peT
`
`(51) International Patent Classification 6 :
`B65D 81126, B29C 45/00, 45/13, 45/14
`
`WORLD INTELLECfUAL PROPERTY ORGANIZA nON
`International Bureau
`INTERNATIONAL APPLICATION PUBLISHED UNDER TIlE PATENT COOPERATION TREATY (PCT)
`WO 96133108
`
`(11) International Publication Number:
`
`Al
`
`(43) International Publication Date:
`
`24 October 1996 (24.10.96)
`
`(21) International Application Number:
`
`PCfIUS96/05261
`
`(22) International Filing Date:
`
`17 April 1996 (17.04.96)
`
`(30) Priority Data:
`08/424,996
`
`19 April 1995 (19.04.95)
`
`US
`
`(71) Applicant: CAPITOL VIAL, INC. [US/US]; 151 Riverside
`Drive, Fultonville, NY 12072 (US).
`
`(81) Designated States: AL, AM, AT, AU, AZ, BB, BG, BR, BY,
`CA, CH, CN, CZ, DE, DK, EE, ES, FI, GB, GE, HU, IS,
`KE, KG, KP, KR, KZ, LK, LR, LS, LT, LU, LV, MD, MG,
`MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE,
`SG, SI, SK, TI, TM, TR, TT, UA, UG, UZ, VN, ARIPO
`patent (KE, LS, MW, SD, SZ, UG), Eurasian patent (AM,
`AZ, BY, KG, KZ, MD, RU, n, TM), European patent (AT,
`BE, CH, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC,
`NL, PT, SE), OAPI patent (BF, BI, CF, CG, CI, CM, GA,
`GN, ML, MR, NE, SN, TD, TG).
`
`(72) Inventor: HEKAL, Ihab, M.; 121 Blackberry Drive, Stanford, Published
`With international search report.
`Cf 06903 (US).
`
`(74) Agents: REYNOLDS, David, D. et al.; Novak Druce Reynolds
`Burt, King Street Station, Suite 750, 225 Reinekers Lane,
`Alexandria, VA 22314 (US).
`
`(54) Title: DESICCANT MATERIAL INCLUDED IN A CLOSED CONTAINER
`
`2
`
`(57) Abstract
`
`Shipping and storage container (01) having a body (12) and a cap (14) that together create an enclosure that is constructed from
`thermoplastic and that includes at least one insert (200) of high-concentration desiccant integrally molded therewith. The containers may be
`injection molded about a pre-formed insert is so that the insert is at least partially encased within the body of the container. Alternatively,
`the insert may be co-molded with the body of the container so that the two components are bonded together into one unitized and continuous
`body.
`
`CLARIANTX 1015 Page 1
`
`

`

`FOR THE PURPOSES OF INFORMATION ONLY
`
`Codes used to identify States party to the PCI' on the front pages of pamphlets publishing international
`applications under the PCI'.
`
`AM
`AT
`AV
`BB
`BE
`BF
`BG
`BJ
`BR
`BY
`CA
`CF
`CG
`CH
`CI
`CM
`CN
`CS
`CZ
`DE
`DK
`EE
`ES
`FI
`FR
`GA
`
`Annenia
`Auslria
`Australia
`Barbados
`Belgium
`Bunina Faso
`Bulgaria
`Benin
`Brazil
`Belarus
`Canada
`Central African Republic
`Congo
`Switzerland
`COte d'lvoire
`Cameroon
`China
`Czechoslovakia
`Czech Republic
`Gennany
`Denmark
`Estonia
`Spain
`Finland
`France
`Gabon
`
`GB
`GE
`GN
`GR
`HV
`IE
`IT
`JP
`KE
`KG
`KP
`
`KR
`KZ
`LI
`LK
`LR
`LT
`LV
`LV
`MC
`MD
`MG
`ML
`MN
`MR
`
`United Kingdom
`Georgia
`Guinea
`Greece
`Hungary
`Ireland
`Italy
`Japan
`Kenya
`Kyrgystan
`Democratic People's Republic
`of Korea
`Republic of Korea
`Kazakhstan
`Liechtenstein
`Sri Lanka
`Liberia
`Lithuania
`Luxembourg
`Latvia
`Monaro
`Republic of Moldova
`Madagascar
`Mali
`Mongolia
`Mauritania
`
`MW
`MX
`NE
`NL
`NO
`NZ
`PL
`PT
`RO
`RU
`SD
`SE
`SG
`SI
`SK
`SN
`SZ
`TD
`TG
`TJ
`TT
`VA
`UG
`US
`UZ
`VN
`
`Malawi
`Mexiro
`Niger
`Netherlands
`Norway
`New Zealand
`Poland
`Portugal
`Romania
`Russian Federation
`Sudan
`Sweden
`Singapore
`Slovenia
`Slovakia
`Senegal
`Swaziland
`Chad
`Togo
`Tajikistan
`Trinidad and Tobago
`Ukraine
`Uganda
`United Stales of America
`Uzbekistan
`Viet Nam
`
`CLARIANTX 1015 Page 2
`
`

