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Abstract

The present invention relates to an improved method of manufacture of molded polymeric devices using variable frequency microwaves. Molded polymeric devices include, for example, contact lenses, corneal rings, intraocular lenses and drug delivery devices such as anterior or posterior chamber inserts. Contact lenses include soft and rigid gas permeable contact lenses as well as, lens blanks lathed into finished contact lenses. Molded polymeric devices further include medical devices such as prosthetics including hip joints. According to the present invention, a mold having a cavity the shape of the desired molded polymeric device, the cavity containing a composition comprising one or several monomers having double polymerizable bonds, is placed in a microwave chamber. The mold can be plastic, glass, ceramic or metal. Plastic is preferred. The mold is then swept with at least one range of microwave frequencies to polymerize the composition, thus forming the molded polymeric device. A range of frequencies includes a central frequency selected to rapidly heat the composition. A range is selected to generate a plurality of modes within the chamber. Sweeping is performed at a rate selected to avoid damage to the polymer formed and the mold.

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First Claim