| History of Polystyrene foam: | | | | Polystyrene's most common use, however, is as |
| Polystyrene was accidentally discovered in 1839 | | | | expanded polystyrene (EPS). Expanded |
| by Eduard Simon; an apothecary in Berlin, | | | | polystyrene is produced from a mixture of about |
| Germany. From storax, the resin of Liquidambar | | | | 90-95% polystyrene and 5-10% gaseous blowing |
| orientalis, he distilled an oily substance, a monomer | | | | agent, most commonly pentane or carbon dioxide. |
| that he named styrol. Several days later Simon | | | | Through the use of heat, usually stem, the solid |
| found that the styrol had thickened, presumably | | | | plastic is expanded into foam. |
| due to oxidation, into a jelly he dubbed styrol | | | | Expanded polystyrene used to contain CFCs, but |
| oxide ("Styroloxyd"). By 1845 English chemist John | | | | other, more environmentally safe blowing agents |
| Blyth and German chemist August Wilhelm von | | | | are now used. Because it is an aromatic |
| Hofmann showed that the same transformation | | | | hydrocarbon, it burns with an orange-yellow flame, |
| of styrol took place in the absence of oxygen. | | | | giving off soot. |
| They called their substance metastyrol. Analysis | | | | Uses for Polystyrene: |
| later showed that it was chemically identical to | | | | Polystyrene, shaped and cut with hot wire foam |
| Styroloxyd. In 1866 Marcelin Berthelot correctly | | | | cutters, is used in architecture models, actual |
| identified the formation of metastyrol from styrol | | | | signage, amusement parks, movie sets, airplane |
| as a polymerization process. About 80 years | | | | construction, aerospace and much more. Such |
| went by before it was realized that heating of | | | | cutters may cost just a few dollars (for a |
| styrol starts a chain reaction, which produces | | | | completely manual cutter) to tens of thousands |
| macromolecules, following the thesis of German | | | | of dollars for large CNC machines that can be |
| organic chemist Hermann Staudinger (1881 - | | | | used in high-volume industrial production. |
| 1965). This eventually led to the substance | | | | Cutting EPS foam: |
| receiving its present name, polystyrene. The I.G. | | | | Expanded polystyrene is very easily cut with a |
| Farben Company began manufacturing | | | | hot-wire foam cutter, which is easily made by a |
| polystyrene in Ludwigshafen, Germany, about | | | | heated and taut length of wire, usually nichrome. |
| 1931, hoping it would be a suitable replacement for | | | | The hot wire foam cutter works by heating the |
| die cast zinc in many applications. Success was | | | | wire to the point where it can vaporize foam |
| achieved when they developed a reactor vessel | | | | immediately adjacent to it. The foam gets |
| that extruded polystyrene through a heated tube | | | | vaporized before actually touching the heated |
| and cutter, producing polystyrene in pellet form. | | | | wire, which yields exceptionally smooth cuts. |
| Characteristics of Polystyrene: | | | | Polystyrene can also be cut with a traditional |
| Pure solid polystyrene is a colorless, hard plastic | | | | cutter. In order to do this without ruining the sides |
| with limited flexibility. It can be cast into molds | | | | of the blade one must first dip the blade in water |
| with fine detail. Polystyrene can be transparent or | | | | and cut with the blade at an angle of about 30?. |
| can be made to take on various colors. It is | | | | The procedure has to be repeated multiple times |
| economical and is used for producing plastic model | | | | for best results. |
| assembly kits, plastic cutlery, CD "jewel" cases, | | | | Polystyrene can also be cut on 3 and 5-axis CNC |
| and many other objects where a fairly rigid, | | | | routers, enabling large-scale prototyping and |
| economical plastic of any of various colors is | | | | model-making. |
| desired. | | | | |