WO2000003856A9 - Rotational molding process - Google Patents
Rotational molding processInfo
- Publication number
- WO2000003856A9 WO2000003856A9 PCT/US1999/015889 US9915889W WO0003856A9 WO 2000003856 A9 WO2000003856 A9 WO 2000003856A9 US 9915889 W US9915889 W US 9915889W WO 0003856 A9 WO0003856 A9 WO 0003856A9
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- mold
- resin
- rotational molding
- molding method
- melt
- Prior art date
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C41/00—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
- B29C41/02—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor for making articles of definite length, i.e. discrete articles
- B29C41/04—Rotational or centrifugal casting, i.e. coating the inside of a mould by rotating the mould
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C41/00—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
- B29C41/02—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor for making articles of definite length, i.e. discrete articles
- B29C41/22—Making multilayered or multicoloured articles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C41/00—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
- B29C41/34—Component parts, details or accessories; Auxiliary operations
- B29C41/36—Feeding the material on to the mould, core or other substrate
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C41/00—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
- B29C41/02—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor for making articles of definite length, i.e. discrete articles
- B29C41/08—Coating a former, core or other substrate by spraying or fluidisation, e.g. spraying powder
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
- B29K2995/0037—Other properties
- B29K2995/0063—Density
- B29K2995/0064—Non-uniform density
Definitions
- the present invention relates generally to rotational molding methods and particularly to a rotational molding which create a shiny and hard surface layer for a molded part.
- Rotational molding which is often referred to as "rotomolding”
- Rotomolding is a process where a powdered thermoplastic is poured into a mold and the mold is suspended in an oven.
- the material utilized for the powdered thermoplastic is often polyethylene, while the mold is ordinarily constructed from metal. Once suspended in the oven, the metal mold is heated beyond the melting point of the powder and rotated to evenly coat the inner surface of the mold with the melted plastic. Once properly heated, the mold is then cooled and the part is demolded.
- the mold serves two purposes: (1) to transfer heat to the resin to establish the shape to be formed and (2) to provide a cavity in which to cool the material.
- a pre-measured resin is loaded into the mold and the mold is disposed within an oven and rotated on both its vertical and horizontal axis. As the resin melts it sticks to the inner surface of the mold, coating such surface evenly. Usually, the rotation of the mold continues during the cooling cycle to allow the intended part to maintain an even wall thickness. Once the part is cooled, it is removed from the mold. Rotomolding has been utilized, amongst other items, for the manufacture of boats.
- Rotomolding provides for consistent wall thickness and sharp outside corners which are essentially stress free.
- Rotomolding has also been traditionally limited to use with a single material.
- one specific problem with rotomolded products is that the surface of the product is soft.
- the present invention discloses a process for creating an improved rotomolded products.
- the inner mold area is sprayed with a material, such as an acrylic polyethylene alloy, prior to loading the resin into the mold.
- a material such as an acrylic polyethylene alloy
- the acrylic polyethylene alloy is loaded into the mold with ihe resin. Once loaded, the mold is then heated, rotated and cooled. Once cooled the part is then removed from the mold.
- a mold is opened and a first resin which is to become the outer surface of the part is added.
- the mold is closed, heated and rotated.
- a "drop" box is opened within the mold to introduce a second resin into the mold.
- the second resin will become the body or structure of the molded part.
- the mold is again heated and rotated as described above. As heating begins, the second resin material begins to melt and sticks to the inner surface of the mold over the first resin.
- the first resin will form the surface layer of the part . Once cooled the mold is opened and the part is removed.
- a mold is opened and a first resin which is to become the outer surface of the part is added.
- the first resin is not an alloy but rather preferably consist of a separate material such as acrylic, polycarbonate, styrenic or other hardened plastic which will create a hardened outer shell .
- a first drop box is opened within the mold to introduce a second resin which acts as a tie coat or bond layer.
- the tie coat bonds to the first resin.
- the mold is heated and rotated to evenly bond to the first resin which is provided over the inner surface of the mold.
- a second drop box is opened within the mold and a third resin is released.
- the third resin will become the body or structure of the molded part.
- the mold is once again heated and rotated, allowing the third resin to become melted and evenly distributed over the inside of the mold.
- This third resin bonds to the tie coat layer.
- the previously released tie coat acts as a bridge or intermediary allowing the main body resin to bond to the first layer, thereby bonding two materials which might not normally bond.
