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WO1984003065A1 - Method of manufacturing a hollow plastics article - Google Patents

Method of manufacturing a hollow plastics article Download PDF

Info

Publication number
WO1984003065A1
WO1984003065A1 PCT/SE1984/000036 SE8400036W WO8403065A1 WO 1984003065 A1 WO1984003065 A1 WO 1984003065A1 SE 8400036 W SE8400036 W SE 8400036W WO 8403065 A1 WO8403065 A1 WO 8403065A1
Authority
WO
WIPO (PCT)
Prior art keywords
container
article
core
manufacturing
injection moulding
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
Application number
PCT/SE1984/000036
Other languages
French (fr)
Inventor
Lennart Wilhelm Castwall
Pentti Juhani Jaentti
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Electrolux AB
Original Assignee
Electrolux AB
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 Electrolux AB filed Critical Electrolux AB
Priority to GB08423718A priority Critical patent/GB2144074B/en
Publication of WO1984003065A1 publication Critical patent/WO1984003065A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/14—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles
    • B29C45/14065—Positioning or centering articles in 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
    • B29C33/00—Moulds or cores; Details thereof or accessories therefor
    • B29C33/44—Moulds or cores; Details thereof or accessories therefor with means for, or specially constructed to facilitate, the removal of articles, e.g. of undercut articles
    • B29C33/52—Moulds or cores; Details thereof or accessories therefor with means for, or specially constructed to facilitate, the removal of articles, e.g. of undercut articles soluble or fusible
    • 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
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/14—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles
    • B29C45/14836—Preventing damage of inserts during injection, e.g. collapse of hollow inserts, breakage
    • 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
    • B29C33/44—Moulds or cores; Details thereof or accessories therefor with means for, or specially constructed to facilitate, the removal of articles, e.g. of undercut articles
    • B29C33/52—Moulds or cores; Details thereof or accessories therefor with means for, or specially constructed to facilitate, the removal of articles, e.g. of undercut articles soluble or fusible
    • B29C2033/525—Cores made of frozen liquids, e.g. ice

Definitions

  • This invention relates to a method of manufacturing a hollow plastics article.
  • Another method which is previously known is the so-called rotary moulding process, in which the plastics material in plastic state is entered into a cavity which rotates. The plastics material spreads over the walls of the cavity and covers the walls. When the plastics material has stiffened a shell having the intended shape has been obtained.
  • a drawback of this method is that it is limitated with respect to accuracy , wall thickness, material to be chosen and shrinking problems.
  • a third well-known method is the so-called blow moulding, in which an extruded plastics tube in heated condition is entered into a cavity in which the tube is blown or sucked to the walls of the mould in order to form the cavity.
  • this method can only be used with thermoplastics and for articles of simple shape. It is also known to use cores of plaster or sand with suitable bonding agents in order to form articles with cavities but remainders of the plaster or sand core can stay in the article after cleaning, which for instance in petrol tanks for combustion engines can cause engine failure.
  • German OS 18 10 311 Still another method of manufacturing articles of the above type is described in German OS 18 10 311. According to this method a core for instance of ice is produced which shapes the cavity during the injection. The core is then allowed to melt and the water is removed by an opening in the article.
  • OS 28 83 566 is to produce a core consisting of bellows containing particles which are stabilized to solid shape by means of vacuum. After injection moulding around the core air of atmospheric pressure is allowed to enter into the bellows which then together with the particles can be taken out from the article.
  • the object of this invention is to provide another method of manufacturing articles of the shape concerned which compared to known methods has the advantage that different materials can be integrated to a single unit. For instance
  • O PI it is possible to combine an impact-resistant material and a chemically resistant material. Such a combination can be used for instance in chain saws when a petrol tank shall be an integrated part of the saw.
  • Fig. 1 is a vertical length section through an article according to the invention and Fig. 2 is a vertical section on the line H - II of Fig. 1 with the article in the tool.
  • Fig. 1 shows a detail of a chain saw, the detail being injection moulded in plastics and comprising an outer hull 10 of impact-resistant plastics into which the sword of the saw is to be fastened.
  • the hull 10 continues into a handle 11 and encloses a container 12.
  • the object of this container is to hold fuel for the chain saw.
  • the detail is manufactured in the following way.
  • a container 12 with an opening 13 is made.
  • the container is filled with water and a mandrel 14 is inserted through the opening 13 so that a part of the mandrel extends outside the container.
  • the container is cooled so that the water freezes to ice 15. This causes the container to expand a little at the same time as the mandrel is fixed to the container.
  • the container with mandrel is inserted into the tool, the two halves of which being denoted 16 and 17, respectively.
  • the mandrel is inserted in a corresponding hole 18 in the tool.
  • the melted plastics, forming the hull 10 and the handle 11, is entered through several gates 19 so that the plastics will completely surround the container 12.
  • the injection moulded article is then taken out from the tool and is placed with the opening 13 directed downwards.
  • the ice melts, the mandrel falls out and the water escapes through the opening 13.
  • the article can be completed with engine, sword and other details.
  • the container can for instance be particles. By creating a vacuum in the container the particles can form a hard interior counter -acting the said pressure.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)

