industrial
Plastic
Submitted by admin on Wed, 10/21/2009 - 08:45The word plastic derives from the Greek plastikos- fit for molding and plastos- molded. Plastic is a wide range of synthetic or semisynthetic organic amorphous solid materials suitable for the industrial or commercial products. Plastics are polymers of high molecular mass, that may contain other substances to reduce costs or improve performance. Modern manufacturing processes allow them to be pressed, cast, or extruded into different kinds of shapes—such as bottles, fibers, boxes, plates, films, and much more.
There are two types of plastics:
Thermosets, that can melt and take shape once, and stay solid after they have solidified,
Thermoplastics, that will soften and melt when enough heat is applied, for example: polyvinyl chloride, polystyrene, polyethylene, and polytetrafluoroethylene (PTFE).
Plastics can be classified by the chemical process used in their synthesis; for example, as cross-linking, condensation or polyaddition.
Plastics can also be classified by their chemical structure, for example, silicone, halogenated plastics, polyesters, polyurethanes or the acrylics.
They can also be ranked by various physical properties, such as tensile strength, resistance to various chemical products, density, glass transition temperature, etc.
Other classifications are based on qualities that are relevant for manufacturing or product design, for example, electrically conductive, elastomer, biodegradable, structural, the thermoplastic and thermoset, etc.
Plastics have already displaced many traditional materials, such as paper, wood, stone, leather, metal, glass, horn and bone; and ceramic.
They are used in a huge range of products because they can easily be manufactured, they are relatively low cost and imperviousness to water and versatility.
