Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B3/00—Cleaning by methods involving the use or presence of liquid or steam
  • B08B3/04—Cleaning involving contact with liquid
  • B08B3/08—Cleaning involving contact with liquid the liquid having chemical or dissolving effect
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B17/00—Methods preventing fouling
  • B08B17/02—Preventing deposition of fouling or of dust
  • B08B17/04—Preventing deposition of fouling or of dust by using removable coverings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D1/00—Containers having bodies formed in one piece, e.g. by casting metallic material, by moulding plastics, by blowing vitreous material, by throwing ceramic material, by moulding pulped fibrous material, by deep-drawing operations performed on sheet material
  • B65D1/02—Bottles or similar containers with necks or like restricted apertures, designed for pouring contents
  • B65D1/0207—Bottles or similar containers with necks or like restricted apertures, designed for pouring contents characterised by material, e.g. composition, physical features
  • B65D1/0215—Bottles or similar containers with necks or like restricted apertures, designed for pouring contents characterised by material, e.g. composition, physical features multilayered
• • 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
  • B29C49/22—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor using multilayered preforms or parisons
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/728—Hydrophilic
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2439/00—Containers; Receptacles

Definitions

• the present invention relates to a container adapted for safe disposal of hazardous residues, and to a method of producing a container.
• Thermoplastic containers are known in the art. Conventional containers may have removable inner linings.
• EP-A-182094 discloses a package and a method for producing a package with a flexible inner liner. The contents of the inner liner can be evacuated under positive or negative pressure exerted between the outer support and the inner liner. The inner liner can then be removed manually.
• Soluble films are also known in the art in many different fields. In recent years such films have been used, for example in the laundry industry, to provide dosage units where the whole sachet or envelope is added to the fluid and the film dissolves completely. In this way the user does not come into contact with the contained chemical. Examples are disclosed in US 4,765,916 and EP 011502.
• the disadvantage of the sachet where more toxic chemicals are concerned is that the film is liable to rupture.
• One idea to overcome this problem is to suspend the sachet within a rigid container so that the sachet is protected from damage, and in use is tipped whole from the container into the fluid. Such an arrangement is described in EP-A-347219. However, this arrangement also has disadvantages. It does not completely remove the risk of spillage within the container in transit and any weaknesses in the film would increase this risk.
• the user may be tempted to remove the sachet from the container and may rupture it in the process, particularly if it is suspended by a tear strip.
• a container comprising a single or multi-layer outer shell characterised in that the outer shell is provided with an inner-most wall or coating of a material which is insoluble while the container is in use but is soluble or so ulisable in a wash liquid.
• the present invention is suitable for many different types of conventional rigid or semi-rigid containers, for example, bottles, cartons, drums, tanks.
• the outer shell of the container is rigid or semi-rigid and may suitably made of a thermoplastic material such as polyethylene, ethylvinyl alcohol (EVOH), nylon, polypropylene or polyethylene terephthalate (polyester) or mixtures of these plastics.
• the outer shell may be single layered or multi-layered with almost any combination of thermoplastic materials.
• the container may be in the form of a drum or pail made with an outer shell of metal such as steel or tin plate.
• Containers with an outer shell made of plastics may have been produced by a moulding process, where the outer shell is built up in layers of the same or different plastics with or, in some cases, without an adhesive bonding layer (tie-bond) between the plastics layers.
• a layer may also consist of a blend of different plastics as, for example, with Selar (Trademark of Dupont) plastic which is a blend of polyethylene with platelets of nylon.
• the neck of the container can be made of a. different plastics material than the body of the container.
• the adhesive layer is a plastics material which has the property of binding to the given materials on either side of it. Commonly used examples are polyethylene and polyamide.
• the layers of plastics are generally hundreds of microns thick and the adhesive layer is generally only a few microns thick.
• the final laminate is generally l-2mm thick in.total.
• the container may also be of the 'bag in the box' type, where the inner flexible bag itself could be provided with a soluble or solulisable inner wall or coating or indeed the inner flexible bag could be completely soluble according to the present invention.
• One or more concentric tubes of plastics material are extruded and passed into a blow mould.
• the blow moulding operation forms the outer shell of the container and incorporates in the structure of the shell such inner or outer barriers or other layers as are required.
