Development of a Two-Piece Mask and Lens and Mold for Same

摘要

Modified contract objective was to screen and modify available elastomers for use as lenses for a mask. Also, a program to bond such a lens to a rubber faceblank was required. Two molds-one faceblank less lens area mold and one lens mold were required. By many tests named in the keywords of this and next pages, a Nordel 1320 vulcanizate; covulcanized Nordel 1320/Vynathene CY903; Vynathene EY903 vulcanizate; Elvax 150 vulcanizate and LR3-463 polyurethane vulcanizate were selected as final candidates for lens substance. Final candidate appears to be Nordel 1320, 100; Cabosil MS-7,3,0; Vul-Cup R, 1.5 and Antioxidant 330, 0.5 parts by weight. Loctite 420 was chosen as adhesive for the lens to the faceblank. Photos of the molds and of assembling operations for the two-piece mask are given.