze

Binder Penetration

17.11.2015

EFPRO European Paper Week 2015

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Staining the

binder

Coating

Embedding

Serial

Sectioning

Image

Processing

3D Data

Calculations

Serial

Sectioning

Segmentation

3D data evaluation

Image

Processing

3D Data

Calculations

CD

ZD

MD

12µm

5,4mm

100 cuts

in MD

u www.tugraz.at

RESULTS

8

The Influence of Base Paper Properties on

Latex Penetration

Recipe [%] I II III

CaCO3 100 100 100

Latex stained 8 16 6

Starch 4

NaOH set pH to 8,5 set pH to 8,5 set pH to 8,5

Target solids

content

65 65 65

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Base paper type Pulp Refining Additive

A Eucalyptus bleached 2000 PFI -

B Eucalyptus bleached 6000 PFI -

C Eucalyptus bleached 2000 PFI 20% filler (CaCO3) + Retention agent

(Percol 8383)

D Eucalyptus bleached 2000 PFI Pre-Calendering – once each side per

sheet (2000daN, room temperature)

Coating Formulation

Base Paper Type

The Influence of Base Paper Properties on

Latex Penetration

17.11.2015

EFPRO European Paper Week 2015

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0,0

5,0

10,0

15,0

20,0

25,0

30,0

35,0

40,0

0,0 5,0 10,0 15,0 20,0

Pe

ne

tra

tio

n d

ep

th [

µm

]

Coat weight [g/m²]

Base Paper A Base Paper B Base Paper C Base Paper D0

5

10

15

20

25

30

35

0,010,1110

incre

me

nta

l s

pe

cif

ic in

tru

sio

n [

µl/

g]

pore diameter [µm] 2000rpm PFI 6000rpm PFI 2000rpm PFI

+ filler 2000rpm PFI

calendered

Results of SSFM

Mercury Porosimetry base paper

The Influence of Solids Content on Starch

Penetration

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EFPRO European Paper Week 2015

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Recipe [%] ST 70 ST 60

CaCO3 100 100

Latex 6 6

Starch 4 4

Thickener 0,1 0,1

NaOH set pH to 8,5 set pH to 8,5

Target solids content 70 60

Coating Formulation

0

200

400

600

800

1000

1200

1400

1600

1800

0 5 10 15 20 25 30 35

low

sh

ear

vis

co

sit

y B

F100 [

mP

as]

Penetration depth [µm]

Blade Sumet

ST 70

ST 60

ST 60

Depletion

of starch

at the

coating

surface

Double staining to localize Latex and Starch

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Latex Latex + Starch Starch

Evaluation of SSFM via CLSM

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R² = 0,8755

0

5

10

15

20

25

30

35

40

45

50

0 5 10 15 20 25 30 35 40 45

CL

SM

P

en

etr

ati

on

de

pth

[µ

m]

SSFM Penetration depth [µm]

Conclusion and Outlook

SSFM is an appropriate method to localize the binder after

the coating process

3D-data evaluation can be performed and a mean

penetration depth into the base paper can be calculated

Staining procedure for starch and latex (most common

coating binders) was developed

Good correlation with CLSM

Further influences on binder penetration can be tested

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EFPRO European Paper Week 2015

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EFPRO European Paper Week 2015

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Thank you for your attention!

Contact:

Karin Hofer

University assistant

Institute of Paper Pulp and Fibre Technology

Graz University of Technology

Inffeldgasse 23

8010 Graz/ Austria

Tel: +43 316 873 30756

Mail: karin.hofer@tugraz.at

Web: www.ipz.tugraz.at

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