A desiccant system and a method for producing the same wherein
a container is provided with a desiccant sheet that is trapped within
the container and a water vapor impermeable cover for the container
making a water impermeable seal thereto. The sheet may have a first
substrate, and optionally, a second substrate, and desiccant particles
adhered to the first substrate or trapped between the first substrate
and the second substrate. A binder material may fuse the desiccant
particles to one another and to the substrates. The sheet may be
trapped within the bottle due to its tendency to unfurl to a flat
condition, or it may be adhered to an inner surface of the bottle.
What is claimed is:
1. A desiccant system comprising: a bottle; and a sheet of desiccant
material trapped within said bottle.
2. The desiccant system of claim 1 wherein said sheet has characteristics
which cause it to assume a position against at least a portion of
an inner wall of said bottle.
3. The desiccant system of claim 1 wherein said bottle has a neck
having a smaller diameter than a remainder of said bottle, and wherein
said sheet has resilient characteristics causing said sheet to attempt
to return to a flat condition when said sheet is rolled, said sheet
being trapped within said bottle when unrolling against an inner
surface of said bottle.
4. The desiccant system of claim 1 further comprising an adhesive
for affixing said desiccant sheet to an internal surface of said
5. The desiccant system of claim 4 wherein said adhesive is non-toxic.
6. The desiccant system of claim 1 wherein said sheet comprises:
a first substrate; and a composite layer formed on said substrate,
said composite layer including desiccant particles and binder particles,
a portion of said binder particles adhering said desiccant particles
to one another and a portion of said binder particles adhering said
desiccant particles to said substrate.
7. The desiccant system of claim 6 further comprising a second
substrate, said second substrate being adhered to said composite
layer by a portion of said binder particles.
8. The desiccant system of claim 1 further comprising a cover
for sealing said bottle so that said bottle is moisture-tight.
9. A method for providing a desiccant system comprising: inserting
into a bottle a sheet of desiccant material, said sheet being inserted
into said bottle so that said sheet is trapped within said bottle.
10. The method of claim 9 further comprising; rolling said sheet
into a generally cylindrical shape having a diameter smaller than
a neck of said bottle; placing said sheet within said bottle; and
allowing said sheet to unfurl so as to be trapped within said bottle.
11. The method of claim 9 further comprising adhering said sheet
to an inner surface of said bottle.
12. The method of claim 9 wherein said sheet comprises desiccant
particles adhered or entrapped within or upon said substrate.
13. The method of claim 9 wherein said sheet has a first substrate
and a second substrate, at least one of said substrates being water
vapor permeable, and desiccant particles trapped between said first
substrate and said second substrate.
BACKGROUND OF THE INVENTION
 1. Field of the Invention
 The present invention relates to desiccant systems. More
particularly, it relates to systems wherein the contents of a bottle,
such as, for example, pharmaceuticals (pills, tablets, capsules)
are stored in a low humidity environment.
 2. Prior Art
 There are a variety of ways to package desiccant materials
used to provide humidity control in bottles or enclosures such as
those used to store moisture-sensitive scientific instruments, specialty
chemicals, or pharmaceuticals. Generally, these consist of packets
that are filled with desiccant materials, canisters containing such
materials, or solids such as tablets or cylinders containing desiccant.
All of these approaches have respective disadvantages.
 First, desiccant packages take up space. Thus, they reduce
the volume of material that can be stored within an enclosure. In
some cases, this may not be a major disadvantage. However, once
a sealed enclosure is opened, these desiccant packs can fall out
and are often lost. In fact, in some cases, individuals not aware
of their purpose tend to discard these packs. Thus, the contents
are no longer safeguarded against excessive moisture. In those cases
where the desiccant package is retained, it is often removed from
the package and exposed to dust, atmospheric moisture and other
forms of contamination before being returned to the package. Thus,
unwanted bacterial contamination may take place and the contents
may no longer be appropriate for consumption.
 If small desiccant cylinders are permitted to remain in
a bottle containing, for example pills, there is a chance of them
being accidentally ingested. While this in itself may not be dangerous,
the failure of someone to take a critically required medication,
because that person believes it has already been taken, may be extremely
 Desiccant canisters, while avoiding some of these problems,
are expensive to manufacture. The costs involved in making an entire
enclosure of a desiccant material are inherently significant.
 Accordingly, there is a need for a system for placing and
retaining a desiccant in a container so as to overcome the disadvantages
inherent in existing desiccant systems.
SUMMARY OF THE INVENTION
 It is an object of the present invention to provide a desiccant
and container system wherein the usable space available in the container
is not significantly reduced by the presence of the desiccant.
