Molecular sieve abstract
A composition of matter comprising a mixture of activated or CO.sub.2
loaded zeolite molecular sieve material, a small amount of a tabletting
lubricant and an effective amount of some non-swelling fibers, preferably
of the size of from about 100 to about 2000 microns in length and
from about 1 to about 50 microns in diameter, said composition of
matter being used for making structurally stable, non-fired, zeolite
tabletted, rigid, composite bodies therefrom. When charged with
CO.sub.2 the fiber-reinforced tabletted body makes an excellent
beverage carbonation device.
Molecular sieve claims
What is claimed is:
1. A composition of matter for preparing a non-fired, rigid composite,
porous and activated zeolite molecular sieve material tablet for
adsorbing and releasing adsorbable gases, said composition comprising:
(a) from about 82 to about 98.5% wt. % of activated crystalline
zeolite molecular sieve material;
(b) from about 1 to about 15 wt. % of fibrous material selected
from the group consisting of hydrophobic fibers and non-swelling
hydrophilic fibers; and
(c) from about 0.5 to about 3 wt. % of tabletting lubricant;
wherein said (a), (b) and (c) are uniformly mixed and tabletted
into said rigid composite, porous and activated tablet.
2. The composition of claim 1 wherein said composition comprises:
(a) from about 87.5 to about 98 wt. % of said zeolite material;
(b) from about 1 to about 10 wt. % of said fibers; and
(c) from about 1 to about 2.5 wt. % of said lubricant.
3. The composition of claim 1 wherein said zeolite material comprises
from about 94 to about 97%, said fibers comprise from about 2 to
about 5%, and 1% of said lubricant.
4. The composition of claim 1 wherein said lubricant is a metal
fatty acid ester.
5. The composition of claim 1 wherein said lubricant is metal stearate
selected from the group consisting of magnesium, aluminum or calcium
stearate.
6. The composition of claim 1 wherein said lubricant is magnesium
stearate.
7. The composition of claim 1 wherein said lubricant is hydrogenated
vegetable oil.
8. The composition of claim 1 wherein said lubricant is a hard
polyethylene glycol.
9. The composition of claim 1 wherein said fibers have a length
of from about 100 to about 2000 microns and a diameter of from about
1 to about 50 microns.
10. The composition of claim 1 wherein said fibers have a length
of from 400 to about 1500 microns and a diameter of from about 1
to about 40 microns.
11. The composition of claim 1 wherein said fibers have a length
of from about 800 to about 1000 microns and a diameter of from 1
to about 20 microns.
12. The composition of claim 1 wherein said fibers are selected
from the group consisting of polyethylene, polypropylene, polyester,
nylon, and cellulose.
13. The composition of claim 1 wherein said tablet is charged with
CO.sub.2 in an amount of at least 5% by weight of said activated
zeolite material.
14. A composition of matter for preparing a CO.sub.2 -load rigid
composite tablet comprising:
(a) from about 82 to about 98.5 wt. % of activated crystalline
zeolite molecular sieve material;
(b) from about 1 to about 15 wt. % of fibrous material selected
from the group consisting of hydrophobic fibers and non-swelling
hydrophilic fibers; and
(c) from about 0.5 to about 3 wt. % of tabletting lubricant;
wherein said activated crystalline zeolite material is loaded with
CO.sub.2 in an amount of at least 5% by weight of said zeolite material,
and wherein said loaded zeolite material, said fibers and said lubricant
are intimately mixed and compacted and granulated to form free-flowing
granules, and wherein said granules are tabletted into said CO.sub.2
-loaded rigid composite tablet.
15. The rigid composite tablet of claim 1 or claim 14 wherein said
tablet is shaped in a geometric form selected from the group consisting
of disks with or without channels cylinders with one channel.