`

`W096/33108
`
`PCfJUS96/05261
`
`DESICCANT MATERIAL INCLUDED IN A CLOSED CONTAINER
`
`TECHNICAL FIELD:
`
`The present invention relates to containers having desiccating abilities.
`
`5
`
`More particularly, the present invention relates to thermoplastic containers.
`
`DESCRIPTION
`
`BACKGROUND ART: There are many articles that are preferably stored and/or shipped in an
`
`environment that is as moisture free as possible. Therefore, containers having the ability to absorb
`
`excess moisture have been recognized as desirable. One application in which moisture absorbing
`
`10
`
`containers are desired is for the shipment and storage of medications whose efficacy is
`
`compromised by moisture. The initial placement of medicines into a sealed moisture free container
`
`is usually controllable. Furthermore, the container for the medicine is selected so that it has a low
`
`permeability to moisture. Therefore, the medication will normally be protected from moisture until
`
`it reaches the end user. Once the medicine is received by the consumer, however, the container
`
`15
`
`must be repeatedly opened and closed to access the medication. Each time the container is
`
`opened and unsealed, moisture bearing air will most likely be introduced into the container and
`
`sealed therein upon closure. Unless this moisture is otherwise removed from the atmosphere or
`
`head space of the container, it may be detrimentally absorbed by the medication. For this reason,
`
`it is a well known practice to include a desiccating unit together with the medication in the
`
`20
`
`container.
`
`In other instances, moisture may be released from items that have been placed in
`
`containers for shipping and/or storage. Prime examples of such items are food stuffs that release
`
`moisture during shipping and storage.
`
`In the instance of containers that are sealed and
`
`substantially impermeable to moisture, the released moisture will remain within the container about
`
`25
`
`the product.
`
`If not removed, this released moisture may have ill effects on the very item that
`
`released the moisture. It has been found that a substantial amount of moisture is released from
`
`certain food products within the first forty-eight (48) hours after manufacture and packaging. This
`
`released moisture will remain about the product until removed.
`
`If the moisture is not removed
`
`shortly after its release, it may cause the food to degrade into a condition that is not saleable. In
`
`30
`
`these cases, desiccants may be included together with the contained items to continually absorb
`
`the released moisture until the product is unpacked. In this way, a relatively dry environment is
`
`maintained about the stored item.
`
`The need to eliminate moisture from within sealed containers has been previously
`
`recognized. Early attempts to achieve these goals included the provision of desiccant materials
`
`35
`
`in fabric or similar bags that are placed in the containers, together and commingled with the matter
`
`being shipped or stored. A consumer related problem, however, exists when the desiccant is loose
`
`and commingled together with consumable items. If not carefully and thoroughly processed upon
`
`CLARIANTX 1015 Page 3
`
`

