Patent ID: 6627124
Filing Date: 2003-09-30
Classification: B29C,B29D,B29K,Y10S

Abstract:
A process for producing a multiplicity of contact lenses from a starting material which can be crosslinked by applying suitable energy, the process comprising the steps of:(a) providing a unit having a plurality of individual reusable moulds, wherein each mould has a female mould half, a male mould half, wherein the female and male mould halves, independently of each other, include one or more guide surfaces, wherein the guide surfaces of the female and male mould halves provide centering and adjusting elements which are all necessary for substantially accurate and automatic centering/positioning of the female and male mould halves in relation to each other in each individual reusable mould, without additional adjustment work, when the female and male mould are joined to form a mould cavity defining the shape of a contact lens to be produced; (b) Metering the starting material into the female mould halves; (c) Simultaneously closing the individual moulds to join the male mould halves to the female mould halves to form mould cavities containing the starting material and at the same time to individually and automatically perform, by means of the guided surfaces of the female and male mould halves of each individual mould, accurate alignment of the female and male mould halves of each of the individual moulds; (d) Applying energy to crosslink and/or polymerize the starting material within the mould cavities in order to produce the contact lenses; (e) Separating the male mould halves from the female mould halves; (f) Washing the contact lenses to remove uncrosslinked starting material; (g) Ensuring that the contact lenses are resting on selected mould halves; (h) Checking whether the contact lenses are free of faults; (i) Gripping the contact lenses in order to remove the contact lenses from the selected mould halves; (j) Depositing each fault-free contact lens into a package; (k) Cleaning and drying the female and the male mould halves; (l) Bringing the female and male mould halves into a position for metering the starting material; and (m) cyclically repeating steps (b) to (l).