Abstract

Method of manufacturing a hollow plastics article by means of injection moulding and by using a core which is inserted in a mould. The core (15) is formed by a container (12) which is filled with non-compressible material, such as liquid or liquid frozen to solid form. The article (10) is moulded around the core. After the injection moulding the material is removed through an opening in the article and the container, respectively, whereas the container remains in the article in order to form a part which is integrated with the article.

Description

Method of manufacturing a hollow plastics article
This invention relates to a method of manufacturing a hollow plastics article.
It is commonly known to manufacture articles of the above type in two halves by injection moulding and to join the two halves together so as to form the complete article. This technique is usually simple to apply but it involves several working operations after the injection moulding and separation of the component parts during the handling before the parts are put together.
Another method which is previously known is the so-called rotary moulding process, in which the plastics material in plastic state is entered into a cavity which rotates. The plastics material spreads over the walls of the cavity and covers the walls. When the plastics material has stiffened a shell having the intended shape has been obtained. However, a drawback of this method is that it is limitated with respect to accuracy , wall thickness, material to be chosen and shrinking problems. A third well-known method is the so-called blow moulding, in which an extruded plastics tube in heated condition is entered into a cavity in which the tube is blown or sucked to the walls of the mould in order to form the cavity. However, this method can only be used with thermoplastics and for articles of simple shape. It is also known to use cores of plaster or sand with suitable bonding agents in order to form articles with cavities but remainders of the plaster or sand core can stay in the article after cleaning, which for instance in petrol tanks for combustion engines can cause engine failure.
Still another method of manufacturing articles of the above type is described in German OS 18 10 311. According to this method a core for instance of ice is produced which shapes the cavity during the injection. The core is then allowed to melt and the water is removed by an opening in the article.
Another method of manufacturing articles of the above type, see German
OS 28 83 566, is to produce a core consisting of bellows containing particles which are stabilized to solid shape by means of vacuum. After injection moulding around the core air of atmospheric pressure is allowed to enter into the bellows which then together with the particles can be taken out from the article.
The object of this invention is to provide another method of manufacturing articles of the shape concerned which compared to known methods has the advantage that different materials can be integrated to a single unit. For instance
O PI it is possible to combine an impact-resistant material and a chemically resistant material. Such a combination can be used for instance in chain saws when a petrol tank shall be an integrated part of the saw.
An embodiment of the invention will now be described with reference to the accompanying drawings in which Fig. 1 is a vertical length section through an article according to the invention and Fig. 2 is a vertical section on the line H - II of Fig. 1 with the article in the tool.
Fig. 1 shows a detail of a chain saw, the detail being injection moulded in plastics and comprising an outer hull 10 of impact-resistant plastics into which the sword of the saw is to be fastened. The hull 10 continues into a handle 11 and encloses a container 12. The object of this container is to hold fuel for the chain saw.
The detail is manufactured in the following way.
In a first step a container 12 with an opening 13 is made. The container is filled with water and a mandrel 14 is inserted through the opening 13 so that a part of the mandrel extends outside the container. Then the container is cooled so that the water freezes to ice 15. This causes the container to expand a little at the same time as the mandrel is fixed to the container.
The container with mandrel is inserted into the tool, the two halves of which being denoted 16 and 17, respectively. The mandrel is inserted in a corresponding hole 18 in the tool. The melted plastics, forming the hull 10 and the handle 11, is entered through several gates 19 so that the plastics will completely surround the container 12. The injection moulded article is then taken out from the tool and is placed with the opening 13 directed downwards. Thus, the ice melts, the mandrel falls out and the water escapes through the opening 13. Then the article can be completed with engine, sword and other details.
It is of course possible within the scope of the invention to fill the container with other types of non-compressible material in order to take up the pressure created during the injection moulding, after which the material can be removed via the opening. The material can for instance be particles. By creating a vacuum in the container the particles can form a hard interior counter -acting the said pressure.
O PI

