The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 10, 2003
Filed:
Apr. 30, 2001
Hao-Wen Chiu, Clearwater, FL (US);
Hsinjin Edwin Yang, Palm Harbor, FL (US);
Essilor International Compagnie Generale d'Optique, Charenton Cedex, FR;
Abstract
Disclosed is an injection molding method. The method comprises injecting a melt of thermoplastic material at a temperature higher than the glass transition temperature (T ) of the thermoplastic material in a molding cavity defined by a two-piece mold insert. The article is recovered after cooling and disassembling of the two piece mold insert. Each of the two pieces of the mold insert comprise at least one portion partly defining the mold cavity which is made of a material or combination of materials, other than glass, the thermal diffusivity &agr; of which fulfills the condition: 1<&agr;/&agr; <11, wherein &agr; is the thermal diffusivity of a borosilicate glass and is equal to 6.20×10 m s . The portion is at least 1 mm thick. The injection molding method can be used to form weld free minus lenses.