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Black Ink of Activated Carbon Derived From
Palm Kernel Cake (PKC)
M.H. Selamat and A. H. Ahmad
Faculty of Applied Sciences, Universiti Teknologi MARA,
40500 Shah Alam, Selangor, Malaysia
Abstract. Recycling the waste from natural plant to produce useful end products will benefit many
industries and help preserve the environment. The research reported
in
this paper is
an
investigation
on
the use of
the natural waste
of
palm kernel cake (PKC)
to
produce carbon residue
as a
black
carbon
for
pigment source
by
using pyrolysis process.
The
activated carbons (AC)
is
produced
in
powder form using ball milling process. Rheological spectra
in
ink
is
one
of
quality control process
in determining
its
performance properties. Findings from this study will help expand
the
scientific
knowledge-base
for
black ink production and formulation base
on
PKC. Various inks with different
weight percentage compositions
of
AC will
be
made
and
tested against
its
respective rheological
properties
in
order
to
determine ideal
ink
printing system.
The
items
in the
formulation used
comprised
of
organic
and
bio-waste materials with added additive
to
improve
the
quality
of
the
black ink. Modified Polyurethane was used
as
binder. The binder’s properties highlighted
an
ideal
vehicle
to be
applied
for
good black
ink
opacity performance.
The
rheological behaviour
is a
general foundation
for ink
characterization where
the wt% of
AC-PKC resulted
in
different
pseudoplastic behaviors, including
the
Newtonian behavior. The result found that Newtonian field
was located
in
between 2wt% and 10wt%
of
AC-PKC composition with binder. Mass spectroscopy
results shown that the carbon content in PKC
is
high and very suitable for black performance. In the
ageing test,
the
pigment
of
PKC perform fairly according
to the
standard pigment
of
Black carbon
(CB)
of
ferum oxide pigment. The contact angle
for
substrate's wettability
of
the
ink
system shown
a good angle proven
to be a
water resistive coating on paper subtrates;
an
advantage of the PKC ink
pigment performance.
Keywords: Carbon residue; ink; Palm Kernel Cake; Rheology; Polyurethane; Dispersion additive
PACS : 61.46.Fg INTRODUCTION
Activated carbons have very high active surface area with typical surface
areas of 1500 m2 g-1
[1,2].
Biomass such as wood, palm kernel and coconut has
for many years been used for the production of powdered activated carbons but
none has been reported in usage of PKC as black ink pigment source. Physical
pyrolization involves pyrolysis of the source material to produce a black carbon
[1,2,4].
The source in ink at the level to find an acceptable printing evolution
derived from PKC is now motivated. Black activated carbon (AC) from PKC is
believed to be cost effective since it is derived from biomass waste product. This
activated carbon, normally can be derived from charcoal that has high surface area.
In the past 30 years, the field of carbon black (CB) research has expanded and
detected in many important research directions. In another work, the kernel shell
was charred until the finely ground size of activated carbon produced. Preparation
of activated carbon from palm kernel shell by quenching method has been carried
out
[2,3].
Rheological spectras in ink are a critical analysis for its quality control and
determination of its performance properties. The right viscosity of ink mixture will
enable ink to be absorbed well on paper. The ink used in printing process is
subjected to a high degree of shear on a roller system of a printing machine
[4,5,8].
CP1136, Nanoscience andNanotechnology, International Conference on Nanoscience
andNanotechnology, (NANO-Sci-Tech 2008), edited
by
M. Rusop and T. Soga
© 2009 American Institute
of
Physics 978-0-73 54-0673-5/09/$25.00
350
It is a necessity to measure the shear rate of the ink mixtures for determining the
behavior of the ink and whether it represents viscoelastic or pseudoplastic of fluids.
Rheological behavior of ink mixture with different weight percentage (wt%) of
carbon (CB) composition prepared from PKC were viewed.
2.0 Experimental
2.1 Preparation of Black Ink Using Raw Materials from Two Different
Sources
2.1.1 Preparation of Black Ink Base Using Commercial Carbon Black.
The raw material sample of carbon black (i.e. Yippin Pigment) was
obtained from local industry and dispersed in a mixture of PU with solvent at a
ratio of 1:4 for 30 minutes using mixer until it became a homogeneous black ink.
Dispersion-products were prepared using the single binder system forming a
suspension of ink mixture at 25oC with aqueous polymerization method.