• the method comprising extrusion and blow-moulding operations when used to form a multi-layer container is generally known as a co-extrusion or multi-extrusion technique.
• a further method is co-injection stretch blow-moulding, for example, with polyethylene terephthalate containers
• the outer shell may be in the form of an envelope of polyethylene with a different plastics material sandwiched between.
• a yet further alternative method of forming the inner wall or coating is by spraying onto the inside of the outer shell of the container as a secondary operation after the outer shell has been formed by conventional methods, for example, extrusion blow moulding or injection stretch blow-moulding. Conventional or electrostatic spray techniques could be used.
• the outer shell of the container could be dip coated on the inside and, if wished, on the outside. If the container is a drum the inner soluble wall or coating could be powder coated onto the inside.
• the inner wall is co-extruded or co-injected in the same process as the formation of the outer shell of the container provided the material of the inner wall is -suitable for use in this process.
• the base of a blow moulded container is pinched at the base between the two halves of the mould to form a weld.
• the weld in the outer shell is insufficient to be air or fluid tight and in order to make the weld air or fluid tight a secondary welding operation is carried out.
• the inner wall or coating can be pushed back into the container while the base weld is formed along the pinch.
• An alterative method is to provide a plug which fits tightly or is welded within the opening left in the base.
• Such a plug and opening arrangement may be used as an access port for the application of an external pressure for evacuating the contents of the container. External pressure applied in this way has a similar effect as dispensation of the contents under vacuum from the neck of the container.
• the base can be left open to the atmosphere, so that when the inner wall or coating is removed, the outer shell is open to the atmosphere and the container is no longer suitable for its purpose.
• a process for manufacture of a container as described herein by co-extrusion or co-injection moulding techniques wherein the outer shell and the inner-most wall or coating are moulded in a single operation.
• a process for manufacture of a container as described herein wherein the container is manufactured by any conventional technique and the inner-most wall or coating is applied in a separate operation.
• the thickness of the inner wall or coating can be anything from a few angstroms (ie. one or two molecules thick) to a film which is sufficiently thick to stand alone, for example, to support the weight of the contents for the container and sufficiently thick to resist mechanical abrasion from a powder or granules.
• the films may range from 1 angstrom to 200 microns depending on the size of container.
• a small container such as a plastics bottle containing typically between 1 and 15 litres of a formulated chemical may have a inner wall or coating of from 1 angstrom to 60 microns or more preferably from 1 micron to 40 microns.
• the inner wall or coating is from 20 to 30 microns thick.
• the inner wall or coating may be between 1 micron and 200 microns, and is typically from 50 to 150 microns thick.
• the contents of the container may be, for example, aqueous based or non-aqueous based liquids or fluids, (for example, emulsifiable concentrates), gels, powders, granules and the like.
• aqueous based or non-aqueous based liquids or fluids for example, emulsifiable concentrates
• gels for example, powders, granules and the like.
• a non-aqueous based substance can be contained in :
• An aqueous based substance can be contained in : (a) a water soluble inner wall or coating, such that when empty the container is rinsed with water containing a trigger or catalyst which reacts with the inner wall or coating to remove it and the residues;
• insoluble, soluble and solulisable are intended to have their usual meanings. That is to say insoluble is substantially non-soluble in the given material or substance, soluble means soluble to the extent of dissolving the inner wall or coating into the wash liquid and the term solulisable is interchangeable with solublisable meaning that there is the potential for the inner wall or coating to dissolve into the wash liquid under the correct conditions.
• a particularly suitable wash liquid is water.
• the inner wall or coating of the container may be formed of a water-soluble substance such as polyvinyl alcohol (PVOH), polyvinyl pyrollidone (PVP), polyethylene oxide, polyethylenimine, acrylic based films, for example polyacrylic acid and polyacrylamide, high amylose cornstarch, or hydroxylated methyl, ethyl and propyl celluloses; or a suitable blend of such materials.
• PVOH coating materials are Mowiol (Registered Trademark of Hoechst), Polyox (Registered Trademark of Union Carbide Corporation) and Vinex (Trademark of Air Products and Chemicals, Inc.) resins.
• Mowiol can be thermoplastically processed with the addition of known plasticizers and a little water.