`

`W0961J3108
`
`PCI'lUS96/05261
`
`unpacking, the desiccant may not be separated from the consumables and could harm a person
`
`if unknowingly ingested.
`
`Another known mode by which a desiccant may be provided within a container includes
`
`coating the interior surface of the container vessel with a desiccant bearing material. Still further,
`
`5
`
`it is known to provide desiccating abilities in a container through the use of layered structures in
`
`which a desiccant is "sandwiched" between moisture permeable material that confines the
`
`desiccant. These layered structures often take the form of flexible sheeting that may be formed
`
`into bag type containers into which items requiring a reduced moisture environment are placed.
`
`Several of the known means by which desiccant bearing containers are constructed require
`
`10
`
`mUltiple steps and result in more complex and layered structures than are desired. Furthermore,
`
`the provision of desiccant capsules together with contained items is not always satisfactory. As
`
`previously explained, commingling of desiccant with food items and medications is undesirable
`
`from a consumer stand point in that the desiccant may be inadvertently ingested. Still further, if
`
`the desiccant is not integrally constructed with the container, or at least attached thereto, it may
`
`15
`
`be prematurely removed while still needed for continued removal of moisture from within the
`
`container. Therefore, a need has been recognized for containers that include a desiccant as an
`
`integral component of the container's body. Regarding the included desiccant of the container,
`
`it is desired to enhance its capabilities of moisture absorption with respect to both rate and
`
`quantity. Still further, as in all manufacturing processes, it is desired to reduce the required steps
`
`20
`
`for constructing desiccating containers and simplify the resulting structures.
`
`DISCLOSURE OF THE INVENTION:
`
`One embodiment of the present invention includes a
`
`container having desiccating capabilities. The container includes a container body that forms at
`
`least a partial enclosure so that an inside space and an outside space is created with respect to
`
`25
`
`the container body. There is an insert formed from desiccant entrained thermoplastic that is fixed
`
`relative to the container body. At least a portion of the insert is exposed to the inside space of
`
`the container body so that it can absorb moisture therefrom. The desiccant entrained
`
`thermoplastic from which the insert is constructed has a high desiccant concentration of at least
`
`forty percent desiccant to thermoplastic by weight. The container body is constructed from
`
`30
`
`substantially desiccant-free thermoplastic in one embodiment and from low desiccant concentrate
`
`thermoplastic having at most twenty percent desiccant to thermoplastic by weight in another
`
`embodiment. In a preferred embodiment, the container body is constructed from polypropylene.
`
`A cap that is sealably engageable with the container body and constructed from polyethylene may
`
`optionally be provided.
`
`It is contemplated that the insert may be sufficiently encased by the
`
`35
`
`container body so that the insert is only exposed to the inside space of the container and not to
`
`the exterior of the container. In one embodiment, the insert is fixed to the container body by a
`
`retainer lip 211 formed by the container body about the insert. In another, the insert is fixed to
`
`the container body by a shrink-fitting of the container body about the insert. It is contemplated
`
`2
`
`CLARIANTX 1015 Page 4
`
`

`

`W096/33108
`
`PCfroS96/0526I
`
`that the insert and the container body may be co-molded into a unitized body. As an optional
`
`enhancement, the desiccant entrained thermoplastic from which the insert is constructed may
`
`include a polar organic compound that enhances the absorption capabilities of the desiccant. The
`
`insert may take the form of a liner that covers at least a majority of the interior surface area of the
`
`5
`
`container body.
`
`In an alternative embodiment, a container having desiccating capabilities is disclosed. It
`
`includes a container body that forms at least a partial enclosure so that an inside space and an
`
`outside space is created with respect to the container body. There is an insert constructed from
`
`desiccant entrained thermoplastic that is integrally joined to the container body by a co-molding
`
`10
`
`process that forms a single unitized body from the two components. After the co-molding
`
`process, at least a portion of the insert is exposed to the inside space of the container body for
`
`absorbing moisture therefrom.
`
`A method for co-molding the above container having desiccating capabilities is also
`
`disclosed. The steps of the method include injecting a high desiccant concentrate thermoplastic
`
`15
`
`insert into a container mold. A container body is injected about the insert so that a single unitized
`
`body is formed from the two components. When the container body is formed, the insert is
`
`enclosed within the container body so that the insert is only exposed to an inside space of the
`
`container.
`
`The step of injecting
`
`the container body about
`
`the
`
`insert
`
`is performed
`
`contemporaneously with the step of injecting the insert so that the insert and the body meld
`
`20
`
`together at an interface thereby forming the unitized body. Alternatively, the injection of the
`
`container body about the insert is performed at a temperature sufficiently elevated so that the
`
`insert and the body meld together at an interface thereby forming the unitized body. Before the
`
`thermoplastic is injected into the mold, the various desiccant concentrations are prepared. During
`
`the injection process, the high desiccant concentrate thermoplastic is introduced into the mold
`
`25
`
`through a
`
`first injection port 209 and the desiccant-free or low concentrate thermoplastic is
`
`introduced into the mold through a second injection port 210. In one embodiment, the mold is
`
`moved from a first injection station to a second injection station. A preferred means for moving
`
`the mold between stations is on a rotating table.
`
`The present invention provides a container, and process for constructing the same that
`
`30
`
`satisfies the need for more effective desiccating storage and shipping containers. The containers
`
`of the present invention provide superior desiccating abilities, while at the same time permitting
`
`efficient construction of a container that has and maintains structural integrity. Furthermore, the
`
`present invention provides a means by which the container may be formed having a substantially
`
`unitized and continuous body.
`
`35
`
`3
`
`CLARIANTX 1015 Page 5
`
`

