Kelas : 4EA14
NPM : 12209277
Due to the unique nature and characteristics,
wood is the material most widely used for construction purposes. The
ever-increasing demand for wood and forest potential of dwindling demand the
use of wood in an efficient and expedient, by utilizing such waste sawdust into
useful products. On the other hand, along with the development of technology,
the need for plastics continue to increase as a consequence, increased waste
plastikpun inevitable. Waste plastic is a material that can not be decomposed
by microorganisms decomposing (non-biodegradable), so penumpukkannya in nature
feared to cause environmental problems.
Technological developments, particularly in the
field of composite board, has produced a composite product which is a
combination of sawdust with recycled plastic. The technology was developed in
the early 1990s in Japan and the United States. With this technology it is
possible utilization of sawdust and recycled plastic to the maximum, thus will
reduce the amount of waste generated. In Indonesia, research on these products
is limited, whereas raw material waste potential is enormous.
This paper will present a brief overview of the
potential and utilization of wood waste, particularly sawdust, and plastic
waste as a product of wood-plastic composite powder recycling.
POTENTIAL AND UTILIZATION OF WASTE WOOD
POWDER
Human need for wood as building material for the purposes of construction, decoration, and furniture continues to increase along with the increase in population. Timber demand for the timber industry in Indonesia is estimated at 70 million m3 per year with an average of 14.2% per year while roundwood production estimated at 25 million m3 per year, so there was a deficit of 45 million m3 (Priyono, 2001). This suggests that the actual carrying capacity of the forest has been unable to meet the demand for wood. This situation is exacerbated by the presence komversi natural forests into agricultural land, shifting cultivation, forest fires, harvesting practices are not efisen and infrastructure development, followed by forest encroachment. These conditions require the use of wood in an efficient and prudent, among others, through the concept of the whole tree utilization, while increasing the use of non-wood berlignoselulosa, and the development of innovative products as a substitute for wood building materials.
Human need for wood as building material for the purposes of construction, decoration, and furniture continues to increase along with the increase in population. Timber demand for the timber industry in Indonesia is estimated at 70 million m3 per year with an average of 14.2% per year while roundwood production estimated at 25 million m3 per year, so there was a deficit of 45 million m3 (Priyono, 2001). This suggests that the actual carrying capacity of the forest has been unable to meet the demand for wood. This situation is exacerbated by the presence komversi natural forests into agricultural land, shifting cultivation, forest fires, harvesting practices are not efisen and infrastructure development, followed by forest encroachment. These conditions require the use of wood in an efficient and prudent, among others, through the concept of the whole tree utilization, while increasing the use of non-wood berlignoselulosa, and the development of innovative products as a substitute for wood building materials.
Regrettably, to date harvesting and processing of
timber in Indonesia still produces large amounts of waste. Purwanto et al,
(1994) stated the composition of waste in harvesting and wood processing
industry are as follows:
1. On timber harvesting, waste generally shaped
logs, reaching 66.16%
2. In industrial sawmill wood waste sawdust
covering 10.6 &. Sebetan 25.9% and 14.3% cuts, a total waste 50.8% of the
total raw material digubakan
3. Industrial waste at the waste pieces of
plywood covering 5.6%, 0.7% sawdust, 24.8% wet veneer waste, dry waste veneer
peeling the remaining 12.6% 11.0% and a piece of plywood edges 6.3% . Total
waste plywood for 61.0% of total raw materials used.
Data from the Ministry of Forestry and
Plantations in 1999/2000 showed that Indonesia’s plywood production reached 4.61
million m3 of sawn timber while achieving 2.06 million m3. Assuming the waste
generated is estimated to reach 61% of the wood waste generated reached more
than 5 million m3 (CBS, 2000).
Wood waste in the form of pieces of logs and
sebetan been used as the core block board and particle board material. The
waste floured kergaji utilization is still not optimal. For large, integrated
industrial, waste sawdust sawn been utilized as a form of charcoal briquettes
and activated charcoal are sold commercially. But for the sawmilling industry
small-scale industries, which accounted for thousands of units and the
countryside, the waste has not been used optimally. An example is the
industrial mills in Jambi, amounting to 150 pieces of which are located on the
edge of the river Batang, sawn wood waste generated is dumped into the river,
causing siltation and reduction process stream segment (Pari, 2002). In most of
the wood processing industry waste sawdust are commonly used as furnace fuel,
or burned away without meaningful use, which can cause environmental pollution
(Febrianto, 1999). In order to efficient use of wood are needed to use sawdust
into a more useful product.
