Abstract: Designs for basecurves are disclosed which are designed to promote adhesion of an excess polymer HEMA ring to the basecurve during a demolding operation such that the excess polymer HEMA ring is removed along with the basecurve during the demolding operation. The basecurve mold designs promote and maintain adhesion of an excess polymer HEMA ring to the basecurve in a process for molding cast contact lenses in mold assemblies, each comprising a frontcurve and a spaced basecurve, and wherein a molded lens is formed therebetween. In an embodiment of the invention, the annular area of the basecurve mold can be formed with an annular step which includes projecting teeth positioned therearound which project into the excess polymer HEMA ring.

Abstract: An on-demand fast cycle mold for producing injection molded products such as polypropylene blister package bases. The on-demand fast cycle mold has a heated and cooled hot runner system which provides a short response time and optimal temperature control. On-demand injection molding is made possible by a pulse modulated closed loop mold cooling system, the cooling design of brazed gate inserts, and an effective layout of the cooling channels. The programming of the software for a computer control system has also been designed to achieve on-demand injection molding. The design of the closed loop mold cooling system incorporates an advanced cooling circuit layout, and provides for easy maintenance and better quality control of the coolant which significantly reduces corrosion and scale buildup. Mold cooling is controlled by sensors installed inside the mold which are used in feedback control loops.