- the first resin will form the surface layer of the part, the second layer the tie coat and the third layer the main body or substrate of the part .
- a rotomolded product can be constructed having an outer surface with different characteristics and properties as compared to its inner surface or substrate .
- the methods provided for stronger bonds between the materials as compared to conventional methods, such as lamination.
- the molded part can be provided with a shinier and harder surface layer as compared to previous rotational molding methods.
- the present invention allows for a softer surface layer with a harder substrate layer. Accordingly, it is an object of the present invention to provide a rotational molding process which yields a harder outer surface of a molded part as compared to conventional rotational molding processes.
- Figure 1 is a block diagram of a first method for the rotational molding process of the present invention
- Figure 2 is a block diagram of a second method for the rotational molding process of the present invention.
- Figure 3 is a block diagram of a third method for the rotational molding process of the present invention.
- Figure 4 is a block diagram of a fourth method for the rotational molding process of the present invention.
- a first method is illustrated for the rotational molding process of the present invention.
- a mold is provided which is shaped to correspond to the shape of the intended part.
- a metal mold is utilized, however such is not limiting.
- an inner area of the mold can be sprayed with an alloy consisting of acrylic and polyethylene in the preferred embodiment.
- the invention is not limited to the specific acrylic polyethylene alloy for the outer surface.
- other materials or alloys that will provide for a relatively hard outer surface can be substituted for the acrylic polyethylene alloy and are considered within the scope of the invention.
- a conventional aerosol is utilized to spray the acrylic polyethylene alloy.
- a conventional solvent material such as alcohol
- the alcohol eventually evaporates off, after transporting the alloy, once the mold is heated.
- the mold is preferably preheated prior to spraying the acrylic polyethylene alloy. Where preheated, upon being sprayed by the aerosol sprayer, the acrylic polyethylene alloy melts and sticks to the inner surface of the mold and ultimately will become the outer surface of the molded part. Having an outer surface consisting of the acrylic polyethylene alloy provides the molded part with a relatively harder appearance as compared to conventional rotational methods. The acrylic polyethylene alloy also provides a harder outer surface, less likely to crack.
- the mold After spraying, the mold is loaded with a resin charge.
- the preferred material for the resin is at least one form of polyethylene.
- the resin can consist of polyethylene and can include two sizes of polyethylene to create a "sandwich" type structure having solid skins and a foamed polyethylene core.
- the resin is also provided in powder form.
- the mold is preferably disposed within a conventional rotomolding oven where it is heated and rotated. Any conventional method can be used for the heating and rotating of the mold.
- the mold can be suspended or disposed within an oven and rotated on both its vertical and horizontal axis. The mold is heated to a temperature beyond the melting point of the resin which causes the resin to melt and stick to the inner surface of the mold which is already coated with the acrylic polyethylene alloy.
- Rotating the mold allows for an even coat of the inner surface of the mold with the resin and the acrylic polyethylene alloy.
- the mold is heated to a temperature ranging between 350° to 500°, however such range should not be considered limiting.
- the resin and acrylic polyethylene alloy form the shape of the intended part, with the composite acting as a thin surface layer and bonding alloy, and the resin forming the substrate of the part.
- the shape of the part corresponds to the shape of the mold.
- the mold After the mold has been sufficiently heated and rotated, the mold remains closed and is allowed to cool. While cooling the mold can continue to be rotated to allow the part inside the mold to maintain an even wall thickness. Once properly cooled, the mold is opened or separated and the molded part is removed.
- Figure 2 illustrates the second method for the rotational molding process of the present invention.
- a mold similar to the mold described above is provided.
- the acrylic polyethylene alloy is not sprayed prior to loading the resin. Rather, the acrylic polyethylene alloy is preferably provided in powder form and loaded into the mold at the same time the resin is loaded.
- the resin is also preferably provided in powder form and can consist of one or more polyethylene materials. When loading, the alloy powder and the resin powder can be mixed together.
- the particles consisting of the alloy powder are preferably smaller in size as compared to the particles constituting the resin powder.
- the forces of gravity will caused the smaller size particles to move outward within the mold.
- the smaller size alloy particles will also melt quicker than the larger size resin particles.
- the force of gravity and quicker melting characteristics assure that the particles constituting the acrylic polyethylene alloy form the outer surface layer of the molded part .
- the alloy material can be cryogenically ground to ensure that the size of the alloy material is smaller than the size of the resin material .
