U.S. patent application number 14/351996 was filed with the patent office on 2014-11-13 for systems and methods for multi-stage sealing of contact lens packaging.
This patent application is currently assigned to MENICON SINGAPORE PTE LTD.. The applicant listed for this patent is MENICON SINGAPORE PTE LTD.. Invention is credited to Stephen D. Newman.
Application Number | 20140331602 14/351996 |
Document ID | / |
Family ID | 54256933 |
Filed Date | 2014-11-13 |
United States Patent
Application |
20140331602 |
Kind Code |
A1 |
Newman; Stephen D. |
November 13, 2014 |
SYSTEMS AND METHODS FOR MULTI-STAGE SEALING OF CONTACT LENS
PACKAGING
Abstract
A contact lens package includes a first package layer, a second
package layer, a lens receiving area defined between the first and
second package layers, and first and second seal portions. The
first seal portion extends around a first portion of the lens
receiving area. The second seal portion extends around a second
portion of the lens receiving area. The second seal portion has
different sealing properties than the first seal portion. The first
seal portion may include a releasable seal between the first and
second package layers, and the second seal portion may include a
permanent seal between the first and second package layers.
Inventors: |
Newman; Stephen D.;
(Singapore, SG) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MENICON SINGAPORE PTE LTD. |
Singapore |
|
SG |
|
|
Assignee: |
MENICON SINGAPORE PTE LTD.
Singapore
SG
|
Family ID: |
54256933 |
Appl. No.: |
14/351996 |
Filed: |
October 18, 2012 |
PCT Filed: |
October 18, 2012 |
PCT NO: |
PCT/SG2012/000388 |
371 Date: |
April 15, 2014 |
Current U.S.
Class: |
53/405 ; 206/5.1;
53/329; 53/329.3; 53/422; 53/471; 53/478; 53/488 |
Current CPC
Class: |
B29C 66/8161 20130101;
A45C 2011/006 20130101; B65B 25/008 20130101; B29C 65/1412
20130101; B29C 66/71 20130101; B29C 66/8246 20130101; B65D 75/327
20130101; B29C 66/8322 20130101; B29C 66/71 20130101; B29C 66/131
20130101; B29C 65/76 20130101; B29C 66/53461 20130101; B29L
2011/0041 20130101; B29C 65/04 20130101; B29C 66/81463 20130101;
B29C 65/16 20130101; B29C 66/72321 20130101; B65B 51/22 20130101;
B29C 66/244 20130101; B29C 65/08 20130101; B65B 51/14 20130101;
B29C 66/112 20130101; A45C 11/005 20130101; B65B 7/2878 20130101;
B29C 66/8242 20130101; B29C 66/3452 20130101; B29C 65/18 20130101;
B29K 2023/06 20130101; B29K 2023/12 20130101; B29C 66/24245
20130101; B29C 66/71 20130101; B29L 2031/7164 20130101; B29C 66/305
20130101; B65B 51/10 20130101; B29C 66/849 20130101 |
Class at
Publication: |
53/405 ; 53/329;
53/329.3; 53/488; 53/478; 53/471; 53/422; 206/5.1 |
International
Class: |
B65B 25/00 20060101
B65B025/00; B65B 51/10 20060101 B65B051/10; A45C 11/00 20060101
A45C011/00; B65B 7/28 20060101 B65B007/28 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 18, 2011 |
SG |
201107630-4 |
Claims
1. A contact lens package, comprising: a first package layer; a
second package layer; a lens receiving area defined between the
first and second package layers; a first seal portion extending
around a first portion of the lens receiving area; a second seal
portion extending around a second portion of the lens receiving
area, the second seal portion having different sealing properties
than the first seal portion.
2. The contact lens package of claim 1, wherein the first seal
portion is a releasable seal between the first and second package
layers, and the second seal portion is a permanent seal between the
first and second package layers.
3. The contact lens package of claim 1, wherein the first and
second seal portions together extend around an entire periphery of
the lens receiving area.
4. The contact lens package of claim 1, wherein the first and
second package layers comprise foil.
5. The contact lens package of claim 1, wherein the second seal
portion overlaps a portion of the first seal portion.
6. The contact lens package of claim 1, wherein the second seal
portion provides a greater seal strength between the first and
second package layers than a seal strength provided by the first
seal portion.
7. The contact lens package of claim 1, further comprising an
internal member positioned in the lens receiving area, and a third
seal portion between the internal member and at least one of the
first and second package layers.
8. A press adapted to seal a contact lens package, the press
comprising: a first portion configured to support at least one
contact lens package, the contact lens package including a lens
receiving area sized to hold a contact lens; a second portion
having at least one first sealer configured to create a first seal
portion around only a portion of the lens receiving area; a third
portion having at least one second sealer configured to create a
second seal portion around a different portion of the lens
receiving area, the second seal portion having different sealing
properties than the first seal portion.
9. The press of claim 8, wherein the first portion is defined by a
lower sealing head, and the second and third portions are carried
by an upper sealing head.
10. The press of claim 8, wherein the first portion includes at
least one recess sized to receive the contact lens package.
11. The press of claim 8, wherein the first seal portion defines an
unsealed gap at a location around a periphery of the lens receiving
area, and the second seal portion overlaps and closes the gap.
12. The press of claim 8, wherein the second seal portion has a
greater seal strength than the first seal portion.
13. The press of claim 8, wherein at least one of the second and
third portions remove gases from the lens receiving area before
creating the second seal portion.
14. The press of claim 8, wherein the first and second portions
each include an alignment feature configured to align the contact
lens package with the first and second portions.
15. The press of claim 14, wherein the alignment feature is an
orifice, and the press is configured to apply a vacuum force to the
contact lens package through the orifice.
16. The press of claim 14, wherein at least one of the first,
second and third portions is heated.
17. The press of claim 8, wherein the second and third portions are
carried by a common press head.
18. A method for manufacturing a contact lens package, comprising:
providing first and second package layers that define a lens
receiving area there between; forming a first seal portion around
all but a portion of a periphery of the lens receiving area;
forming a second seal portion to completely seal closed the lens
receiving area.
19. The method of claim 18, wherein forming the second seal portion
includes overlapping the second seal portion with the portion of
the periphery of the lens receiving area not included in the first
seal portion.
20. The method of claim 18, wherein forming the second seal portion
includes forming the second seal portion with a greater seal
strength than a seal strength of the first seal portion.
21. The method of claim 18, wherein forming the first seal portion
includes creating a releasable seal between the first and second
package layers.
22. The method of claim 18, wherein forming the second seal portion
includes creating a permanent seal between the first and second
package layers.
23. The method of claim 18, wherein forming the second seal portion
includes applying at least one of a greater heat and a greater
pressure than applied when forming the first seal portion.