FROM PLASTIC TO PLASTIC WASTE RECYCLING
Plastic name representing thousands of different physical properties of materials, mechanical, and chemical. Broadly speaking, the plastic can be classified into two major categories, namely plastics are thermoplastic and thermoset that is. Thermoplastic can be reshaped easily and processed into other forms, whereas when it has hardened types of thermosets can not be softened again. The most common plastic used in everyday life in the form of thermoplastic.
Plastic name representing thousands of different physical properties of materials, mechanical, and chemical. Broadly speaking, the plastic can be classified into two major categories, namely plastics are thermoplastic and thermoset that is. Thermoplastic can be reshaped easily and processed into other forms, whereas when it has hardened types of thermosets can not be softened again. The most common plastic used in everyday life in the form of thermoplastic.
Along with the development of technology, the
need for plastic continues to increase. BPS data in 1999 showed that the volume
of trade of Indonesia’s imports of plastic, especially polypropylene (PP) in
1995 amounted to 136,122.7 tons, while in 1999 amounted to 182,523.6 tons, so
that in this period there was an increase of 34.15%. The number is expected to
continue to increase in subsequent years. As a consequence, an increase in
waste plastikpun inevitable. According to Hartono (1998) the composition of the
waste or plastic waste dumped by each household was 9.3% of total household
waste. In Jabotabek average each plant produces one ton of plastic waste every
week. That number will continue to grow, due to the properties owned plastics,
among others, can not rot, do not decompose naturally, it can not absorb water,
and can not rust, and eventually ended up being a problem for the environment.
(YBP, 1986).
Utilization of waste plastics is an effort to
suppress plastic waste to a minimum and within certain limits save resources
and reduce dependence on imported raw materials. Utilization of waste plastics
can be done with reuse (reuse) and recycling (recycle). In Indonesia, the use
of plastic waste in the scale of general household usage is back with different
purposes, for example, place a plastic paint used for pot or bucket. Reuse ugly
side, particularly in the form of packaging is often used for product
counterfeiting as it often happens in the big cities (Syafitrie, 2001).
Utilization of waste plastics for recycling is
generally done by the industry. Generally, there are four requirements for a
plastic waste can be processed by an industry, among others, certain wastes
must be in the form as needed (seed, pellets, powder, pieces), the waste must
be homogeneous, uncontaminated, and sought not oxidized. To overcome these
problems, before use of plastic waste is processed through a simple step, the
separation, cutting, washing, and removal of substances such as iron, and so on
(Sasse et al., 1995).
There are things that benefit in the use of
plastic waste in Indonesia compared to developed countries. This is possible
because manual separation is considered not possible in developed countries,
can be done in Indonesia, which has abundant labor so that the separation does
not need to be done with advanced equipment that require high costs. These
conditions allow the development of plastics recycling industry in Indonesia
(Syafitrie, 2001).
Use of recycled plastic in the manufacture of
plastic goods back has been growing rapidly. Almost all types of plastic waste
(80%) can be processed back into the original item must be done despite mixing
with new raw materials and additives to improve the quality (Syafitrie, 2001).
According to Hartono (1998) four types of plastic waste are popular and sell
well in the market, namely polyethylene (PE), High Density Polyethylene (HDPE),
polypropylene (PP), and asoi.
UTILIZATION OF WASTE WOOD AND POWDER WOOD
PLASTIC COMPOSITES AS PLASTIC RECYCLING
Composite wood is a term used to describe any product that is made from sheets or small pieces of wood glued together (Maloney, 1996). Referring to the definition above, composite wood powder composite plastic is made of plastic as a matrix and wood powder as filler (filler), which has properties of both. The addition of filler into the matrix aims to reduce density, increase stiffness and reduce the cost per unit volume. In terms of wood, with the polymer matrix inside the strength and physical properties will also increase (Febrianto, 1999).
Composite wood is a term used to describe any product that is made from sheets or small pieces of wood glued together (Maloney, 1996). Referring to the definition above, composite wood powder composite plastic is made of plastic as a matrix and wood powder as filler (filler), which has properties of both. The addition of filler into the matrix aims to reduce density, increase stiffness and reduce the cost per unit volume. In terms of wood, with the polymer matrix inside the strength and physical properties will also increase (Febrianto, 1999).
