Introduction
Most consumers always considered plastics as a cheap product, but that notion is no longer practiced today. Manufacturers are often finding different uses of plastics, such as in automobiles parts, computers, toys, medical equipment, school or sports equipment, cutlery, and a cloth or textile products. This is an indication that the plastic manufacturing industries are on a steady and fast growth scheme. Historically, the natural materials that were in use included the horns from animals and other parts such as scales and the trees.
A good example of a tree is the gutta-percha. Plastic is therefore either a manmade or a synthetic polymer that has very high similarities to other plants and trees. A polymer is a complex organic but versatile substance produced through a procedure known as polymerization, which presents capability for change through casting, casting or extruding. This term paper forms an analysis of the manufacturing process referencing particularly on the plastic cups.
Historical Overview
Shells such as that tortoise, amber, and horns are natural polymers and from history, people often similarly used them as contemporary manufactured plastics. According to (Rosato, 2006), “unveiling of the first man-made plastic occurred in 1862 when Alexander Parkes made and presented it in a London’s great international exhibition.” Registration of the widely used and obvious material called polyvinyl chloride (PVC), occurred in 1914 but people utilized it extensively after the First World War (Rosato, 2006). The enhancement of plastics products occurs by means of petroleum. Today’s products have replaced other materials such as glass, wood and metal.
Other new plastic materials such as polyester, polyurethane, polycarbonates, polypropylene, silicones, emerged later and are in use up-to-date for various appliances. The cost-effectiveness of plastics makes them locally available for end-users and common among consumers. High technological plastics are common in health and hi-tech worlds. Today, there is a continuous approach to production of new types and forms of plastics used in a wide range of applications. They are able to offer different customized properties for unique applications (Rosato, 2006).
Technical description of the material
Manufacturing of plastic cups mainly occurs from the high density or low-density polythene, polyvinyl Chloride (PVC) or polystyrenes often called resins (Leadbitter et al, 1994). The recycling programs avail a variety of plastic materials for recycling. All plastics have an initial health and environmental impact however, they all differ on the manufacturing procedures and different additional materials used in the manufactory procedures.
Some of the chemical raw materials contain combinations that are more toxic and are thus more hazardous during production, use as well as disposal. None of the aforementioned materials is environmentally friendly, but polyethylene contains lesser chemical hazards compared to other options. The manufacturing firms therefore prefer them compared to polystyrenes and Polyvinyl Chloride (PVC) (Leadbitter et al, 1994).
Manufacturers choose this material due to various qualities such as simplicity and the ability to enhance high performers in various industries. Manufacturers measure plastic performance levels by checking on the strength of the material and the reinforcement ability or compatibility with other materials such as fiberglass.
Manufacture of the polyvinyl Chlorine (PVC) occurs through polymerization. The raw materials are mainly natural gases and oils. The plastic cup as a result emanates from hydrocarbons monomers. Monomers join to form a long chain-link of the polymer compound. The common examples of these polymers include polystyrene, polypro pane, and polyethylene. Carbon and hydrogen molecules link to form the monomers.
Other elements include chlorine, oxygen, nitrogen and fluorine, which are in majority of the plastics. In line with (Rosato, 2006), “Polyvinyl chloride (PVC) contains chlorine. Nylon contains nitrogen. Teflon contains fluorine. Polyester and polycarbonates contain oxygen.”
Manufacturers break up the plastic materials into thermo-sets and thermoplastics. The majority of the plastic cups are recyclable thermoplastics. Meaning that it is possible to heat and reform them repeatedly. The easiness of processing and recycling consequently facilitates reprocessing to conserve the environment. On the other hand, thermo-sets are not recyclable. Reheating such materials causes decompositions rather than melting.
Material properties
The general attributes of plastics include resistance to chemicals such as cleaning solvents. They have strong and aggressive resistance to powerful chemical solvents. Plastics have unique characteristics that relate to portability and strength. The plastics are easy to process in various ways, and it is possible to intricate them to various molds. Some of these plastics are very flexible since the manufacturing process utilizes materials that mimic cotton, wool, fiber, cotton or silk.
The flexibility enhances ability to mold materials, drums and mix with different solvents, thus facilitating the emergence of paints or adhesives. The characteristics and color of polymers seem limitless and as a result, they have broader application capabilities. Although mainly made from naturally occurring gases such as crude oils and polymers for plastic cups, other materials can also be from other economically viable renewable materials, for instance the cellulose acetate for the handles of equipment.
The safety of health requires a material that is not able to chip out or break easily. This means that ability to remain durable and strong under harsh conditions eases the manufacturing process and enhances the environmentally conducive alternatives of plastics. A manufacture ought to consider various factors before deciding on the raw materials. They include ability to facilitate color, stability under harsh conditions, processing easiness and the overall cost.
Durability, safeness of operation and support for different operating conditions enhance the strength of polymer materials. Plastic cups should generally be resistant to possible breakages, abrasion-resistant, rigid and resistant to deforms. People often subject the cups too high temperatures; therefore, they must be resistant to such general conditions. According to Bryce (1996), “Unstable chemicals and weak bonds are more prone to oxidative cleavage, which initiates a chain reaction of degradation.” The chemical combination hence withstands degradation.
Plastics are equally resistant to chemical reactions, water and oil solvents. Other than being non-toxicant to the user, the cups are free from reaching. Reliance is also an important property that the plastic cups must possess. They are often subject to abuse and to prevent breakage, it is important that manufacturers ensure they are fatigue resistant and retain shape. This calls for flexibility and depends on the molecular structure, crystalline nature, humidity and other secondary forces of attraction such as hindering static problems and polarity (Bryce, 1996).
