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
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/0005—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor characterised by the 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
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/42—Component parts, details or accessories; Auxiliary operations
  • B29C49/78—Measuring, controlling or regulating
  • B29C2049/7879—Stretching, e.g. stretch rod
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/07—Preforms or parisons characterised by their configuration
  • B29C2949/0715—Preforms or parisons characterised by their configuration the preform having one end closed
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/07—Preforms or parisons characterised by their configuration
  • B29C2949/081—Specified dimensions, e.g. values or ranges
  • B29C2949/0811—Wall thickness
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/20—Preforms or parisons whereby a specific part is made of only one component, e.g. only one layer
  • B29C2949/22—Preforms or parisons whereby a specific part is made of only one component, e.g. only one layer at neck portion
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/20—Preforms or parisons whereby a specific part is made of only one component, e.g. only one layer
  • B29C2949/24—Preforms or parisons whereby a specific part is made of only one component, e.g. only one layer at flange portion
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/20—Preforms or parisons whereby a specific part is made of only one component, e.g. only one layer
  • B29C2949/26—Preforms or parisons whereby a specific part is made of only one component, e.g. only one layer at body portion
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/20—Preforms or parisons whereby a specific part is made of only one component, e.g. only one layer
  • B29C2949/28—Preforms or parisons whereby a specific part is made of only one component, e.g. only one layer at bottom portion
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/30—Preforms or parisons made of several components
  • B29C2949/3008—Preforms or parisons made of several components at neck portion
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/30—Preforms or parisons made of several components
  • B29C2949/3012—Preforms or parisons made of several components at flange portion
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/30—Preforms or parisons made of several components
  • B29C2949/3016—Preforms or parisons made of several components at body portion
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/30—Preforms or parisons made of several components
  • B29C2949/302—Preforms or parisons made of several components at bottom portion
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/30—Preforms or parisons made of several components
  • B29C2949/3024—Preforms or parisons made of several components characterised by the number of components or by the manufacturing technique
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/30—Preforms or parisons made of several components
  • B29C2949/3024—Preforms or parisons made of several components characterised by the number of components or by the manufacturing technique
  • B29C2949/3026—Preforms or parisons made of several components characterised by the number of components or by the manufacturing technique having two or more components
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/30—Preforms or parisons made of several components
  • B29C2949/3024—Preforms or parisons made of several components characterised by the number of components or by the manufacturing technique
  • B29C2949/3026—Preforms or parisons made of several components characterised by the number of components or by the manufacturing technique having two or more components
  • B29C2949/3028—Preforms or parisons made of several components characterised by the number of components or by the manufacturing technique having two or more components having three or more components
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/30—Preforms or parisons made of several components
  • B29C2949/3024—Preforms or parisons made of several components characterised by the number of components or by the manufacturing technique
  • B29C2949/3026—Preforms or parisons made of several components characterised by the number of components or by the manufacturing technique having two or more components
  • B29C2949/3028—Preforms or parisons made of several components characterised by the number of components or by the manufacturing technique having two or more components having three or more components
  • B29C2949/303—Preforms or parisons made of several components characterised by the number of components or by the manufacturing technique having two or more components having three or more components having more than three components
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/30—Preforms or parisons made of several components
  • B29C2949/3032—Preforms or parisons made of several components having components being injected
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/30—Preforms or parisons made of several components
  • B29C2949/3032—Preforms or parisons made of several components having components being injected
  • B29C2949/3034—Preforms or parisons made of several components having components being injected having two or more components being injected
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/30—Preforms or parisons made of several components
  • B29C2949/3032—Preforms or parisons made of several components having components being injected
  • B29C2949/3034—Preforms or parisons made of several components having components being injected having two or more components being injected
  • B29C2949/3036—Preforms or parisons made of several components having components being injected having two or more components being injected having three or more components being injected
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/30—Preforms or parisons made of several components
  • B29C2949/3032—Preforms or parisons made of several components having components being injected
  • B29C2949/3034—Preforms or parisons made of several components having components being injected having two or more components being injected
  • B29C2949/3036—Preforms or parisons made of several components having components being injected having two or more components being injected having three or more components being injected
  • B29C2949/3038—Preforms or parisons made of several components having components being injected having two or more components being injected having three or more components being injected having more than three components being injected
• • 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
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/02—Combined blow-moulding and manufacture of the preform or the parison
  • B29C49/06—Injection blow-moulding
• • 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
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/08—Biaxial stretching during blow-moulding
  • B29C49/087—Means for providing controlled or limited stretch ratio
• • 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
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/42—Component parts, details or accessories; Auxiliary operations
  • B29C49/42394—Providing specific wall thickness
• • 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
  • B29K2033/00—Use of polymers of unsaturated acids or derivatives thereof as moulding material
  • B29K2033/18—Polymers of nitriles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2031/00—Other particular articles
  • B29L2031/712—Containers; Packaging elements or accessories, Packages
  • B29L2031/7158—Bottles