- the mold is heated and rotated as described above. As heating begins, the smaller alloy material will melt first, as compared to the resin material. By melting first, the alloy material will stick to the inner surface of the mold. Once the resin material begins to melt it will also stick to the inner surface of the mold over the alloy material. Thus, when the mold is cooled, the alloy material will form the surface layer of the part, with the polyethylene portion of the composite acting as an alloy to bond the surface layer to the substrate formed by the resin material .
- the substrate in one embodiment can consist of "sandwich” type structure with solid skins and a foamed polyethylene core.
- the solid skins can also constructed from a polyethylene material.
- the polyethylene material which makes up the solid skins will be sized smaller then the polyethylene material comprising the foamed core. As such, the polyethylene skin material will melt quicker then the core material causing it to travel outward from the foam material inside the mold.
- the polyethylene material which comprises the substrate's core can be provided with a blowing agent to create a foam substrate.
- the mold can also be preheated prior to loading the resin and alloy.
- the preheating of the mold may cause the smaller alloy material to begin to melt, prior to the mold being fully heated during the heating and rotating steps.
- the mold is also allowed to cool as described above, and thus, the mold can continue to be rotated during cooling to allow the part inside the mold to maintain an even wall thickness. Once cooled the mold is opened and the part is removed.
- Figure 3 illustrates the third method for the rotational molding process of the present invention.
- a mold similar to the mold described above is provided. Initially, the mold is opened and a first resin which is to become the outer surface of the part is added.
- the first resin consist of any acrylic polyethylene alloy, though such is not limiting.
- the resin is also preferably provided in powder form.
- the mold is closed, heated and rotated.
- the mold is heated to a temperature which causes the first resin to melt.
- the melted first resin evenly sticks to the entire inner surface of the mold and ultimately will become the outer surface of the molded part.
- a box commonly referred to as a "drop box”
- the second resin will become the body or structure of the molded part .
- the resin consist of a polyethylene material, though other materials can be used and are considered within the scope of the invention.
- the mold is again heated and rotated as described above .
- the second resin material begins to melt and sticks to the inner surface of the mold over the first resin.
- the first resin will form the surface layer of the part.
- the polyethylene portion of the first resin composite acts as an alloy to bond the surface layer to the substrate formed by the second resin material.
- the substrate in one embodiment can consist of "sandwich" type structure with solid skins and a foamed polyethylene core.
- the solid skins can also constructed from a polyethylene material .
- the polyethylene material which comprises the substrate's core can be provided with a blowing agent to create a foam substrate.
- the mold can also be preheated prior to loading the first resin. The preheating of the mold, may cause the first resin to begin to melt, prior to the mold being fully heated during the heating and rotating steps.
- the mold is also allowed to cool as described above, and thus, the mold can continue to be rotated during cooling to allow the part inside the mold to maintain an even wall thickness. Once cooled the mold is opened and the part is removed.
- Figure 4 illustrates the fourth method for the rotational molding process of the present invention.
- a mold similar to the mold described above is provided. Initially, the mold is opened and a first resin which is to become the outer surface of the part is added.
- the first resin is not an alloy but rather consist of a separate material such as acrylic, polycarbonate, styrenic or other hardened plastic which will create a hardened outer shell .
- the resin is also preferably provided in powder form.
- the mold is closed, heated and rotated.
- the mold is heated to a temperature which causes the first resin to melt.
- the melted first resin evenly sticks to the entire inner surface of the mold and ultimately will become the outer surface of the molded part.
- a first drop box is opened within the mold to introduce a second resin which acts as a tie coat or bond layer, preferably consisting of a modified polyethylene or alloy material, though other materials can be used and are considered within the scope of the invention.
- the tie coat bonds to the first resin.
- the mold is heated and rotated to evenly bond to the first resin which is provided over the inner surface of the mold.
- the tie coat is properly melted, a second drop box is opened within the mold and a third resin is released.
- the third resin will become the body or structure of the molded part .
- the resin consist of a polyethylene material, though other materials can be used and are considered within the scope of the invention.
- the mold is once again heated and rotated, allowing the third resin to become melted and evenly distributed over the inside of the mold.
- This third resin bonds to the tie coat layer.
- the previously released tie coat acts as a bridge or intermediary allowing the main body resin to bond to the first layer, thereby bonding two materials which might not normally bond.
- the first resin will form the surface layer of the part, the second layer the tie coat and the third layer the main body or substrate of the part .