16. A method of carbonating an aqueous beverage at the point of
consumption which comprises contacting a non-fired CO.sub.2 -loaded,
rigid composite body with the aqueous beverage to be carbonated,
said rigid composite body comprising:
(a) from about 82 to about 98.5 wt. % of activated crystalline
zeolite molecular sieve material;
(b) from about 1 to about 15 wt. % of a fibrous material selected
from the group consisting of non-swelling hydrophilic fibers and
hydrophobic fibers; and
(c) from about 0.5 to about 3 wt. % of tabletting lubricant;
wherein said activated crystalline zeolite material, said fibers
and said lubricant are intimately mixed and compacted and granulated
to form free-flowing granules, and wherein said granules are tabletted
into said rigid composite body containing said activated zeolite
molecular sieve material, said fibers and said lubricant and wherein
said body is loaded with said CO.sub.2 in an amount of at least
5% by weight of said activated zeolite material.
17. The method of claim 16 wherein said rigid composite body comprises:
(a) from about 87.5 to about 98 wt. % of said zeolite material;
(b) from about 1 to about 10 wt. % of said fibers; and
(c) from about 1 to about 2.5 wt. % of said lubricant.
18. The method of claim 16 wherein said zeolite material comprises
from about 94 to about 97%, said fibers comprise from about 2 to
about 5%, and 1% of said lubricant.
19. The method of claim 16 wherein said lubricant is a metal fatty
acid ester.
20. The method of claim 16 wherein said lubricant is metal stearate
selected from the group consisting of magnesium, aluminum or calcium
stearate.
21. The method of claim 16 wherein said lubricant is magnesium
stearate.
22. The method of claim 16 wherein said lubricant is hydrogenated
vegetable oil.
23. The method of claim 16 wherein, said lubricant is a hard polyethylene
glycol.
24. The method of claim 16 wherein said fibers have a length of
from about 100 to about 2000 microns and a diameter of from about
1 to about 50 microns.
25. The method of claim 16 wherein said fibers have a length of
from 400 to about 1500 microns and a diameter of from about 1 to
about 40 microns.
26. The method of claim 16 wherein said fibers have a length of
from about 800 to about 1000 microns and a diameter of from 1 to
about 20 microns.
27. The method of claim 16 wherein said fibers are selected from
the group consisting of polyethylene, polypropylene, polyester,
nylon, and cellulose.
28. The method of claim 16 wherein said rigid composite body is
charged with CO.sub.2 in an amount of at least 5% by wt. of said
activated zeolite material prior to mixing with said fibers and
said lubricant.
Molecular sieve description
TECHNICAL FIELD
Non-fired rigid composite bodies containing crystalline zeolite
molecular sieves for charging with a gas, e.g., carbon dioxide,
to be released when said body is brought into contact with water
or an aqueous beverage.
BACKGROUND ART
This invention relates to a zeolite device adaptable for the carbonation
of aqueous beverages at the point of consumption. Carbonation is
accomplished by contacting the water or the beverage to be carbonated
with the device comprising "molecular sieves", i.e., crystalline
aluminosilicates, which contain adsorbed gaseous carbon dioxide.
Carbon dioxide is released from the molecular sieves by displacement
with water from the beverage solution. The liberated carbon dioxide
is then dissolved into the liquid to form the carbonated beverage.
The molecular sieves are bonded into a monolithic structure having
sufficient surface area for contact between the aqueous beverage
to be carbonated and the molecular sieves so as to provide means
for a ready displacement of the carbon dioxide to be released by
water from the beverage solution.
Commercial beverage carbonation usually involves carbon dioxide-liquid
contact under pressure with intensive mixing in a cooled container.
Such commercial methods, of course, require elaborate and sophisticated
equipment not available at the point of beverage consumption.
Thus, it was proposed in U.S. Pat. No. 3888998 June 10 1975
to Sampson et al., which was a continuation-in-part of application
Ser. No. 200849 filed Nov. 22 1971 now abandoned, that aqueous
beverages could be advantageously carbonated at the point of consumption
with the use of an effective amount of a crystalline aluminosilicate
molecular sieve material having adsorbed therein at least about
5% by weight of carbon dioxide.
