This research studies the potential of a renewable material, aluminum foil, as filler in high density polyethylene (HDPE). The filler was used in range of 0-40% by weight. Aluminum foil/HDPE compounding was prepared using single screw extruder.. The incorporation of al foil into HDPE increased hardness where as decrease tensile modulus and tensile strength of HDPE. The highest hardness of compounded was 56.8 Shore D scales at 40 wt% aluminum foil content. It was found that increasing the aluminum foil content resulted in very similar trend of increase in hardness properties. Because aluminum foil is harder than matrix. The highest tensile modulus and tensile strength of compounded was 345 MPa and 25 MPa at 10 wt% aluminum foil content. The decreases in the mechanical properties of HDPE with aluminum foil were explained in associate with the presence of interface defects between aluminum foil and polymer. SEM micrographs indicated poor dispersion and adhesion of HDPE/aluminum foil compounding. Furthermore, the optical microscope results show flake structure of aluminum foil that immiscible with HDPE. The overall results in this research suggest that the properties of HDPE/aluminum foil composites were influenced by aluminum foil content.

1. Study in Physical and Mechanical Properties of Renewable
Aluminum Foil-Filled Polyethylene
Jadsada Wong-On,1*
Supaporn Thumsorn,2
1
Department of Industrial Engineering, Faculty of Engineering, Pathumwan Institute of Technology, Bangkok, 10330
2
Department of Textile Engineering, Faculty of Engineering, Rajamangala University of Technology Thanyaburi,
Pathumtani, 12110
E-mail: rabit_in_themoon@yahoo.com*
Abstract
This research studies the potential of a renewable material,
aluminum foil, as filler in high density polyethylene (HDPE).
The filler was used in range of 0-40% by weight. Aluminum
foil/HDPE compounding was prepared using single screw
extruder.. The incorporation of al foil into HDPE increased
hardness where as decrease tensile modulus and tensile
strength of HDPE. The highest hardness of compounded was
56.8 Shore D scales at 40 wt% aluminum foil content. It was
found that increasing the aluminum foil content resulted in
very similar trend of increase in hardness properties. Because
aluminum foil is harder than matrix. The highest tensile
modulus and tensile strength of compounded was 345 MPa
and 25 MPa at 10 wt% aluminum foil content. The decreases
in the mechanical properties of HDPE with aluminum foil
were explained in associate with the presence of interface
defects between aluminum foil and polymer. SEM
micrographs indicated poor dispersion and adhesion of
HDPE/aluminum foil compounding. Furthermore, the optical
microscope results show flake structure of aluminum foil that
immiscible with HDPE. The overall results in this research
suggest that the properties of HDPE/aluminum foil composites
were influenced by aluminum foil content.
1. Introduction
Packing laminates are versatile and cost effective in their use
of raw materials. The properties offered by laminates include
those of barrier nature against moisture, oxygen
microorganism and dust together with properties related to
stiffness and durability [1]. Laminates structure which
comprises paper complexes with aluminum foil in widespread
use as packing materials. Management of packaging waste
indicated for re-use, recycling, incineration with and without
energy recovery and disposal via landfill. The packaging
waste was purposed for recovery and recycling. Secondary
fiber is a raw material which is correctly used to make paper
and board products worldwide. Otherwise a recovery of
aluminum foil was less in widespread. For environmental
consideration, less energy consumption and major political
drive to re-use the plastic scraped and another using a
renewable material for lower plastic consumption. Renewable
materials and natural products were commonly use as filler for
plastic such as wood, sugarcane or sawdust. Especially in this
research, the recovery of aluminum foil from packing
laminates (Tetrapak) has been investigated as a renewable
material in type of filler in high density polyethylene for
reducing formulation costs and modifies the bulk mechanical
properties [2].
2. Methodology
The recovery of aluminum foil from packing laminates
(Tetrapak) donated by Green Board (Thailand) Co., Ltd.
First, aluminum foil was cut into a length 5-10 cm. and soak
in water for 3 days. After that, it was prepared in to a length of
0.5-1mm. The preparation of aluminum foil filler, aluminum
foil from packing laminates (Tetrapak) as showed in figure 1.
A commercial grade (H501Y) of high density polyethylene
(HDPE) supplied by Cement Thai Chemicals Co., Ltd. HDPE
was compounded with 0-40 wt% of filler, aluminum foil, in
high speed mixer before mixing in single screw extruder
(Haake/Polylab Rheomex R25). Mixing temperature at zone
1, Zone 2, Zone 3 and die were 135/140/145/155 °C,
respectively. A constant screw speed of 60 rpm was used.
Compounded were molded in compression molding at
pressure 750 psi at temperature of 180 °C and pressing time
of 10 minutes. Molded dogbone-type specimen dimension was
in accordance with ASTM D638. The molded specimens were
used in determination of tensile modulus, tensile strength and
hardness. The first 2 mechanical properties were determined
in accordance with ASTM D638 on universal tensile testing
machine (INSTRON 5569). The latter was accordance with
ASTM D2240 using ATSFARR. Dogbone specimens were
broken in liquid N2 for morphology investigation. Scanning
Electron Microscope (JEOL/JSM-5800) was used and set at
20 keV. Gold coating was applied on specimens for electron
conducting. The texture surface of compounded was
determined using optical microscopy.
Figure 1: A preparation of aluminum foil filler

