Patent DE-102014202017-A1 (DE)
Title: Injection molding an optical component comprises a two-step injection molding process where the mold gate is positioned in alignment with the two lateral surfaces of the baffles to allow molten optical material flow
Inventor: CHOQUET ERIC
IPC: B29D11/00
Filed: 2014-02-05
Abstract: Injection molding an optical component comprises injecting a first amount of a molten optical material through a first mold gate into the first mold cavity; and injecting a second amount of the optical material in the second mold cavity through a second mold gate where the mold gate is positioned in alignment with the two lateral surfaces of the elongated baffles to allow the flow of the molten optical material. Injection molding an optical component comprises providing a first mold cavity formed between a first mold cap and a mold core, the first mold cap having a cap injection surface, the mold core having a core injection surface and at least two spaced apart undercuts, each of the undercut having two lateral walls a depth, a width and a length; injecting a first amount of a molten optical material through a first mold gate into the first mold cavity, where the mold gate is located opposite to the undercuts in such a manner that the molding material flows into the first mold cavity in a direction parallel to the lateral walls of the undercuts and along the length of the undercuts; cooling the optical material in the first mold cavity, where the optical material makes cooling contact with the undercut walls so that at the end of the cooling time a first section of the optical component is formed , the first section including at least two elongated baffles formed by the molded material located in the undercuts, where each elongated baffle includes a front surface, an opposed back surface and two lateral surfaces; providing a second mold cavity formed between the first section of the optical component and a second mold cap; and injecting a second amount of the optical material in the second mold cavity through a second mold gate where the mold gate is positioned in alignment with the two lateral surfaces of the elongated baffles to allow the flow of the molten optical material. An independent claim is an optical lens made by injection molding in a mold through the injection of a single molten material in two injection shots of using a two step process, the optical lens comprising a first surface having a first periphery and a second surface having a second periphery; a lens body defined between the first surface and the second surface for a light beam to enter the lens through the first surface and exit the lens through the second surface where the first surface is injection molded in the first injection shot and the second surface in a second injection shot; a first mold gate mark located at the first periphery and a second mold gate mark located at the second periphery; and a first melt flow pattern including at least two spaced apart and continuous streams that fully extend within the first periphery injected through the first gate in the first shot and a second flow pattern including at least two spaced apart and continuous streams that fully extend within the second periphery injected through the second gate in the second shot, the first and second flow patterns being visible using optical testing devices.