Method for removing lens forming material deposited on a lens forming surface
AssigneeAlcon Inc.
InventorsStefan Kastl, Steffen Paulekuhn, Stephan Pirl, Gabriela Cocora
Life of this patent
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Abstract
A method of removing a lens forming material deposited on a lens forming surface (1) of a reusable glass mold for forming ophthalmic lenses, in particular contact lenses or intraocular lenses, comprises the steps of providing a plasma (2), exposing the lens forming surface (1) of the reusable glass mold to the plasma (2) for removing the lens forming material deposited on the lens forming surface (1). The plasma (2) is generated under atmospheric pressure and potential-free, or is generated under reduced pressure.
Claims5
Method of removing lens forming material deposited on a lens forming surface (1) of a reusable glass mold for forming contact lenses, the method comprising the steps of:
- a) removing a lens from the reusable glass mold,
- b) providing a plasma (2),
- c) exposing the lens forming surface (1) of the reusable glass mold with the lens forming material deposited thereon after step a) to the plasma (2) for removing the lens forming material deposited on the lens forming surface (1), and
- d) aspirating an off-gas generated by exposing the deposited lens forming material to be removed to the plasma (2), wherein lens forming material is a silicone hydrogel,
- wherein the plasma (2) is generated under atmospheric pressure and potential-free,
- wherein the generating the plasma (2) under atmospheric pressure comprising generating the plasma (2) with a plasma jet (4) using air as a process gas, and wherein the plasma is generated with the aid of a plasma torch (6) comprising the plasma jet (4), a tubular plasma jacket (7) and an aspirator connection (8), the plasma jacket (7) surrounding the space between the plasma jet (4) and the lens forming surface (1) of the mold, and wherein the method further comprises applying vacuum to the aspirator connection (8), thereby allowing aspiration of the off-gas.
Dependencies are inferred from the claim text.