 It is another object of the invention to provide a desiccant
and container system wherein the desiccant material is not easily
lost or contaminated.
 It is a still another object of the invention to provide
a desiccant container system that is easy to manufacture and low
 In accordance with the invention, a sheet of desiccant material
is placed in an enclosure or bottle which requires humidity control.
The sheet may be sized and shaped so that it can be rolled up, placed
through the neck of the bottle, and allowed to expand inside the
bottle against the walls thereof. Accordingly, the sheet is then
effectively secured in place within the bottle against its walls.
It cannot easily be removed from the bottle and lost. Further, it
is not subject to exposure to atmospheric moisture, contaminants
and bacteria that may be found outside the bottle. Finally, it is
not subject to being accidentally ingested.
 As used herein, the term "bottle" refers to a
bottle, enclosure, or other container, and may include jars, pill
bottles, or other similar structures in which moisture sensitive
products may be packaged.
 The present invention is also directed to a method for producing
the container and desiccant system described above. In accordance
with the method, a desiccant sheet of appropriate size and shape
is rolled into a cylindrical configuration, placed through the neck
of the bottle into the interior of the bottle, and then allowed
to expand against the walls of the bottle, thus securing the sheet
within the bottle. If the opening or neck of the bottle is not smaller
in size than the remainder thereof, a small amount of an adhesive
may be used to secure the sheet in place.
BRIEF DESCRIPTION OF THE DRAWINGS
 The foregoing aspects and other features of the present
invention are explained in the following description, taken in connection
with the accompanying drawings, wherein:
 FIG. 1 is a cross section of a desiccant sheet that may
be used in the present invention.
 FIG. 2 is a perspective view of a bottle having a desiccant
sheet in accordance with the invention, inserted there.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
 Referring to FIG. 1 there is shown a cross sectional view
of a desiccant sheet 10 which may be used in the present invention.
Although the present invention will be described with reference
to the single embodiment shown in the drawings, it should be understood
that the present invention can be embodied in many alternate forms
of embodiments. In addition, any suitable size, shape or type of
elements or materials could be used.
 In FIG. 1 a desiccant sheet 10 includes a first substrate
12 and a second substrate 14. Substrates 12 and 14 have, disposed
between them a composite layer 16 including particles of a desiccant
material, such as for example, silica gel, activated alumina, zeolite
or similar material, and a suitable binder material for binding
at least a portion of the desiccant particles to each other, and
at least a portion of the desiccant particles to one of the substrates
12 and 14. Substrates 12 and 14 are preferably non-woven fabrics
such as non-woven polypropylene available from Polymer Group, Inc.
(PGI) of North Charleston, S.C., USA, and having a weight of 0.5
to 1.5 ounces per square yard. For example, substrates 12 and 14
may have weights of 1.5 and 1.0 ounces per square yard, respectively.
Alternatively, substrates 12 and 14 may have weights of 1.0 and
0.6 ounces per square yard, respectively. It is important that at
least one of the substrates 12 and 14 be water vapor permeable so
that the desiccant particles can absorb water vapor when sheet 10
is placed in the enclosure or bottle.
 Sheet 10 may be formed by the process described in detail
in U.S. Pat. Nos. 5792513 and 6077588 which are incorporated
by reference in their entirety, as if fully set forth herein. Materials
of this general nature are sold under the trademark PLEKX.RTM.,
by KX Industries, L.P. of Orange, Conn., USA, the assignee of these
 Although shown in this embodiment as a material with two
substrates, it will be understood that the medium may be formed
with a composite layer of desiccant particles and binder upon a
single substrate, in accordance with the process of the above mentioned
patent. In addition, multiple layer versions are possible with alternating
layers of water vapor permeable substrates and desiccants. A thin
sheet 10 is preferred.
 The binder used to hold the structure of FIG. 1 together
can be low-density polyethylene ("LDPE") binder particles,
such as grade FN510 supplied by Equistar Chemicals, L.P. of Tuscola,
Ill., USA, and manufactured and sold under the trade name Microethane.RTM..
These LDPE particles are primarily in the range of 10 to 30 microns
in diameter, with some portion of the size distribution being outside
this range. This material can be combined with an additive of approximately
one half of one percent (0.5%) of synthetic amorphous precipitated
silicon dioxide, specifically a synthetic amorphous silicon dioxide
hydrate sold under the name Sipernate.RTM. 22LS, supplied by Degussa-Huls,
through its Degussa Corporation Pigment Group of Richfield Park,
 The silica gel particles have an average size of 149 microns,
with an approximately normal distribution about that size. The mixture
of silica gel particles and binder may be applied at a density of
300 grams per square meter, with the binder comprising approximately
17% by weight of the mixture.