24. The method of claim 18, further comprising removing gases from
the lens receiving area before forming the second seal portion.
25. The method of claim 18, further comprising positioning a
contact lens and at least one liquid in the lens receiving area
before forming the first and second seal portions.
26. The method of claim 18, further comprising providing an
internal member disc positioned in the lens receiving area, and
forming a third seal portion between the internal member and at
least one of the first and second package layers.
27. A method of manufacturing a contact lens package, comprising:
positioning a first package layer on a first press portion;
positioning a contact lens on the first package layer; positioning
a second package layer on the first package layer and covering the
contact lens; creating a first seal portion between the first and
second package layers with a second press portion; creating a
second seal portion between the first and second package layers
with a third press portion.
28. The method of claim 27, wherein the first package layer
includes a pre-formed lens receiving area, and positioning the
contact lens includes positioning the contact lens in the lens
receiving area.
29. The method of claim 27, wherein the first and second seal
portion have different properties.
30. The method of claim 27, wherein creating the first seal portion
includes creating the first seal portion as a releasable seal
between the first and second package layers.
31. The method of claim 27, wherein creating the second seal
portion includes creating the second seal portion as a permanent
seal between the first and second package layers.
32. The method of claim 27, wherein creating the second seal
portion includes applying at least one of a greater heat and a
greater pressure as compared to a heat and pressure used to create
the first seal portion.
33. The method of claim 27, further comprising applying a vacuum to
align the second package layer with the first and second press
portions.
34. The method of claim 27, further comprising removing gas from
the lens receiving area before creating the second seal
portion.
35. The method of claim 27, further comprising positioning a
support disc adjacent to the contact lens between the first and
second package layers, and forming a third seal portion between the
support disc and at least one of the first and second package
layers.
36. A method of assembling a contact lens package, comprising:
arranging first and second foil package layers at least partially
overlapping each other with a contact lens positioned there
between; creating a first sealed portion between the first and
second foil package layers; and creating a second sealed portion
between the first and second foil package layers.
37. The method of claim 36, wherein the contact lens is positioned
in a lens receiving area defined between the first and second foil
package layers, and creating the first sealed portion includes
sealing around all but a gap portion of a periphery of the lens
receiving area, and creating the second sealed portion includes
sealing the gap portion.
38. The method of claim 36, wherein creating the second sealed
portion occurs after creating the first sealed portion.
39. The method of claim 36, wherein creating the first sealed
portion includes creating a releasable seal between the first and
second foil package layers, and creating the second sealed portion
includes creating a permanent seal between the first and second
foil package layers.
40. The method of claim 36, further comprising positioning a
support member between the first and second foil package layers and
in contact with the contact lens, and creating a third sealed
portion between the support member and at least one of the first
and second foil package layers.
Description
TECHNICAL FIELD
[0001] The present systems and methods relate to contact lens
packaging methods and devices. Specifically, the present disclosure
provides methods and apparatuses for sealing contact lens packages
in multiple stages.
BACKGROUND
[0002] Contact lenses are commonly stored in disposable packages.
Particularly, soft disposable contact lenses are often stored in
small disposable packages. Due to the sensitive nature of contact
lenses, care must be taken that the package is sufficiently durable
to ensure sterility. Traditionally blister packaging has been used
for disposable lenses consisting of a contact receptacle portion
(herein after referred to as a "boat") and a film cover. The boat
typically consists of a polypropylene and the cover a multi-layer
film comprising polyethylene, aluminum, a bonding agent, and
polypropylene. The boat is typically an injected mold plastic
capable of limited elastic deflection filled with a sterile saline
solution configured to receive a single contact lens.
[0003] After the boat is filled with an appropriate aqueous
solution, a contact lens is placed within and the film cover is
bonded to the boat. The blister pack is then autoclaved using steam
and pressure to ensure sterility. The objective is to present a
contact lens package to a patient that is aesthetically pleasing,
sterile, and easy to open. The packaging is typically used once and
then discarded along with the aqueous solution. In order to reduce
the overall cost to the patient, the cost and size of the packaging
should be kept to a minimum. Additionally, the disposability of the
lens packages necessitates conformity with ecological standards,
particularly with single-use (or 1-day) contact lenses.
[0004] It is necessary that the package be well-sealed to withstand
the autoclave process as well as the shipping and handling by
patients. For this reason, conventional wisdom in the contact lens
industry has been to use preformed stiff packaging for the boat to
protect the lens from damage, and a multi-layer film to bond and
seal the lens within the boat. Examples of typical traditional
blister packs are shown in: U.S. Pat. No. 5,704,468; U.S. Pat. No.
4,392,569; U.S. Pat. No. 5,620,088; U.S. Pat. No. 5,620,088; U.S.
Pat. No. 4,691,820; U.S. Pat. No. 5,823,327; U.S. Pat. No.
5,853,085; EP Patent Publication No. 1 092 645 A1; EP Patent
Publication No. 1 092 645.
[0005] Typically, the multi-layer film is bonded to the boat using
a high temperature heated press. The sealing heads of the heated
press are heated and used to press the film layer against the outer
perimeter of the boat. The film layer is bonded along the outer
perimeter of the boat. The boat and film layer materials as well as
the aqueous solution surrounding the contact become heated and
expand during the bonding process. The increase in temperature and
volume imparts significant strain on the seal between the film
layer and the boat. Consequently, the boat, the film layer, and the
seal itself must be sufficiently resilient to withstand the forces
created by the expansion during heating, as well as the contraction
during cooling. Additionally, if the boat is not large enough or
does not contain enough aqueous solution, then the contact lens
itself may be compromised.
[0006] Further to these effects on the package, a downstream
consequence of the aforementioned internal heating phenomenon
manifests itself as poor post autoclave aesthetics and potentially
compromised package sealing. During the heating and cooling phases
in the thermal sterilizing process, the internal contents of the
package, particularly the air and aqueous solution, expand and
contract at different rates and amounts to the surrounding package.
The use of a ballasted autoclave (where external air or water is
pumped into the sterilizing chamber at strategic pressure levels
and key process times to counter the differential pressure effects)
can mitigate this effect somewhat, but does not remove it entirely.
Key examples of this phenomenon are crumpled packages and seal
leaks. If the overall package has distorted sufficiently, there may
be more than one leak in the seal surrounding the lens cavity.
SUMMARY
[0007] One aspect of the present disclosure relates to a contact
lens package that includes a first package layer, a second package
layer, a lens receiving area defined between the first and second
package layers, and first and second seal portions. The first seal
portion extends around a first portion of the lens receiving area.
The second seal portion extends around a second portion of the lens
receiving area. The second seal portion has different sealing
properties than the first seal portion. The first seal portion may
include releasable seal between the first and second package
layers, and the second seal portion may include a permanent seal
between the first and second package layers.
