WO2004069526A1 - Method for fast prototyping of large parts in composite material without molds - Google Patents

Method for fast prototyping of large parts in composite material without molds Download PDF

Info

Publication number
WO2004069526A1
WO2004069526A1 PCT/IT2003/000067 IT0300067W WO2004069526A1 WO 2004069526 A1 WO2004069526 A1 WO 2004069526A1 IT 0300067 W IT0300067 W IT 0300067W WO 2004069526 A1 WO2004069526 A1 WO 2004069526A1
Authority
WO
WIPO (PCT)
Prior art keywords
production
prototypes
thin film
composite material
create
Prior art date
Application number
PCT/IT2003/000067
Other languages
French (fr)
Inventor
Francesco Grasso
Original Assignee
G.G.G. Elettromeccanica Srl
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by G.G.G. Elettromeccanica Srl filed Critical G.G.G. Elettromeccanica Srl
Priority to AU2003209701A priority Critical patent/AU2003209701A1/en
Priority to PCT/IT2003/000067 priority patent/WO2004069526A1/en
Publication of WO2004069526A1 publication Critical patent/WO2004069526A1/en

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
    • B29C33/00—Moulds or cores; Details thereof or accessories therefor
    • B29C33/56—Coatings, e.g. enameled or galvanised; Releasing, lubricating or separating agents
    • B29C33/68—Release sheets
    • 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
    • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
    • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
    • B29C70/28—Shaping operations therefor
    • B29C70/30—Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core
    • B29C70/34—Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core and shaping or impregnating by compression, i.e. combined with compressing after the lay-up operation
    • B29C70/342—Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core and shaping or impregnating by compression, i.e. combined with compressing after the lay-up operation using isostatic pressure
    • 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
    • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
    • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
    • B29C70/28—Shaping operations therefor
    • B29C70/40—Shaping or impregnating by compression not applied
    • B29C70/42—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles
    • B29C70/44—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles using isostatic pressure, e.g. pressure difference-moulding, vacuum bag-moulding, autoclave-moulding or expanding rubber-moulding

Definitions

  • the invention concerns a method for making prototypes in composite material with shapes obtained by automatic milling on light material. It has the aim to drastically reduce costs and time to create prototype parts.
  • the method allows to obtain one or more prototypes without the requirement of creating a mold.
  • Prototypes are made to verify technical characteristics, design and functional correctness, feasibility of production and assembly and can be used subsequently to create mold to be utilized in production lines.
  • Prototypes are particularly important for production of composite material parts and products.
  • fast prototyping it is meant all the advanced technologies that can turn an idea of a product into the prototype, in a very short time compared to traditional manual product development.
  • Prototypes obtained using traditional fast prototyping techniques have usually mechanical properties of lower quality compared to final production parts and are usually employed only for design validation and dimensional and assembling compatibility testing. These technologies accompanied by high costs per unit of volume are applicable only in specialty fields such as precision mechanics and large production lines in order to spread the elevated cost over very large number of pieces.
  • the prototyping here described overcomes the above limitations and makes it possible to obtain in a few days a prototipe starting from the CAD phase without the requirement of manual labour and without the creation of a mold.
  • the prototype can be made of the material and with the same mechanical properties of the final piece and thus used for functional tests
  • Prototyping systems consist of the creation of the negative of the required shape in any soft homogeneous material which can be machined, such as light metals, wood, MDF, plastic resins, plastic polymeric foams, PVC foams, etc.; the shape is molded from these materials by CNC machining from a 3D CAD drawing.
  • the shapes created on soft materials are not suited, however, for the production of a piece, but a number of additional phases are required to harden the surface, pre- finishing, finishing and application of detaching substance, in order to obtain a false mold able to support the deposition of the composite material components.
  • the invention described here a thin film is employed to avoid the intermediate phases.
  • the film is characterized by a very high elongation ratio, that is it can be stretched without damage up to many times its original area.
  • the film is made adhere to the 3D shape created by machining very closely.
  • the part is then created directly on the film using the standard composite material techniques.
  • the prototype obtained following the above procedure is very low cost calculated to be four to five times lower compared to the currently employed fast prototyping techniques.
  • the system can be used for "one-off models as well as the basis to make a mold for production, this latter step using traditional methods.
  • the method does not require specialized labour to sculpt dummies, expertise which is very costly and difficult to find nowadays.
  • the fast prototyping system consists of the creation of negative shape of the desired part made of a low cost soft and homogeneous material, such as wood, MDF, plastic resins, plastic or polymeric foams, PVC foams, etc., that can be machined; this shape is then generated by CNC milling from a 3D CAD drawing.
  • a low cost soft and homogeneous material such as wood, MDF, plastic resins, plastic or polymeric foams, PVC foams, etc.
  • the shape is inserted in a vacuum pumped container and covered with a thin film of high degree of elongation material, that is capable of withstanding stretch up to several times its original area.
  • the film is made adhere to the machined shape in order to stretch it to follow closely the surface.
  • the composite material is formed using the traditional techniques for composite material parts, that is:
  • the thin film to be used for the fast prototyping process is chosen so that the surface of the material is smoothed, and it depends on the porous nature of the material as well as roughness deriving from CNC machining; it therefore acts as a surface pre-finish.
  • the thin film composition can be chosen to not stick to material used for making the prototype; in this case the film acts as a detaching compound.
  • the thin film can be chosen to permanently stick to the material used for making the prototype, in this case the film will be the outer skin of the prototype itself.
  • the prototype created with the method described here has the same mechanical properties of the production parts which can be obtained with traditional production methods for composite materials.
  • the prototype can in some cases, depending on the material chosen for the machining phase, display a varying roughness, which can be constrained within a maximum thickness by changing material for machining, film material and machining precision; the prototype can be made to have a roughness below the gel-coat layer thickness.
  • the final finish of the prototype is then, when required, limited to fine sanding using traditional techniques.
  • the figure depicts the method to create the prototype.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Composite Materials (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)

