Patent ID: 6949217

Claim:
A method of molding including: a) providing an upper mold and a lower mold, at least one of which is formed substantially of silicon or silicon alloy and which is at least partially transparent or translucent to electromagnetic radiation at one or more wavelengths in the infrared range, the upper and lower molds together or separately defining one or more cavities when said upper and lower molds are brought into contact with each other; b) providing a sheet of thermoplastic material between said upper and lower molds, said thermoplastic being at least partially absorbing of electromagnetic radiation at said one or more wavelengths; c) pressing the sheet between the first and second molds; d) during said pressing step, heating substantially the entire sheet by radiating the sheet with electromagnetic radiation at said one or more wavelengths through the mold or molds at least partially transparent or translucent to electromagnetic radiation at said one or more wavelengths, the combination of heat and pressure causing the sheet material to flow into the one or more cavities; maintaining said sheet between said first and second molds after completion of the heating step to cool said sheet, said sheet thereby substantially retaining a molded shape.