2.1.2 Preparation of Black Carbon Ink using PKC
2.1.2.1 Pyrolysis process
PKC was crunched and ground into small particles before it undergone the
pyrolysis process. A fixed-bed batch reactor was used in the pyrolysis process for
the production of activated carbons. The reactor was constructed of stainless steel
with an inner-core bed of 65mm diameter and 250mm length and was heated by an
electrical ring furnace. The reactor was continuously purged with nitrogen at a
fixed metered flow rate to maintain inert conditions in the reactor. The reactor was
heated at a controlled heating rate of 2oC/min to the final temperature of 550 oC.
After cooling in nitrogen overnight, the carbons were removed from the reactor
and weighed. The activated carbon (AC) is then ball-milled using a stainless steel
beads for finer powdered sample before undergoing a dispersion process.
2.1.2.2 Black PKC ink
Two types of black ink were prepared and the effect of silylating agent on
the homogeneousity of the black ink was studied. Various samples were weighed
up-to three weight percentages and mixed in the ink blends. It was stirred for 20
minutes until homogenous flow was reached. The mixtures of ink base were added
with silylating agents according to weight percentages to form a black reacted
mixture and to separate the other particles of carbon component. Dispersion-
products were prepared using binder and additive with the AC to form a
suspension with binder and several additive ratios for black ink.
2.2 Rheology behavior of Ink
The test for viscosity measurement was conducted. Newtonian fluids were
characterised by observing a constant viscosity with applied deformation rate at
ambient temperature. Viscosity is measured by using rotational viscometer
Brookfield viscometer to characterised the rheology/viscosity of ink with defined
351
shear rate (ISO 3219-93). The viscosity is measured over a span of shear rate to
determine if the ink is Newtonian and having the same viscosity at shear rates
applied. The relationship of viscosity to the fluid rheology is important to produce
homogeneous ink dispersions and stability for various ink application.
2.3 Mass Spectroscopy
Mass spectroscopy was evaluated using Differential Scanning Calorimeter
DSC to provide carbon content information for the AC of PKC. The
characterization of the mixture was carried out to determine the carbon contents to
provide pigment in the paint/in. Samples of AC were digested until complete
incineration for the investigated structures content.
2.4 Ageing Test
The accelerated ageing of printed paper was studied using two different
substrates (1= brown, 2= white) treated at room temperature (27oC) using
spectrophotometer from Data Color (SF600X). The printed paper was exposed to
light generated by Mercury-Tungsten light of Halifax, England for several duration
of tests.
The three basic coordinates represent the lightness of the color (L* L* = 0
yields black and L* = 100 indicates white), its position between red/magenta and
green (a* negative values indicate green while positive values indicate magenta)
and its position between yellow and blue (b* negative values indicate blue and
positive values indicate yellow)
RESULTS AND DISCUSSION
3.1 Rheological behavior
The Otswald, (1960) of power law model was employed to study the flow
behavior of the ink mixture. The power law model describes the relationship
between the shear stress, x and the shear rate as follows;
TJ
=
k
\ dt \ (i)
T
= kyn (ii) (1)
ln
77
=lnk + nlny (iii)
Where xis the shear stress; k is a constant; y is the shear rate,
77
is the viscosity
and n is a parameter of Ostwald Model [8,9,10]
352
FIGURE 1.: Standard model of fluid properties FIGURE 2.
:
n-characteristic of Newtonion behavior
from black ink PKC
Figure 1 shows the standard model of Newtonion fliud behavior for ink jet where
constant viscosity was observed. For a Newtonion fluid,
n=1,
n<1 is associated to
the pseudoplastic and n>1 is dilatant. Figure 2 showed a linear relationship (a
straight line) observed and the value of n was computed. From figure 2, the curves
illustrate n-characteristics of the viscosity where the value of n decreases with wt%
of AC composition (Black pigment). Depicted graph meant that ink in various
weight percent of AC has given different rheological behavior. The 20wt% of AC
gives dilatant and 30wt% of AC gives the pseudoplastic behaviors.
3.3. Mass Spectroscopy
Mass spectroscopy shown that the carbon content in the AC from PKC was
found to be high and therefore, suitable to be used as pigment. In opacity, the
pigment strength requirement for coating standards for black color is needed to be
high. Figure 3 shows that the peak of carbon content in the PKC sample is the
highest.
