Most plastics are derived from oil, natural gas, and some plant materials. Although plastic products have been called the ultimate symbol of a throwaway consumer society, everyone uses them. Even the most ardent critics express their concerns via plastic computer keyboards. Thermoforming is a manufacturing process that shapes this raw material into finished products.
Environmental concerns regarding fossil fuel dependence are real, but plastic production accounts for less than 3% of the total amount of natural gas and oil consumed in the United States. While that is still a considerable amount, eliminating all production would do little or nothing to diminish reliance on oil as a fuel source, and would probably increase overall consumer prices.
The process begins by transforming refined oil into a continuous sheet of polyvinyl chloride, polypropylene, acrylic, or similar related polymers. They are fed into a production line where they are heat-treated enough to become pliable, but not completely liquid. Using one of three common methods, the plastic is forced into or over a mold, cooled, and the excess removed.
The sheets are commonly processed using radiant electrical heat coming from devices positioned around five inches away. The type of polymer being used determines how long the heat must be applied. Once pliable, there are three primary methods of achieving the final shape. The first is called vacuum forming, which uses negative pressure to draw the warm plastic into a mold.
Pressure forming is also possible using positive energy. Vacuum processes are limited by physics, but positive pressure reaches higher levels, making it a more versatile choice. In order to avoid thin spots, the sheets undergo pre-stretching. Once in place, the trapped air escapes via vents in the mold, and the cooled product is then ready to trim.
Many products require two-sided molds. The unformed plastic is heated, forced between the parts under pressure, and assumes the texture and shape of the space in between. This gives manufacturers much better control over important product details, but is costlier. Regardless of the method being used, only thermoplastics can survive reheating without breaking down.
Thicker gauges are used to make vehicle parts, medical industry accessories, electronic component housings, and are even important in some bathroom fixtures. Thinner gauges are perfect for packaging foods, cosmetic products, and numerous other small items such as screws or paper clips. While most are not biodegradable, methods of disposal and recycling are improving.
Environmental concerns regarding fossil fuel dependence are real, but plastic production accounts for less than 3% of the total amount of natural gas and oil consumed in the United States. While that is still a considerable amount, eliminating all production would do little or nothing to diminish reliance on oil as a fuel source, and would probably increase overall consumer prices.
The process begins by transforming refined oil into a continuous sheet of polyvinyl chloride, polypropylene, acrylic, or similar related polymers. They are fed into a production line where they are heat-treated enough to become pliable, but not completely liquid. Using one of three common methods, the plastic is forced into or over a mold, cooled, and the excess removed.
The sheets are commonly processed using radiant electrical heat coming from devices positioned around five inches away. The type of polymer being used determines how long the heat must be applied. Once pliable, there are three primary methods of achieving the final shape. The first is called vacuum forming, which uses negative pressure to draw the warm plastic into a mold.
Pressure forming is also possible using positive energy. Vacuum processes are limited by physics, but positive pressure reaches higher levels, making it a more versatile choice. In order to avoid thin spots, the sheets undergo pre-stretching. Once in place, the trapped air escapes via vents in the mold, and the cooled product is then ready to trim.
Many products require two-sided molds. The unformed plastic is heated, forced between the parts under pressure, and assumes the texture and shape of the space in between. This gives manufacturers much better control over important product details, but is costlier. Regardless of the method being used, only thermoplastics can survive reheating without breaking down.
Thicker gauges are used to make vehicle parts, medical industry accessories, electronic component housings, and are even important in some bathroom fixtures. Thinner gauges are perfect for packaging foods, cosmetic products, and numerous other small items such as screws or paper clips. While most are not biodegradable, methods of disposal and recycling are improving.
About the Author:
Genevive B. Mata has over 20 years of professional sales experience, 10 of them directly in the plastic pallets and materials handling industry. On her spare time she works on applied-sustainability projects. If you are interested in buy plastic pallet, she suggests you check out her friends PTM.
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