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
  • B29C35/00—Heating, cooling or curing, e.g. crosslinking or vulcanising; Apparatus therefor
  • B29C35/02—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould
  • B29C35/08—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation
  • B29C35/10—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation for articles of indefinite length
• • 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
  • B29C35/00—Heating, cooling or curing, e.g. crosslinking or vulcanising; Apparatus therefor
  • B29C35/02—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould
  • B29C35/0266—Local curing
• • 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
  • B29C35/00—Heating, cooling or curing, e.g. crosslinking or vulcanising; Apparatus therefor
  • B29C35/02—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould
  • B29C35/04—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould using liquids, gas or steam
  • B29C35/06—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould using liquids, gas or steam for articles of indefinite length
• • 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
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/395—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die using screws surrounded by a cooperating barrel, e.g. single screw extruders
• • 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
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/50—Details of extruders
  • B29C48/695—Flow dividers, e.g. breaker plates
  • B29C48/70—Flow dividers, e.g. breaker plates comprising means for dividing, distributing and recombining melt flows
  • B29C48/705—Flow dividers, e.g. breaker plates comprising means for dividing, distributing and recombining melt flows in the die zone, e.g. to create flow homogeneity
• • 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
  • B29C35/00—Heating, cooling or curing, e.g. crosslinking or vulcanising; Apparatus therefor
  • B29C35/02—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould
  • B29C35/08—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation
  • B29C35/0805—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation using electromagnetic radiation
  • B29C2035/0827—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation using electromagnetic radiation using UV radiation
• • 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
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/022—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the choice of material
• • 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
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
  • B29C48/06—Rod-shaped
• • 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
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
  • B29C48/07—Flat, e.g. panels
  • B29C48/08—Flat, e.g. panels flexible, e.g. films
• • 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
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
  • B29C48/09—Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
• • 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
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/285—Feeding the extrusion material to the extruder
  • B29C48/29—Feeding the extrusion material to the extruder in liquid form
• • 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
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/0005—Condition, form or state of moulded material or of the material to be shaped containing compounding ingredients
• • 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
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/24—Condition, form or state of moulded material or of the material to be shaped crosslinked or vulcanised
• • 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
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/24—Condition, form or state of moulded material or of the material to be shaped crosslinked or vulcanised
  • B29K2105/243—Partially cured