H
CIU
SHI Cufon
I41J 3SBi) 4Kil 57ISJ5 :
Time
(sec)
FIGURE 3. : Mass spectroscopy of PKC
3.5 Accelerated Aging
353
Spectrophotometer Data color was used for the accelerated ageing test of
ink layer. The color space L, a, b was applied on the investigation of black ink
from PKC and commercial black AC ink which were printed on brown and white
papers. These three basic coordinates that represent the lightness of color were
measured and recorded before and after the accelerated ageing procedure. The
difference in color intensity were tabulated in table 1 to depict the AE values.
The total color difference AE was calculated according to equation:
AE* =V(M*)2
+(A«*)2
+(A&*)2
(2)
Where AL = L (t) - L (0); Aa = a (t) - a (0); Ab = b (t) - b (0) are the
differences calculated for aged ink film (t) and the original (0) ink layers. [5].
TABLE
1
:
The total color change
AE*
calculated
based on measured data from accelerated aging
test
acceleration aging
of
pure
carbon black and carbon black PKC on different substrates (_B =
brown
paper;
_W=white
paper).
Time
(min)
30
60
90
120
150
PKC
B
1.25
0.52
2.14
2.88
3.62
PKC
W
3.18
0.75
6.88
3.67
0.46
PURE
C B
0.44
0.69
0.25
0.21
0.17
PURE
C W
2.01
1.85
1.65
0.91
0.17
FIGURE
5 : The total color change
ΔE*
calculated based on measured data from accelerated aging test.
Figure 5 summarizes the color changes occurred during the accelerating
ageing process on lightfast test applied on two different substrates. Most of the
samples show the rapid changing of color except for black PKC ink on brown
substrate. The total color difference of black PKC ink on white paper decline was
twice reduced compared to black PKC on brown paper. Whereas the color
difference for both commercial AC ink were also fluctuated towards time.
CONCLUSION
Composition of inks are strictly dependent on correct flow of the ink
droplets. The study was to realize the phenomenological of ink rheological
behaviors to make ink compositions. The dissolvability of carbon is going to be
investigated using silylating agent to improve the solubility of carbon in the ink.
The properties of black ink prepared for PKC have been characterized by viscosity,
Mass spectroscopy and accelerated ageing. The investigation rheological behavior
354
of black ink from PKC shows that 20wt% of composition gives dilatant and 30wt%
gives the pseudoplastic behaviors. Mass spectroscopy measurement of black
carbon from PKC show the carbon content is at the highest in the PKC elemental
structures. Accelerated ageing of color for both ink of carbon black were
determined at various rate of degradations while white substrate (paper) degrade
faster than the brown substrate.
REFERENCES
[1] I.K. Adewumi and M.O. Ogedengbe, Optimising Conditions for Activated Charcoal
Production from Palm Kernel Shells,J: Applied Sciences 5(6): 1082-1087, 2005
[2] J. Pastor-Villegas, J.F. Pastor-Valle, J.M. Menese Rodrigues and M. Garcia Garcia, Study
of commercial wood charcoals for the preparation of carbon adsorbents, J: Analytical and
applied pyrolsis 76 : 103-108, 2006
[3] D. H. Dalwadi, C. Canet, Nick Roye and Kaj Hedman, Rheology: An Important Tool In
Ink Development, Application Note: American Laboratory, Nov. 2005
[4] B. Halinova. L. Hornakova, V. Brezova, Z. Liptakova, J. Kindernay and V. Jancovicova
Ink receptivity on paper –
chatacterization
of paper materials, J: Colloids and Surfaces A
168:
p: 251-259, 2000
[5] H. Yano, P.J. Collins and Y. Yazaki, Plastic-like moulded products made from renewable
forest
resources,
J: Materials Science, 36 p: 1939-1942, 2001
[6] B. Halinova. L. Hornakova, V. Brezova. The Stability of offset inks on paper upon
ageing,
J: Dyes and Pigments, p: 173-188, 2002
[7] S. El-Sherbiny and H. Xiao, Effect of polymeric thickeners on pigment coatings:
Adsorption, rheological behaviour and surface structures, J: Materials Science, 39 p:4487-
4493,
2004.
[8] M. Ginic-Markovic, N.R Choudhury, J.G Matisons and D.R.G Williams, Characterisation
of
Polyurethane
Coating using
thermoanaytical
techniques, J: Thermal Analysis and
Calorimetry, 59, p:409-424, 2000
[9] P. J. Carreau, D. De Kee and Raj P. Chhabra; Rheology of Polymeric System, Principles
and Application, Hanser Publisher, New York, 1997
355