Abstract

A method for fast prototyping to create prototypes of large parts in composite material (typical dimensions are several metres). The method make it possible to obtain one or more prototypes without manual labor and without the requirement of the mold. The prototype, which can be made of the same material used for production and with the same mechanical properties of the final production part, can be also used as a 'one-off' piece, or to verify the suitability of the part before starting production, or as a dummy to create the mold used for production. The method makes use shaped created on light materials by automatic milling using CAD-CNC-CAM, which is then covered with a vacuum deformable thin film, that can act as superficial finish as well as detaching means.

Description

METHOD FOR FAST PROTOTYPING OF LARGE PARTS IN
COMPOSITE MATERIAL
Description
The invention concerns a method for making prototypes in composite material with shapes obtained by automatic milling on light material. It has the aim to drastically reduce costs and time to create prototype parts.
The method allows to obtain one or more prototypes without the requirement of creating a mold.
The need for prototypes is more and more widespread in many industrial fields to facilitate the development of new products. Prototypes are made to verify technical characteristics, design and functional correctness, feasibility of production and assembly and can be used subsequently to create mold to be utilized in production lines.
Prototypes are particularly important for production of composite material parts and products.
In recent years many fast prototyping techniques have been developed, now used in different industrial fields. By fast prototyping it is meant all the advanced technologies that can turn an idea of a product into the prototype, in a very short time compared to traditional manual product development.
Fast prototyping technologies are usually based on computer based design systems, such as CAD, and numerically controlled (CNC) machines for shaping.
Among fast prototyping technologies it is worth mentioning stereolithography, CNC milling, laser sintering, thermoforming.
In general all the above mentioned techniques are limited to small sized objects (usually fractions of a meter) with relatively high cost, only feasible for productions of large quantities.
Prototypes obtained using traditional fast prototyping techniques have usually mechanical properties of lower quality compared to final production parts and are usually employed only for design validation and dimensional and assembling compatibility testing. These technologies accompanied by high costs per unit of volume are applicable only in specialty fields such as precision mechanics and large production lines in order to spread the elevated cost over very large number of pieces.
The above described technologies are unavailable to industrial fields where prototypes of large sizes and small number of pieces produces on yearly basis. This is due to the high cost of prototypes, made with traditional fsat prototyping, as well as to the unavailability of equipment large enough (for example the field of small production boats).
When large sized dummies are needed the manual shaping is still the most widespread technique used or for more advanced applications the construction is based on laser cut cross sections assembled with sheet wood. This implies a considerable amount of manual labour for finishing and to apply detaching compounds. In addition until the whole process of creation of the first piece (design, manually sculpted dummy, mold, part) any prototype verification is impossible.
The prototyping here described overcomes the above limitations and makes it possible to obtain in a few days a prototipe starting from the CAD phase without the requirement of manual labour and without the creation of a mold.
Moreover the prototype can be made of the material and with the same mechanical properties of the final piece and thus used for functional tests
Prototyping systems consist of the creation of the negative of the required shape in any soft homogeneous material which can be machined, such as light metals, wood, MDF, plastic resins, plastic polymeric foams, PVC foams, etc.; the shape is molded from these materials by CNC machining from a 3D CAD drawing.
The shapes created on soft materials are not suited, however, for the production of a piece, but a number of additional phases are required to harden the surface, pre- finishing, finishing and application of detaching substance, in order to obtain a false mold able to support the deposition of the composite material components.