Definitions

• the present invention relates to a method according to the preamble of claim 1 , which is a method in a process for preparing extruded article by flowing heat plastified stream of extrudable resinous thermoplastic crosslinking material through an extrusion orifice and to a process according to preamble of claim 10 which is an extrusion process for preparing extruded article(s) in which process heat plastified stream of extrudable resinous thermoplastic crosslinking material is arranged to flow through an extrusion orifice, the process comprising the following steps, providing a source of heat plastified extrudable synthetic resinous thermoplastic crosslinking material and advancing the material along a first flow path toward the extrusion orifice.
• the present invention also relates to an apparatus according to preamble of claim 15, which is an apparatus for preparing extruded article(s) by flowing heat plastified stream of extrudable resinous thermoplastic crosslinking material through an extrusion orifice.
• Othe properties of polymer-based articles may be significantly enhanced by crosslinking the polymer-based material.
• heat resistance, mechanical strength and chemical resistance are altered.
• crosslinking methods available in the industry, such as peroxide, silane and radiation based methods.
• the material is fully crosslinking so that the degree of crosslinking and the crosslinking gradient in the produced article are difficult to control.
• it is desirable to create a surface layer on an extruded article so as to obtain an article having altered crosslinking properties on the surface layer in relation to the rest of the article for providing certain advantageous properties.
• this crosslinked surface layer for an extruded article is produced by co- extruding it on the article.
• An object of the present invention is thus to provide a method, a process and an apparatus for implementing the method to overcome the above disadvantages.
• the objects of the invention are achieved by a method according to the characterizing portion of claim 1 which is characterized in that the method comprises the following step, - introducing modified crosslinking additive(s) to the surface portion of the stream of extrudable resinous thermoplastic material before the extrusion step for altering the crosslinking properties of the surface portion of the extrudable material.
• apparatus according to the characterizing portion of claim 15 which is characterized in that apparatus comprises before the extrusion orifice (10) introducing means (8) for introducing modified crosslinking additive(s) to the surface portion of the stream of extrudable resinous thermoplastic crosslinking material for altering the crosslinking properties of the surface portion of the extrudable material.
• the preferred embodiments of the invention are disclosed in the dependent claims.
• the invention is based on the idea of creating an altered crosslinking surface layer in-situ extruder a part fter the melt zone by adding the modified crosslinking components/additives of the crosslinking method in question only to the surface layer of the heat plastified stream of extrudable resinous thermoplastic crosslinking material before the actual extrusion step.
• the result is produced an extruded article having altered crossliking properties on the surface layer in relation to the rest of the article, that is the core of the article.
• the crosslinked surface layer may be formed as an integral part of the extruded article and no separate crosslinked surface layer, for instance by co-extruding, is needed.
• modified crosslinking additives may be for example reaction promoters for boosting the crosslinking reaction or they may be reaction inhibitors for decelerating the croslinking reaction.
• This integral crosslinked surface layer may created for example by physically separating the stream of the extrudable resinous thermoplastic material into a central core stream and at least one boundary stream on the outside of the core stream before the extrusion step, while maintaining physical separation of the core and boundary stream by selectively introducing crosslinking additive(s) to the boundary streams and thereafter recombining the streams prior expelling the material in the extrusion step out of the extrusion orifice, said boundary streams being applied as a relatively thin surface layer having altered crosslinking properties between the core layer and the surfaces of the extrusion orifice.
• the surface layer having altered crosslinking properties is thus created as an integral surface layer during normal extrusion.
• Other parts of the article except the surface layer may also be crosslinked during the extrusion process, but because of the crosslinking additive supplied on the surface of the article, the crosslinking structure of the surface layer is different than the structure of the other parts of the article.
• Another way is to apply the modified crosslinking additives directly on the surface of the heat plastified stream of the extrudable resinous thermoplastic crosslinking material.
• An advantage of the present invention is that this kind of integral surface layer having altered crosslinking properties in relation to other parts or the core of the extruded article provides a mechanically stronger surface. Additionally the invention also enables better ultraviolet radiation protection, thermal stabilization and combinations of colouring and filling agents. Also the degree of the crosslinking and the crosslinking density may be controlled more precisely and the surface and the core of the extruded article may have altered crosslinked structures while being integral parts.
• figure 1 is a schematic view of an extrusion method and apparatus according to the present invention.
• the modified cross ⁇ nking additive or additives is applied through an extrusion orifice on the surface of the heat plastified stream of extrudable resinous thermoplastic crosslinking material before the actual extrusion step.
• the modified crosslinking additive spreads on the resinous crosslinking material to form a surface layer having altered crosslinking properties in relation to the rest of the resinous material to be extruded. Therefore also the extruded article comprises a surface layer having altered crosslinking properties.
• This applying of the modified crosslinking additive is carried out using introducing means.
• FIG. 1 shows a schematic view of the apparatus and method according to another embodiment of the present invention. The features described with this embodiment are also applicable with the above mentioned embodiment.
• the method in a process for preparing extruded article by flowing heat plastified stream of an extrudable resinous thermoplastic material through an extrusion orifice comprises separating the stream of an extrudable resinous thermoplastic material into a central core stream and at least one boundary stream on the outside of the core stream.
• crosslinking additive(s) are selectively introduced to the boundary streams.
• These crosslinking additives comprise at least one component to be crosslinked. They may also comprise crosslinking initiators and optionally other reactive components. These components and initiators are mixed and the thus formed additive is homogenized.
• the crosslinking additive is then selectively introduced and mixed to the boundary stream prior to the extrusion orifice.
• the boundary stream and the core stream are further recombined prior to expelling the material out of the extrusion orifice so that the boundary stream forms the outer layer of the recombined stream, the boundary stream being applied as a relatively thin surface layer having altered crosslinking properties between the core layer and the surfaces of the extrusion orifice.
• the resinous material of the recombined stream is then expelled through the extrusion orifice so as to prepare an extruded article in which the surface layer of the recombined stream forms the outer layer of the extruded article having altered crosslinking properties.
• the crosslinking of the surface layer of the extruded article is initiated using initiation means, for instance ultraviolet initiation means.
