摘要:
The invention is concerned with the problem that with known plastic casting moulds, especially those of polypropylene, the lenses produced with these moulds have a slippery surface. The invention solves this problem through the use of polymers which are notable for their very low oxygen permeability.
摘要:
The invention is concerned with the problem that with known plastic casting molds, especially those of polypropylene, the lenses produced with these molds have a slippery surface. The invention solves this problem through the use of polymers which are notable for their very low oxygen permeability.
摘要:
The invention is concerned with the problem that with known plastic casting molds, especially those of polypropylene, the lenses produced with these molds have a slippery surface. The invention solves this problem through the use of polymers which are notable for their very low oxygen permeability.
摘要:
The invention is concerned with the problem that with known plastic casting moulds, especially those of polypropylene, the lenses produced with these moulds have a slippery surface. The invention solves this problem through the use of polymers which are notable for their very low oxygen permeability.
摘要:
The invention is concerned with the problem that with known plastic casting moulds, especially those of polypropylene, the lenses produced with these moulds have a slippery surface. The invention solves this problem through the use of polymers which are notable for their very low oxygen permeability.
摘要:
The invention is concerned with the problem that with known plastic casting moulds, especially those of polypropylene, the lenses produced with these moulds have a slippery surface. The invention solves this problem through the use of polymers which are notable for their very low oxygen permeability.
摘要:
There is described a method of separating excess lens forming material from a molded ophthalmic lens, in particular a contact lens. After polymerization and/or cross-linking of a lens forming material (P) within a mold cavity (4) of a mold (1) comprising female and male mold halves (2, 3) to form an ophthalmic lens non-polymerized and/or non-cross-linked lens forming material is flushed away from the mold halves (2, 3) with a jet of a fluid flushing medium, such as, e.g., water or a solvent or an inert gas. Subsequently the molded lens is dried. In accordance with the invention the flushing is accomplished with the mold halves (2, 3) still in the closed position. There is also described an apparatus for carrying out the method.
摘要:
There is described a method of separating excess lens forming material from a molded ophthalmic lens, in particular a contact lens. After polymerization and/or cross-linking of a lens forming material (P) within a mold cavity (4) of a mold (1) comprising female and male mold halves (2, 3) to form an ophthalmic lens non-polymerized and/or non-cross-linked lens forming material is flushed away from the mold halves (2, 3) with a jet of a fluid flushing medium, such as, e.g., water or a solvent or an inert gas. Subsequently the molded lens is dried. In accordance with the invention the flushing is accomplished with the mold halves (2, 3) still in the closed position. There is also described an apparatus for carrying out the method.
摘要:
A process of dosing a starting material (SM) for optical lenses, into a female mold half (2), comprises the steps of: positioning a dosing tip (1) at a start position (P2) above the female mold half (2) and close to the edge of or laterally outside that portion (20) defining the lens-shaping surface, creating a continuous flow of starting material (SM) through the dosing tip (1) into the female mold half (2), moving the dosing tip (1) from the start position (P2) towards an end position (P3) in the region of the center of the female mold half (2) once the starting material (SM) has contacted the surface (21) of the female mold half (2) with the dosing tip (1) being in the start position (P2), wherein the continuous flow of starting material (SM) through the dosing tip (1) and the movement of the dosing tip (1) from the start position (P2) to its end position (P3) are controlled such, that a continuous bead (B) of starting material (SM) is deposited on the surface (21) of the female mold half (2) and that the essential part of the overall volume of starting material (SM) dosed into the female mold half (2) is deposited within the female mold half (2) with the dosing tip (1) being in the end position (P3).
摘要:
Efficient and consistent processes for manufacturing moldings, especially ophthalmic lenses such as contact lenses. The processes comprises a series of improvements, including improvements in the areas of conditions for dispensing liquid prepolymer into lens molds, male and female mold mating, reusable molds, mold cleaning, lens separation from molds (demolding), lens handling, and in-line inspection. Cyclic series of processing steps are also disclosed. Additionally, an improved molding tool is disclosed, with the molding tool including a male mold housing and a female mold housing, each of which have disposed therein a plurality of mold halves.