Economics
The economics of scale places the plastic material under high competitive status. Plastic overthrows alternative materials because it provides similar or better strength and quality compared to another material type. Availability of alternative materials requires analysis based on the financial viability. Any kind of manufacturing must ensure the economics of scale measures up to the health, safety, flexibility and returns.
Manufacturability
The manufacturing process of plastic substances such as cups utilizes an energy-saving mechanism. The polythene bottles and cups manufactory also utilizes several toxic materials that often lead to emissions. High-Density Polyethylene (HDPE) rarely requires plasticizers to reduce contaminations. In most cases, highly intoxicating substances use additives such as phthalates, to reduce the quantity, amount as well as the rate of toxicities. According to United States, Congress (1990), on the issue of competing manufacturing, “Some applications use flame-retardant additives, which brominate and may end up being toxic.” The plastic has a high probability of mechanical recycling. Through recycling, the manufacturers have to collect the used materials for curbside programs that cater to recycling.
Manufacturing Process
The production of plastic cups involves blending the High-Density Polyethylene (HDPE) material with additives to process the final products. The additives enhance the physical, mechanical, and chemical properties of the raw material. The additives also assist in protection of the products from degrading effects such as effects by light, moderate heat and bacterial effects. The additives enhance other properties such as the likelihood of color changes or structural change and provide an improvement of appearance for instance improvement of surface appearance, and reduction of friction.
“Plasticizers are materials incorporated during the manufacturing process to improve or enhance on the workability and flexibility of plastic products.” (United States, Congress, 1990) The additives are safe and standardized by food bodies such as the U.S. Food and Drug Administration (FDA) to guarantee health or human safety (United States, Congress, 1990). There are various processing procedures. The first process includes extrusion.
Plastic pallets are loaded into a heat chamber known as an extruder or hopper and moved along the chamber in a rotating process to ensure uniformity of the liquidated plastic. The heating mechanism in the compartment emanates from the mechanical process of revolution and sidewall metals that become extremely hot. The molten plastic material forcedly flows out of the extruder through a small aperture to shape the required equipment. The cooling process occurs at the end by the use of cool air or water (Harper, 2006).
Alternative manufacturing process
The injection molding mechanism involves almost a similar heating mechanism to the extrusion mechanism. The granules pass through the heating chamber and become softer to fluid state. The process subjects the resin to high pressure, which forces it through an outlet to the cooling process to produce a solid shape. Another alternative involves the blow molding, which is a conjunction between injection and extrusion techniques. In the aim of producing uniform molten mold, the extrusion process pusses the plastic through the heating chamber of the extruder and the material become softer to a fluid state.
The molten plastic is able to melt because of the extrusion procedure of blowing mold. The process forces compressed air into the tube for conformation and brings out the exact shape of the product. The goal of the procedure is to produce an interior made of uniform mold and blown to a specific shape of the product. The procedure also tries to avoid production of separate parts of an item that requires some joining to form the final product.
In injection molding, the process subjects an intermediate form known as performing to heat and blow the softened plastic to the required shape of chilled mold (Harper, 2006). Lastly, rotational molding comprises a closed mold mounted to a special machine that rotates on double axis and is able to distribute molten plastic into uniform coating on the inside of the machine until the final product appears through cooling.
Comparison between Different Cups from a Manufacturing View
Non-durable Vs Durables Plastic Products
The classification of plastic products occurs through analysis of their life spans. Durables have more than three years lifespan and the products are mainly “appliance, furniture, consumer goods, automobiles parts, building and construction materials” (Harper, 2006). The comparison also depends on the major plastics such as Polyethylene Terephthalate (PETE) a major material for the manufacture of food and beverage containers due to properties such as clarity, heat resistance as well as moisture resistance. The ability to cater to high temperatures enables manufacturers to consider items that are applicable in food preheating procedures such as food dishes. The cups can be ideal microwave heat-resistant products.
On the other hand, ‘High-Density Polyethylene (HDPE)’, provides excellent resistance to moisture and chemicals. The plastics are however limited to food containers and other similar applications that do not require an oxygen or carbon dioxide barricade. They are mainly for the non-carbonated foods and packaging of most household foods due to the chemical resistance mechanism. Lastly, Polyvinyl Chloride (PVC) has remarkable characteristics such as excellent transparency, resistance to chemicals, overall stability, ability to withstand harsh weather conditions and characteristics in support of electric energy insulation, resistance to corrosions and flexibility. PVC is more suitable for the construction markets.
Conclusion
Plastic has a vital role in today’s economy, the versatility allows people to have a wide range of applications. The provision by plastics is at consumer-friendly costs and food containers such as cups are readily and locally available. The main qualities a consumer ought to check is safety, health, durability, value for money and performance. The manufacture of plastic is for helping consumers to find effective alternatives.
References
Bryce, D. (1996). Plastic injection moulding: manufacturing process fundamentals. New York, NY: Society of Manufacturing Engineers press.
Harper, C. (2006). Handbook of plastic processes. Canada. Wiley Publishers.
Leadbitter, J. Day, J and Ryan, J. (1994). PVC-Compounds, Processing and Applications. Rapra Review Reports. 7(6). United Kingdom: Rapra Technology Limited.
Rosato, D. (2006). Plastics Engineering, Manufacturing & Data Handbook. Plastics Institute of America. (Volume, 2). Massachusetts, MA: Kluwer Academic Publishers.
United States, Congress. (1990). Making Things Better: Competing In Manufacturing. Washington, WA: U.S. Government Printing Office.