Gentex Optics, Inc.

Paresh V Kitchloo

Robert A Sallavanti

Russell F Weymouth, Jr

Séverine Tisné

Boris L Serebrennikov

Timothy Murray

Daniel Gazaille

Jr Russell F Weymouth

Timothy P Murray

An apparatus and method for producing defect-critical articles from a molding resin comprising at least 98% clear polymer and additives including a heat stabilizer and a UV blocker in an injection molding machine. According to the apparatus, there is provided an injection molding machine in combination with a molding resin. The injection molding machine's resin delivery assembly is made from a powder metallurgy formed into solid non-coated parts having a Chromium-Vanadium (Cr/V) blend. As the molding resin interacts with the resin delivery assembly, the resin only contacts the solid non-coated parts whereby the resin experiences less degradation and provides improved quality for the defect-critical articles. The method includes the steps of plasticizing, injecting, and cooling. During the plasticizing and injecting steps, the molding resin only contacts solid non-coated parts made from a powder metallurgy material containing a Chromium-Vanadium (Cr/V) blend thereby producing reduced defect articles.

Uncoated, corrosion resistant resin delivery system

A method and system for monitoring lens material residence within a conduit to improve the quality of molded products by reducing defects arising from entrapped lens material. According to the method a finite element mesh representative of a conduit is stored in a digital storage device. A simulation is run on a digital computer in which one type of lens material sequentially flows through the conduit in discrete batches temporal history of the batches within the conduit is tracked. The simulation is useful for analyzing material delivery conduits in injection molding and casting systems, for example, for lens manufacturing. According to the system, a digital storage device stores a finite element mesh representative of a conduit. A digital computer is coupled to the digital storage device for executing a set of instructions to run a simulation and track the temporal history of the batches within the conduit.

Method and system employing flow simulation for improving material delivery in lens manufacturing

Optical qualities of a production lot of base material used in the fabrication of semi-finished lenses may be accurately determined by employing chipper plate samples produced from the base material in accordance with aspects of the present invention. In various implementations of the present invention, the chipper plates samples may be fabricated by subjecting base material to an extended cycle time and temperature profile using a mold having cavities of different thicknesses. The resulting chipper plates provide an improved indication of the color of semi-finished lenses molded from the production lot as well as an improved indication of resin stabilizer defects that may be utilized during a pelletizing process to control and enhance the quality of a production lot. Furthermore, the chipper plates may be provided by suppliers as samples of a production lot to enable customers to base purchasing decisions on a reliable and accurate measure of optical properties.

Methods for controlling and enhancing the quality of base materials employed for the production of semi-finished ophthalmic lenses

A method and apparatus for improving the performance of rimless spectacle lenses. An abrasive wire is provided for polishing bore holes which are drilled in lenses. The abrasive wire includes a wire substrate with abrasive particles embedded along its length. The wire and particles are dimensioned for threading through the bore hole and allowing space to perform a soft-filing operation. By polishing the micro cracks formed during drilling, propagation leading to lens failure which arises from spectacle use can be reduced.

Rimless spectacle lens bore polishing method and apparatus

A method of infusing a dye into the surface of an article formed of a plastic material comprises contacting the surface with a solution including one or more solvents each aggressive to the plastic material, one or more dyes and one or more substances each capable of plasticizing the plastic material. If the plastic material is polycarbonate, then the aggressive solvent may be one or more chlorinated hydrocarbons. The dye may be a photochromic dye, a cosmetic tinting dye, dyes for absorbing infrared, laser and ultraviolet radiation, or combinations thereof. A wide range of plasticizers has been investigated. The article is contacted by the solution for ten seconds to one minute; and nearly all the infused solvent is then evaporated from the article by heating. The use of one or more plasticizers reduces or eliminates bubbling or hazing of the contacted surface during solvent evaporation. The dyed article comprises a surface layer having a depth of the order of magnitude of 100 microns containing one or more dyes, one or more plasticizers and, likely, a trace amount of the one or more aggressive solvents.

Infusion of dye using a plasticizer

A surface of an article, such as an optical element, formed of a polycarbonate-polyester copolymer, is subsequently tinted to a predetermined degree by first subjecting said surface to ultraviolet radiation of predetermined intensity for a predetermined period of time.

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North Attleborough, MA, United States of America

Paresh V Kitchloo