Abstrict A container for containing moisture sensitive items has at least
one wall having a desiccating agent wherein the desiccating agent
absorbs moisture so as to inhibit such moisture from contacting
moisture sensitive items contained within the bag. The wall preferably
has a durable outer layer, a moisture barrier intermediate layer,
and a desiccant containing inner layer. The desiccant containing
inner layer preferably comprises microporous polyolefin impregnated
with silica.
Claims What is claimed is:
1. A container for containing moisture sensitive items, said container
comprising at least one first wall comprising a durable non-desiccant
containing outer layer, and an inner layer containing desiccating
agent for adsorbing moisture, wherein said inner layer comprises
a microporous polyolefin layer impregnated with moisture adsorbent
silica such that said impregnated polyolefin layer is exposed to
an inside of the containers.
2. The container as recited in claim 1 wherein said desiccating
agent is integrally formed with said inner layer.
3. The container as recited in claim 1 wherein said first wall(s)
comprises a moisture barrier intermediate layer disposed between
the outer layer and the inner layer.
4. The container as recited in claim 3 wherein: a) said outer layer
comprises a material selected from the group consisting of: i) polyester
terrephlalate; ii) nylon; iii) heat and abrasion resistant lacquer;
iv) polypropylene, and b) said intermediate layer comprises a metal
foil.
5. The container as recited in claim 3 further comprising: a) a
first adhesive layer disposed intermediate said outer layer and
said intermediate layer for bonding said outer layer to said intermediate
layer; and b) a second adhesive layer disposed intermediate said
intermediate layer and said inner layer for bonding said intermediate
layer to said inner layer.
6. The container as recited in claim 4 wherein said first and second
adhesive layers comprise at least one adhesive selected from the
group consisting of: a) solventless adhesive; b) solvent based adhesive;
and c) extruded polymers.
7. The container as recited in claim 5 wherein said first and second
adhesive layers comprise at least one of extruded polyethylene or
extruded polyethylene copolymer.
8. The container as recited in claim 1 further comprising at least
one second wall comprised of metal foil to which said first wall(s)
is attached so as to define a bag.
9. The container as recited in claim 1 wherein said first wall(s)
is configured so as to define a bag.
10. The container as recited in claim 1 comprising two first walls
bonded together to define a bag.
11. The container as recited in claim 10 further comprising a heat
seal lacquer bonding said two first walls together.
Description FIELD OF THE INVENTION
The present invention relates generally to packaging materials
and more particularly to a desiccant barrier container for containing
moisture sensitive items, wherein the desiccant barrier container
comprises microporous polyolefin impregnated with silica so as to
absorb moisture and thereby inhibit the moisture from contacting
moisture sensitive items contained within the container.
BACKGROUND OF THE INVENTION
Bags and the like for containing moisture sensitive items, such
as electronic components, are well known. Moisture sensitive items
are typically packaged within such moisture resistant bags at their
place of manufacture and are typically only removed therefrom immediately
prior to being utilized. Thus, the moisture sensitive items so packaged
are generally isolated from moisture contained within the air, as
well as from accidental moisture contamination through handling,
e.g., leaks, spills, body fluids, etc.
Further, it is well known to include a desiccant, such as silica,
within the moisture resistant package containing such items. Such
desiccant is typically enclosed within a moisture permeable package
such that the desiccant is isolated from the moisture resistant
items packaged therewith and such that moisture is readily absorbed
thereby. Thus, the moisture contained in the ambient air when the
package is sealed, as well as any moisture subsequently entering
the package is generally absorbed by the desiccant rather than substantially
contaminating the moisture sensitive item contained therein.
Although the use of such moisture resistant packaging in combination
with a desiccant has proven generally suitable for its intended
purpose, it possesses inherent deficiencies which detract from its
overall effectiveness and desirability.
For example, according to contemporary methodology, it is necessary
to purchase and store such desiccants prior to their use. When needed,
such desiccants must be retrieved from inventory, unpackaged, and,
generally, manually placed within each moisture resistant package
along with the moisture sensitive item contained therein. Thus,
the use of such desiccants according to contemporary methodology
requires substantial handling. As those skilled in the art will
appreciate, the costs associated with the use of such contemporary
desiccants thus includes not only their purchase price, but additionally
the cost associated with the labor required for such handling.