- the substrate in one embodiment can consist of "sandwich" type structure with solid skins and a foamed polyethylene core.
- the solid skins can also constructed from a polyethylene material .
- the polyethylene material which comprises the substrate's core can be provided with a blowing agent to create a foam substrate.
- the mold can also be preheated prior to loading the first resin.
- the preheating of the mold may cause the first resin to begin to melt, prior to the mold being fully heated during the heating and rotating steps.
- the mold is also allowed to cool as described above, and thus, the mold can continue to be rotated during cooling to allow the part inside the mold to maintain an even wall thickness . Once cooled the mold is opened and the part is removed.
- the molded part can be provided with a harder, shinier and stronger surface layer as compared to parts molded by conventional rotational molding techniques.
- the surface layer is also relatively thin as compared to the remaining portion of the molded part.
- the outer surface layer can be the softer layer, with the substrate acting as the harder layer.
- the present invention allows for an outer surface layer having different characteristics and properties than those of the inner surface layer.
- the above-described methods also provide for a relatively stronger bond between the materials, as compared to traditional lamination.
- a polyethylene material is used for the resin which the part is molded from.
- a polyethylene material is included in the composite to act, amongst other things, as an alloy with the polyethylene resin.
- the present invention should not be considered limited to polyethylene materials. Accordingly, it is within the scope of the invention to use other materials for the resin. In such event, it is preferred that a similar material, as the material selected for the resin, be selected as at least a part of the alloy material which forms the surface layer of the molded part .
- the alloy material is not limited to being only the material used for the surface layer. It is within the scope of the invention to use a alloy material, such as the acrylic polyethylene combination, as the resin for the mold. In such cases, it is not necessary to provide a alloy material prior to adding the resin.
- the above described methods can be utilized with various conventional molds.
- the heating, rotating and cooling steps of the methods are performed utilizing conventional devices, i.e. ovens, molds, etc.
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA002337454A CA2337454C (en) | 1998-07-14 | 1999-07-13 | Rotational molding process |
AU52123/99A AU5212399A (en) | 1998-07-14 | 1999-07-13 | Rotational molding process |
EP99937248A EP1109658A1 (en) | 1998-07-14 | 1999-07-13 | Rotational molding process |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/115,132 US6214272B1 (en) | 1998-07-14 | 1998-07-14 | Rotational molding process |
US09/115,132 | 1998-07-14 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2000003856A1 WO2000003856A1 (en) | 2000-01-27 |
WO2000003856A9 true WO2000003856A9 (en) | 2000-07-20 |
Family
ID=22359473
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1999/015889 WO2000003856A1 (en) | 1998-07-14 | 1999-07-13 | Rotational molding process |
Country Status (5)
Country | Link |
---|---|
US (1) | US6214272B1 (en) |
EP (1) | EP1109658A1 (en) |
AU (1) | AU5212399A (en) |
CA (1) | CA2337454C (en) |
WO (1) | WO2000003856A1 (en) |
Families Citing this family (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0995568A1 (en) * | 1998-10-21 | 2000-04-26 | Recticel | Method for manufacturing a multilayered moulded synthetic part and thus obtained part |
US6409954B1 (en) * | 1999-10-05 | 2002-06-25 | Roto Plastics, Inc. | Method of making a rotary molded plastic member with variable wall thickness |
AU2002245383B2 (en) * | 2001-02-05 | 2006-01-19 | Environmental Recycling Technologies Plc | Processes for forming plastic, apparatuses for forming plastic, and articles made therefrom |
US6602452B2 (en) * | 2001-07-18 | 2003-08-05 | Mcghan Medical Corporation | Rotational molding of medical articles |
GB0128252D0 (en) * | 2001-11-24 | 2002-01-16 | Ellis Gordon & Co | Rotomoulded articles and a method of producing same |
