Packaging seal plate having a shaped face
A seal plate for use in sealing ophthalmic lens blister packages having a laminate foil cover and plastic shell for containing an ophthalmic lens and lens solution therein, the seal plate including a heated plate body and sealing face. The sealing face protrudes from the plate body and has an irregular shape. The sealing face further engages the laminate foil cover and displaces moisture present between the foil cover and plastic bowl body to induce a heat seal therebetween.
This application claims the benefit under 35 USC § 119 (e) of U.S. provisional application number 60/984,119 filed Oct. 31, 2007, incorporated by reference in its entirety.
TECHNICAL FIELDThe present invention relates generally to the packaging of ophthalmic lenses, and more particularly to seal plates used to cover and seal blister packages during the lens packaging process. The invention also relates to seal plates used to package other goods.
BACKGROUND OF THE INVENTIONOphthalmic lenses, such as contact lenses, are often packaged in individual packages, typically known as “blister packages.” A blister pack generally consists of a plastic shell defining a concave bowl adapted to house a sterile aqueous solution and at least one lens, and a laminate foil used to cover the plastic bowl and contain the solution and lens therein. Such packaging keeps the lens in a hydrated state before being opened and worn by a user. Often, a lens is contained within a blister package for a significant amount of time while the lens is being shipped and held in storage before use. Therefore, it is important that the aqueous solution be hermetically sealed therein, to ensure that the solution cannot leak out and to prevent contaminants from entering the lens containment area. One method of hermetically sealing the laminate foil to the plastic shell utilizes a heating element, or heated seal plate, to create a heat seal between the foil and the area surrounding the plastic bowl. Heated seal plates presently known and used typically include a flat face that corresponds to the area of the shell surrounding the bowl, such that a heat seal is induced where the flat plate engages and applies pressure and heat against the laminate foil/plastic shell. A known seal plate 10 can be seen in
Unfortunately, under certain conditions a hermetic seal is not formed between the foil cover and plastic shell, which can permit the aqueous solution to leak out of the blister package or contaminants to infiltrate the lens area. For example, droplets or moisture between the cover and seal area can create wrinkles in the foil and/or prevent the foil from properly adhering to the plastic shell. These conditions can create small channels or pathways between the foil and bowl, through which the aqueous solution may escape the blister package.
Accordingly, needs exist for improvements to ophthalmic lens packaging systems that prevent poor seals from developing between the cover and plastic shell of a blister package. It is to the provision of these needs and others that the invention of present invention is directed.
SUMMARY OF THE INVENTIONIn example forms, the present invention relates generally to a seal plate for use in sealing ophthalmic lens blister packages having a laminate foil cover and a plastic shell with a bowl for containing an ophthalmic lens and lens solution therein. The seal plate includes a heated plate body and sealing face. The sealing face protrudes from the plate body and has an irregular shape adapted to engage the laminate foil cover and displace any droplets or moisture present between the foil cover and plastic shell to induce a heat seal therebetween. The irregular shape of the sealing face permits the seal plate of the present invention to displace or “squeegee” any moisture that may be present between the foil cover and shell during the sealing process. Although described herein with reference to contact lens applications, the present invention is also suitable for packaging of food, pharmaceuticals, and/or other products.
In various embodiments, the shape of the irregular face can take a variety of forms, including with limitation: radiused; angled; having multiple tiers; comprising a grid or mesh-like pattern of raised and/or lowered channels; having recesses bored into the face; having a plurality of tracks, the tracks forming channels therebetween; and/or having one or more chamfered edges.
These and other forms, features and advantages of the invention will be understood with reference to the drawing figures and detailed description herein, and will be realized by means of the various elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following brief description of the drawings and detailed description of the invention are exemplary and explanatory of preferred embodiments of the invention, and are not restrictive of the invention, as claimed.
The present invention may be understood more readily by reference to the following detailed description of the invention taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this invention is not limited to the specific devices, methods, conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting of the claimed invention. Also, as used in the specification including the appended claims, the singular forms “a,” “an,” and “the” include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment.
With reference now to the drawing figures,
It has been found that by utilizing a seal plate 20 having a shaped or irregular face 25, moisture that is present between the cover and plastic bowl can be displaced away from the seal area to improve contact and sealing between the cover and bowl. Direct contact between the cover and bowl facilitates a proper hermetic heat seal between the same. As previously mentioned, known seal plates 10, such as shown in
In the embodiment shown in
With reference now to
Another example embodiment of a seal plate 20C is shown in
Another embodiment of a seal plate 20E is shown in
In further embodiments of the present invention, the seal plate 20G comprises a face 25G having one or more chamfered edges 80, as shown in
While the invention has been described with reference to preferred and example embodiments, it will be understood by those skilled in the art that a variety of modifications, additions and deletions are within the scope of the invention, as defined by the following claims.
Claims
1. A seal plate for use in sealing ophthalmic lens blister packages, the seal plate comprising:
- a plate body; and
- a sealing face protruding from the plate body, the sealing face having a radiused profile for engaging and sealing the blister packages.
2. A seal plate for use in sealing ophthalmic lens blister packages having a laminate foil cover and plastic shell defining a bowl for containing an ophthalmic lens and lens solution therein, the seal plate comprising:
- a heated plate body; and
- a sealing face protruding from the plate body, the sealing face having an irregular shape;
- wherein the sealing face engages the laminate foil cover and displaces moisture present between the laminate foil cover and the plastic shell in a sealing area around the bowl to induce a heat seal therebetween.
3. The seal plate of claim 2, wherein the irregular shape is radiused.
4. The seal plate of claim 2, wherein the irregular shape is angled.
5. The seal plate of claim 2, wherein the irregular shape comprises multiple tiers.
6. The seal plate of claim 2, wherein the irregular shape comprises a cross-hatched grid.
7. The seal plate of claim 2, wherein the irregular shape includes a plurality of recesses in the sealing face.
8. The seal plate of claim 2, wherein the irregular shape includes tracks extending from the face.
9. The seal plate of claim 8, wherein the tracks form channels therebetween.
10. The seal plate of claim 2, wherein the face is chamfered.
Type: Application
Filed: Oct 29, 2008
Publication Date: May 7, 2009
Inventors: Stephen N. Carr (Stansbury, UT), James Shay Foley (Snellville, GA), Kent M. Grothe (Buford, GA), Roland Schmieder (Friedrichsdorf), Charles Henry Walton, IV (Cumming, GA)
Application Number: 12/290,329