Patent ID: 11938694
Assignee: ESSILOR INTERNATIONAL
Field: Other special machines (Mechanical engineering)
Classification: CPC B  G | IPC B  G

Claim 0:
1. A method for producing an optical article, the method comprising:
(a) setting a surface temperature of a mold cavity to a cooling temperature at least 5° F. to 150° F. lower than a softening temperature of a thermoplastic material;
(b) injecting the mold cavity with the thermoplastic material, the mold cavity including a Fresnel surface;
(c) applying a compacting pressure to the thermoplastic material;
(d) raising the surface temperature of the mold cavity to a heating temperature at least 20° F. higher than the cooling temperature; and
(e) lowering a temperature of the mold cavity to the cooling temperature to form an optical article;, wherein the thermoplastic material is a thermoplastic polyurethane (TPU), polyvinylchloride (PVC), or thermoplastic elastomer (TPE).