`

`W096/33108
`
`PCTlUS96/05261
`
`BRIEF DESCRIPTION OF DRAWINGS:
`
`Figure 1 is a cross-sectional view of a desiccating container with an insert in the form of
`
`a disk molded therein.
`
`Figure 2 is a cross-sectional view of a desiccating container with an insert in the form of
`
`5
`
`a liner molded therein.
`
`Figure 3 is a partial cross-sectional view of the container body showing a lip retainer.
`
`Figure 4 is a side view of a mold in partial section mounted upon a rotatable table for
`
`transport between injection stations and showing a container and insert molded therein.
`
`Figure 5 is a side view of a mold in partial section showing a container and insert molded
`
`10
`
`therein in a single station configuration with two injection ports.
`
`Figure 6 is a schematic of the method by which the container is co-molded.
`
`MODE(S) FOR CARRYING OUT THE INVENTION:
`
`In one embodiment of the present invention.
`
`a relatively small container may be manufactured similar in construction to the aseptic vial and cap
`
`15
`
`of U.S. Patent 4.783,056 of Robert S. Abrams. the disclosure of which is expressly incorporated
`
`herein by reference. Therein. the injection molding of capped sample vials from thermoplastic
`
`material is disclosed. Like reference numerals are used in the present application to those of the
`
`4,783.056 patent to designate similar or like apparatus or process.
`
`The presently disclosed invention includes and is applicable to the manufacture of similar
`
`20
`
`containers. The containers 01 disclosed herein, however. are not limited to vials.
`
`It is
`
`contemplated that containers 01 constructed according to the present invention may be larger or
`
`smaller than the vials of 4,783,056 and of variable shape. Furthermore, the caps 14 may be
`
`integrally formed with the bodies 12 of the containers 01. or they may be manufactured as
`
`separate units. Still further. the present invention may be embodied exclusively within the body
`
`25
`
`of a container 12 or a cap 14 for a container 01.
`
`The material used in the construction of these containers 01 typically provides a barrier
`
`between the interior 201 and exterior 202 of the container 01 that is substantially moisture
`
`impermeable and most often is a thermoplastic. While it is contemplated that any thermoplastic
`
`may be utilized, polypropylene is preferred for the construction of the body 12 of the container
`
`30
`
`01. Polypropylene is desirable because of its durability, rigidity and resistance to breakage after
`
`being molded into the form of a container 01. Other examples of suitable thermoplastics may be
`
`selected from the following groups: polyolefin. polyethylene. polycarbonate. polyamide, ethylene(cid:173)
`
`vinyl acetate copolymer. ethylene-methacrylate copolymer. polyvinyl chloride. polystyrene.
`
`polyester. polyester amide. polyacrylic ester, and polyvinylidene chloride. acrylic. polyurethane.
`
`35
`
`polyacetal, and polycarbonate. These and other thermoplastics may be utilized either singularly,
`
`or in combinations.
`
`The present invention includes the manufacture of a container 01 in which the majority
`
`of the container's body 12 is constructed from the base thermoplastic. e.g. polypropylene.
`
`4
`
`CLARIANTX 1015 Page 6
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`

