US 11,938,694 B2
High speed injection molding with heat/cool cycle for making optical articles
Hao-Wen Chiu, Dallas, TX (US); and Shannon Loiselle, Dallas, TX (US)
Assigned to Essilor International, Charenton-le-Pont (FR)
Appl. No. 16/754,883
Filed by Essilor International, Charenton-le-Pont (FR)
PCT Filed Oct. 8, 2018, PCT No. PCT/EP2018/077332
§ 371(c)(1), (2) Date Apr. 9, 2020,
PCT Pub. No. WO2019/072767, PCT Pub. Date Apr. 18, 2019.
Claims priority of application No. 17306380 (EP), filed on Oct. 12, 2017.
Prior Publication US 2020/0316886 A1, Oct. 8, 2020
Int. Cl. B29D 11/00 (2006.01); B29C 45/00 (2006.01); B29C 45/37 (2006.01); B29C 45/73 (2006.01); B29C 45/78 (2006.01); G02B 3/08 (2006.01); B29K 21/00 (2006.01); B29K 27/06 (2006.01); B29K 75/00 (2006.01); B29L 11/00 (2006.01)
CPC B29D 11/00269 (2013.01) [B29C 45/0025 (2013.01); B29C 45/372 (2013.01); B29C 45/7306 (2013.01); B29C 45/78 (2013.01); B29D 11/00432 (2013.01); G02B 3/08 (2013.01); B29C 2045/7393 (2013.01); B29C 2945/7604 (2013.01); B29C 2945/7626 (2013.01); B29K 2021/003 (2013.01); B29K 2027/06 (2013.01); B29K 2075/00 (2013.01); B29L 2011/005 (2013.01)] 13 Claims
OG exemplary drawing
 
8. An injection molding system for producing an injection molded optical article, the injection molding system comprising:
a mold having a mold cavity for receiving a thermoplastic material, the mold cavity including a Fresnel surface;
a heat source in thermal communication with the mold; and
a processor configured to successively perform:
(i) controlling the heat source to set a surface temperature of the mold cavity to a cooling temperature at least 5° F. to 150° F. lower than a softening temperature of the thermoplastic material before an injection of said thermoplastic material in the mold cavity;
(ii) after the injection of said thermoplastic material in the mold cavity, controlling the heat source to raise the surface temperature of the mold cavity to a heating temperature at least 20° F. higher than the cooling temperature; and
(iii) controlling the heat source to lower a temperature of the mold cavity to the cooling temperature;
wherein the thermoplastic material is a thermoplastic polyurethane (TPU), polyvinylchloride (PVC), or thermoplastic elastomer (TPE).