[0008] Another aspect of the present disclosure relates to a press
adapted to seal a contact lens package. The press includes first,
second and third portions. The first portion is configured to
support at least one contact lens package, wherein the contact lens
package includes a lens receiving area sized to hold a contact
lens. The second portion includes at least one first sealer
configured to create a first seal portion around only a portion of
the lens receiving area. The third portion includes at least one
second sealer configured to create a second seal portion around a
different portion of the lens receiving area. The second seal
portion has different sealing properties than the first seal
portion.
[0009] A further aspect of the present disclosure relates to a
method for manufacturing a contact lens package. The method
includes providing first and second package layers that define a
lens receiving area there between, forming a first seal portion
around all but a portion of a periphery of the lens receiving area,
and forming a second seal portion to completely seal closed the
lens receiving area. Forming the second seal portion may include
forming the second seal portion with a greater seal strength than a
seal strength of the first seal portion.
[0010] Another example method in accordance with the present
disclosure relates to a method of manufacturing a contact lens
package that includes positioning a first package layer on a first
press portion, positioning a contact lens on the first package
layer, and positioning a second package layer on the first package
layer and covering the contact lens. The method also includes
creating a first seal portion between the first and second package
layers with a second press portion, and creating a second seal
portion between the first and second package layers with a third
press portion. The first and second seal portions may have
different properties.
[0011] A further aspect of the present disclosure relates to a
method of assembling a contact lens package. The method includes
arranging first and second foil package layers at least partially
overlapping each other with a contact lens positioned there
between, creating a first sealed portion between the first and
second foil package layers, and creating a second sealed portion
between the first and second foil package layers. The contact lens
may be positioned in a lens receiving area defined between the
first and second foil package layers, and creating the first sealed
portion may include sealing around all but a gap portion of a
periphery of the lens receiving area, and creating the second seal
includes sealing the gap portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The accompanying drawings illustrate various embodiments of
the principles described herein and are a part of the
specification. The illustrated embodiments are merely examples and
do not limit the scope of the disclosure.
[0013] FIG. 1 is an exemplary schematic illustrating a heated press
having multi-stage sealing heads according to one exemplary
embodiment.
[0014] FIGS. 2A and 2B are schematics illustrating upper sealing
heads having a row of first-stage sealers and a row of second-stage
sealers according to one exemplary embodiment.
[0015] FIG. 3A is a top view of a contact lens package sealed with
the upper sealing heads of FIGS. 2A and 2B according to a first
sealing stage.
[0016] FIG. 3B is a top view of the contact lens package of FIG. 3A
sealed with the upper sealing heads of FIGS. 2A and 2B according to
a second sealing stage.
[0017] FIG. 3C is a top view of the contact lens package of FIG. 3B
having additional seals formed with a support disc of the contact
lens package according to a third sealing stage.
[0018] FIG. 4A is a schematic illustrating a lower sealing head
according to one exemplary embodiment.
[0019] FIG. 4B is a schematic illustrating a lower sealing head
having a contact lens receptacle according to one exemplary
embodiment.
[0020] FIG. 4C is an alternative embodiment of a lower sealing head
having six orifices according to one exemplary embodiment.
[0021] FIG. 5A illustrates an upper sealing head configured to
perform a first stage of sealing according to one exemplary
embodiment.
[0022] FIG. 5B illustrates an upper sealing head configured to
perform a second stage of sealing according to one exemplary
embodiment.
[0023] FIG. 6A is a top view of a contact lens package sealed using
one method described herein according to one exemplary
embodiment.
[0024] FIG. 6B is a side view of a contact lens package sealed
using one method described herein according to one exemplary
embodiment.
[0025] FIG. 6C is a cut-away view of a contact lens package
illustrating a sealed lens receptacle according to one exemplary
embodiment.
[0026] FIG. 7 is a flow chart illustrating a method for sealing a
contact lens package in multiple stages to reduce thermal damage
and increase sterility assurance according to one exemplary
embodiment.
[0027] In the drawings, identical reference numbers identify
similar elements or acts.
DETAILED DESCRIPTION
[0028] The present disclosure provides several systems and methods
for sealing a contact lens within a package. Specifically, a method
for sealing a contact lens within a package is described that
minimizes detrimental thermal effects of a sealing process by
sealing the package in at least two stages. The presently described
systems and methods for packaging a contact lens may be different
in many respects from a traditional blister pack contact lens
package. For example, the systems and methods of the present
disclosure provide sealing of a package in multiple stages.
Furthermore, because of the decreased thermal stress on the
package, the present systems and methods provide a sealing method
that permits foil-on-foil packaging to be used.
[0029] While many traditional systems utilize a heated press to
seal a top layer onto a bottom "boat" layer, traditional systems do
not utilize multiple stages. Consequently, as the top layer is
sealed using heat and pressure to the bottom layer, the aqueous
solution and the gasses within the boat become heated and expand.
Due to the relatively large amount of space and material in a
traditional boat type configuration, the expansion can, for the
most part, be absorbed by the package. However, this expansion does
cause significant stress on the packaging material as well as the
seal itself. For at least this reason, robust packaging materials
must be used in the traditional systems and methods to ensure
sterility and a durable seal. The present systems and methods, by
allowing expanding gases to escape during the first sealing stage,
allow for less robust materials to be used while maintaining a high
assurance of sterility and appropriate sealing.
[0030] A heated press is described similar to heated presses used
in traditional contact lens blister pack production. The heated
press and its function are not unique to the present system and
methods and are consequently not described in great detail. Various
traditional heated presses are suitable for use with the present
systems and methods. These traditional presses may be adapted for
multi-stage packaging of foil-on-foil contact lens packages by
adapting the press sealing heads.
[0031] According to one exemplary embodiment, a press sealing head
suitable for multi-stage sealing of contact lens packages is
configured to seal around the perimeter of the contact lens
container or lens receiving area, leaving at least one small gap in
the perimeter unsealed. This gap allows fluids (e.g., expanding
gases and, if desired, liquids) to escape during the first stage of
sealing, thereby reducing the internal pressure of the pack. A
corresponding second stage of sealing will seal the gap shut. Due
to the small size of the gap, the second stage of sealing will not
significantly thermally impact the packaging or its contents.
[0032] According to various embodiments, the first and second
stages of sealing are performed using the same press sealing head.
According to alternative embodiments, separate press sealing heads
are configured for each stage of sealing. Furthermore, according to
alternative embodiments, more than two stages of sealing are
performed to complete the seal around the outer perimeter of the
boat. Furthermore, according to alternative embodiments, the
sealing parameters of the process are different from the first seal
to the second seal.