Composite manufacturing using a matrix of plastic
that has been recycled, in addition to improving the efficiency of wood
utilization, can also reduce the load on plastic waste in addition to producing
innovative products as a substitute for wood building materials. The advantages
of this product include: cheaper production costs, abundant raw materials,
flexible in the manufacturing process, low density, it is biodegradable (rather
than plastic), possesses properties better than the original raw material, can
be applied for various purposes, as well as can be recycled (recycleable). Some
examples of the use of this product are as interior parts of vehicles (cars,
trains, airplanes), furniture, or building components (windows, doors, walls,
floors and bridges) (Febrianto, 1999: Youngquist, 1995).
Wood powder as Filler
Wood powder as Filler
Filler is added to the matrix in order to improve
the mechanical properties of plastics through the deployment of effective
stress between the fiber and the matrix (Han, 1990). Besides the addition of
filler to reduce costs as well as improve some properties of its products.
Inorganic materials such as calcium carbonate,
talc, mica, and fiberglass is the material most commonly used as a filler in
the plastics industry. The addition of calcium carbonate, mica and talc may
increase the strength of the plastic, but the weight of the product is also
increased so that the transportation costs would be higher. In addition,
calcium carbonate and talc are abrasive to equipment used, thereby shortening
the service life. The addition of fiberglass to increase the strength of the
product but the price is very expensive. Therefore the use of organic
materials, such as wood filler in the plastics industry began to receive
attention. In Indonesia, the potential for very large timber as a filler,
especially the utilization of waste sawdust is still not optimal.
According Strak and Berger (1997), sawdust has
advantages as a filler when compared to filler minerals such as mica, calcium
carbonate, and talc are: process temperature is lower (less than 400 º F)
thereby reducing energy costs, can be degraded naturally, weight species are
much lower, so the cheaper the cost per volume, low geseknya style so not to
damage equipment on the manufacturing process, and comes from renewable sources
Some factors to consider in the use of sawdust as
a filler in the manufacture of wood plastic composite is a type of wood, the
size ratio between powder and sawdust and plastic. Another thing to consider is
the nature of wood dust itself. Wood is a material composed mostly of cellulose
(40-50%), hemicellulose (20-30%), lignin (20-30%), and small amounts of
inorganic materials and extractive. Therefore hydrophilic wood, rigid, and can
be biologically degraded. The properties of the wood causes less suitable when
combined with plastic, because it is in the manufacture of wood-plastic
composites required assistance coupling agent (Febrianto, 1999).
Plastic Recycling In The Matrix
Plastic Recycling In The Matrix
In Indonesia, most of the recycled plastic used
again as the original product with lower quality. Use of recycled plastic as a
construction material is still very rare. In the 1980s, the UK and Italy have
been recycled plastic used to make telephone poles instead of wooden poles or
iron. In Sweden recycled plastic used to manufacture the plastic brick
multistory buildings, because lighter and more powerful than common brick (YBP,
1986).
Use of recycled plastic in the field of composite
wood in Indonesia is still limited at the research stage. There are two
strategies in the manufacture of wood composites by using plastic, plastic
first used as a binder, while the wood as the main component, the second used
wood filler / filler and a plastic matrix. Research on the use of recycled
polypropylene plastic as a substitute for thermoset adhesives in the
manufacture of particle board made by Febrianto et al (2001). Particle board
product produced has dimensional stability and high mechanical strength
compared to conventional particle boards. Research recycled plastic as wood
plastic composite matrix made Setyawati (2003) and Sulaeman (2003) by using
recycled polypropylene plastic. In the manufacture of wood plastic composite
recycling, some thermoplastic polymers can be used as a matrix, but is limited
by low temperature decomposition beginning and heating wood (approximately 200
° C).
Making Process
Basically composite manufacturing recycled
plastic wood powder not unlike the plastic matrix composites with pure. These
composites can be made through the process one stage, two-stage process, and
the continuous process. At one stage of the process, all the raw materials mixed
first manually and then entered into the tool pengadon (kneader) and processed
to produce a composite product. In the two-stage process of modified plastic
raw materials first, then filler mixed together in the kneader and formed into
a composite. The combination of these stages is known as a continuous process.
In this process the raw materials incorporated gradually and sequentially in a
kneader and then processed through a composite product (Han and Shiraishi,
1990). Generally a two-stage process produces a better product than the one
stage, but the process takes one step shorter.
Diagram of basic manufacturing process is presented in Figure 1.
Diagram of basic manufacturing process is presented in Figure 1.
Preparation of filler
In principle the preparation of filler intended to get sawdust or wood flour size and uniform moisture content. The more fine powders greater the contact surface between the matriknya filler, so the products become more homogeneous. However, if the terms of decorative composite powder size larger will produce a better appearance because the distribution of the powder timber provides its own value.