Molecular sieves of the type used in carbonating beverages at the
point of consumption are taught in said U.S. Pat. No. 3888998
herein incorporated by reference in its entirety.
Carbonation in accordance with the latter-named method necessitates
contacting the molecular sieves with the beverage liquid. Generally,
the molecular sieves loaded with CO.sub.2 are placed in a container,
and the liquid to be carbonated is then added in sufficient amount
to cover the sieves. Heretofore, referred to above, as U.S. Pat.
No. 3888998 carbonation has been accomplished by utilizing a
multiplicity of small molecular sieve agglomerates, such as produced
following the teachings of U.S. Pat. No. 2973327 issued Feb.
28 1961 to William J. Mitchell et al., or by utilizing a solid
disk of molded and fired molecular sieves. The agglomerates are
typically either spherical in shape, commonly known as beads, or
roughly cylindrical in shape, commonly known as pellets.
The use of a multiplicity of molecular sieve agglomerates, however,
is disadvantageous due to the disadvantages inherent in using the
small particles. Since the molecular sieve agglomerates are not
in themselves designed for internal consumption, the molecular sieve
bodies must be enveloped or otherwise constrained so as to be readily
separable from the liquid beverage upon consumption. These various
encasements of the molecular sieve bodies may have economical, aesthetic,
or other disadvantages which preclude their use for commercial marketing
purposes. A composite molecular sieve body would overcome many of
these disadvantages inherent in the use of a multiplicity of small
agglomerates. However, there are severe technical problems in formulating
a suitable monolithic structure. Many of these problems were solved
by an extruded zeolite device containing molecular sieves and clay,
and having a number of liquid-permeable channels, as taught in U.S.
Pat. No. 4007134 to Liepa and Japikse, Feb. 8 1977 herein incorporated
by reference in its entirety.
Tabletting problems as stated in the Liepa and Japikse patent are
as follows:
"A solid molecular sieve disk, or tablet, made from either
compressed molecular sieves or from a mixture of aluminosilicates
bonded together with a clay mineral binder tends to be unsatisfactory
in that these bodies have encountered problems when used for carbonating
liquid beverages. In order to obtain sufficient carbonation of the
aqueous beverage, that is, both a sufficient amount of CO.sub.2
released into the beverage and a minimal rate of CO.sub.2 generation
to maintain the beverage in a carbonated state, the molecular sieves
must have adsorbed therein at least a certain amount of CO.sub.2.
However, when these solid disks which contain an effective amount
of gaseous carbon dioxide are placed in the liquid beverage environment,
the pressure generated by the carbon dioxide release from the molecular
sieves is often so extreme as to cause disintegration or destruction
of the disk body. If precautions are taken to prevent this, specifically,
using a binder composition which imparts sufficient strength to
the composite body so as to maintain its structural integrity, then
the binder causes a decrease in the rate of release of the carbon
dioxide. This can result in either unacceptably low carbonation
levels or unacceptably long carbonation times."
Thus, it is the object of the present invention to formulate a
fiber reinforced non-fired zeolite rigid composite body which, when
charged with a sufficient amount of carbon dioxide, will satisfactorily
carbonate an aqueous beverage without the destruction or dissolution
of said body.
It is also an object of this invention to provide a non-fired fiber
reinforced zeolite tabletted device which effectively carbonates
a beverage in a commercially acceptable time period at the point
of consumption.
Yet another object of the present invention is to provide a method
of making a non-fired rigid composite zeolite tablet.
It is a further object of the instant invention to provide simple
but effective devices for suitable gas adsorption. These and other
objects readily apparent to those skilled in the art will be apparent
from the disclosure and appended claims.
BRIEF SUMMARY OF THE INVENTION
The instant invention provides methods, compositions and devices
for carbonating instant beverages, prepared from dry beverage mixes.