Definitions

• the present invention relates in general to the technique of blow moulding biaxially oriented containers of plastics material, and in particular to a container having excellent oxygen barrier properties and thus being suitable for packaging of beer, juice or other beverages and liquids sensitive to oxygen.
• PEN polyethylene naphthalate
• the oxygen barrier of PEN is about five times better than that of PET, but at the same time PEN is about five times more expensive than PET. This means that PEN is not a realistic alternative since the market is not willing to pay the price for the enhanced oxygen barrier.
• HNRs High Nitrile Resins
• a major supplier of HNRs is the British company BP Chemicals Ltd which is marketing a commercial HNR under their trademark
• BAREX which is a modified acrylonitrile-methyl acrylate copolymer.
• this pamphlet injection stretch blow moulding of Barex 2101 is discussed, a stretch ratio of 4:1 being indicat- ed as appropriate.
• the supplier of this material recommends this stretch ratio for obtaining a suitable orientation of the material and thereby the aimed-at oxy- gen barrier.
• the side wall of the blow moulded container should have a wall thickness that is four times less than the wall thickness of the preform body.
• Barex 2101 is believed to be about seven times better than that of PET, while the price is only about the double .
• BAREX materials have an oxygen transmission rate of 0.15-0.8 cm 3 .mm/m 2 .24h.bar, measured in accordance with ASTM standards, which should be compared with the corresponding rate for PET which is
• polymer comprises polymers as well as less polymerised variants thereof, the latter being considered as oligomers or prepolymers thereof.
• copolymer as used herein comprises copolymers, graft copolymers as well as higher polymers, such as terpolymers .
• the preform is formed from polymeric material comprising a modified nitrile-acrylate copolymer as defined in appended claim 1.
• the preform is formed from polymeric material comprising a modified nitrile-acrylate copolymer as defined in appended claim 1.
• ® consists of Barex 2101 which in the blow moulding step is stretched into a container following a stretch ratio of about 12:1. In its unoriented state, this material has a oxygen transmission rate of 0.3 cm 3 .mm/m 2 .24h. bar, and by stretching the material 12 : 1 this rate is below 0.016 cm 3 .mm/m 2 .24h.bar . Thus, the oxygen barrier is increased at least in the magnitude of about twenty times .
• the preform is formed from polymeric material comprising a modified copolymer of a nitrile monomer and an aromatic compound as defined in appended claim 6. If this preform is blow moulded and stretched in the way discussed with respect to the first aspect above, a significant increase of the oxygen barrier is achieved. In preferred embodiments, substantially the same oxygen barrier is achieved by blow moulding a preform of the second aspect of the invention as in the first aspect.
• the general inventive concept is based on the idea that a preform comprising a suitable HNR material should be blow moulded in such a way that the wall thickness of the side wall of the finished blow moulded container is 6-20 less than the wall thickness of the preform body.
• the PET is crystallised (as is describ- ed in EP-A-521 841 mentioned by way of introduction)
• HNR is amorphous throughout this process.
• it is advantageous that the material is maintained amorphous since the finished container will then always be transparent .
• Containers of PET and the like having crystallised wall and/or bottom portions are sometimes somewhat opaque which may be an undesired pro- perty.
• the first aspect of the present invention relates to a biaxially oriented container blow moulded from a preform of polymeric material, wherein the container side wall has a wall thickness which is 6-20 times less than the wall thickness of the preform body, the polymeric material comprising a modified nitrile-acrylate copolymer.
• the polymeric material comprises a copolymer of a nitrile monomer and an acrylate monomer having the general formula I and II, respectively:
• R is hydrogen or an alkyl group having from 1 to 4 carbon atoms ;
• R x is hydrogen or an alkyl group having from 1 to 4 carbon atoms ;
• the polymeric material comprises a first component being a copolymer of the nitrile monomer I and the acrylate monomer II admixed or polymerised with a second component selected from the group consisting of a monomer, a polymer and a copolymer.
• the polymeric material comprises a copolymer of the nitrile monomer I and the acrylate monomer II admixed with a rubber selected from the group consisting of: i ) a polymer of a diene monomer having the general formula III :
• R 3 is hydrogen or an alkyl group having from 1 to 4 carbon atoms ; ii ) a polymer of an aromatic compound having the general formula IV:
• R 4 is hydrogen or an alkyl group having from 1 to 4 car- bon atoms; iii ) a copolymer of the nitrile monomer I and the diene monomer III; iv) a copolymer of the nitrile monomer I and the aromatic compound IV; v) a copolymer of the diene monomer III and the aromatic compound IV .
• the polymeric material comprises a terpolymer of the nitrile monomer I, the acrylate monomer II and a monomer selected from the group consisting of: i ) the diene monomer III, or a polymer thereof; ii ) the aromatic compound IV, or a polymer thereof;
• the second aspect of the present invention relates to a biaxially oriented container blow moulded from a preform of polymeric material, wherein the container side wall has a wall thickness which is 6-20 times less than the wall thickness of the preform body, the polymeric material comprising a modified copolymer of a nitrile monomer and an aromatic compound having the general formula I and IV, respectively:
• R is hydrogen or an alkyl group having from 1 to 4 carbon atoms
• R 4 is hydrogen or an alkyl group having from 1 to 4 carbon atoms .
• the polymeric material comprises a terpolymer of the nitrile monomer I, the aromatic compound IV and a diene monomer having the general formula III:
• R 3 is hydrogen or an alkyl group having from 1 to 4 carbon atoms .
• R is preferably H in the nitrile monomer I .
• R x is preferably H in the acrylate monomer II in the first aspect.
• R 2 is preferably a methyl group in the first aspect.
• R 4 is preferably H in the aromatic compound IV.
• R 3 is either H or a methyl group in the diene monomer III.
• the polymeric material comprises a terpolymer of acrylonitrile, methyl acrylate and butadiene.
• the polymeric material comprises a terpolymer of acrylonitrile, styrene and butadiene.
• the preform is of the general type shown in appli- cant's EP-A-521 841.
• the preform comprises a tubular body having a closed hemispherical end and one open end defining a mouth portion having outer threads for engagement with corresponding inner threads of a closure cap.
• the tubular preform body has a cylindrical portion between the mouth portion and the closed end portion. This cylindrical portion defines the side wall of the preform, and in the blow moulding step this preform side wall is transformed to an expanded cylindrical body defining the side wall of the container.
• the container to be produced is a transparent bottle for juice or beer having a volume of 0.5 litre.
• the weight of the Barex preform is 47g which should be compared with corresponding known preforms of PET and
• PEN which have a weight of 54g. Since the Barex material has a lower density (1.11 kg/m 3 ) than PET and PEN (1.33 kg/m 3 ) , a lighter preform can be used, which makes it possible to reduce the material costs.
• the cylindrical body portion of the Barex preform has a wall thickness of about 3.6 mm, and the wall thickness of the side wall of the finished container should be about 0.3 mm, taking into account strength requirements placed on the container.
• the container in this example is of the disposable type and blow moulded basically in accordance with a known single-stage process, for instance, of the type described in the introductory portion of the before-mentioned document WO 97/32711.