2. 3. Result and Discussion
3.1 Effect of filler content on mechanical properties
3.1.1 Tensile modulus
Figure 2 showed that tensile moduli of aluminum foil filled
HDPE were decrease as filler content increase. This behavior
was also found by Djidjelli et al [3]. The decrease of tensile
modulus was attributed to possible reason, the poor dispersion
of aluminum foil particle throughout of the HDPE matrix. It
can be explained using the optical microscopy showed in
figure 3. We found that aluminum foil particle to cling
together and resisted dispersion of the individual particle as
aluminum foil content increased.
0
10
20
30
40
0
50
100
150
200
250
300
350
400
Modulus
(MPa)
Aluminum foil content
Figure 2: Schematic diagram of tensile modulus of HDPE
filled aluminum foil 0-40 wt%
Figure 3: Optical micrograph of HDPE filled with 40 wt%
aluminum foil. (°100)
3.1.2 Tensile strength
Figure 4 showed that tensile strength of filled HDPE decrease
when increasing aluminum foil content. The decrease in
tensile strength was probably caused by poor adhesion of filler
in the matrix and increase of interfacial defects due to use of
untreated filler [4]. The poor adhesion was observed in SEM
micrographs of composite with 40% aluminum foil as shown
in Figure 5 and 6.
0
10
20
30
40
0
5
10
15
20
25
30
Tensile
strength
(MPa)
Aluminum foil content
Figure 3: Schematic diagram of tensile strength of HDPE
filled aluminum foil 0-40 wt%
Figure 5: SEM micrograph of HDPE filled with 40 wt%
aluminum foil (°500)
Figure 6: SEM micrograph of HDPE filled with 40 wt%
aluminum foil (°1000)
3.1.3 Hardness
Aluminum foil increased hardness of HDPE as shown in
Figure 7. Filler, which is harder than HDPE, added up the
degree of hardness in HDPE matrix. This behavior was also
found by N.Thavarangkul et al [5].
Aluminum foil
Void
Void

3. 0 10 20 30
40
50
51
52
53
54
55
56
57
Hardness
(Shore
D)
alumium foil content
Figure 7: Schematic diagram of hardness of HDPE filled
aluminum foil 0-40 wt%
3.2 Texture surface
Figure 8-10 showed texture surface of HDPE/aluminum foil
composite with containing different aluminum foil content.
The surface of the HDPE/aluminum foil composite is very
smooth. Aluminum foil changed color of the composites that
showed in Figure 8. Figure 9 and 10 showed aluminum foil
particle in the composite. It was indicated that aluminum foil
was immiscible with HDPE. That was another reason that
explained the decrease value of tensile modulus and tensile
strength.
Figure 8: Texture surface of HDPE filled with 0-40 wt%
aluminum foil
Figure 9: Closed up of texture surface of HDPE filled
with 10-40 wt% aluminum foil
Figure 10: Optical micrograph of HDPE filled with 40 wt%
aluminum foil (100°)
4. Conclusion
The effect of addition of untreated aluminum foil particles on
properties of HDPE/aluminum foil composites was examined.
Aluminum foil, as filler, increased hardness of HDPE where
as decreased tensile modulus and tensile strength of HDPE.
SEM micrograph indicated poor adhesion and dispersion of
aluminum foil on HDPE matrix. The decreases in the
mechanical properties of HDPE with aluminum foil were
explained in associate with the presence of interface defects
between aluminum foil and polymer and poor dispersion of
aluminum foil in the HDPE matrix. The optical micrograph
showed a particle of aluminum foil that immiscible with
HDPE. It can be possible to use aluminum foil as filler for
HDPE. A renewable aluminum foil, recovered from packing
laminate, could achieve as role by filling in polymer to
increase the level of recycling of packing materials.
5. References
[1] Et Evans,M J Kay, N kirkoatrick and D s Wales: The
chemistry and processing of wood and plant fibrous
materials, Wood Publishing Co Ltd., Great Britain, 1996.
[2] Coutinho FMB, Costa THS and Carvalho,
“Polypropylene-wood fibre composite: effect of treat and
mixing conditions on mechanical properties.'', J. Appli
Polym Sci., 65: 1227-1235, 1997
[3] Djidjielli H,Martinez-Vega JJ and Park CB. “Effect of
wood flour content on thermal, mechanical and dielectric
properties of poly(vinyl chloride)”. Macromol Mater
Eng. ,287 : 611-618 (2002)
[4] Sombatsompop N., Chaochanchaikul K., Phromchirasuk
C. and Thongsang S. “Effect of wood sawdust content on
rheological and structural changes,and thermo-
mechanical properties of PVC/sawdust composite”,
Polym Int., 52 : 1847-1855 (2003)
[5] N Thrvarangkul, S. Thumson and J Wong-on,
“Structure-Processing-property relationships of cockle
shell-filled polyethylene”. AWPP 2006 , P.154-157,2006
HDPE 90:10 80:20 70:30 60:40
90:10 80:20 70:30 60:40