In another respect this invention provides an improved method of
making tabletted devices from activated or CO.sub.2 -loaded crystalline
zeolite molecular sieves comprising uniformly mixing said zeolite
molecular sieves, a tabletting lubricant, and some hydrophobic or
non-swelling hydrophilic fibers, and tabletting. The CO.sub.2 -loaded
zeolite tablet device provides improved release of adsorbed carbon
dioxide for beverage carbonation. Such tablets as are produced by
the present invention provide a convenient and economical carbonation
system for both individual and multiple servings of carbonated beverages.
They can readily be combined with a suitable liquid-containing vessel
to provide unique point-of-consumption carbonated beverages. The
employment of fibers provides a structurally stable device which
allows an increase in aqueous penetration rates into the zeolite
tablet for an increase in the rate of CO.sub.2 release.
BRIEF DESCRIPTION OF THE DRAWINGS
Although the specification concludes with claims particularly pointing
out and distinctly claiming the subject matter forming the present
invention, it is believed that the same will be better understood
by reference to the following specification taken in connection
with the accompanying drawings in which:
FIG. 1 is a perspective view of a preferred embodiment of the present
invention wherein the crystalline zeolite tablet is in the shape
of a disk or tablet having several elongated channels running substantially
parallel to the vertical dimension of the tablet;
FIG. 2 is a perspective view of another preferred embodiment of
the present invention wherein the rigid composite tablet is in the
form of a cylinder with one elongated channel running through the
vertical center of the cylinder;
FIG. 3 is another preferred embodiment wherein the tablet is in
the shape of a disk having four elongated channels running through
the vertical dimension of the disk;
FIG. 4 is a tabletted solid disk;
FIG. 5 is another preferred embodiment of this invention in the
shape of a cube.
While the invention will be described in connection with the preferred
embodiments illustrated in the figures, it will be understood that
it is not intended to limit the invention to such embodiments. On
the contrary, it is intended to cover all alternatives, modifications
and equivalents as may be included within the spirit and scope of
the invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
The instant invention provides a composition of matter comprising:
(a) from about 82 to about 98.5 wt. % of activated crystalline
zeolite molecular sieves material;
(b) from 1 to about 15 wt. % of hydrophobic or non-swelling hydrophilic
fibers;
(c) from about 0.5 to about 3 wt. % of a tabletting lubricant,
wherein said composition is uniformly mixed and tabletted into
a rigid composite tablet. Preferably, this composition comprises:
(a) from about 87.5 to about 98 wt. % of said zeolite material;
(b) from about 1 to about 10 wt. % of said fibers; and
(c) from about 1 to about 2.5 wt. % of said lubricant.
Most preferably, said zeolite material comprises from about 94%
to about 97%; said fibers comprise from about 2% to about 5%; and
1% said lubricant.
To obtain the necessary carbon dioxide adsorption capability needed
to carbonate a beverage at the point of consumption, it has been
found necessary to employ molecular sieves since some common adsorbents,
such as charcoal and silica gel, do not have the adsorptive capacity
necessary for this purpose. Molecular sieves, or crystalline aluminosilicates,
are also sometimes referred to as crystalline zeolites and are both
natural and synthetic in origin. Natural crystalline aluminosilicates
exhibiting molecular sieve activity include, for example, analcite,
paulingite, ptilolite, clinoptilolite, ferrierite, chabazite, gmelinite,
levynite, erionite, and mordenite.
Since not all of the natural crystalline aluminosilicates are available
in abundance, considerable attention has been directed to the production
of synthetic equivalents. Three basic types of crystalline aluminosilicate
molecular sieves most readily available on a commercial scale have
been given the art-recognized designation of "zeolite A",
"zeolite X" and "zeolite Y". Other molecular
sieves which have been synthesized include Zeolites B, F, G, H,
K-G, J, L, M, K-M, Q, R, S, T, U and Z.
A full disclosure of the above zeolites are found in U.S. Pat.
No. 4007134 to Liepa and Japikse, Feb. 8 1977 herein incorporated
by reference in its entirety.
