Delrin (Industrial Mechanical Engineering) Plastic
Delrin plastic is the DuPont trade name of a form of acetal homopolymer thermoplastic (acetals are generally abbreviated as POM for polyoxmethylene). DuPont patented the first practical form of the resin in 1956, synthesizing a thermally unstable form that was invented by a German chemist in the 1920s. Delrin has been in production by DuPont since 1960.
POM has a number of special properties that make it very useful industrially.
Delrin can be purchased in granular form that can be melted and formed into desired shapes by applying heat and pressure. It is sold in a range of viscosities, which make it amenable to a wide range of fabrication processes. It can be heat molded and extruded with standard equipment into rods, slabs, sheeting, or small diameter tubing. It is an ideal candidate for injection molding, rotational molding, or blow molding. It can be machined using traditional milling machines. It can be drilled or cut with infra-red laser cutters.
Although POM is difficult to bond, special processes of surface etching, flame treatments and mechanical abrasion are available to improve the effectiveness of epoxies and other adhesives. Once treated, POM will bond with metals, leather, rubber and other plastics. Thermal welding has been used successfully as well. POM has excellent solvent resistant properties which have the downside of making solvent welding largely unsuccessful.
It is a comparatively dense crystalline plastic (more dense than about 72% of similar plastic materials). The material is almost self-lubricating, with a low friction coefficient and high abrasion tolerance. Special grades of Delrin are classified as static dissipative. It does not hold static electric charges but conducts the electrical charges internally as well as on the surface. With volume resistivity close to the insulator range, it will not hold static charges and can be used in an insulation function.
Delrin has been used in mechanical gears, sliding and guiding elements, housings, springs, chains, screws, nuts, fan wheels, pump parts, and valve bodies. It has been used in electrical parts manufacturing including insulators, bobbins, connectors. Delrin has been widely used in vehicle manufacture because of its electrical and mechanical properties. The Food and Drug Administration has approved acetals for use in food packaging.
For more info about the differences between Delrin and acetal copolymer check out this previous Colorado Plastics blog post.
Colorado Plastics is a full service wholesale distributor of Delrin plate and rod. We also provide custom manufacturing and contract manufacturing services. Contact us to discuss your needs.