If you look around your home or place of business, you will find it difficult to locate any item that does not make use of plastics. Although they are often used in our lives, many of us are not familiar with the process of plastics manufacturing. Here is a brief overview of the process which can help you to have a greater understanding of how the plastic items that you use are made.
The first step in the process is to gather the raw materials. In the past, plastics were manufactured from vegetable matter, including oils, starches and cellulose. Today, the majority of plastics come from petrochemicals because they are easy to obtain and less expensive than the other materials which may be used in the manufacturing process. In recent years, a shift has been taking place to using plant-based plastics because of environmental concerns and because of the limited availability of oil (Source: http://chej.org/campaigns/pvc/resources/plant-based-plastics/).
Polymerization is the next step in the process, which can take place when the materials are condensed or if there are additives introduced to the raw materials. This process typically takes place when the polymer is either in a liquid or gaseous state but there are times when it may take place in a solid state polymer as well.
It is necessary to compound the polymer at this point so that it is a material which can be fabricated. A number of additives may be included in order to achieve the characteristics that are desired. Some of the additives may include flame retardants, plasticizers, ultraviolet stabilizers, lubricants and antioxidants. There may also be additional additions to the plastic, such as carbon fibers or glass which can increase their stability as well as their strength.
The final step in plastics manufacturing is shaping the plastic and finishing it. This is commonly done through a process known as injection molding, in which plastic that has been softened is forced into a mold and cooled, in order to hold its shape (Source: http://www.acrylicart.com/plastic-fabrication-services.html). It may also go through a process known as extrusion, in which the softened plastic is forced through a shaped die and holds the form. Another process is computer numerical controlled manufacturing, in which a larger piece is shaped by removing material in order to achieve the desired product. These are some of the ways in which plastic is manufactured in order to provide us with the products that we need.