As such, it is beneficial to provide a moisture resistant package
which inhibits moisture contamination of moisture sensitive items
contained therein and which does not require the addition of a separate
desiccant.
SUMMARY OF THE INVENTION
The present invention specifically addresses and alleviates the
above-mentioned deficiencies associated with the prior art. More
particularly, the present invention comprises a container comprised
of a moisture isolating material for containing moisture sensitive
items. The container comprises at least one wall comprising a desiccating
agent. The desiccating agent absorbs moisture contained within the
container so as to inhibit any moisture disposed within the container
from substantially contacting moisture sensitive items contained
within the container.
According to the preferred embodiment of the present invention,
the desiccating agent is integrally formed with at least a first
wall of the container. The wall(s) with which such desiccating agent
is integrally formed preferably comprise microporous polyolefin
impregnated with silica.
Further, according to the preferred embodiment of the present invention,
the wall(s) within which such desiccating agent is integrally formed
comprise a durable outer layer and a desiccant containing inner
layer. The wall(s) preferably further comprise a moisture barrier
intermediate layer disposed between the durable outer layer and
the desiccant containing inner layer.
The outer layer preferably comprises either polyester terrephlalate,
nylon, heat and abrasion resistant lacquer, or polypropylene, and
the intermediate layer preferably comprises a metal foil. A first
adhesive layer is disposed intermediate the outer layer and the
intermediate layer for bonding the outer layer to the intermediate
layer. Similarly, a second adhesive layer is disposed intermediate
the intermediate layer and the inner layer for bonding the intermediate
layer to the inner layer. The first and second adhesive layers preferably
comprise either solventless adhesive, solvent based adhesive, or
extruded polymer, such as extruded polyethylene, extruded polyethylene
copolymer, or extruded ionomers.
The container may optionally be configured so as to comprise at
least one wall comprised of metal foil, to which said desiccant
containing wall is attached so as to define a bag, for example.
Thus, for a two-walled bag, for example, one of the walls comprises
a desiccant containing inner layer and the other wall does not.
Thus, according to the present invention, various different containers,
e.g., boxes, bags, etc., may be fabricated so as to provide a substantially
moisture resistant enclosure to which additional desiccant does
not need to be added in order to effectively protect moisture sensitive
items from exposure to moisture. According to various alterative
configurations of the present invention, either one or a plurality
of the walls of such containers may be fabricated so as to integrally
contain desiccant. The remaining walls need not contain such integral
desiccant, but must be resistant to moisture permeation.
These, as well as other advantages of the present invention will
be more apparent from the following description and drawings. It
is understood that changes in the specific structure shown and described
may be made within the scope of the claims without departing from
the spirit of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exemplary container or bag formed to provide a moisture
resistant desiccant barrier according to the present invention;
and
FIG. 2 is a cross section of a wall having outer, intermediate,
and inner layers, as utilized in the construction of a moisture
resistant desiccant barrier container according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The detailed description set forth below in connection with the
appended drawings is intended as a description of presently preferred
embodiment of the present invention, and is not intended to represent
the only form in which the present invention may be constructed
or utilized. The description sets forth the functions and sequence
of steps for constructing and operating the invention in connection
with the illustrated embodiments. It is to be understood, however,
that the same or equivalent functions and sequences may be accomplished
by different embodiments that are also intended to be encompassed
within the spirit and scope of the invention.
The moisture resistant desiccant barrier container of the present
invention is illustrated in FIGS. 1 and 2 which depict a presently
preferred embodiment of the invention. Referring now to FIG. 1
one example of a container formed according to the present invention
is a bag 10 having at least one wall 12a or 12b formed so as to
comprise integrally formed desiccant upon the inner surface 32 thereof.
Thus, either one or both of the two walls 12a or 12b is formed to
comprise integrally formed desiccant, the other wall 12b or 12a
is comprised of a moisture isolating material, so as to inhibit
the flow of liquid into the bag, as discussed in detail below and
lacks an integrally formed desiccant. Of course, both walls 12a
and 12b may be comprised of integrally formed desiccant, if desired.
