Plastic technology
introduction
Plastics engineering encompasses the processing, design, development,
and manufacture of plastics products. A plastic is a polymeric material that is
in a semi-liquid state, having the property of plasticity and exhibiting flow.
Plastics engineering encompasses plastics material and plastic machinery.
Plastic Machinery is the general term for all types of machinery and devices
used in the plastics processing industry. The nature of plastic materials poses
unique challenges to an engineer. Mechanical properties of plastics are often
difficult to quantify, and the plastics engineer has to design a product that
meets certain specifications while keeping costs to a minimum. Other properties
that the plastics engineer has to address include: outdoor weatherability,
thermal properties such as upper use temperature, electrical properties,
barrier properties, and resistance to chemical attack.
In plastics engineering, as in most engineering disciplines, the
economics of a product plays an important role. The cost of plastic materials
ranges from the cheapest commodity plastics used in mass-produced consumer
products to the very expensive, specialty plastics. The cost of a plastic
product is measured in different ways, and the absolute cost of a plastic
material is difficult to ascertain. Cost is often measured in price per pound
of material, or price per unit volume of material. In many cases however, it is
important for a product to meet certain specifications, and cost could then be
measured in price per unit of a property. Price with respect to processibility
is often important, as some materials need to be processed at very high
temperatures, increasing the amount of cooling time a part needs. In a large
production run cooling time is very expensive.
Some plastics are manufactured from re-cycled materials but their use
in engineering tends to be limited because the consistency of formulation and
their physical properties tend to be less consistent. Electrical and electronic
equipment and motor vehicle markets together accounted for 58 percent of
engineered plastics demand in 2003. Engineered plastics demand in the US was
estimated at $9,702 million in 2007.
A big challenge for plastics engineers is the reduction of the
ecological footprints of their products. First attempts like the Vinyloop
process can guarantee that a product's primary energy demand is 46 percent
lower than conventional produced PVC. The global warming potential is 39
percent lower.