• the Barex preform is first heated to a temperature of about 180°-200°C, then cooled to a temperature of about 100°C, and finally transferred to a blow mould in which it is blow moulded into the container in a manner known per se using a so-called stretching rod.
• the blow mould cavity has an inner shape corresponding to the outer shape of the finished container.
• the material is stretched and biaxially oriented in such a way that the wall thickness of the container side wall is about 12 times less than the wall thickness of the cylindrical portion of the preform. By this excessive orientation, the container obtains excellent oxygen barrier properties.
• the oxygen barrier of the finished container is tested in oxygen transmission rate measuring equip- ment referred to as "OX-TRAN 2/20", which is marketed by the US company Modern Controls, Inc. and which is well known to people skilled in the art. This test shows that the container has an oxygen transmission rate below 0.016 cm 3 .mm/m 2 .24h.bar, which is extremely good. This rate may be compared with the correspond-
• the oxygen barrier is improved at least in the magnitude of about twenty times .
• the oxygen transmission rate is also significantly im- proved (lowered) over oriented Barex ® 2101 which accord- ing to details given in the BP Chemicals pamphlets has a rate of 0.15 cm 3 .mm/m 2 .24h.bar .
• the oxygen barrier is improved at least in the magnitude of ten times.
• the oxygen barrier may be even better than described herein since the OX-TRAN equipment can hardly measure such low rates.
• the amount of nitrile in the polymeric material is also believed to be a parameter of interest when it comes to obtaining low oxygen transmission rates.
• the tests have shown that this amount of nitrile, as calculated from nitrile monomer (s) used, should be about 60-80% by weight, preferably about 70% by weight.
• This temperature (Tg) should be about 70-90°C, preferably about 75-85°C, and more preferably about 82 °C.
• the container may be either of the monolayer type consisting of said polymeric material, or of the multilayer type in which said polymeric material is a barrier layer included in the multilayer structure.
• a multilayer container may have a side wall comprising a central core or barrier layer of said polymeric material and layers of another thermoplastic material, such as PET, on each side of the barrier layer. Further, there may be so-called tie layers between the barrier layer and the two PET layers.
• said polymeric material comprises a terpolymer of acrylonitrile, methyl acrylate and butadiene.
• methyl acrylate may be replaced by styrene .
• the inventive concept is applicable to both injection blow moulding processes and injection stretch blow moulding processes, as is appreciated by the skilled person. Further, it should be emphasised that the inventive concept is applicable to both disposable one-way containers and reusable or returnable containers. Of course, this includes modern refillable containers for various liquids.
• the blow moulding process in which the invention is practised may be either of the so-called single-stage type, that is forming of the preform and the container "in line", or of the so-called two-stage type in which the preform is first injection moulded and then stored before the blow moulding step. These two processes are well known to the skilled person and described in WO 97/32711 mentioned in the introductory portion of this description.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
• Containers Having Bodies Formed In One Piece (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=20411884

Family Applications (1)

Country Status (6)

Family Cites Families (10)

• 1998
  • 1998-06-29 SE SE9802313A patent/SE9802313D0/xx unknown
• 1999
  • 1999-06-17 PL PL99345029A patent/PL345029A1/xx not_active IP Right Cessation
  • 1999-06-17 CZ CZ20004917A patent/CZ20004917A3/cs unknown
  • 1999-06-17 AU AU49414/99A patent/AU4941499A/en not_active Abandoned
  • 1999-06-17 EP EP99933347A patent/EP1093491A1/en not_active Withdrawn
  • 1999-06-17 WO PCT/SE1999/001089 patent/WO2000000545A1/en not_active Ceased

Non-Patent Citations (1)

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