The invention described here a thin film is employed to avoid the intermediate phases. The film is characterized by a very high elongation ratio, that is it can be stretched without damage up to many times its original area.
Using a vacuum system the film is made adhere to the 3D shape created by machining very closely. The part is then created directly on the film using the standard composite material techniques.
The process consists of the following phases:
1. 3D CAD design of the part;
2. automatic generation of tool-paths by CAM systems;
3. machining using a CNC machine to create the negative shape with the desired material (usually inexpensive and low density materials, such as wood, plastic resins, etc);
4. application, using a vacuum pumping system, on the machined shape of a thin film with a high degree of elongation to obtain a smooth surface;
5. creation of the composite material prototype, fiber-glass or other composite material, either in air or in vacuum, optionally with the same mechianical properties of the final desired part;
The prototype obtained following the above procedure is very low cost calculated to be four to five times lower compared to the currently employed fast prototyping techniques.
The system can be used for "one-off models as well as the basis to make a mold for production, this latter step using traditional methods.
In addition to the obvious advantages deriving from the automatic process involving the whole chain, which reduces the chance for errors and the overall tolerance, the method does not require specialized labour to sculpt dummies, expertise which is very costly and difficult to find nowadays.
Among the advantages of the method a few are worth mentioning such as the precision of all the parts of an assembly (for example boats are made up of several parts that have to be mechanically compatible). This is achieved thanks to the computer based process, from the CAD based design of all parts of the assembly and the CNC machining of each individual part.
Description of the Process
The fast prototyping system consists of the creation of negative shape of the desired part made of a low cost soft and homogeneous material, such as wood, MDF, plastic resins, plastic or polymeric foams, PVC foams, etc., that can be machined; this shape is then generated by CNC milling from a 3D CAD drawing.
The shape is inserted in a vacuum pumped container and covered with a thin film of high degree of elongation material, that is capable of withstanding stretch up to several times its original area.
Using a vacuum pumping system the film is made adhere to the machined shape in order to stretch it to follow closely the surface.
On the stretched film the composite material is formed using the traditional techniques for composite material parts, that is:
* optional deposition of a gel-coat layer; o deposition of the composite fiber and resin using manual painting or spraying;
• (as an alternative) deposition of the composite material using vacuum forming with the use of an additional thin film to be applied over the fibers and then formed by injection of resins.
The thin film to be used for the fast prototyping process is chosen so that the surface of the material is smoothed, and it depends on the porous nature of the material as well as roughness deriving from CNC machining; it therefore acts as a surface pre-finish.
The thin film composition can be chosen to not stick to material used for making the prototype; in this case the film acts as a detaching compound.
Alternatively, when desired, the thin film can be chosen to permanently stick to the material used for making the prototype, in this case the film will be the outer skin of the prototype itself.
The prototype created with the method described here has the same mechanical properties of the production parts which can be obtained with traditional production methods for composite materials.
The prototype can in some cases, depending on the material chosen for the machining phase, display a varying roughness, which can be constrained within a maximum thickness by changing material for machining, film material and machining precision; the prototype can be made to have a roughness below the gel-coat layer thickness. The final finish of the prototype is then, when required, limited to fine sanding using traditional techniques.
The same method can be used without any variation to construct molds, creating the final part shape in negative.
The figure depicts the method to create the prototype.