The two walls 12a and 12b are joined via seam 32 which may be
formed via heat sealing, adhesively bonding, or otherwise formed
in a manner which inhibits flow of liquid or moisture ladened air
therethrough. In a similar manner, the opening 14 of the bag 10
may be sealed via heat sealing, adhesive bonding, or via the use
of a zip-lock.
Referring now to FIG. 2 at least one wall of the bag 10 is preferably
formed to have a durable outer layer 30 preferably formed of polyester
terrephlalate, nylon, heat and abrasion resistant lacquer, or polypropylene.
The durable outer layer 30 provides a gas barrier and also provides
the strength and durability required of packaging materials. The
durable outer wall 30 is bonded, preferably via adhesive layer 26
to a moisture barrier intermediate layer 22 which is preferably
comprised of a metal foil, e.g., aluminum foil, tin foil, etc. The
moisture barrier intermediate layer 22 is bonded to inner layer
24 preferably via adhesive layer 28. As those skilled in the art
will appreciate, the particular adhesive materials utilized are
dependent upon the chosen fabrication process. Solventless adhesive,
waterborn adhesive, or solvent based adhesives may be utilized if
an adhesive laminator is used. Alternatively, the adhesive layers
are extruded polymers such as polyethylene or polyethylene copolymers
or ionomers, which are preferably applied to the outer layer 30
immediate layer 22 and inter layer 24 in a sandwich-like fashion
immediately after extrusion. Alternatively, the sandwiched layers
are assembled and then heated to effect bonding. Thus, the three
wall materials may be laminated together by either adhesive or extrusion
lamination.
The inner layer 24 which defines the inner surface 32 of the bag
10 is preferably formed of microporous polyolefin impregnated with
silica, so as to absorb moisture which is enclosed therein along
with the moisture sensitive article, as well as any moisture which
permeates the durable outer layer 30 and the moisture barrier intermediate
layer 22.
Thus, the user need merely insert the moisture sensitive item into
the container 10 of the present invention and seal the container
10 in order to achieve desired moisture resistant packaging. No
separate desiccant needs to be added to the container, since such
desiccant is formed integrally therewith. Thus, the need for separate
desiccant packets is eliminated. Bags formed according to the present
invention are suitable for either vacuum or ambient packaging of
moisture sensitive items. The silica impregnated microporous polyolefin
inner layer 24 is heat sealable to various polyolefins and heat
seal lacquers, so as to facilitate the construction of various different
containers therewith.
The moisture barrier material of the present invention is suitable
for heat sealing to a foil laminate having a polyethylene inner
layer so as to form a two-part bag. Thus, that wall of the two-part
bag comprising integrally formed desiccant inhibits moisture formation
within the bag. The moisture isolating material formed according
to the present invention can also be sealed to itself via the use
of heat-seal lacquer applied to one or both portions thereof which
are to be sealed together, thereby facilitating the construction
of various bags, boxes, and other packages.
After being fabricated, the moisture isolating material of the
present invention is heated sufficiently to drive off any moisture
absorbed during processing, handling, and storage prior to being
formed into a container. Alternatively, the final, assembled container
may be heated, as necessary.
Containers and/or materials formed according to the present invention
are preferably packaged in a moisture resistant container, preferably
also formed according to the present invention, so as to inhibit
moisture absorption during shipping and storage thereof.
The durable outer layer 30 of the moisture isolating material provides
an effective gas barrier and the metal foil intermediate layer 22
provides an effective barrier against moisture permeation. The durable
outer layer 30 also provides an effective moisture barrier.
It is understood that the exemplary moisture resistant container
described herein and shown in the drawings represents only a presently
preferred embodiment of the invention. Indeed, various modifications
and additions may be made to such embodiment without departing from
the spirit.and scope of the invention. For example, as those skilled
in the art will appreciate, various different configurations of
containers are suitable for fabrication according to the present
invention. Additionally, various different configurations of the
moisture isolating material are contemplated. Thus, these and other
modifications and additions may be obvious to those skilled in the
art and may be implemented to adapt the present invention for use
in a variety of different applications. |