Claims

Claims
1. A method of manufacturing a hollow plastics article by means of injection moulding and by using a core which is inserted in a mould, character¬ ized in that the core (15) is formed by a container (12) which is filled with non-compressible material, such as liquid or liquid frozen to solid form, that the article (10) is moulded around the core and that the material after the injection moulding is removed through an opening in the article and the container, respectively, whereas the container remains in the article in order to form a part which is integrated with the article.
2. A method according to Claim 1, characterized in that water in- serted in the container is used as core.
3. A method according to Claim 1, characterized in that particles inserted in the container are used as core and that vacuum is established in the container during the injection moulding.
4. A method according to Claim 1, characterized in that when manufacturing the core a distance means (14) is inserted through the opening of the container (12) and is fixed into the material and that said distance means is engaged with the mould (16,17) in order to keep the core at a distance from the surrounding walls during the injection moulding operation.
PCT/SE1984/000036 1983-02-07 1984-02-07 Method of manufacturing a hollow plastics article Ceased WO1984003065A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08423718A GB2144074B (en) 1983-02-07 1984-02-07 Method of manufacturing a hollow plastics article

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE8300614A SE8300614D0 (en) 1983-02-07 1983-02-07 PUT TO MAKE A VACATION-MADE PLASTIC FORM

Publications (1)

Publication Number Publication Date
WO1984003065A1 true WO1984003065A1 (en) 1984-08-16

Family

ID=20349909

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE1984/000036 Ceased WO1984003065A1 (en) 1983-02-07 1984-02-07 Method of manufacturing a hollow plastics article

Country Status (5)

Country Link
JP (1) JPS60500410A (en)
DE (1) DE3490046T1 (en)
GB (1) GB2144074B (en)
SE (2) SE8300614D0 (en)
WO (1) WO1984003065A1 (en)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1993013926A1 (en) * 1988-11-10 1993-07-22 R. Alkan & Cie Method and apparatus for fabricating hollow parts made of draped composite material
US5262113A (en) * 1992-08-06 1993-11-16 Carmien Joseph A Method of making a plastic encased tool component having a lightweight hollow core
US5375486A (en) * 1991-06-10 1994-12-27 Carmien; Joseph A. Surface protective striking tools
EP0635672A1 (en) * 1993-07-20 1995-01-25 Landgraf, Rainer, Dipl.jur.Dipl.agr Pressure vessel, in particular pressure storage vessel, method for its manufacture and plastics for such a vessel
US5960677A (en) * 1998-03-13 1999-10-05 Carmien; Joseph Allen Nonrecoil impact tool
US5996442A (en) * 1997-08-05 1999-12-07 Carmien; Joseph Allen Hand tool having interchangeable and replaceable striking heads, and assembly process
WO2001005570A1 (en) * 1999-07-15 2001-01-25 Moeser Hansjuergen Method for producing complete units using internal pressure systems based on injection moulding with several components, and assemblies of said units
US6227075B1 (en) 1999-01-25 2001-05-08 Joseph Allen Carmien Nonrecoil hammer
FR2831852A1 (en) * 2001-11-08 2003-05-09 Sai Automotive Allibert Ind METHOD AND ASSEMBLY FOR MOLDING A TUBULAR ELEMENT BY COMPRESSION OF PLASTIC MATERIAL
WO2008010600A1 (en) 2006-07-19 2008-01-24 Du Pont-Mitsui Polychemicals Co., Ltd. Manufacturing method of synthetic resin hollow body
DE102006006902B4 (en) * 2006-02-09 2008-02-21 Gräfenthaler Kunststofftechnik GmbH Plastic pressure vessel and process for its manufacture
US8430258B2 (en) 2006-07-19 2013-04-30 Du Pont-Mitsui Poluchemicals Co., Ltd. Synthetic resin hollow body
US8517197B2 (en) 2006-07-19 2013-08-27 Du Pont-Mitsui Polychemicals Co., Ltd. Synthetic resin hollow body

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008060842A1 (en) * 2008-12-05 2010-06-10 Robert Bosch Gmbh Plastic housing production device for pneumatic slide valve, has tool core provided with elastic region, so that tool core is reversibly bringable from basic form into working form comprising undercut for formation of gradated boring
DE102014018599A1 (en) * 2014-12-17 2016-06-23 Stiebel Eltron Gmbh & Co. Kg Method for producing a plastic pressure vessel for a domestic appliance and plastic pressure vessel
DE102017221454B4 (en) * 2017-11-29 2025-10-02 Bayerische Motoren Werke Aktiengesellschaft Tool and method for producing a coated plastic component