• initiation means activate the crosslinking initiators so that crosslinking of the surface layer having these crosslinking additives begins.
• the crosslinking may then continue as conventional thermal crosslinking.
• This thermal crosslinking may be carried out by thermal bath, infra red radiation or the like method.
• This thermal crosslinking may also carry out the crosslinking of other parts than the surface layer of the extruded article. In that case the surface layer and the other parts of the extruded article have different crosslinked structures.
• Properties of the surface layer of the extruded article may be modified as desired by controlling the initiation means to initiate the crosslinking of the surface layer of the extruded article, by for instance ultraviolet radiation intensity of the ultraviolet initiator. These properties may also be modified controlling the duration and temperature of the thermal crosslinking.
• Another possibility for modifying the crossliking properties of the surface layer of the extruded article is to vary the composition of the crosslinking additive to be fed into the boundary stream. This composition of the crosslinking additive may be accomplished by selecting a suitable component to be crosslinked, a suitable crosslinking initiator and a suitable amount and proportion of components and initiators. Suitable initiators are such as peroxide, silane and photo initiators.
• Other optional functional components may also be added to the crosslinking additive to be homogenized for altering the properties of the material for forming the surface layer of the stream of the extrudable resinous thermoplastic material and/or the surface layer of the extruded article.
• the present invention also relates to an extrusion process for preparing anextruded article or articles in which process an heat plastified stream of an extrudable resinous thermoplastic material is arranged to flow through an extrusion orifice.
• a source of heat plastified extrudable synthetic resinous thermoplastic material such as base resin, peroxide or silane material or a combination thereof.
• this extrudable material is advanced along a first flow path toward the extrusion orifice. Before the extrusion orifice a portion of the material is diverged from the first flow path to a second flow path forming a boundary flow path outside the first flow path.
• crosslinking additives are introduced and mixed into the diverted flow, that is the second flow path.
• the first and second flow paths are recombined so that the second flow path comprising the crosslinking additives forms the surface portion of the recombined flow in the first flow path. This way the crosslinking material is applied as a relatively thin layer to the surface of the resin flowing in the first flow path, prior to passing the material through the extrusion orifice.
• This recombined flow having a surface portion comprising altered crosslinking properties is then passed through an extrusion orifice so as to perform the extrusion step.
• the extruded article thus has a surface layer having altered crosslinking properties because of the crosslinking additive.
• the crosslinking of the surface portion of the extruded article provided with the crosslinking additive is initiated. This initiation of the crosslinking of the surface portion of the extruded article is may be performed for instance by ultraviolet radiation.
• the crosslinking is then continued by conventional thermal crosslinking so as to achieve a desired crosslinking gradient and/or degree of crosslinking of the surface portion of the article and/or the other parts of the article.
• crosslinking additive Before applying the crosslinking additive to the diverted flow it is homogenized since it may contain several components including components to be crosslinked, crosslinking initiators and/or other optional reactive components.
• the apparatus according to the present invention for preparing an extruded article by arranging a heat plastified stream of extrudable resinous thermoplastic material to flow through an extrusion orifice 10 comprises a source of extrudable material 1 , such as a base resin, peroxide or silane, a feed hopper 2, driving means 4 and screw means 7 for conveying the extrudable material towards the extrusion orifice 10.
• a source of extrudable material 1 such as a base resin, peroxide or silane
• driving means 4 and screw means 7 for conveying the extrudable material towards the extrusion orifice 10.
• first means 3 for physically separating the stream into a central core stream and at least one boundary stream outside of the core stream
• third means 5 for recombining the streams prior to expelling the material out of the extrusion orifice 10.
• introducing means 8 for selectively introducing crosslinking additives to the surface portion of the stream of the stream of extrudable resinous thermoplastic material, that is to the boundary stream.
• the said boundary streams are applied as a relatively thin surface layer having altered crosslinking properties between the core layer and the surfaces of the extrusion orifice.
• the recombined streams are then passed through the extrusion orifice 10.
• initiation means 22 may be for example an ultra-violet radiation source.
• the crosslinking may be continued by thermal crosslinking means 24.
• the apparatus according to the embodiment of the invention further comprises a source of a component to be crosslinked 16, a source of crosslinking initiator 18 and a source of other optional components 20 which together form the crosslinking additive.
• the homogenizing means 14 may be a mixer or the like apparatus for homogenizing the additive consisting of component to be crosslinked and crosslinking initiator and/or other optional reactive components.
• a source of additive 12 for supplying the homogenized additive to the introducing means 8 and further to the surface portion of the stream of the stream of the stream of extrudable resinous thermoplastic material.
• the apparatus may also comprise a source of an extrudable material, such as a base resin, peroxide or silane, a feed hopper, driving means and screw means for conveying the extrudable material towards the extrusion orifice.
• introducing means for selectively introducing crosslinking additives to the surface portion of the stream of the stream of extrudable resinous thermoplastic material.
• initiation means may be for example an ultra-violet radiation source.
• the crosslinking may be continued by thermal crosslinking means.
• this embodiment of the apparatus may also comprise homogenizing means 14 for homogenizing the crosslinking additive before introducing it to the surface portion of the stream of the stream of extrudable resinous thermoplastic material.
• the initiation means 22 may be selected according to the initiator supplied to the crosslinking additive.
• the initiation means 22 may be a ultra violet radiation source for initiating the crosslinking of the surface layer provided with photo initiators.

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• Health & Medical Sciences (AREA)
• Physics & Mathematics (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Thermal Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Toxicology (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)
• Processes Of Treating Macromolecular Substances (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Citations (5)

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• 2004
  • 2004-11-15 FI FI20045439A patent/FI20045439A7/fi unknown
• 2005
  • 2005-11-14 WO PCT/FI2005/050408 patent/WO2006051171A1/en not_active Ceased
  • 2005-11-14 CA CA002587453A patent/CA2587453A1/en not_active Abandoned
  • 2005-11-14 JP JP2007540667A patent/JP2008519708A/ja active Pending
  • 2005-11-14 US US11/667,291 patent/US20070296123A1/en not_active Abandoned
  • 2005-11-14 RU RU2007122447/12A patent/RU2007122447A/ru not_active Application Discontinuation
  • 2005-11-14 EP EP05804680A patent/EP1814710A4/en not_active Withdrawn
  • 2005-11-14 CN CNA2005800447230A patent/CN101087682A/zh active Pending

Patent Citations (5)

Non-Patent Citations (1)

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