Claims

Claims
1. Method to create composite material prototypes without molds to test shape and functional properties, using a thin film layer deformable in vacuum;
2. Use of a thin film made of Nylon, PVC, Polyethylene, to mention a few, or other material with a high elongation coefficient, variable thickness to be applied in the method described in claim 1 ;
3. Use of a thin film with additional characteristics of shape memory, as an alternative or modification of materials described in claim 2;
4. Use of a vacuum system to apply method described in claims 1-2;
5. Use of heating methods to help the rapid prototyping procedure and curing of prototypes constructed according to claims 1-3;
6. Use of two thin films to create parts with smooth finish on both faces using, in combination with methods described in claims 1-4, a low pressure vacuum forming injection systems.
PCT/IT2003/000067 2003-02-10 2003-02-10 Method for fast prototyping of large parts in composite material without molds WO2004069526A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU2003209701A AU2003209701A1 (en) 2003-02-10 2003-02-10 Method for fast prototyping of large parts in composite material without molds
PCT/IT2003/000067 WO2004069526A1 (en) 2003-02-10 2003-02-10 Method for fast prototyping of large parts in composite material without molds

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/IT2003/000067 WO2004069526A1 (en) 2003-02-10 2003-02-10 Method for fast prototyping of large parts in composite material without molds

Publications (1)

Publication Number Publication Date
WO2004069526A1 true WO2004069526A1 (en) 2004-08-19

Family

ID=32843861

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IT2003/000067 WO2004069526A1 (en) 2003-02-10 2003-02-10 Method for fast prototyping of large parts in composite material without molds

Country Status (2)

Country Link
AU (1) AU2003209701A1 (en)
WO (1) WO2004069526A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2388131A1 (en) * 2010-05-20 2011-11-23 Siemens Aktiengesellschaft Method of moulding a wind turbine blade using a release film, and said film
FR3015339A1 (en) * 2013-12-24 2015-06-26 Plastic Omnium Cie PREFORMING PLASTIC ASSISTED SEMI-PRODUCT OF MEMBRANES

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0036391A2 (en) * 1980-03-17 1981-09-23 Herbert Schreiber Process for preparing fibre-reinforced plastic articles, prepreg to be used in the process and the article so prepared
DE3206905A1 (en) * 1982-02-26 1983-10-27 Weigel, Angela Process for producing reinforced components by means of a vacuum and substrate surfaces; autolaminate method
US4478771A (en) * 1981-03-12 1984-10-23 Herbert Schreiber Method of manufacturing fibre-reinforced plastic articles, a prepreg for the manufacture of fibre-reinforced plastic articles and a fibre-reinforced plastic article
DE3319204A1 (en) * 1983-05-27 1984-11-29 Weigel, Angela Process for producing laminated moulds and components using a vacuum
US4562033A (en) * 1982-07-24 1985-12-31 Rolls-Royce Limited Method of manufacturing articles from a composite material
DE3727926A1 (en) * 1986-08-27 1988-03-10 Dornier Gmbh Process for producing moulded parts
JPH05177704A (en) * 1992-01-07 1993-07-20 Mitsubishi Paper Mills Ltd Shaping release material and production thereof
US5304339A (en) * 1990-05-23 1994-04-19 Le Comte Adolf Method for manufacturing a large-sized object of fiber reinforced synthetic resin
EP1038656A1 (en) * 1999-03-02 2000-09-27 LS Technologies, Inc. A Pennsylvania Corporation Vacuum resin impregnation process
WO2001041993A2 (en) * 1999-12-07 2001-06-14 The Boeing Company Double bag vacuum infusion process and system for low cost, advanced composite fabrication