[0033] According to several embodiments, pre-formed bottom layers
of varying materials are configured with contact lens receptacles
(hereinafter referred to as boats). According to other embodiments
the receptacles in the bottom layers are formed during the sealing
process. For example, the bottom layer in a foil-on-foil process
may comprise a generally flexible foil material that permits the
foil to be pulled under vacuum into a desired shape using a lower
sealing head with a vacuum hole defined therein. Alternative
embodiments utilize a small vacuum hole in the bottom of each
receptacle in the lower sealing head to maintain accurate
positioning of the contact lens, fluid, and any other elements in
the package, for creating a precise seal around the perimeter of
the boat.
[0034] Alternative embodiments of sealing heads are possible.
According to various embodiments, a number of configurations for a
first sealing stage are possible. Many variations are possible
where a top layer of packaging is sealed around the perimeter of a
boat formed in a bottom layer of the packaging where one or more
gaps are created in the seal. Subsequent sealing stages seal each
of these gaps to complete the seal around the perimeter.
[0035] In the following description, certain specific details are
set forth in order to provide a more complete understanding of
various embodiments of the present systems and methods for sealing
contact lens packages in multiple stages. However, one skilled in
the relevant art will recognize that the present exemplary systems
and methods may be practiced without one or more of these specific
details, or with other methods, components, materials, etc. In
other instances, well-known structures associated with heated press
systems and blister pack creation have not been shown or described
in detail to avoid unnecessarily obscuring descriptions of the
present exemplary embodiments.
[0036] Unless the context requires otherwise, throughout the
specification and the claims that follow, the word "comprise" and
variations thereof, such as, "comprises" and "comprising" are to be
construed in an open, inclusive sense, that is, as "including, but
not limited to."
[0037] Reference in the specification to "one embodiment" or "an
embodiment" means that a particular feature, structure, or
characteristic described in connection with the embodiment is
included in at least one embodiment. The appearance of the phrase
"in one embodiment" in various places in the specification are not
necessarily all referring to the same embodiment. Furthermore, the
particular features, structures, or characteristics may be combined
in any suitable manner in one or more embodiments.
[0038] While two distinct sets of upper sealing heads are described
herein, one of ordinary skill in the art will recognize that many
variations are possible for multi-stage sealing of a primary
contact lens package. Additionally, while the present system and
method may be adaptable for use with traditional blister packs and
the material typically used in those processes, the present
disclosure also allows for the use of foil-on-foil packaging and
any other suitable contact lens packaging that includes a perimeter
seal. Traditional systems and methods for sealing blister packs are
substantially less compatible with foil-on-foil packaging as they
introduce too much thermal stress. Example foil-on-foil packaging
and related systems and methods are disclosed in U.S. Pat. No.
7,828,137, which is hereby incorporated in its entirety by this
reference. Other features and functionality related to lens
packages are described in Singapore Patent
[0039] Application filed on 18 Oct. 2011 and entitled "Packaging
for Disposable Soft Contact Lenses Having Pre-Formed Multi-Layer
Structural Laminate", which patent application is incorporated
herein in its entirety by this reference.
[0040] As disclosed in the above-mentioned Singapore Patent
Application entitled "Packaging for Disposable Soft Contact Lenses
Having Pre-Formed Multi-Layer Structural Laminate", a primary lens
package may include a preformed laminate substrate. One layer of
the laminate substrate is configured to provide sufficient
structural rigidity to maintain a shape (e.g., a lens receiving
portion) that is preformed in the substrate. In one example, the
first layer includes a polymer material such as polypropylene.
Another layer of the laminate substrate may include a second
material that provides different properties from the first-layer
such as, for example, light-reflectivity, strength, and resistance
to water/vapor permeability. The package also includes a cover
sheet that is connected to the substrate and seals a contact lens
within a lens receiving portion formed in the substrate. The cover
sheet may also be a laminate having at least two layers. The first
layer may comprise, for example, a polymer that assists in
connecting the cover sheet to the substrate. Another layer of the
cover sheet may include a material having different properties such
as, for example, greater light-reflectivity, strength, or
resistance to water/vapor permeability properties.
[0041] A further aspect related to the primary lens package is
directed to a single contact lens package that houses multiple
contact lenses. The contact lens package may include a plurality of
lens receiving portions (e.g., recesses, depressions or "boats")
formed in the substrate. The lens receiving portions may be
arranged in multiple directions such as multiple rows, wherein each
row includes at least one contact lens receiving portion. The rows
may be arranged opposite each other or side-by-side. Some contact
lens packages may provide for separation of at least one lens
receiving portion from the other lens receiving portions. Other
arrangements may include a plurality of lens receiving portions
that are inseparable from each other once the contact lens package
is assembled.
[0042] Some primary contact lens packages may include layers of
material for the cover sheet and substrate that are added during
assembly of the contact lens package rather than being provided
with the substrate and/or cover sheet as a laminate. In one
example, at least one layer of light-reflective material or
liquid/vapor impermeable material is added to the substrate or the
cover sheet after sealing a contact lens within a lens receiving
portion of the substrate.
[0043] The primary lens package may include an internal member that
is disposed within the lens receiving portion along with a contact
lens. The internal member may help compress the contact lens within
the lens receiving portion to decrease a side profile (e.g., depth)
of the contact lens from a sagittal depth to compressed depth.
Alternatively, the internal member may reliably position the lens
within the lens receiving portion or aid in the return of the lens
from a compressed state to an uncompressed state. The internal
member may be secured within the lens receiving portion or,
alternatively, may be free floating within the lens receiving
portion of the primary contact lens package. The internal member
and portions of the substrate (e.g., lens receiving portion) may
include a plurality of perforations that provide a more
advantageous interface with some types of contact lenses.
Compressing the contact lens within the contact lens package may
make it possible to provide the contact lens package with a reduced
overall thickness, which may provide a number of advantages related
to packaging, storing, and shipping the contact lens package.
[0044] The primary lens packages may be created in a single
manufacturing line. The substrate and sheet may comprise materials
capable of maintaining a sterile environment within the package
where the lens is disposed. The sterile environment may be created
by heating the first material of the substrate. Light-sensitive
materials disposed within the package may also be protected from
light to limit degradation of the light-sensitive materials. The
substrate and cover sheet may comprise materials that permit
printing of graphics that minimize negative effects on the
light-reflecting attributes or the sterile environment of the
contact lens package. In some arrangements, the contact lens
package may be configured for use as an insertion aid. The
materials of the contact lens package may promote improved sealing
between the substrate and cover sheet layers. For example, the
laminate materials used for at least one of the substrate and cover
sheet may include layers of material in the area where a seal is
formed between the substrate and cover sheet that provide improved
seals (e.g., releasable seals, permanent seals, hermetic seals,
heat seals, etc.).
