Constantine Georgakopoulos

Plastics

Plastics are one of the most versatile materials ever developed. Plastics can be made to resemble or replace things like metals, wood, glass, stone cloth, rubber, jewels, glue, cardboard, varnish and leather. The main reason why plastic can replace all these things is because it is strong, durable, lightweight, resistant to corrosion and it costs less.

A valve made of plastic, assembled by a technician, will replace a defective heart valve.

Plastics are made from the breakdown products of petroleum and coal. Plastics are organic compounds because they contain carbon. Atoms of carbon join together to form an extremely long molecule.

The long molecule chain of an organic compound: Plastic.

Plastic is very easy to make. The resin (or pure plastic) is melted and then molded into any shape or form that is desired. The interesting thing about them is that things can be added to the resin to give the plastic different and unique properties. For example if smoke and flame retardant materials like aluminum tryhydrate are added to the plastic it becomes less flammable and toxic in case of a fire. Adding calcium carbonate to the plastic makes it more rigid, resistant to impact and cracking.

There are different ways of molding plastics, which include:

Other methods include extrusion molding, transfer molding, low-pressure molding, high-pressure molding, reaction injection molding and foam molding.

Important plastics and their uses

Acrylics. Molding compound, glazing.

Epoxies. Protective coatings, adhesives, laminating compounds, composites.

Melamine-formaldehyde (aminos). Molding compounds.

Nylon. Filaments, fibers, bristles, engineering applications.

phenol-formaldehyde (phenolics). Molding and laminating compounds, adhesives, cast sheets, rods, tubes.

Polyesters, saturated. Fabrics, food packaging, molding compounds, engineering applications.

Polyesters, unsaturated. Laminating and molding compounds, protective coatings, castings.

Polyethylene. Film, extruded tubing, sheets.

Polystyrene, or styrene. Molding compounds, foamed resins.

Polyurethanes. Protective coatings, adhesives, foamed resins.

Polyvinyl chloride. Film, sheets, extruded tubing, casting.

Silicones. Rubber compounds, molding compounds, protective coatings, paints, and varnishes.

Urea-formaldehyde (aminos). Textile-treating compounds, molding compounds, foamed resins.

Vinyls (several types). Protective coatings, extruded tubing, film, molding compounds, foamed resins.

I would like to finish of by saying that if water is the universal solvent than plastic should be the universal moldable material.