A. Extraction
Plastics encompass most disposable items that American use daily, 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 world oil and gas usage is used to manufacture plastics and 4% is used as a component of plastics. Plastics are mostly 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 carriers, such as yogurt cups and Ziploc bags (Andrady, 2009). Oil and natural gas are the primary raw materials of plastics. The process begins by treating components of oil or natural gas in the cracking process. This process results in the formation of hydrocarbon monomers (ethylene, propylene). These monomers are further processed into more monomers (stryene, ethylene glycol). These monomers are then bonded together by polymerization to form a polymer backbone, a reaction carried out by addition or condensation reactions (American Chemistry Council Inc, 2005)
B. Produced
Plastics are never used alone, usually additives are used to strengthen, thermal stabilizers, colorers, UV stabilizers, and fire retardants (Andrady, 2009). These additives are blended with plastics to improve their basic attributes. Plasticizers a specific type of additive is used to increase flexibility, and is sued in film wraps and flexible tubing. There are four main methods of processing plastics, extrusion, injection molding, blow molding, and rotational molding (American Chemistry Council, Inc, 2005). In extrusion plastic pellets are heated and then forced out through a ...
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...ttles) and HDPE milk bottles, these bottles can be recovered, sanitized and reused to make new PET and HDPE bottles. HDPE bottles can also be downgraded into plastic crates and bins or the production of the creation of plastic lumber. Feedstock recycling can recover the raw materials (oil and natural gas) used to create the plastic. These recovered raw materials can be used to make new plastics or other synthetic materials. This process is sometimes uneconomical because it takes 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 the use of less raw materials to create the same products. This accomplished by using less packaging of materials by redesigning products, using packaging that reduces the amount of waste, and reusing packaging.
The popular teen movie “Mean Girls” accurately portrays several concepts from Chapter Two including Interaction Appearance Theory and Undue Influence, just to name a few that allow teen viewers to see the type of communication there is or will be in high school. Through the interactions with her new peers, Cady Heron is able to communicate and experience several of the concepts learned in Chapter Two thanks to the interactions she had with the deceiving Regina George.
National Center for Manufacturing Sciences. (2004, August 11). Environmental Roadmapping Initiative. Retrieved October 14, 2011, from Plastics Impacts, Risks and Regulations: http://ecm.ncms.org/ERI/new/IRRPlastics.htm
According to the American Council of Chemistry, plastics, which are otherwise known as polymers, are comprised of carbon, hydrogen, chlorine, nitrogen, sulfur, oxygen, and other elements that are combined through the conversion of natural products like oil, natural gas, or coal (ACA, n.d.). Between 7 and 8 % of the oil and natural gasses produced annually are used either directly in the conversion of such fossil fuels to plastics, or in powering the processes to produce plastics (Hopewell, Dvorak & Kosior, 2009). Plastic combinations can either form as thermoplastics, which are plastics whose atoms are connected in long chains that can be melted and reused, or thermosets, which are plastics whose atoms are arranged in three dimensional patterns that cannot be melted or reused (ACC, n.d.). Plastics are used in a wide range of products. For example, polyesters are used in textiles and fabrics, polyvinylidene chlorides are used for food packaging, polycarbonates are used for glasses and disks, and more. By the United States energy averages of 2015, each kg of plastic produced requires 62-108 mega joules of energy. The plastic requiring the largest amount of energy per kg is silicon which required about 235 mega joules of energy per kg. Three hundred and twenty two million metric tons of plastic produced in 2015 alone, and that value continues to raise, (Global plastic production,
Over the course of the past 60 years, an increasing amount of the current population is using plastic and reusable products to try and reduce the amount of waste that is being thrown away. Bisphenol A (BPA) is used to manufacture polycarbonate #7 plastic which have help strengthen plastic bottles, food containers and epoxy resins (University of Minnesota, 2008). BPA is used in a range of products from every day plastic beverage containers and plastic dinnerware, to compact disks, impact-resistant safety equipment, automobile parts, and toys (Centers for Disease Control and Prevention, 2013). The CDC (2013) also states that BPA epoxy resins are used in the protective linings of food cans, in dental sealants, and in other products (Centers for Disease Control and Prevention, 2013).
Plastic materials have become so numerous that you cannot go through a single day without touching something made of plastic. Toothbrushes, ballpoint pens, unbreakable dishes, cabinets and knobs for machines and appliances, light switches – all of these things and many more are made of plastic.