[0045] Also of note is that the present systems and methods
increase the likelihood of preserving sterility and of creating a
lasting seal. A general heated press is described followed by
exemplary upper and lower sealing heads. An exemplary contact lens
package is described that may be created using the systems and
methods described herein. Further, an exemplary process for
multi-stage sealing is described. The following specific details of
the present system and method provide a more thorough understanding
of a multi-stage sealing process for contact lens packaging.
However, many variations are possible and are likely to be used in
practice to obtain maximum efficiency within the sealing
process.
[0046] FIG. 1 illustrates a heated press (100) commonly used to
create and/or form packages for contact lenses. The present systems
and methods for sealing a contact lens package in multiple stages
may utilize any of a wide variety of heated presses similar to that
heated press (100) shown in FIG. 1. However, for illustrative
purposes, FIG. 1 provides an exemplary embodiment of a suitable
heated press (100). The exemplary heated press (100) comprises a
lower platform (120) and an upper platform (110) connected by posts
(130). Each platform (110, 120) is fitted with a sealing head (150,
160). The lower platform (120) has a lower sealing head (150)
configured to receive a preformed bottom portion of a package
within a plurality of contact lens receptacles (180). The upper
platform (110) is fitted with an upper sealing head (160). The
upper sealing head (160) is connected to the upper platform (110)
via a plurality of springs (175) and other connection members.
While the present exemplary sealing heads (150, 160) are described
as a lower and upper sealing head, respectively, it will be
understood that the sealing heads are interchangeable and may
operate in juxtaposed or any number of alternative
orientations.
[0047] The heated press (100) is operable to bring the upper
sealing head (160) in contact, or almost in contact, with the lower
sealing head (150). According to various embodiments, at least
portions of the lower and upper sealing heads (150, 160) are
heated. In conjunction with the springs (175) and other connecting
members of the heated press (100), the amount of force exerted on
the packaging materials between the upper and lower sealing heads
(150, 160) is controlled very accurately by way of either
pneumatics or servo control actions. Precise control of the lower
and upper sealing heads (150, 160) is important because the sealing
of a foil on foil pack is critical. Unlike a traditional blister
boat that is made from PP and is soft enough to absorb some surface
irregularities to complete a successful seal, a foil on foil pack
cannot take up any irregularities in the seal or substrate
surfaces. Rather, the foil on foil pack is controlled via external
processes/tools in order to ensure a safe and even seal is
achieved
[0048] The heated press (100) may be configured with a sealing head
capable of sealing, at least partially, a plurality of contact
lenses at one time. This can be seen as the lower sealing head
(150) is configured with nine contact lens receptacles (180).
However, it should be understood that any number of alternative
heated presses are suitable for use with the present systems and
methods. Moreover, the size and number of packages sealed with each
press may vary as well. That is, a heated press that is capable of
sealing any number of packages at a time will likely be used to
increase production and efficiency.
[0049] A brief description of a sealed contact lens package will be
given in conjunction with FIGS. 3A-3C and 6A-6C to explain an
example sealing process before returning to FIGS. 2A and 2B.
[0050] FIG. 3A illustrates a top view of a set of contact lens
packages (300A-300C) according to a first sealing stage. The
contact lens packages (300A-300C) may be separable along
perforations (316). Each of the contact lens packages (300A-300C)
includes a first package layer (301), a second package layer (not
shown), a lens receiving area (302), a contact lens (304), a
support disc (306), and a first seal portion (308). The first seal
portion (308) extends around a periphery of the lens receiving area
(302) to seal the first package layer (301) to the second package
layer. The first seal portion (308) is a peelable seal that may
include a sacrificial peel layer to facilitate the separation of
the first package layer (301) from the second package layer. As
illustrated, the first seal portion (308) includes a peel release
portion (313) or point that may provide an easier release of the
first seal portion (308) when separating the first package layer
(301) from the second package layer (not shown).
[0051] The first seal portion (308) may have a gap (312) defined
therein where no seal is present. The contact lens packages
(300A-300C) may be compressed after forming the first seal portion
(308) to remove fluids (e.g., gases) from the lens receiving area
(302) prior to closing the gap (312). The contact lens packages
(300A-300C) have an unsealed portion (314) along a front end (305)
to define one or more user separation tabs so that the first
package layer (301) and second package layer may be more easily
grasped by a user when opening the contact lens package.
[0052] FIG. 3B illustrates a top view of the contact lens packages
(300A-300C) according to a second sealing stage. In the second
sealing stage, a second seal portion.(310) is provided along a rear
end (307) of the contact lens package at a location that overlaps
and seals closed the gap (312). The first and second seal portions
(308), (310) may have different characteristics (e.g., releasable
versus permanent). The different characteristics of the first and
second seal portions (308), (310) may assist a user in opening the
contact lens package and maintaining the first package layer (301)
connected to the second package layer after opening.
[0053] FIG. 3C illustrates a top view of the contact lens packages
(300A-300C) according to a third sealing stage. In the third
sealing stage, a third seal portion (317A-317C) is provided along
at least a portion of the support disc (306). The third seal
portion (317A-317C) may be formed between the support disc (306)
and the first package layer (301), may be formed between the
support disc (306) and the second package layer (not shown), or may
be formed between the support disc (306) and both the first package
layer (301) and second package layer. The third seal portion
(317A-317C) may include multiple seal locations around a periphery
of the support disc (306), may be defined at a single seal location
around a limited portion of the perimeter, or may extend completely
and continuously around the perimeter.
[0054] The third seal portion (317A-317C) may be formed using
different sealing techniques than the heated press described with
reference to FIGS. 2A and 2B. In one example, the third seal
portion (317A-317C) may be formed using, for example, ultrasonic
welding, laser welding, infrared (IR) bonding, or other techniques
that may have a lower risk of damaging the contact lens (304)
during the third sealing stage. Additionally, according to one
exemplary embodiment, the third seal portion (317A-317C) may be
performed at any stage in the manufacturing process of the
exemplary primary package. Specifically, the third seal portion
(317A-317C) may be performed prior to the assembly of the package
or after insertion and sealing of a contact lens within the primary
contact lens package. Sealing the support disc (306) to at least
one of the top and bottom package layers may, for example, improve
discharge of the contact lens (304) from the contact lens package
and may maintain assembly of the support disc (306) with the
contact lens package after opening the contact lens package. Any
one of the first, second and third sealing portions (308), (310),
(317A-317C) may be formed using multiple sealing stages.
[0055] FIG. 6A illustrates a top view of a sealed contact lens
package (600) according to an alternative embodiment. As
illustrated, a top package layer (610) has been sealed with a seal
(615) around the outer perimeter of each of the boats (675) of a
bottom package layer (650) (see FIG. 6B). The top package layer
(610) is sealed around the perimeter of the boat (675) and includes
a cover portion (625) that extends over the boat (675).