`

`W096/33108
`
`PCflUS96/0526 1
`
`because of its durability and resistance to breakage. To establish and/or increase a desiccating
`
`capacity of the molded container 01, an insert 200 that has been formed from a desiccant
`
`entrained thermoplastic is integrally constructed with the body 12 of the container 01. The
`
`concentration of desiccant entrained within the insert 200 may exceed seventy-five percent
`
`5
`
`(75%). Typically, however, the desiccant concentration in the insert 200 will fall within a range
`
`of forty to seventy-five percent (40-75%) desiccant to thermoplastic, by weight.
`
`This
`
`concentration is considered to be a high concentration for most thermoplastics. The maximum
`
`desiccant bearable concentrations will vary among the various types of thermoplastics due to their
`
`differing characteristics.
`
`In the instance of polypropylene as the base material, an upper
`
`10
`
`concentration of desiccant will be considered to be about sixty percent (60%) by weight. In the
`
`instance of polyethylene, however, the maximum concentration of desiccant will be about
`
`seventy-five percent (75 %) by weight. As the desiccant concentrations within the thermoplastics
`
`increase, the performance of the material degenerates to unacceptable levels.
`
`In one embodiment, the insert 200 is located in the base or bottom 203 of the container
`
`15
`
`body 12 and is exposed to the interior space 201 of the container 01. The configuration of this
`
`embodiment is similar to a sample vial. Because the durability and resistance to breakage is
`
`lessened in the higher ranges of desiccant content, it is advantageous to have the polypropylene
`
`used in the construction of the container's body 12 formed about the insert 200 except for at
`
`those surfaces to be exposed to the interior 201 of the container 01. A container 01 of this
`
`20
`
`configuration provides desired structural integrity while also providing the greater desiccating
`
`ability of the high desiccant laden insert 200 that is directly exposed to the interior 201 of the
`
`container 01. It is also contemplated that the insert 200 may be included in the construction of
`
`the container's cap 14. In this case, the insert will be integrally formed with the cap 14 so that
`
`an exterior surface of the insert 200 is exposed to the interior 201 of the container 01 when
`
`25
`
`installed thereupon.
`
`As a further alternative embodiment, the insert 200 may be less localized, and extended
`
`to a greater degree about a greater portion of the interior surface 204 of the container body 12.
`
`In this instance, the high desiccant bearing thermoplastic forms more of a liner 205 at the interior
`
`surface 204 of the container 01. To provide maximum desiccating abilities, the liner 205 may
`
`30
`
`completely cover the interior surface 204 of the container 01; this may optionally include the
`
`interiorly exposed surfaces of a cap 14 of a closed container 01.
`
`One contemplated method for the manufacture of the container 01 includes the provision
`
`of a preformed insert 200 about which the thermoplastic of the remainder of the body 12 of the
`
`container 01 is injection molded. In this process, it is important that the insert 200 be affixed to
`
`5
`
`CLARIANTX 1015 Page 7
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`

`

`W096/33108
`
`PCfIUS96/05261
`
`or within the body 12 of the container 01. This may be achieved merely by molding the body 12
`
`about the insert 200 so that the two components are mechanically connected one to the other.
`
`The mechanical connection may take the form of a retaining lip 206 formed by the container body
`
`12 about the insert 200 that effectively fixes the insert 200 with respect to the rest of the
`
`5
`
`body 01.
`
`Alternatively, it is also contemplated that a "shrink-fit" may be achieved by the body 12
`
`forming thermoplastic about the insert 200. A particular example of this shrink-fit application
`
`would be the provision of a desiccant loaded insert 200 constructed from a base thermoplastic
`
`of polyethylene and a container body 12 molded thereabout from a base thermoplastic of
`
`10
`
`polypropylene. Upon cooling after being injection molded, polyethylene shrinks less than
`
`polypropylene under similar circumstances. Therefore, if a polypropylene body is injection molded
`
`about a polyethylene insert 200 that has been either previously formed, or is injection molded
`
`contemporaneously with the container body 12, the polypropylene container body 1 2 will shrink
`
`about the polyethylene insert 200. This shrink-fit method may be implemented whether or not the
`
`15
`
`insert 200 is relatively small and localized with respect to the container body 1 2 or whether the
`
`insert 200 takes the form of a previously described liner 205 configuration.
`
`In either case, the
`
`exteriorly formed container body 12 may shrink about the insert 200 if the thermoplastics from
`
`which the insert 200 and container body 12 are appropriately selected. The use of the retaining
`
`lip 206 and shrink-fit method of affixing the insert 200 or liner 205 to the container body 12 is
`
`20
`
`used primarily when the materials of construction of the insert 200 and container body 12 are not
`
`compatible. The two components will be considered incompatible if they do not automatically
`
`adhere one to the other as a result of the manufacturing process.
`
`Alternatively, the insert 200 will be constructed from a material that bonds to the body
`
`12 of the container 01 when the body 12 is placed thereabout. Therefore, a preferred method for
`
`25
`
`constructing the insert 200 bearing container 01 of the present invention is co-molding. That is,
`
`the primary body 12 of the container 01 is molded, while the high desiccant insert 200 is also
`
`molded. The two portions are said to be co-molded because they are either simultaneously or
`
`sequentially injection molded in a single process. The process of co-molding results in the
`
`construction of a unitized container body 12 in which the insert 200 is seamlessly combined with
`
`30
`
`the body 12. In most instances, the insert 200 and container body 12 adhere one to the other
`
`as a result of a melding together of the base thermoplastics from which each is constructed at an
`
`interface therebetween. The melding action takes place when the insert 200 and container body
`
`12 are each injected into the mold 10 sufficiently closely with respect to time so that each is in
`
`at least a semi-molten state while in contact one with the other. Alternatively, heat from the
`
`35
`
`thermoplastic of a body 12 injected about an insert 200 may cause the contacted portions of the
`
`insert 200 to melt slightly and meld with the thermoplastic of the body 12 adjacent thereto. In
`
`each case, there will be a phase between the high desiccant concentrate insert 200 and container
`
`6
`
`CLARIANTX 1015 Page 8
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`

