Contact lens package
View Patent ↗A plastic container for storing a hydrogel contact lens in a liquid, the container comprising: a cavity and a substantially flat flange that extends in a plane around the opening periphery of the cavity, and the flange having a sealing area round the circumference of the cavity. Furthermore, the sealing area has a micro-texture pattern. When sealing the container with a flexible cover sheet which is a laminate material having a metal foil layer and at least one polymer layer to form a storage package of the soft contact lens, the micro-texture pattern of the sealing area engages a laminate foil cover and displaces water beads present between the laminate foil cover and the plastic container in the sealing area around the cavity to form a heat seal.
1. A method for packaging a hydrogel contact lens, comprising the steps of:
(a) providing a plastic container having a cavity and a flat flange that horizontally extends in a plane around the perimeter of the cavity, wherein the flange having a sealing area surrounding circumferentially and adjacently about of the cavity, wherein the sealing area having a micro-texture pattern,
(b) placing an amount of a packaging solution and the hydrogel contact lens in the container, wherein the amount of the packaging solution is sufficient to have the hydrogel contact lens to be fully immersed;
(c) heat sealing the container using a heated flat seal plate with a flexible cover sheet which is a laminate material comprising a metal foil layer and at least one polymer layer to form a storage package of the soft contact lens;
wherein during the step of heat sealing, the micro-texture pattern engages a laminate foil cover and displaces water beads present between the laminate foil cover and the plastic container in the sealing area to form a heat seal, provided that after heat sealing the sealing area is smooth and leveled to the flange wherein the micro-texture pattern comprises a step height rough surface, wherein the step height rough surface pattern thereon has an overall root mean square surface roughness of between 5 μm to 50 μm.
2. The method of claim 1 , wherein the micro-texture pattern comprises a plurality of raised spots.
3. The method of claim 1 , wherein the micro-texture pattern comprises a plurality of raised parallel lines.
4. The method of claim 1 , wherein the step height rough surface pattern thereon has an overall root mean square surface roughness of between 8 μm to 30 μm.
5. The method of claim 1 , wherein the step height rough surface pattern thereon has an overall root mean square surface roughness of between 10 μm to 20 μm.
6. The method of claim 1 , wherein the step height rough surface pattern thereon has an overall root mean square surface roughness of between 11 μm to 15 μm.
7. The method of claim 1 , wherein the step height rough surface has a sectional height gradually higher from the outer edge of the cavity (c of FIG. 2 ) toward the inner edge of the cavity (c of FIG. 2 ).
8. The method of claim 1 , wherein the step height rough surface has a sectional height gradually higher from the inner edge of the cavity (c of FIG. 2 ) toward the outer edge of the cavity (c of FIG. 2 ).