[0056] FIGS. 6B and 6C illustrate a cross-section view of the
sealed bottom package layer (650) and the boats (675). The top
package layer (610) is placed over the bottom package layer (650)
with the cover portions (625) extending over the boats (675). The
top package layer (610) is sealed around the perimeter of the boats
(675) with the seal (615). Additional seals having different
characteristics or properties may be formed between the top package
layer (610) and the bottom package layer (650). The additional
seals may at least partially overlap the seal (615). In some
embodiments, the seal (615) may include a gap (e.g., see-gap (312)
in FIGS. 3A-3C) that is sealed closed in a second sealing step. In
another embodiment, a seal may be formed between a support disc or
other structure retained within the boats (675) and one of the top
and bottom package layers (610), (650). FIGS. 6A-6C will be
described in greater detail below; however this general
understanding of the contact lens package is useful for
understanding the purpose and function of the sealing heads and the
method of multi-stage sealing.
[0057] Returning now to FIGS. 2A and 2B, the drawings are
essentially identical with FIG. 2B being a top plan view of an
upper sealing head (200) and FIG. 2A illustrating the upper sealing
head (200) in an isometric view. The drawings are discussed in
tandem as a description of the upper sealing head (200) applies to
both figures equally.
[0058] The upper sealing head (200) may include a row of first
stage sealers (on the left in FIGS. 2A and 2B) and a row of second
stage sealers (on the right in FIGS. 2A and 2B). The first stage of
sealing, according to one exemplary embodiment, is configured to
seal the top layer of packaging around the perimeter of the boat
formed in the bottom layer of packaging. While the boats in FIG. 5A
appear as rounded squares, the boat shape may be that of any of a
variety of shapes. As illustrated in FIGS. 2A and 2B, the seal will
be flat or linear on one side and a triangular shape on the other
side. Regardless of what shape is used, the first stage of sealing
is intended to seal the top layer of packaging around the boat
formed in the bottom layer of packaging while leaving a gap (235)
in the seal for fluids (e.g., expanding gasses and/or liquids) to
escape.
[0059] The sealing platform (230) of the first stage of sealing
forms a boat defining seal leaving only the gap (235) in the raised
platform associated with each boat. The sealing platforms are
heated and operable to compress the top package layer against the
bottom package layer to bond the two layers together.
[0060] The heat generated during the first stage of sealing may
cause some liquid and gas within the boat to expand. The gap (235)
leaves a portion of the seal incomplete. This gap (235) in the seal
allows expanding gasses and liquids to escape thereby limiting
these same fluids from exerting stresses on the packaging materials
and the seal. In addition, because the hot expanding gases and
liquids are allowed to escape, the partially sealed contact lens
package may cool relatively quickly.
[0061] According to one exemplary embodiment, a second row of
sealers is also illustrated on the left side of the upper sealing
head (200). The sealing platform (250) of the second stage of
sealing corresponds to the gap (235) left in the first stage of
sealing. That is, the sealing platform (250) will complete the seal
around the boat by sealing closed the gap (235). In the second
stage, the packaging is aligned relative to the sealing platform
(250). Once positioned, the sealing platform (250) operates to
compress the top and bottom package layers together in the location
of the gap (235) and applies energy to complete sealing together of
the top and bottom layers of packaging. As noted previously, the
sealing portions of the sealing heads may generate seals by
selectively imparting any number of energies to the package
including, but in no way limited to, thermal energy, ultrasonic
energy, radio frequency (RF) energy, or infrared (IR) energy.
[0062] Alternative embodiments of such sealing heads may include
more than two stages. As illustrated in FIGS. 2A and 2B the seal is
completed in two stages. However, it may readily be understood that
sealing stages leaving two, three, or more gaps may potentially be
sealed in two, three, or more stages.
[0063] The shape, size and other aspects of the first and second
seal portions (308), (310) shown in FIGS. 3A-3B may result from the
construction and operation of the sealing platforms (230), (250).
The sealing platform (230) may provide the first seal portion (308)
that extends around substantially all of a periphery of the lens
receiving area (302) of the contact lens packages (300A-300C) (see
FIG. 3A). The gap (312) may be defined by the size and shape of the
gap (235) of the sealing platform (230). The gap (312) may be
configured to help control the flow of gases and liquids relative
to the lens receiving area (302) where the contact lens (304) is
retained during the various sealing stages. In one example, fluids
are expelled from the lens receiving area (302) through the gap
(312) after the first seal portion (308) is formed and before and
during formation of the second seal portion (310).
[0064] The sealing platform (250) may provide the second seal
portion (310) around a different portion of a periphery of the lens
receiving area (302) (see FIG. 3B). The second seal portion (310),
together with the first seal portion (308), may complete a seal
around an entire periphery of the lens receiving area (302). The
second seal portion (310) may cover or overlap the gap (312). The
second seal portion (310) may have different characteristics and
properties as compared to the first seal portion (308). For
example, the second seal portion (310) may have a different seal
strength than the first seal portion (308). In one embodiment, the
second seal portion (310) has a greater seal strength than a seal
strength of the first seal portion (308) and may be configured as a
permanent seal that is not intended to separate, while the first
seal portion (308) provides a releasable seal.
[0065] The first and second seal portions (308), (310) may be
formed using different applications of heat, pressure and other
conditions in connection with use of the sealing platforms (230),
(250). For example, the second seal portion (310) may be formed
using a greater heat and/or a greater pressure associated with use
of the sealing platform (250) than the heat and/or pressure
associated with use of the sealing platform (230). In other
examples, different materials may be used in the first package
layer (301) or second package layer, or additional layers
positioned there between, in the area of the first or second seal
portions (308), (310) to provide different sealing
characteristics.
[0066] FIGS. 4A-4C illustrate various embodiments of a lower
sealing head configuration and manufacturing platform, according to
one exemplary embodiment. The configuration of FIG. 4A includes a
lower sealing head having a base (400), a raised platform (405),
and indentations (410) corresponding to the boats of a bottom layer
of packaging. The indentations (410) are configured to receive the
boat portion of the bottom package layer. The raised platform (405)
will support the package layer as an upper sealing head (e.g., see
FIG. 2A), through compression and heat, bonds the upper layer of
packaging to the lower layer of packaging.
[0067] FIG. 4B differs in that a base (400) and a raised platform
(405) are configured with first and second indentations (420, 425).
A first, larger indentation (420) is configured to receive a lower
layer of packaging material that includes the boat portion. A
second, deeper indentation (425) is configured to receive the boat
portion of the bottom package layer. The first and second
indentations (420, 425), according to various embodiments, serve to
accurately position the boat and ensure a proper seal is created.
The upper sealing head seals against the raised platform (405). The
sealing platforms may be configured to enter into the first
indentation (420) and seal against the bottom of the first
indentation (420) while the boat remains within the second
indentation (425).