 While silica gel particles are preferred, other desiccant
particles may be used. In particular, such particles include activated
alumina, zeolite, calcium sulfate, calcium oxide and other particles
that are hydrophilic and can provide a desiccant action for the
contents of a container in which sheet 10 is placed. The particles
may have a size in the range of 5 to 5000 microns.
 Desiccant sheet 10 can be produced by other means. Hydrophilic
particles may be adhered to an appropriate substrate with an adhesive.
The particles may also be trapped in a bi-component fiber web. Other
methods well known in the art may be used to produce desiccant sheet
 Referring to FIG. 2 a bottle 20 receives as a liner, a
sheet 10 in accordance with FIG. 1. Sheet 10 is sized and shaped,
such as by slitting and sheeting, to a configuration that allows
it to be rolled up into a generally cylindrical shape, placed through
the mouth 21 of bottle 20 and then released therein to expand so
as to become a liner of at least a portion of bottle 20. Preferably,
sheet 10 is thus disposed in bottle 20 at a position separate and
apart from any cap or closure that may be applied to bottle 20.
Sheet 10 preferably has characteristics that causes it to unfurl
towards its normally flat configuration, and thus will become lodged
against the wall of bottle 20. In a bottle 20 where neck 22 is smaller
in diameter than the remainder of bottle 20 sheet 10 will be trapped
within bottle 20. While it is possible to remove sheet 10 from bottle
20 depending upon the size of neck 22 it may be difficult, require
significant manual dexterity or may require the use of special tools.
In general, sheet 10 will remain trapped in bottle 20 and will not
be lost or subject to contamination by dirt or bacteria. Accidental
ingestion is not possible.
 In cases where the mouth 21 and neck 22 of a bottle are
large and of the same, or nearly the same, diameter as bottle 20
sheet 10 may be secured within bottle 20 by adhesive bonding thereto.
Specifically, a small amount of a non-toxic adhesive 25 (shown,
but not required in the embodiment of FIG. 2), may be applied to
the one of substrates 12 or 14 that will come in contact with the
inner surface of bottle 20. The adhesive is then allowed to set
and the sheet is affixed within bottle 20.
 As noted above, a sheet 10 having a single substrate and
a composite layer with desiccant particles and binder particles
fused thereto may also be used. If such layer is used, it is generally
preferable that the single substrate be positioned so that it is
facing, and in contact with, the contents of bottle 20. In this
case, the single substrate must be water-vapor permeable. If a sheet
having two substrates is used, at least one must be water vapor
permeable and should face the contents when in place.
 In use, bottle 20 is then filled with its customary contents
which may include pharmaceuticals. A suitable humidity tight cap
or cover 26 of the snap-on or screw-on variety, is then placed over
the receiving end of mouth 21 to seal bottle 20. Suitable tamper
resistant packaging is then used to package bottle 20 in a manner
well known in the art.
 When bottle 20 is used by the ultimate user or consumer,
the tamper-proof packaging is removed and bottle 20 is opened by
removing cap or cover 26 from mouth 21. Periodically, a portion
of the contents is removed for use. After such removal, the bottle
is again resealed by replacing cap or cover 26 over mouth 21.
 It will be understood that sheet 10 will remain within bottle
20 during all such use. Sheet 10 will not be subject to loss, contamination
by dirt or bacteria, or accidental ingestion by the consumer. Thus,
the present invention provides an inexpensive and virtually foolproof
way for keeping the contents generally free from moisture for the
life of the product placed in bottle 20 or at least until the desiccant
sheet becomes saturated. To the extent that sheet 10 covers a significant
portion of the interior of bottle 20 it will also provide a cushioning
effect for the contents thereof, tending to, for example, make the
fragmenting of pills or tablets less likely if bottle 20 undergoes
rough handling during shipping or use.
 It will be understood that the present invention may be
implemented in other ways. For example, it may be possible to mold
a plastic bottle around a cylindrical sheet 10 or alternatively
sheet 10 may be inserted into the mold that produces bottle 20.
In either case, a structure similar to that described in detail
herein, and having exactly the same functionality and advantages
will be produced.
 In certain cases, it may be advantageous to seal the edges
of sheet 10 in any one of a variety of ways well known in the art,
such as for example, by application of a sealant around the periphery,
or by supplemental heating or welding (including ultrasonic welding)
of the exposed edge thereof. This will assure that desiccant particles
do not break away from sheet 10 so as to mix with the contents of
 It should be understood that the foregoing description is
only illustrative of the invention. Various alternatives and modifications
can be devised by those skilled in the art without departing from
the invention. Accordingly, the present invention is intended to
embrace all such alternatives, modifications, and variances which
fall within the scope of the appended claims.