`

`WO 96133108
`
`PCfroS96/0S261
`
`body 12 in which the two construction materials blend to some degree creating a seamless
`
`interface and therefore unitized container 01 out of the two components.
`
`As explained, in a preferred embodiment, the high-desiccant insert 200 is located in the
`
`base or bottom 203 of the container 01. A surface of the insert 200 may be directly exposed to
`
`5
`
`the interior 201 of the container 01, or the insert 200 may be fully encapsulated by the primary
`
`body 12. Still further, it is contemplated that the bottom 203 portion of the container 01 may be
`
`constructed exclusively from the high-desiccant thermoplastic if the material's reduced qualities
`
`do not adversely affect the performance of the container 01. This may be the case if the
`
`container 01 is not going to be exposed to high stresses or rough handling. To produce such a
`
`10
`
`container 01, it is contemplated that the lower portion and upper portion will be formed from
`
`thermoplastic of differing desiccant concentration, that is, thermoplastic of lesser desiccant
`
`concentration will be injected into the upper portion of the mold 10 and higher desiccant
`
`concentration will be injected into the lower portion. The thermoplastic of the two portions will
`
`commingle at an interface and meld together into a unitized container body 12, provided that the
`
`15
`
`base thermoplastics of each are compatible. Like the other injection processes, it is contemplated
`
`that each portion may be injected from separate injection ports 209 and 210 or the same port.
`
`As a result, the portions may be injected either sequentially or contemporaneously. In each case,
`
`the proportion of the container body 12 formed by each portion will be controlled by the amount
`
`of thermoplastic injected into each.
`
`20
`
`In any event, the thermoplastic in which the desiccant is entrained is moisture permeable
`
`to the degree that moisture from the interior 201 of the container 01 may be transferred to and
`
`stored in the desiccant.
`
`It is possible that the thermoplastic from which the insert 200 is
`
`manufactured may have a higher moisture permeability than that from which the remainder of the
`
`body 12 of the container 01 is constructed. In this case, the insert 200 may be enclosed within
`
`25
`
`the container 01 by a lower moisture permeable thermoplastic of the container's body 12. In this
`
`way, moisture will not readily be transferred from outside the container 01 to the interior. In view
`
`of the possibility of desiring differing moisture permeabilities in the insert 200 and the container
`
`body 12, it is contemplated that the two components 200,12 may be constructed from different
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`materials that are potentially incompatible.
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`30
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`The process of the present invention in which the insert 200 is co-molded within the
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`primary body 12 of the container 01 may vary.
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`In a first embodiment of the molding process, it
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`is contemplated that the mold 10 will move between two injection stations. An injection assembly
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`that is generally designated by reference numeral 96 may be installed and withdrawn from the
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`mold frame 24. At one station, typically the first station, the insert 200 will be injection molded.
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`35
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`In order to mold the insert 200, a ring shaped barrier will be provided that has a circumference
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`substantially matching the perimeter of a lower end of core 48. It is desired that the thickness
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`of the insert 200 be approximately one-eighth of an inch, therefore the thickness or height of the
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`barrier ring will likewise be one-eighth of an inch. As the injection assembly 96 is installed within
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`7
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`CLARIANTX 1015 Page 9
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`W096/33108
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`PCflUS96/05161
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`the mold frame 24, the barrier ring is the leading component. The ring contacts the lower surface
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`of the core 48 forming a barrier within which thermoplastic may be injected. High concentrate
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`desiccant thermoplastic is then injected into the interior of the ring thereby forming the insert 200.
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`The high concentrate desiccant thermoplastic of the insert 200 may be injected at a temperature
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`5
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`that is less than the temperature at which the thermoplastic of the container body 12 is injected.
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`The lowered temperature may be required so that the desiccant contained therein does not
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`degrade. The necessity of the lowered temperature may be obviated by using different and/or
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`high-grade desiccants that are not susceptible to degradation within the normal temperature
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`ranges of the injection process.
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`'0
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`When the insert 200 has sufficiently cooled to a point that it will maintain its shape after