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1200536A (en) * 1958-05-12 1959-12-22 S M Soc Improvements to the processes for obtaining hollow plastic objects
DE1810311A1 (en) * 1968-07-01 1970-02-19 Wacker Werke Kg Low temperature injection or casting mould made of ice
SE340879B (en) * 1967-02-15 1971-12-06 Tetra Pak Int
DE2832566A1 (en) * 1978-07-25 1980-02-07 Bayer Ag METHOD FOR PRODUCING HOLLOW BODIES

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1200536A (en) * 1958-05-12 1959-12-22 S M Soc Improvements to the processes for obtaining hollow plastic objects
SE340879B (en) * 1967-02-15 1971-12-06 Tetra Pak Int
DE1810311A1 (en) * 1968-07-01 1970-02-19 Wacker Werke Kg Low temperature injection or casting mould made of ice
DE2832566A1 (en) * 1978-07-25 1980-02-07 Bayer Ag METHOD FOR PRODUCING HOLLOW BODIES

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1993013926A1 (en) * 1988-11-10 1993-07-22 R. Alkan & Cie Method and apparatus for fabricating hollow parts made of draped composite material
US5375486A (en) * 1991-06-10 1994-12-27 Carmien; Joseph A. Surface protective striking tools
US5262113A (en) * 1992-08-06 1993-11-16 Carmien Joseph A Method of making a plastic encased tool component having a lightweight hollow core
EP0635672A1 (en) * 1993-07-20 1995-01-25 Landgraf, Rainer, Dipl.jur.Dipl.agr Pressure vessel, in particular pressure storage vessel, method for its manufacture and plastics for such a vessel
US5996442A (en) * 1997-08-05 1999-12-07 Carmien; Joseph Allen Hand tool having interchangeable and replaceable striking heads, and assembly process
US5960677A (en) * 1998-03-13 1999-10-05 Carmien; Joseph Allen Nonrecoil impact tool
US6227075B1 (en) 1999-01-25 2001-05-08 Joseph Allen Carmien Nonrecoil hammer
US6234048B1 (en) 1999-01-25 2001-05-22 Joseph Allen Carmien Nonrecoil hammer
DE19932700C1 (en) * 1999-07-15 2001-05-03 Hansjuergen Moeser Process for the production of plastic objects by multi-component injection molding
WO2001005570A1 (en) * 1999-07-15 2001-01-25 Moeser Hansjuergen Method for producing complete units using internal pressure systems based on injection moulding with several components, and assemblies of said units
FR2831852A1 (en) * 2001-11-08 2003-05-09 Sai Automotive Allibert Ind METHOD AND ASSEMBLY FOR MOLDING A TUBULAR ELEMENT BY COMPRESSION OF PLASTIC MATERIAL
WO2003039831A1 (en) * 2001-11-08 2003-05-15 Faurecia Interieur Industrie Method and assembly for over-moulding a tubular element by plastic material compression
DE102006006902B4 (en) * 2006-02-09 2008-02-21 Gräfenthaler Kunststofftechnik GmbH Plastic pressure vessel and process for its manufacture
WO2008010600A1 (en) 2006-07-19 2008-01-24 Du Pont-Mitsui Polychemicals Co., Ltd. Manufacturing method of synthetic resin hollow body
EP2046553A4 (en) * 2006-07-19 2011-03-30 Mitsui Du Pont Polychemical METHOD FOR MANUFACTURING SYNTHETIC RESIN HOLLOW BODY
US7988897B2 (en) 2006-07-19 2011-08-02 Du Pont-Mitsui Polychemicals Co., Ltd. Manufacturing method of synthetic resin hollow body
CN102357980A (en) * 2006-07-19 2012-02-22 三井-杜邦聚合化学株式会社 Manufacturing method of synthetic resin hollow body
US8430258B2 (en) 2006-07-19 2013-04-30 Du Pont-Mitsui Poluchemicals Co., Ltd. Synthetic resin hollow body
US8517197B2 (en) 2006-07-19 2013-08-27 Du Pont-Mitsui Polychemicals Co., Ltd. Synthetic resin hollow body

Also Published As

Publication number Publication date
DE3490046T1 (en) 1985-04-04
SE8404742D0 (en) 1984-09-21
JPS60500410A (en) 1985-03-28
SE450823B (en) 1987-08-03
GB2144074A (en) 1985-02-27
GB2144074B (en) 1986-10-01
SE8404742L (en) 1984-09-21
SE8300614D0 (en) 1983-02-07
GB8423718D0 (en) 1984-10-24

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