It has been discovered that the formation of a tablet with high-speed
commercial equipment requires the use of a lubricant in the powder
formula to allow for removal from the die. A preferred high-speed
press is the Dorst Powdered Metal Compaction Press, Model DK100
manufactured by Dorst Keramikmaschinen Bau Inhaber Otto Dorst und.
Dipl.-ing, Walter Schlegel, 8113 Kochel am See Bundes-republik Deutschland,
and sold in the U.S. by A.C. Compacting Presses, 1952 Woodbridge
Ave., Edison, N.J. 08817.
The tabletting lubricant is preferably a metal fatty acid ester
and more preferably a metal stearate selected from the group consisting
of magnesium, aluminum or calcium stearate. Other common tabletting
lubricants are useful in the practice of the present invention,
i.e. a hard Carbowax.RTM. (polyethylene glycol) and hydrogenated
vegetable oil. However, the most preferred tabletting lubricant
is magnesium stearate. The desired performance characteristics of
the resulting pressed powder tablet are controlled by three factors.
They are tablet shape, compaction pressure, and the addition of
hydrophobic or non-swelling hydrophilic fibers. The first controls
the amount of wettable tablet surface and the diffusional path length
while the latter two affect the porosity and strength of the tablet.
In order to activate the molecular sieve material, the material
is fired at elevated temperatures before mixing in the fibers. The
activated sieve material is then mixed with a small percentage of
specially prepared fibers and a small amount of lubricant, and then
compacted and granulated to yield free-flowing granules, i.e. powder.
The following fibers have been processed such that they provide
the desired characteristics: polyethylene, polypropylene, polyester,
nylon and cellulose. The physical characteristics of the fibers
are critical. They must be hydrophobic or substantially non-swelling
when brought in contact with water. A hydrophilic fiber treated
with a hydrophobic agent will suffice. Thus, the term "hydrophobic
fibers" as used herein includes substantially non-swelling
hydrophilic fibers too. Suitable physical dimensions for the fibers
for the preferred embodiment of this invention have a length of
from about 100 to about 2000 microns and a diameter of from about
1 to about 50 microns; more preferably, about 400 to about 1500
microns in length and most preferably about 800 to about 1000 microns
in length with diameters of 20 to 40 microns.
For purposes of the present invention, the material adsorbed within
the molecular sieve tablet is gaseous carbon dioxide. Carbon dioxide
is strongly adsorbed on such sieves, but is readily displaced by
the stronger and preferential adsorption of water. Hence, release
of the adsorbed carbon dioxide from molecular sieves in aqueous
solution provides the basis for the carbonation technique utilized
in the present invention.
The total amount of carbon dioxide capable of being adsorbed by
the molecular sieves and the rate of desorption, that is, the rate
at which the carbon dioxide is released by the molecular sieves
by displacement with water molecules, varies with the pore size
of the molecular sieves. Thus, varying the pore size of the molecular
sieves employed in the instant invention, that is, utilizing different
molecular sieve types in the formulation of the composite body,
affects both the carbonation rate and the final carbonation level
of the aqueous beverage.
Also, in accordance with the present invention, the tabletted composite
bodies may contain any of a number of optional materials, as long
as the ultimate use of the bodies, i.e. carbonating an aqueous beverage,
is not adversely affected thereby. Of course, those skilled in the
art will appreciate that there are a large number of such optional
materials which may be added to the composite bodies of the present
invention without adversely affecting their adsorption capacities.
In keeping with the present invention, the composite bodies are
prepared by blending or mixing the molecular sieves, a suitable
hydrophobic or non-swelling hydrophilic fiber material, and a suitable
tabletting lubricant. A preferred method involves blending together
CO.sub.2 -loaded molecular sieves, the fibers and the tabletting
lubricant. The mixture is then pressed in a die to form a tabletted
body. A preferred amount of pressure for tabletting the rigid composite
bodies of the present invention is about 1400 kg/cm.sup.2 or 20000
lb/in.sup.2 in English units. The tabletted body is then ready.
No firing is necessary or desirable.
