Nearly all forms of plastic are made from natural gas, oil, and some types of vegetation. Plastics have been demonized as a symbol of all that is wrong with society, but nearly everyone still uses them. Even the most vocal opponents express their disapproval using a plastic computer keyboard. The manufacturing method that makes these finished products possible is called thermoforming.
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 material used in this process begins as a continuous sheet of acrylic, polypropylene, polyvinyl chloride, or other similar polymer. That thin layer is carefully heated to the point that it becomes pliable, but not liquid. Using one of three methods, it is then applied to a specifically designed mold, allowed to cool, and trimmed. The result is a smooth, finished piece or component.
The heat is provided by radiant electrical units positioned approximately five inches from the sheet. Different polymers require specific warming periods, but once the correct temperature has been reached, they are ready to be molded into the requested shape. The most common method is called vacuum forming, which employs negative pressure similar to a home vacuum device.
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.
Mechanical forming uses both positive and negative molds. When plastic sheeting is placed between the two, pressure is applied, and the material assumes the shape and texture of the space between pieces. This gives manufactures better control over detailing, but is somewhat more expensive. No matter which process is being used, only thermoplastics can be reheated successfully.
Thicker sheets are used to make different vehicle components, are molded into health care accessories, and even make an appearance in the bathroom. Thinner gauge plastic sheeting is used to package cosmetics, small individual products like screws, and fresh and processed foods. While not yet biodegradable, recycling and disposal methods have been greatly improved.
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 material used in this process begins as a continuous sheet of acrylic, polypropylene, polyvinyl chloride, or other similar polymer. That thin layer is carefully heated to the point that it becomes pliable, but not liquid. Using one of three methods, it is then applied to a specifically designed mold, allowed to cool, and trimmed. The result is a smooth, finished piece or component.
The heat is provided by radiant electrical units positioned approximately five inches from the sheet. Different polymers require specific warming periods, but once the correct temperature has been reached, they are ready to be molded into the requested shape. The most common method is called vacuum forming, which employs negative pressure similar to a home vacuum device.
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.
Mechanical forming uses both positive and negative molds. When plastic sheeting is placed between the two, pressure is applied, and the material assumes the shape and texture of the space between pieces. This gives manufactures better control over detailing, but is somewhat more expensive. No matter which process is being used, only thermoplastics can be reheated successfully.
Thicker sheets are used to make different vehicle components, are molded into health care accessories, and even make an appearance in the bathroom. Thinner gauge plastic sheeting is used to package cosmetics, small individual products like screws, and fresh and processed foods. While not yet biodegradable, recycling and disposal methods have been greatly improved.
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 plastic pallets price, she suggests you check out her friends PTM.
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