CHAPTER ONE
INTRODUCTION
1.1 Background
During last decades, the great
population increase worldwide together with the need of people to adopt
improved conditions of living led to a dramatically increase of the
consumption of polymers (mainly plastics). Materials appear interwoven
with our consuming society where it would be hard to imagine a modern
society today without plastics which have found a myriad of uses in
fields as diverse as household appliances, packaging, construction,
medicine, electronics, and automotive and aerospace components. A
continued increase in the use of plastics has led to increase the amount
of plastics ending up in the waste stream, which then becomes a threat
to the environment when the wastes are not decomposable(Hamad et al.,
2013). Environmental issues are becoming prioritized in most government
and community development agendas. This has motivated the search for
economically efficient and ecologically effective material and energy
recycling technologies (Petts, 2000). For example, the development and
use of strategic technologies driven by recycling credit scheme and the
imposition of the landfill tax to preserve landfill void for the future
disposal of untreatable residues in England(Read et al.,1998).
The potential environmental impacts from plastics are categorized under
global warming, acidification, eutrophication and photochemical ozone
creation(Bos et al., 2007).
Polypropylene account for around 22% of
the total production of plastics in 2008, making it the second largest
plastic produced beside polyethylene which is 23.7% (Plastic waste
Management Institute, 2009).Polypropylene plastics or also known as
polypropene, are materials that are used worldwide since the 19th
century (Scheirs, 1998). Polypropylene plastics are widely used in our
daily life as kitchen utensils, in toy productions, as insulators for
electrical devices, and also in industrial sites as safety
equipment(Gaurina-Medijumurec, 2014). Since polypropylene is widely
used today in industries and also at home, its production has increase
drastically over the years with increasing production of polypropylene
made products. Therefore, polypropylene products is a major contributor
to the pollution in the world today and now acting as a threat to both
man and the whole biodiversity(Anthony, 2003). Itsnon-biodegradability
makes post-consumer polypropylene a major environmental issue. Disposal
of polypropylene waste by burning is not an environmentally friendly as
the gases released are toxic.
Several options have been considered to reduce polypropylene waste such as reuse and recycling (Aurrekoetxeaet al.,
2011). The most common examples of reuse are with glass containers,
where milk and drinks bottles are returned to be cleaned and used
again(Hamad et al., 2013). Reuse is not widely practiced in
relation to plastic packaging of plastic products in general tend to be
discarded after first use. However, there are examples of reuse in the
marketplace. For example, a number of detergent manufacturers market
refill sachets for bottled washing liquids and fabric softeners.
Consumers can refill and hence reuse their plastic bottles at home, but
in all of these cases the reusing of the plastic bottles and containers
do not continue for long time especially in the food applications which
makes recycling the best alternative.
Mechanical recycling and chemical
recycling are the most widely practiced of these methods. However, from
industrial point of view, the mechanical recycling is the most suitable
because its low cost and reliability (Hamad et al., 2013).
Mechanical recycling also known as physical recycling, the plastic is
ground down and then reprocessed and compounded to produce a new
component that may or may not be the same as its original use (Cui and
Forssberg, 2003).
As to this, the recycling of
post-consumer polypropylene polymer products is one of the factors in
reducing the amount of wastes material produced every day (Harold,
2003). However, until today, the research on the mechanical properties
of recycled polypropylene is not widely explored in open literature.
Besides that, not much input of the properties of the recycled products
either in mechanical or physical properties is comparable with the pure
polypropylene materials. Thus, the study on the mechanical properties of
the recycled polypropylene product is necessary.
1.2 Project objective
The main objective of this project are:
a) To design and fabricate a mold for purpose of this research
b) To determine how physical and chemical properties of polypropylene changes with recycling.
1.3Justification
Polymer recycling is a way to reduce
environmental problems caused by polymeric waste accumulation generated
from day-to-day applications of polymer materials such as in packaging
and construction. The recycling of polymeric waste helps to conserve
natural resource because the most of polymer materials are made from oil
and gas. Since recycling has been a solution to reduce environmental
problem therefore the limit at which the properties of the materials
produce through this method is of high importance.
It is proven theoretically that
polypropylene materials take a long time for the properties to
deteriorate and also reduce cost of production since no or little virgin
polymer is required and energy is conserved.