US6800195B1 (en) * | 2002-06-04 | 2004-10-05 | Thermaco, Inc. | Low cost grease removal system |
US20040121100A1 (en) * | 2002-12-11 | 2004-06-24 | Potempa Michael Matheau | Sound barrier |
US7273571B2 (en) * | 2004-02-25 | 2007-09-25 | Mfs, Llc | Molded table and its method of manufacture |
US20060055290A1 (en) * | 2004-09-16 | 2006-03-16 | Schalla James P | Reaction-Injection-Molded Cart and Method of Manufacture |
US8142691B2 (en) * | 2004-09-30 | 2012-03-27 | Lawrence Livermore National Security, Llc | Thermal casting of polymers in centrifuge for producing X-ray optics |
EP1721931A1 (en) * | 2005-05-09 | 2006-11-15 | Total Petrochemicals Research Feluy | mono-layer rotomoulded articles prepared from blends comprising polyethylene |
US7273364B2 (en) * | 2005-05-13 | 2007-09-25 | Mfs, Llc | Drop box with thermal isolation |
US20090039548A1 (en) * | 2007-08-08 | 2009-02-12 | Custom Roto-Mold, Inc. | Rotational molding to form multilayer article |
US8431179B2 (en) * | 2008-11-20 | 2013-04-30 | Allergan, Inc. | System and method for molding soft fluid-filled implant shells |
RU2572999C2 (en) * | 2011-05-26 | 2016-01-20 | Адвенира Энтерпрайзис, Инк. | Coating application system and process |
Family Cites Families (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3875275A (en) * | 1958-05-05 | 1975-04-01 | Jerome H Lemelson | Method for molding composite bodies |
US3683062A (en) * | 1970-08-20 | 1972-08-08 | Essex International Inc | Rotational casting method |
US3984511A (en) | 1971-05-24 | 1976-10-05 | Dart Industries Inc. | Method of rotational molding |
US3989787A (en) * | 1975-07-28 | 1976-11-02 | Phillips Petroleum Company | Method of rotational molding a thermosetting article with a thermoplastic insert |
US4238537A (en) * | 1978-12-18 | 1980-12-09 | The National Latex Products Company | Process for rotational molding utilizing EVA and products produced therefrom |
GB2050921B (en) | 1979-06-15 | 1982-12-15 | Sybron Corp | Apparatus for roto-moulding |
US4687531A (en) * | 1982-01-26 | 1987-08-18 | Potoczky Joseph B | Method for centrifugal spray molding of thin-walled structures |
JPS6184214A (en) * | 1984-10-02 | 1986-04-28 | Nippon Petrochem Co Ltd | Preparation of conductive resin molded piece |
US5073325A (en) * | 1989-07-18 | 1991-12-17 | Davidson Textron Inc. | Method for producing a molded article having stabilized decorative features |
DE4202354C2 (en) | 1992-01-29 | 1995-12-21 | Ymos Ag Ind Produkte | Process for the production of a plastic skin |
BE1005821A3 (en) * | 1992-05-18 | 1994-02-08 | Recticel | PROCESS FOR THE PRODUCTION OF SELF-SUPPORTING APPETIZERS PLASTIC PARTS AND THUS MANUFACTURED trim part. |
GB2267675B (en) | 1992-05-21 | 1995-09-20 | Nanma Mfg Co Ltd | Rotational moulding process and product |
DE4221679A1 (en) | 1992-07-02 | 1994-01-13 | Roeder & Spengler Stanz | Prodn. of products containing plastic materials with binder - using appts. which sprays release agent on mould tool, dipping into powdered material, spraying on binder, applying top mould tool and pressing |
US5324472A (en) * | 1992-10-15 | 1994-06-28 | William Page | Method of preparing metalflake plastic |
EP0817711A1 (en) | 1995-03-31 | 1998-01-14 | Exxon Chemical Patents Inc. | Foamed rotationally molded articles |
DE19626272B4 (en) | 1996-06-29 | 2004-11-18 | Köver GmbH & Co. KG Metall- und Kunststoffverarbeitung | Plastic composite element, in particular for suppressing spray mist in the vehicle sector, and method for its production |
-
1998
- 1998-07-14 US US09/115,132 patent/US6214272B1/en not_active Expired - Lifetime
-
1999
- 1999-07-13 EP EP99937248A patent/EP1109658A1/en not_active Withdrawn
- 1999-07-13 WO PCT/US1999/015889 patent/WO2000003856A1/en active Application Filing
- 1999-07-13 CA CA002337454A patent/CA2337454C/en not_active Expired - Fee Related
- 1999-07-13 AU AU52123/99A patent/AU5212399A/en not_active Abandoned
Also Published As
Publication number | Publication date |
---|---|
AU5212399A (en) | 2000-02-07 |
US6214272B1 (en) | 2001-04-10 |
CA2337454A1 (en) | 2000-01-27 |
EP1109658A1 (en) | 2001-06-27 |
CA2337454C (en) | 2009-01-27 |
WO2000003856A1 (en) | 2000-01-27 |
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