In principle the preparation of filler intended to get sawdust or wood flour size and uniform moisture content. The more fine powders greater the contact surface between the matriknya filler, so the products become more homogeneous. However, if the terms of decorative composite powder size larger will produce a better appearance because the distribution of the powder timber provides its own value.
Preparation of Recycled Plastic
Waste plastics are grouped according to the type
of plastic (polypropylene (PP), polyethylene (PE), and so on). Once cleaned,
the waste is chopped to reduce the size, then heated to its melting point, then
processed to form a pellet. Before being used as a composite matrix made
analysts differential thermal (DTA). In the two-stage process, the pellets
diblending first by serving as a coupling agent in the manufacture of composite
compatibilizer.
Blending (Pengadonan)
Blending (Pengadonan)
The stages in this pengadonan adapted to the
process used, one stage, two-stage, or continuous. According to Han (1990)
pengadonan conditions are most influential in the manufacture of composites is
the temperature, rotation rate, and time pengadonan.
The formation of composite
The formation of composite
After the mixing is complete, the sample is
directly incurred to molded into sheets with heat presses. Compression
performed for 2.5 – 3 minutes with a pressure of 100 kgf/cm2 for 30 seconds at
a temperature of 170 º C – 190 º C. After cold compression at the same pressure
for 30 seconds, the sheet is then cooled at room temperature.
Testing of Composites
Testing of Composites
Composite testing conducted to determine whether
the product meets the requirements specified for a particular use. Type adapted
to the needs of testing, testing fterhadap generally includes physical
properties, mechanical, and thermal composites.
Composite of high quality can only be achieved if
the sawdust is well distributed in the matrix. In fact, the affinity of wood
with a plastic powder is very low because the wood is hydrophilic, while the
plastic is hydrophobic. As a result, the composite is formed has a drainage
properties and low moldability and in turn can reduce the strength of materials
(Han, 1990).
The results of research
The results of research
Studies that have been and are being conducted
aiming to produce wood plastic composite with the best properties. Han (1990),
Stark and Berger (1997), and Oksman and Clemons (1997), examines the factors
that play an important role in the manufacture of wood plastic composite
powder, the type and form of raw material, wood species, the ratio of filler to
the matrix, type and compatibilizer levels, as well as the conditions at the
time of pengadonan. The results show that to some extent an increase in
strength of the composite with the smaller size of the powder used, as well as
the type, ratio of sawdust and plastic, as well as the type of wood moisture
content significantly affect the properties of the resulting composites. The
addition of compatibilizer to a certain extent affect both the strength of the
composite.
Research on wood plastic composite mostly still
use plastic purely as a matrix. Research using recycled matrix, performed by
Setyawati (2003), Sulaeman (2003) by using recycled polypropylene. The results
of the study are summarized as follows:
Setyawati (2003) examined the effect of the size
ratio of sawdust to the matrix and compatibilizer content on physical and
mechanical properties of polypropylene wood composite recycling. The results
showed a similar pattern with a composite that uses pure polypropylene, the
properties of the composites increased with increasing particle size and
smoothness. Sawdust ratio of 50:50 with a matrix with the addition of 2.5% MAH
as compatibilizer is accompanied by the addition of initiator produces optimal
composite force, as well as physical properties sufficient.
Sulaeman (2003), examined the deterioration of
wood plastic composite recycled polypropylene by weather and termites. The
results showed a composite of recycled plastic lumber can be degraded by
weather, but resistant to termite attack.
Research The Moderate / Will Do
Research and testing of wood plastic composite so
far has been in the form of thin sheets, so the test is still based on testing
plastics. Currently Sutrisno (personal communication) is conducting research on
the properties of recycled wood plastic composite in the form of small clear
specimen so testing is directed to the possible use of composites instead of
wood.
Future studies will lead to the determination of
the wood plastic composite board manufacturing the best and the quality of
composite board with pre-treatment on the filler, the selection of modifier /
compatibilizer, the initiator, the determination of process variables, and the
use of materials other than wood berlignoselulosa (research plan) .
CLOSING
Manufacture of composite products sawdust and
recycled plastic is one alternative to the use of waste wood and plastic, in
order to improve the efficiency of wood utilization, reducing the environmental
load of the plastic waste and to produce innovative products as a substitute
for wood building materials. The development of these products in the future
will hopefully have a positive impact, not only limited to industrial
development and foreign exchange savings, but also improve the quality of the
environment.