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`the removal of the barrier ring, the injection assembly 96 is withdrawn from the mold frame 24,
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`together with the barrier ring that is attached thereto. The insert 200 adheres to the lower surface
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`of the core 48 and remains within the mold 10.
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`The mold 10 is then moved to a second injection station similar to that previously
`
`15
`
`described, but configured so that the desiccant-free thermoplastic is injected into the cavity 114
`
`thereby forming the body of the container 12. The means for conveying the mold frame 24
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`between stations is preferred to be a rotatable table 207 that operates continuously between the
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`two stations. During this second injection, thermoplastic is injected to form the body 12 of the
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`container 01 and optionally the cap 14. During this same step, thermoplastic is also injected
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`20
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`about the insert 200 that has been previously formed.
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`In this way, those portions of the insert
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`200 that would have been exposed to the exterior 202 of the container 01 are covered by the
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`desiccant-free thermoplastic.
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`The top surface of the insert 200 is not covered by the desiccant-free thermoplastic
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`because it remains in contact with the lower surface of the core 48. Though the insert 200 is
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`25
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`allowed to sufficiently cool to maintain its form between station one and two and during the
`
`second injection, the second injection of thermoplastic is made at a temperature sufficient to
`
`cause the two components 200,12 to bond together as described herein. Depending upon the
`
`conditions, it is possible that the high concentrate insert 200 will melt enough so that it bleeds
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`into the body 12 of the container 01 located adjacent thereto. The amount of bleed, however,
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`30
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`is not significant and does not degrade the performance of the exterior thermoplastic that gives
`
`the container 12 its strength and durability.
`
`In an alternative embodiment of the molding process, only one injection station is utilized,
`
`but two injection ports 209 and 210 are provided thereto. The high concentrate desiccant
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`thermoplastic that forms the insert 200 is injected through one of the ports 209, while the
`
`35
`
`desiccant-free thermoplastic that forms the body 12 of the container 01 is injected through the
`
`other of the ports 210.
`
`In this process, the core 48 must move longitudinally away from the
`
`injection assembly 96 a distance equal to the thickness of the insert 200 that is to be formed.
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`CLARIANTX 1015 Page 10
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`W096/33108
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`PCfIUS96/0S161
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`Like the two station process, the insert 200 is first formed, and the body 12 of the container 01
`
`is formed thereabout. In most other respects, the two processes are similar.
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`It is anticipated that the rate of absorption into the insert 200 may be controlled by the
`
`amount of surface area of the insert 200 exposed to the container's 01 interior 201. If greater
`
`5
`
`absorption rates are desired, more surface area of the insert 200 may be exposed. If it is desired
`
`that a more prolonged absorption process be achieved, then less surface area will be exposed.
`
`It is further contemplated that the rate of absorption by the insert 200 may be controlled by
`
`encapsulation of the insert 200. If slower rates of absorption are desired, then the insert 200 can
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`be encased to greater degrees by the thermoplastic that forms the body 12 of the container 01
`
`10
`
`and which is less permeable to moisture. The rate of absorption may also be controlled by using
`
`different types of thermoplastics having different moisture permeability rates. Still further, the rate
`
`of moisture absorption by the insert 200 may be affected by other add-mixtures to the
`
`thermoplastic. In particular, it has been found that the addition of polar organic compounds, such
`
`as "starch", to the desiccant loaded thermoplastic will greatly increase the rate of absorption. The
`
`15
`
`addition of polyvinyl alcohol (PVOHI has similar boosting effects upon the absorption rate of the
`
`desiccant loaded thermoplastic. In one particular example, the addition of five percent (5%) starch
`
`by weight to polypropylene bearing ten percent (10%) desiccant by weight absorbed moisture at
`
`twice the rate of polypropylene bearing twenty percent (20%) desiccant and no starch.
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`The amount of moisture that can be absorbed by the insert 200 may be controlled in
`
`20
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`several ways. It is contemplated that the amount of moisture absorbable by the insert 200 may
`
`be effected by changing the concentration of desiccant within acceptable ranges; the greater the
`
`concentration, the greater the amount of moisture that can be captured.
`
`In an alternative embo