Plastic Shapes
Plastic shapes are specially-formed plastic objects that have been processed by a plastic shaping process. There are many plastic shaping processes, and they include molding, extrusion, casting, and other methods. Each method is intended to create a different kind of plastic shape. Molding, for example, is the process best suited for the creation of complex, discrete products. Examples of discrete products include fasteners, pallets, and cases for small electronics. Extrusion, on the other hand, allows for the creation of complex, continuous products. Examples of continuous products are trim, hoses, and tubes.
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Applications of Plastic Shapes
Industry and commerce require broad access to discrete plastic shapes as well as plastic shapes produced by continuous manufacturing processes like extrusion. Extruded plastic products like PVC pipes, plastic hoses, plastic tubes, trim, channels, and coextrusions are used extensively in all kinds of applications. Plumbing, gardening, chemical processing, building construction, and furnishing depend heavily on extruded plastics.
A wide variety of plastic materials can be extruded, including:
- High and Low Density Polyethylene
- Butyrate
- Vinyl
- Polypropylene
- Polystyrene
- Acrylic Materials
Plastic Shape Extrusion Process
The plastic extrusion process takes place in a few steps. First, the raw thermoplastic material, in flake or pellet form, is poured into a hopper. From there, it is fed down into a conveyance channel, where it is heated by the turning of a large shearing screw. The friction caused by the turning of the screw combined with heat from electric heating elements causes the plastic to become molten by the time it reaches the end of the channel. At the end of the channel is a die, which is a tool used to shape raw materials into useful products. In the case of plastic extrusion, the die is a specially-cut shape in a metal plate through which the molten plastic passes. Once the plastic has become molten, it is forced through the die and emerges on the other side as a newly extruded plastic shape. Once extruded, the shape is allowed to cool and harden. It can then be cut to the appropriate length and either sent for shipment or prepared for additional processing like painting or labeling.
Innovations in the Plastic Industry
Researchers have recently discovered a polymer that is able to change shape automatically and repetitively. The shape shifting is prompted by temperature; when the material reaches a predetermined temperature, the plastic shifts into the new position. Once the plastic cools, it reverts back to the original form. This new innovation, known as a “polymer actuator,” has the potential to be utilized in a wide range of industries. One of the main advantages of this new polymer design is the fact that it requires no outside electricity to create a linear motion.
Another interesting innovation in the plastic industry is hand moldable plastic. This plastic has a very low melting point and can easily be formed into any desired shape. This product is ideal in situations where a handcrafted plastic solution is necessary perhaps for an attachment or component replacement. The process to utilize this innovation is simple; heat the plastic between 136°F - 140°F and then it is ready to be molded. A big advantage with this type of plastic is it can be reformed an infinite number of times. This moldable plastic is ideal for prototyping, quick fixes and unique design.
These two advances in the plastic industry are only examples of the innovation potential from the industry. The repeatability and usability of these products are key factors to their success. Certain applications that require linear motion could greatly benefit from the self-sustaining feature of the polymer actuator. Further manipulation of these materials on the molecular level will expose a plethora of discoveries that can be beneficial for consumers as well as manufacturers.