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© 2013 Published by Center for Pulp and Paper through REPTech2012
The Effect of Laboratory Precipitated Calcium Carbonate PCC by Sucrose Solution Method on the Paper Properties
Rohaya Othman
1
, Abdul Rahman Abdul Aziz, Nasharuddin Isa
Mineral Research Centre, Minerals and Geoscience Department Malaysia Jalan Sultan Azlan Shah, 31400 Ipoh, Perak, Malaysia Tel. : +605 5477053; Fax: +605 5477185
1
rohayajmg.gov.my
ABSTRACT
Precipitated calcium carbonate PCC is used in papermaking as an alternative iller material to reduce production cost or to get speciic paper properties. There are three methods used in producing PCC namely,
Caustic Soda, Solvay and Re-carbonation. In this study, PCC is produced by a modiied Re-carbonation method in which
sucrose solution is used instead of slurry solution at the re-carbonation stage. The objective of this
work is to determine the effectiveness of the retention of the PCC after deposition on the pulp ibres and on the
paper properties. A commercial mixed tropical hardwood bleached pulp was subjected to different degree of PCC retention using two types of retention aids polyacrylamide, PAM and polyethyleneimine, PEI. The results were
compared to those similarly obtained by using a commercially available PCC. It was found that the PCC retention in paper is affected by the type of PCC and retention aids used. Commercial PCC when
used with PEI resulted in better retention ability. The mechanical properties of the paper which are tear, tensile, burst and folding endurance
of the sample using laboratory PCC were greater than the sample that used commercial PCC. However, generally, tensile and tear indices decreased as the degree of loading and opacity increased. The loading
degree of PCC did not affect the opacity. The micrographs showed the variable PCC distribution throughout the ibre sheet following
these treatments. The results show that the laboratory PCC produced by sucrose solution method is comparable to
commercial PCC in achieving the required paper properties. Keywords: PCC – precipitated calcium carbonate, sucrose solution, mix tropical hardwood bleached pulp, PAM-
polyacrylamide, PEI- polyethyleneimine
1. Introduction
The presence of illers in papermaking industries had been introduced to reduce the production cost
and to improve the brightness, opacity, smoothness and printability of paper [1-3]. Precipitated calcium
carbonate PCC is a type of mineral illers used besides clay, silica and talc. The deposition of the
iller particles on the ibre surface is a function of attractive and repulsive electrostatic forces, as well as
van der Waals forces. The surface charge is important for the electrostatic forces and it can be altered to
increase the interaction. The polymeric retention aid is widely used in papermaking to form bridges between
ibre and illers which are strong enough to resist the turbulences during the papermaking process [4].
Polyacrylamide PAM and polyethylenimine PEI are type of cationic polyelectrolytes which
have been used to improve retention of ibres and illers [5-8]. Cationic PAM had been used by Cho
et al. [9] and Vanerek et al. [10] to induce calcium carbonate particles to be deposited onto ibre surfaces.
Meanwhile few researchers had used PEI in their research as retention aid [11-13]. At high polymer
dosages, PEI creates very large aggregates [3] and produce uneven paper structure [14].
Sucrose solution method is one of the techniques used to produce PCC which was developed by Rahman
and Nasharuddin [15]. In this method, Rahman and Nasharuddin had used sugar sucrose as promoter to
prepare the sucrose ionic solution and further produce the PCC by carbonation process. This method is
able to produce PCC in higher amounts compared to conventional method. The PCC produced by using this
method is negatively charged PCC.
In this study, two types of PCC are used to produce the paper sheets., i.e. PCC which is produced by
Sucrose Solution method and commercial PCC. The mechanical and physical properties of the handsheet
produced are compared. Cationic polyelectrolytes, PAM and PEI have been used to increase the retention
ability of the PCC to be deposited and attached to the
ibre during sheet consolidation.
2. Experimental Procedure
Two types of PCC used in the study were i laboratory prepared PCC by using sucrose solution
method and ii PCC supplied by a local factory. The shape of laboratory PCC was perforated cubical and
shape of commercial PCC was cubical. Bleached mixed tropical hardwood pulp from Sabah Forest
Industries SFI, Malaysia was used in this study.
The pulp ibres used were in the wet condition. Polyacrylamide PAM and poethyleimine PEI were
purchased from Aldrich Chemicals with molecular weight of 10 000. The PCC suspension was prepared
by dispersing 30g of PCC in 300 ml tap water. The
ISBN : 978-602-17761-0-0
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© 2013 Published by Center for Pulp and Paper through REPTech2012
PAM solution was prepared by dispersing 3 ww of PAM in 100 ml tap water on an oven dried pulp. The
same method is practiced to prepare the PEI solution. Meanwhile 24g of pulp was dispersed in 1600 ml of
tap water and disintegrated for 5 minutes to ensure
that all the ibres were well dispersed. The handsheet samples had been prepared in 7 conditions:
1. Handsheet using 100 pulp 2. Handsheet with mixture of pulp and laboratory
PCC 3. Handsheet with mixture of pulp and commercial
PCC 4. Handsheet with mixture of pulp, laboratory PCC
and PAM 5. Handsheet with mixture of pulp, commercial PCC
and PAM 6. Handsheet with mixture of pulp, laboratory PCC
and PEI 7. Handsheet with mixture of pulp, commercial PCC
and PEI Pulp suspensions were disintegrated in
disintegrator until complete 2000 rev which was about 20 minutes. This stage is also called as impregnation
stage whereby the PCC suspension was added into the pulp suspensions and disintegrated together.
For the samples 4 and 5 the pulp suspensions were treated with PAM solution and for the samples 6
and 7, the pulp suspensions were treated with PEI solution after impregnation process. The handsheets
prepared were then dried at room temperature and ready for mechanical and physical testing and also the
morphology test.
3. Results and Discussion 3.1 Zeta Potential