The preferred embodiments illustrated in the figures include a
cube, some disks with and without channels, and a cylinder with
one channel. Other alternative shapes which may be tabletted are
included within the scope of the invention.
INDUSTRIAL APPLICATION
An application of the device of the present invention is use of
one or more of the embodiments illustrated by the figures as a beverage
carbonation device. Other applications of this invention are disclosed
in U.S. Pat. No. 4007134 supra, herein incorporated by reference
in its entirety. Still other applications will be obvious to those
skilled in the art.
The molecular sieves are "loaded", that is, charged,
with carbon dioxide merely by contacting the activated sieve material
with gaseous carbon dioxide under substantially anhydrous conditions
to bring about carbon dioxide adsorption. Typically, the sieve materials
can be dehydrated to less than 1% by weight of water. It is not
necessary that the composite bodies be contacted with carbon dioxide
for an extremely long period of time in order to achieve adequate
adsorption of carbon dioxide by the molecular sieves, as it has
been found that after contacting the molecular sieve bodies with
carbon dioxide for only 5 minutes, 70% of the total capacity of
the bodies for carbon dioxide adsorption has been exhausted through
adsorption of carbon dioxide by the molecular sieves. For use in
the instant beverage carbonation devices, the activated zeolite
molecular sieves should be loaded to the extent of at least about
5% by weight (i.e. weight of carbon dioxide adsorbed/weight of loaded
sieves.times.100%). The extent to which a particular size of sieves,
i.e. sieves with a given pore size, adsorb carbon dioxide at any
particular temperature or pressure is easily determined by experimentation
or by utilization of adsorption data available for commercially
available sieves.
It is important that the carbon dioxide-loaded molecular sieve
bodies be packaged and stored in a manner which will prevent contact
with atmospheric moisture prior to use in the present invention.
Such atmospheric moisture would displace carbon dioxide, rendering
the sieves ineffective for beverage carbonation.
The carbon dioxide-loaded molecular sieves are contacted with an
aqueous potable liquid to effectuate the carbonation of the aqueous
beverage. Carbon dioxide is released from the molecular sieves by
the preferential adsorption of water from the beverage solution.
A carbonated beverage results when this released carbon dioxide
is dissolved in the aqueous liquid. Subsequent release of this dissolved
carbon dioxide in the mouth upon drinking provides the characteristic
feel and taste of a carbonated beverage. Of course, the extent of
carbonation increases as more carbon dioxide is dissolved. Carbonation
is usually measured in a unit, hereinafter referred to as "volumes
of dissolved CO.sub.2 " or "volumes of carbonation"
defined as the volume of gas (reduced to standard conditions, i.e.
760 mm Hg and 0.degree. C.) dissolved in a given volume of beverage.
The solubility of carbon dioxide in aqueous solution is strongly
a function of temperature and pressure. Solubility data under various
temperature and pressure conditions can easily be determined from
prior art literature. General discussions of this subject as it
relates to this field are disclosed in U.S. Pat. No. 4007134
supra. Thus, the discussion of certain temperature and pressure
limitations apply to the carbonation bodies of the present invention.
Carbonation time is important in many applications and faster carbonation
and more control for tabletted bodies are achieved, but is not a
critical variable in the composite carbonation bodies of the present
invention. Time of contact of the loaded molecular sieve disks with
the beverage liquid will naturally vary with the amount of aqueous
solution present, the nature of that solution, the amount, type,
and level of charge of the molecular sieves employed, and the "strength"
of carbonated beverage desired. By employing molecular sieves loaded
with carbon dioxide to the extent of at least 5% by weight and by
carbonating at temperature and pressure conditions of the present
invention, suitably carbonated beverages can be obtained after typical
in-home carbonation times (1-5 minutes). Carbonation systems providing
carbon dioxide release for longer times than typical can be achieved
by utilizing other molecular sieve types or fibers than those illustrated
in the Examples below.