Extrusion produces material such as pipe or tubing, weather-stripping, fencing, plastic films and sheeting, deck railings, window frames, thermoplastic-coatings, and wire insulation. In the plastics extrusion, the raw compound material is usually in the form of nurdles, small beads which often called resin, that are gravity fed into a top mounted hopper then into the barrel of the extruder. Additives like colorants and U.V. inhibitors (liquid/pellet form) are often used and which then can be mixed into the resin precede to arrive at the hopper. The process has very much in common with plastics injection molding from a point of the extruder technology though it may differs in that as it is usually a continuous process. While pultrusion be capable of offering many same profiles in continuous lengths which comes usually with added reinforcing, this is achieved with pulling the finished result out of the die instead of extruding a typical polymer melt through the die. A large number of polymers are used in the production of pipes, rods, rails, plastic tubing, seals, and sheets or films. For example, ABS, HIPS
The food we consume everyday touches plastic infinitely, whether it is during the preparation stages, packaging, storage or even just eating the food from a plastic plate. There is no escaping the fact that the food we eat has a huge contact with plastics. However, what does this mean for our food? There is an adverse effect to plastics and their contact with foods, particularly acidic, fatty or salty foods. The chemicals in plastics go through a process called “leaching” or “migration” which leads to transfer of polymer additives, impurities and polymerisation solvents into packaged goods with a consequent risk of toxic hazard to the consumer (Crompton, T. (1979). [book]). In this
Other alterations such as dying the polymer are less cost efficient to recycle and can be more difficult as well. There are certain types of HDPE (high density polyethylene) that are blown into shapes such as bottles. Different chemicals are used in this process and therefore have to be separated into their own category when recycling. The reason people have moved away from landfill dumping and moved towards recycling is due to the fact that it is much more cost effective to recycle compared to paying engineers and environmentalist to designing landfills.4 The HDPE can also be mechanically recycled through curb side pick ups.
Polypropylene is one of those most versatile polymers available with applications, both as a plastic and as a fiber, in virtually all of the plastics end-use markets.[3]
Plastic bottles are everywhere, whether they are soda bottles, water bottles or even reusable bottles. Each year the number of plastic bottles filling up landfills is increasing by a considerable amount, which is a serious problem and can result in grave consequences for the environment. The average time estimated for a plastic bottle to decompose is approximately seven hundred years. One way to solve this problem is to recycle plastic bottles into the polyester by a process called polymerization. A lot of textile industries select polyester as their choice of fibre and fabric. Polyester is extensively used in manufacturing all kinds of clothes and home furnishings. According to Kris Barber (2011, page2), it takes about three bottles to make
Plastic is used in everything from food containers, to shoe soles, plastic bottles, baby bottles, sippy cups, medical devices, dental sealants, water bottles, specific hard plastics, and reusable water bottles. Additionally, inside these packaged items is a synthetic compound lining that has been used to reinforce these plastics and cans for more than 40 years (Shaw).
Polymers are made from relatively small molecular fragments known as monomers that are joined together. Synthetic polymers which include the large group known as plastics are divided into three groups: commodity thermoplastic, engineering thermoplastics (ETP), and advanced engineering thermoplastics (AETP). The engineering thermoplastics (ETP) have heat resistance, strong mechanical properties, lightness, self-lubrication, and easy manufacturing. This plastic category has been lately used to replace wood and metal applications.
Millions of plastic bags are given out to consumers by supermarkets and stores to carry their goods in. They are also cheap, light, durable, easy to carry and in many cases, free. The most commonly used shopping bag is made of High Density Polyethylene (HDPE). This type is used in the majority of supermarkets and stores. After these bags are used, they often end up in landfills or as litter, roughly only three percent of plastic bags is actually recycled per year (Planet Ark, 2011). The materials used in making plastic bags make them non-biodegradable. According to the science dictionary, 2011 refers to “these materials cannot be decomposed into environmentally safe waste materials by the action of soil bacteria.” These harmful substances are toxic and take approximately four hundred years to break down, or in this case photo-degrade; which is how plastics made from (HDPE) break down. Since they are not biodegradable, they remain in the environment and are absorbed in soil or water (Indian Centre for Plastics in the Environment, 2010). This essay will discuss the various harmful effects of plastic bags, and demonstrate the risks that these bags impose on humans, animals and the environment. It will also discuss a series of suggested solutions that could help reduce plastic bag usage.
But plastic is an extraordinary innovation that replaces many other expensive products with lightweight, strong easy to maintain , longer lasting material with a less expensive plastic. “Plastics are manufactured materials that can be shaped into almost any form.” Most plastics are made when two or more chemical compounds combine and cause chemical reactions to polymerize, or form a long chain of molecules to form. This causes the plastic to form. The plastic is then heated into a molten liquid and then molded into the shape needed. There are two basic types of plastics. They are thermosetting plastics and thermoplastics. The type of plastic it is determined by the way they react when heated. Thermoplastics are plastics that can be heated and melted and still reform its shape. Thermosetting plastics are just the opposite. They can be melted and cannot be reshaped into its original
are required and less energy is needed to make recycled plastic products than to make