[0068] FIG. 4C illustrates an adsorbing layer (450) formed on the
bottom seal plate configured to adsorb the potential of an uneven
seal over multiple seal heads. According to one exemplary
embodiment, the adsorbing layer is formed of a silicone.
[0069] Furthermore, according to one exemplary embodiment, the
bottom of the indentations may include alignment features and/or an
orifice used to create a vacuum. According to one exemplary
embodiment, the vacuum created may be used to maintain the position
of the packaging during a sealing event and/or to contribute to the
shaping of the package. Alternatively, any number of orifices or
other vacuum sources may be formed in bottom of the indentations to
mold a bottom layer of packaging into the desired boat shape or
merely to retain the lens and solution during a sealing process, in
the case of a flexible bottom substrate. That is, a bottom layer of
packaging may include a substantially flat sheet, and when
positioned on the lower sealing head a vacuum force may form the
packaging material into the desired permanent or temporary shape.
While the illustrated indentations are substantially circular,
modifications may be made to create a desired non-cylidrical
shapes.
[0070] FIGS. 5A and 5B illustrate an alternative embodiment of a
first stage upper sealing head (500) and a second stage upper
sealing head (590). Many alternative embodiments are possible in
light of the present teachings. As has been previously iterated, a
first stage of sealing seals a top layer of packaging around a
perimeter of a boat formed in a bottom layer of packaging. FIG. 5A
illustrates an upper sealing head (500) comprising a platform (510)
with alignment tabs (515). A lower sealing head (not shown) may
have corresponding indentations to ensure accurate alignment. The
platform (510) is configured with raised sealing platforms
(521-523). The sealing platforms (521-523) may be heated.
Consequently, substantial heat may be imparted on the packaging
material and its contents during the first stage of sealing. The
gaps (526-528) allow fluids (e.g., expanding gasses and liquids) to
escape during the sealing and packaging process.
[0071] Following the first stage of sealing, one or more subsequent
stages may be utilized to complete the seal and close the,gaps
(526-528). FIG. 5B illustrates a second stage upper sealing head
configured to close all three gaps in one sealing stage. As
previously stated, alternative embodiments may close one gap or
multiple gaps at a time and therefore require multiple stages of
sealing. Furthermore, while it may be readily seen that the
finished seal of FIGS. 5A and 5B will be substantially circular,
various other shapes are possible.
[0072] Returning to FIG. 5B, three raised sealing platforms
(536-538) for each contact lens package may correspond to the gaps
(526-528). Consequently, after a second stage of sealing using the
sealing head (590), a top package layer is completely sealed around
the perimeter of a boat of a bottom package layer.
[0073] While the sealing heads illustrated in FIGS. 5A and 5B are
described as being used for sealing a perimeter of a contact lens
package, they may also be used to thermally adhere an internal
feature to a pack. For example, an internal disc, sponge, or
positioning member (all of which may be generally referred to as an
internal feature or a support member) may be adhered to one
component of a contact lens package using sealing heads similar to
those illustrated in FIGS. 5A and 5B.
[0074] FIGS. 6A-6C have previously been discussed briefly, however,
a more detailed description in light of the sealing mechanisms is
provided. FIG. 6A illustrates a top view of a contact lens package
(600). A top package layer (610) is illustrated that covers the
entire contact lens package (600). The top package layer (610) is
sealed with a seal (615) around the perimeter of the boats (675) to
a bottom package layer (650). The top package layer (610) acts as a
cover over the boats (675) to capture an aqueous solution and a
contact lens within the contact lens package (600). Once packaged,
the package of multiple lenses may be cut into individual packaged
contact lenses or other desired quantities.
[0075] FIGS. 6B and 6C illustrate side and cut-away views,
respectively, of the package layers. The top package layer (610)
includes a cover portion (625) that extends over the boat (675) and
is bonded to the bottom package layer (650) around the perimeter of
the boat with a seal (615). The seal (615) may be formed in
multiple sealing steps or stages, wherein portions of the seal
(615) are formed in each stage. In one example, a seal portion
having a gap (e.g., gap 312 shown in FIGS. 3A-3C) may be formed in
a first stage that permits escape of fluid during the sealing
process, and the gap is filled or closed in a second stage after
the fluids are removed. A third stage may include forming a seal
between a member held within the boat (675) (e.g., the support disc
306 described with reference to FIGS. 3A-3C) and at least one of
the top package layer (610) and bottom package layer (650). The
seal (615) may be formed using any desired sealing technique such
as, for example, the heated press described above with reference to
FIGS. 1 and 2A-2B, laser welding, sonic welding, or infrared (IR)
welding. The seal (615) may include portions having different
properties or characteristics, such as, for example, different seal
strength, shape, size, and location. While the shapes illustrated
for the seal (615) are substantially round or rounded squares, any
desired shape is possible and easily attained in a similar
manner.
[0076] By sealing the perimeter of the boat in two or more stages,
several advantages may be attained. As has been previously
described, because the seal is created using two or more stages,
fluids (e.g., energized gasses and liquids) are able to escape
during the sealing process. Providing an escape route for gasses
and liquids may decrease stresses typically present in traditional
manufacturing methods. The present systems and methods may provide
a greater assurance of sterility because energy generated by the
sealing process will not compromise the seal. Consequently,
sometimes debilitating effects of the autoclave may be minimized so
the seal is better able to remain intact. Furthermore, the
reduction in thermal and other stresses allows for the use of less
robust packaging materials, the use of lighter/thinner seal areas,
and the ability to protect the internals of the package via reduced
stresses.
[0077] Specifically, packaging graphics and appearance may be
improved since the thermal expansion and contraction of the
materials is minimized. The polymers within the packaging materials
may be better protected from negative thermal effects, allowing
alternate primary packaging materials to be used. In addition,
thinner, less robust materials may be used, as the sealing process
does not impose as much stress on the material as in traditional
systems and methods. Further, lower cost packages and more
environmentally friendly packages are possible using the present
system and method because of the increased latitude in packaging
materials. Additionally, because of the increased security in the
seal integrity, lower seal forces and lesser seal widths may be
used to successfully seal the pack, thus rendering the package
easier to open without compromising its hermetic integrity.
[0078] As has been previously mentioned, typical blister packs used
for packaging contact lenses consists of a polypropylene boat and a
multi-layer film comprising, for example, polyethylene, aluminum, a
bonding agent, and; polypropylene as a cover. The boat is typically
an injected mold plastic capable of limited elastic deflection. The
boat is usually filled with a sterile saline solution configured to
receive a single contact lens. Traditional methods of sealing the
multi-layer film to the boat require the boat to comprise a
relatively large volume to reduce the thermal effects on the
contact lens. That is, the heat generated is often absorbed by the
aqueous solution surrounding the lens. The amount of solution must
be sufficient to prevent the sealing process from overheating the
contents of the package.