The type of beverage solution to be carbonated by the process of
the instant invention is not critical. The beverage liquid must,
of course, be aqueous in nature. Such liquids can contain, in addition
to water, any type of non-interfering flavorant, coloring agent,
food additive, medicine, or alcohol. Some materials, such as aroma
and flavor constituents, can alternatively be incorporated into
the molecular sieve bodies. In still another variation, flavorings
and colorings can be provided in an aqueous mixture which is added
to water along with the carbon dioxide-loaded molecular sieve disks.
Examples of the types of beverage which can be made from suitable
liquids by carbonation with the present invention include soft drinks,
medicinal preparations, beer and sparkling wine.
EXAMPLE I
Formation of a Rigid Composite Tablet from a Mixture of Activated
Crystalline Zeolite Molecular Sieve Material and Fibers
Ingredient Preparation:
1. Crystalline zeolite molecular sieve material (zeolite):
Union Carbide Sodium Y Zeolite is heated to 540.degree. C. to drive
off all H.sub.2 O, organic material, etc. from its crystalline structure.
The zeolite is then cooled down under nitrogen to room temperature.
It is now in the "activated" state.
2. Fibers:
Buckeye Cellulose cotton linter dry lap pulp #505 is cut into 5
mm sq. pieces. These pieces are fed through a laboratory hammer
mill with a 0.060" screen. The resulting fibers have a mean
average length of 950 microns and a mean average diameter of 20-30
microns. These fibers are substantially non-swelling hydrophilic
fibers.
Formulation:
Said above ingredients are mixed in a ratio of 97 gms. of activated
zeolite, 2 gms. of fibers, and 1 gm. of Magnesium Stearate (Mg.
Stearate is a common tabletting lubricant and is used as an aid
in compaction and to reduce tablet ejection forces). The ingredients
are intensively mixed in a laboratory sized Waring Blender. They
are kept under a dry air or N.sub.2 atmosphere.
Tablet Formation:
Formation of a 2.25" diameter.times.0.4" thick disk.
Twenty-four gms of the above-formulated material is placed in a
2.25" diameter disk die. The die and materials are vibrated
to insure a uniform material density throughout the die. An upper
punch is placed in the die and pressed against the powder with sufficient
force to exert an average compressive force on the powder of 20000
psi. The now-formed body is ejected from the die having a density
of about 0.82 gm/cm.sup.3. The disk is kept under an N.sub.2 atmosphere.
The strength of this tabletted disk was tested by centering it
on two pedestals separated from each other by about 1.5 inches.
A downwardly directed controlled force was gradually applied to
the center of the disk through a 1/2 inch diameter and 1 inch long
dowel pin, positioned so that its 1 inch center line was laid on
the disk parallel to the edges of the pedestals. It took about one
hundred twelve pounds (112#) of force to break the disk.
The disk possesses good dimensional accuracy which is readily reproducible.
At this time the disk can be placed in the appropriate atmosphere
where the zeolite will readily adsorb certain polar molecules (i.e.
CO.sub.2 H.sub.2 O, etc.).
Rigid composite tablets can be formed in any conceivable shape
(i.e. tablets, balls, cubes, cylinders, stars, etc.) as long as
the appropriate die and punch can be produced.
EXAMPLE II
Strength of Tablet Versus Zeolite-to-Fiber Ratio Ingredient Preparation:
1. Crystalline zeolite molecular sieve material, Union Carbide
Sodium Y Zeolite is heated typically to about 540.degree. C. to
drive off all H.sub.2 O, organic material, etc. from its crystalline
structure. The zeolite is then cooled down under nitrogen. It is
now in the activated state.
2. Hydrophobic Fibers--"Minifibers", polypropylene filament
#753025 of a 3.0 denier and cut to 1/4" length--are fed through
a laboratory hammer mill with a 0.039" screen. The resulting
fibers have a length of from about 100 to about 2000 microns and
a diameter of about 30 microns. Granulated dry ice is also fed into
the hammer mill to prevent over-heating of the fibers. The resulting
fibers are dried in an oven at about 65.degree. C. |