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It is easy to take for granted the use of plastics in our world, particularly so for a young person who has grown up surrounded by these materials. From the moment I was born, I've benefited from products manufactured from plastics. The basinet I was first placed in at the hospital, the bottle I took my first taste of food from, even the lining of the diaper I wore for my first article of clothing, all were undoubtedly comprised of plastic. It is remarkable to me now to realize that among my very first sensations, many of the textures and other characteristics belong to materials that have existed for only 137 years and perhaps in common use for a mere 40 years or less!
Today, as I have become more aware of the many substances used to produce goods, I am even more amazed by the incredible variety and versatility of plastics. I've had the opportunity to learn the basics of woodworking and ceramics. I've built items from metal and learned how metals are refined and shaped into useful forms. I've crafted with leather, and with string and fabric made from natural fiber. All of these experiences have enhanced my recognition and appreciation for the many types and properties of plastics. It seems that there is a plastic made that mimics the properties of almost every natural material, and furthermore that there are plastics with desirable properties possessed by no natural material.
When I sit in an automobile, my hands upon a plastic steering wheel, I sometimes consider how much effort it would take to manufacture that same item from wood or metal. Would it be economical to shape the wood with the same firm grip? Would it be as strong? Would a metal wheel be cold and uncomfortable? Then I touch the upholstery, a smooth textured vinyl which is difficult to distinguish from fine leather. And I know that the comfortable cushioning beneath the upholstery is polymer foam padding. The carpet is a nylon blend that wears better, resist moisture, and in other ways is superior to any natural fiber in this application. I look through the windshield and I know that laminated between sheets of glass is a layer of transparent plastic which will prevent the glass from shattering into sharp fragments should the windshield be broken. The bumper and many exterior body moldings and panels are made of rigid plastic which will not rust and are less expensive to replace than metal . The list goes on and on. And almost every place I go, I can see the same beneficial applications of plastics, in our homes stores and offices, in recreation and sports equipment, in food
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service and packaging, in communications equipment and aircraft.
Some of the extraordinary properties that make plastics so versatile are that they are moldable, castable, machinable, shapable, tintable, glueable, weldable, and non-conductive. Of course, not every type of plastic has all of these properties, but there are literally thousands of types and formulations of plastics. This gives the engineers of today a huge source of options above and beyond the natural materials that have been available for eons. New and better products are the result of this flexibility. In many cases, the products are less costly, more attractive, stronger or otherwise superior than products made from natural materials. I believe our lives are made better by the availability of plastics.
Plastics have been criticized as a problem to our society, however. Many people have pointed to the increase in non-biodegradable waste mass in landfills as a serious environmental issue. Others point out that the primary raw materials used to produce plastics today is crude oil, a non- renewable resource. And some note that dangerous or toxic chemicals are used in the manufacture of some plastics. Each of these statements is true, and there are specific problems or incidents related to each that justify them as legitimate criticisms. It can also be noted, however, that the use of plastics in some ways reduces pollution, reduces the use of other non-renewable resources, or other dangerous materials or processes. This does not minimize or excuse the other problems, but every issue should be considered from all sides. More importantly, significant steps are already being taken to address the criticisms.
Biodegradable plastics have been developed and are appropriate for some applications. Recycling of plastics also has reduced the mass of discarded plastics in landfills. More needs to be done to address the waste issue, and these are the kinds of problems that tomorrow's engineers must tackle.
While crude oil is the source of almost all plastic today, scientists have already developed means to create the resins to produce some plastics from renewable resources such as plants. I believe this is an exciting area that is still in its infancy, which will hopefully produce an economical alternate for raw materials in the future.
(Continued on page 5)
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