[0079] The present system and method provide a multi-stage sealing
process that limits the thermal effects of the sealing process on
the contact lens and thereby allows alternative materials to be
used as well as lower volume boats or lens receptacles.
Specifically, foil-on-foil packaging may be performed using the
systems and methods described herein. The incorporation of
traditional packaging system on foil-on-foil packaging would result
in a low assurance of sterility due to high manufacturing induced
stresses. The presently described systems and methods allow for
thin film foil-on-foil packaging (i.e. <30 microns in
thickness).
[0080] FIG. 7 is a flow chart illustrating one exemplary method of
sealing a contact lens packaging in multiple stages. A first step
(Step 710) comprises forming a contact lens receiving receptacle in
a bottom packaging material. According to various embodiments the
receptacle is preformed during the initial manufacture of the
bottom packaging material. According to alternative embodiments,
the receptacle may be formed using a vacuum or a press using, for
example, the sealing heads described herein. The receptacle is
filled with an appropriate aqueous solution and a contact lens is
placed therein (Step 720). A top layer of packing material is
sealed around the outer perimeter of the contact lens receiving
receptacle leaving at least one unsealed gap in the seal (Step
730).
[0081] The gap(s) in the seal allow excess fluids (e.g., expanding
gasses and aqueous solution) to escape. The gaps may help reduce
the thermal and expansive forces on the seals and packaging
materials typically present in contact lens packaging. Successive
stages of sealing close the at least one gap created during the
first stage of sealing. A subsequent stage of sealing completes the
seal by bonding the top layer of packing material to the bottom
layer of packaging material where the gaps were left in the
perimeter of the lens receiving receptacle (Step 740).
[0082] The contact lens is now sealed within a relatively small
lens receiving receptacle that is filled with an aqueous solution.
Many of the advantages described above may be attained because the
thermal effects have been minimized during the sealing process. The
contact lens package is now ready for autoclaving and/or other
sterilization processes.
[0083] Other example methods are directed to sealing a contact lens
within a package in multiple stages and related systems configured
to perform such methods. By creating the seal in multiple stages,
expanding gases are released to limit strain to the package.
Consequently, as the package is subjected to limited strains (e.g.,
thermal strains), a higher sterility assurance is attained, thinner
and/or thermally sensitive materials (e.g., foils) may be used, and
smaller packages may be created fewer incidence of thermal damage
to the lens during the sealing process.
[0084] According to one exemplary embodiment, a heated press is
used to create a seal between a top portion and a bottom portion of
a contact lens package in multiple stages. A top portion of the
contact lens package may be sealed only partially to a bottom
portion of a contact lens package in a first stage. In a subsequent
second stage, the seal between the top and bottom portions is
completed. In the first sealing stage, a significant majority of
the seal between the top and bottom portions may be created leaving
only a small portion unsealed. The heat and pressure generated
during the first stage of sealing is released through the unsealed
portion. The second stage seals the remaining relatively small area
and therefore limits any thermal impact the packaging.
[0085] According to another exemplary embodiment, a heated press
has an upper sealing member and a lower sealing member. Both the
upper and lower sealing members may be fitted with sealing heads
that directly contact top and bottom portions of a contact lens
packaging. As the upper and lower members of the heated press are
brought together, the top portion of the contact lens package is
bonded to an outer perimeter of the bottom portion of the contact
lens package. The seal created by this bond is only partial,
leaving at least one portion of the outer perimeter of the bottom
portion unsealed. A second stage of sealing, utilizing a second
sealing head, completes the seal.
[0086] In another embodiment, a first stage seals all but a small
portion of the top and bottom portions together thus allowing
expanding gases to escape through an unsealed gap (or gaps). The
second stage closes the gap by completing the seal between the top
and bottom portions. The second stage sealing may also be used to
create a stronger seal than the preceding seal and thus create a
foil "lock" effect. The foil "lock" effect restricts, during the
pack opening process, the top portion (e.g., the foil) from being
inadvertently pulled off the bottom portion (e.g., the boat) in a
way that spills or discharges the contents out of the pack. This
second or "lock" seal is typically positioned at an end of the
package that is opposite to that part of the package to be opened
and may be achieved by a controlled and increased use of heat,
pressure, or a combination of the two during the sealing
process.
[0087] A heated press may be used to create the seals during the
first and the second stages. Specifically, a heated sealing head
may be configured to provide pressure and heat around the outer
perimeter of the bottom portion of the contact lens package. The
pressure and heat provided by the heated sealing head may cause the
top film layer to bond with the outer perimeter of the bottom
portion of the contact lens package. Alternatively, heat may be
used to create the seal, exclusive of pressure, or vice versa.
Other sealing methods may utilize other forms of energy application
including, but in no way limited to, the application of ultrasonic,
radio frequency (RF), or infrared (IR) energy.
[0088] According to various embodiments, the present exemplary
contact lens packaging systems and methods are used in creating a
foil-on-foil package. That is, while the presently disclosed system
and method is applicable to any number of contact lens packaging
such as traditional blister packs used by contact lens
manufacturers, the present disclosure may also provide for improved
sealing of lower volume foil only packages. Specifically, a foil
bottom portion of the package may be pre-formed, or formed prior to
sealing by a pre-forming head or a lower sealing head to create a
contact lens receptacle (e.g., the boat). Alternatively the foil
bottom may be left unformed. The foil bottom is then dosed with
sufficient aqueous solution and a contact lens is placed
therein.
[0089] During a first stage of sealing a foil cover is sealed to
the boat around an outer perimeter of the boat leaving only a small
portion unsealed. Expanding gases or, if desired, liquids may
escape through the unsealed portion minimizing the thermal effects
of the sealing process. A second stage of sealing completes the
seal to enclose the contact lens and aqueous solution within the
foil-on-foil packaging. Traditional methods of sealing the top and
bottom layers are less compatible with foil-on-foil packaging.
Traditional packaging may significantly benefit from this method of
sealing as well.
[0090] Benefits of the present methods of sealing include, for
example, improving foil-on-foil packaging of contact lenses,
providing smaller and lower volume packages, packaging graphics and
package appearance improvements, providing thinner packaging,
reduced stress on packaging materials and contents, reducing stress
on a seal of the packaging resulting in a higher sterility
assurance, reducing costs, and the ability to use more sensitive or
less robust ingredients.
[0091] The preceding description has been presented only to
illustrate and describe embodiments of the principles described
herein. It is not intended to be exhaustive or to limit the
disclosure to any precise form. The principles described herein may
be practiced otherwise than is specifically explained and
illustrated without departing from their spirit or scope. For
example, the principles described herein may be implemented in a
wide variety of packaging systems; however they are particularly
pertinent to the precision and accuracy required during contact
lens packaging. It is intended that the scope of the present
exemplary system and method be defined by the following claims.
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