A. Mined plastic includes most disposable items Americans use every day, such as plastic water bottles, food containers and trash bags. Plastics are cheap, lightweight, strong, tough and corrosion resistant and have high thermal and electrical insulation properties (Thompson et al, 2009). 3-4% of global oil and gas consumption is used to produce plastic, and 4% is used as a component of plastic. Plastics are mainly derived from petrochemicals produced from fossil oil and gas (Thompson et al, 2009). The most commonly used plastic is polypropylene, which is used to make food containers, such as yogurt cups and Ziploc bags (Andrady, 2009). Oil and natural gas are the main raw materials for plastic. The process begins by treating the components of the oil or natural gas in the cracking process. This process leads to the formation of hydrocarbon monomers (ethylene, propylene). These monomers are further transformed into more monomers (striene, ethylene glycol). These monomers are then bonded together through polymerization to form a polymer structure, a reaction carried out via addition or condensation reactions (American Chemistry Council Inc, 2005)B. The plastic produced is never used alone, usually additives are used to strengthen, thermal stabilizers, dyes, UV stabilizers and flame retardants (Andrady, 2009). These additives are mixed with plastic to improve its basic characteristics. Plasticizers: A specific type of additive is used to increase flexibility and is used in film wrapping and hoses. There are four main methods for processing plastics: extrusion, injection molding, blow molding, and rotational molding (American Chemistry Council, Inc, 2005). In extrusion the plastic pellets are heated and then expelled through a... paper medium... bottles) and HDPE milk bottles, these bottles can be recovered, disinfected and reused to produce new PET and HDPE bottles. HDPE bottles can also be downgraded to plastic crates and containers or plastic lumber production. Raw materials recycling can recover the raw materials (oil and natural gas) used to create plastic. These recovered raw materials can be used to produce new plastic or other synthetic materials. This process is sometimes uneconomical because it requires large amounts of energy to reverse the reactions that created the plastic (Hopewell et al, 2009). Source reduction is also an important resource conservation scheme that involves using fewer raw materials to create the same products. This has been achieved by using less packaging materials, redesigning products, using packaging that reduces the amount of waste and reusing packaging.
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