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0036391A2 (en) * 1980-03-17 1981-09-23 Herbert Schreiber Process for preparing fibre-reinforced plastic articles, prepreg to be used in the process and the article so prepared
US4478771A (en) * 1981-03-12 1984-10-23 Herbert Schreiber Method of manufacturing fibre-reinforced plastic articles, a prepreg for the manufacture of fibre-reinforced plastic articles and a fibre-reinforced plastic article
DE3206905A1 (en) * 1982-02-26 1983-10-27 Weigel, Angela Process for producing reinforced components by means of a vacuum and substrate surfaces; autolaminate method
US4562033A (en) * 1982-07-24 1985-12-31 Rolls-Royce Limited Method of manufacturing articles from a composite material
DE3319204A1 (en) * 1983-05-27 1984-11-29 Weigel, Angela Process for producing laminated moulds and components using a vacuum
DE3727926A1 (en) * 1986-08-27 1988-03-10 Dornier Gmbh Process for producing moulded parts
US5304339A (en) * 1990-05-23 1994-04-19 Le Comte Adolf Method for manufacturing a large-sized object of fiber reinforced synthetic resin
JPH05177704A (en) * 1992-01-07 1993-07-20 Mitsubishi Paper Mills Ltd Shaping release material and production thereof
EP1038656A1 (en) * 1999-03-02 2000-09-27 LS Technologies, Inc. A Pennsylvania Corporation Vacuum resin impregnation process
WO2001041993A2 (en) * 1999-12-07 2001-06-14 The Boeing Company Double bag vacuum infusion process and system for low cost, advanced composite fabrication

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 017, no. 595 (M - 1503) 29 October 1993 (1993-10-29) *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2388131A1 (en) * 2010-05-20 2011-11-23 Siemens Aktiengesellschaft Method of moulding a wind turbine blade using a release film, and said film
US9005381B2 (en) 2010-05-20 2015-04-14 Siemens Aktiengesellschaft Method of moulding a wind turbine blade
FR3015339A1 (en) * 2013-12-24 2015-06-26 Plastic Omnium Cie PREFORMING PLASTIC ASSISTED SEMI-PRODUCT OF MEMBRANES
WO2015097397A3 (en) * 2013-12-24 2015-08-20 Compagnie Plastic Omnium Membrane-assisted preforming of plastic semi-finished product

Also Published As

Publication number Publication date
AU2003209701A1 (en) 2004-08-30

Similar Documents

Publication Publication Date Title
Savini et al. A short history of 3D printing, a technological revolution just started
US7255821B2 (en) Layered deposition bridge tooling
Thomas et al. Rapid prototyping of large scale aerospace structures
Udroiu et al. Polyjet technology applications for rapid tooling
US5173220A (en) Method of manufacturing a three-dimensional plastic article
US5296335A (en) Method for manufacturing fiber-reinforced parts utilizing stereolithography tooling
US6630093B1 (en) Method for making freeform-fabricated core composite articles
Novakova-Marcincinova et al. Applications of rapid prototyping fused deposition modeling materials
Deitz Stereolithography automates prototyping
EP3134251A2 (en) Molds and methods of making molds having conforming heating and cooling systems
Haidiezul et al. Surface finish effects using coating method on 3D printing (FDM) parts
EP3246107A1 (en) Method of investment casting using additive manufacturing
KR20030007144A (en) Shaping die and manufacturing method thereof
CA2538359A1 (en) Layered manufactured articles having small-diameter fluid conduction vents and methods of making same
Ciofu et al. Injection and micro injection of polymeric plastics materials: a review
Novakova-Marcincinova et al. Experimental testing of materials used in fused deposition modeling rapid prototyping technology
CN104441641A (en) Stereo lithography apparatus (SLA)-based 3D printing implementation method and device
WO2004069526A1 (en) Method for fast prototyping of large parts in composite material without molds
Singh An overview of three dimensional printing for casting applications
Hyndhavi et al. Rapid prototyping technology-classification and comparison
Tari et al. Rapid prototyping of composite parts using resin transfer molding and laminated object manufacturing
Kochan Solid freeform manufacturing—possibilities and restrictions
Singh et al. Experimental investigations for rapid moulding solution of plastics using polyjet printing
Havryliak New technologies in the field of construction. using 3D printers
Afonso et al. Testing single point incremental forming molds for thermoforming operations

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ OM PH PL PT RO RU SD SE SG SK SL TJ TM TN TR TT TZ UA UG US UZ VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PT SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP

WWW Wipo information: withdrawn in national office

Country of ref document: JP