• Typical plasticizers are water and polyhydric alcohols such as glycerol, trimethylol propane, triethanolamine and ethoxylated phosphoric esters, diglycol, triglycol and neopentyl glvcol. Typically between 5 and 50% by weight of plasticizer is added.
• This mixture can be processed on conventional thermoplastics processing machines such as extrusion blow moulding, injection moulding and compression moulding machines.
• the water solubility of the film produced by this method can be varied depending on the degree of hydrolysis of the Mowiol grade used.
• Such films are biodegradable in aqueous solution, resistant to most organic solvents, resistant to mechanical stress, non-toxi ⁇ and have good weldability and bondability. There are few solvents apart from water for Mowiol.
• the grade of Mowiol, plasticizer concentration, extrusion temperature and residence time in the extrusion cylinder determine the solubility of an extruded Mowiol film in cold water.
• PVOH poly(alkyleneoxy)- acrylate
• Table 1 gives some general examples of solubilities of polyvinyl alcohol films of different thickness at 20°C :
• the solubility was determined by soaking a sample specimen in water and measuring the time to dissolve and disperse without agitation.
• Any of the films known in the art which have a dissolvability in an aqueous or non-aqueous wash liquid of 10 minutes or less with agitation of the rinse solution are particularly suitable for use in the present invention.
• the film is designed to dissolve in 3 minutes or less.
• the film could take up to 24 hours to dissolve without agitation.
• any of the films known in the art which have these properties and can be coated onto the inside of a container by any of the means described herein, are useful in the present invention.
• 3,892,905 discloses films which comprise a mixture of polyvinyl alcohol and polyvinyl pyrollidone. Some examples of the solubility in water of such films are given in Table 2 :
• a preferred method of triggering or catalysing the solulisation is to make the inner wall or coating ⁇ o3uble in a pH which is different to the pH of the contents of the container and to provide a trigger or catalyst with the container so that the pH of the rinse water or solvent can be manipulated at the spray site.
• the inner wall or coating may require additives to manipulate its solubility and render it sensitive, for example, to pH changes. Materials which are sensitive to pH in this manner are known, for example, US 4,469,728 discloses films which are insoluble in water and soluble in a basic medium.
• Homopolymeric or copolymeric acids are suitable for such a film, particularly an acid which itself is produced using an acrylic acid, methacrylic acid, crotonic acid or maleic acid and their anhydrides, for example, vinyl ether, acrylate or methacrylate.
• Suitable solutions for dissolving such films are borates, amines, for example triethanolamine, water -soluble carbonate, silicates, and secondary and tertiary phosphates, for example, triammonium phosphate.
• borates to dissolve the inner wall or coating would be particularly convenient since such solutions can be found in most households in the form of domestic laundry materials.
• Table 3 gives examples of solubility of such films in water, sodium hydroxide and triammonium phosphate.
• MAA maleic acid anhydride 1 insoluble
• the inner-most wall or coating may be formed of a water-insoluble material which is soluble in common organic solvents.
• polyvinyl acetate is a thermoplastic high polymer which is soluble in readily available low molecular weight axcohols such as methanol or ethanol, and polyvinyl ether which is soluble in for example, cyclohexanone or methylethylketone.
• chemicals can be provided which when mixed with water can be used in a spray which will dissolve a particular waterproof plastic, or such chemicals can be incorporated into the inner wall or coating of the container so that as soon as water or solvent touches it the plastic starts to degrade.
• Such materials are known, for example, Belland materials.
• the container may be provided with an amount of solvent or catalyst, for example in the cap which enables the user to provide the correct conditions for solulising the inner wall or coating.
• a further method of enabling an aqueous based substance to be contained in a water soluble inner wall or coating is to use surfactants in the contained substance to stabilise the wall or coating while the container is in use.
• the rinses may be disposed of by putting into the spray tank or using a portable detoxifier, or in the normal way.
• a container according to the present invention could be used for storage and distribution of a wide range of substances, for example, agrochemicals, including public health and household chemicals, fertilizers, organic chemicals, pharmaceuticals, coatings and finishings in the paints industry, and hazardous materials in general.
• a method of providing solvent resistance to a conventional thermoplastic container comprising applying an inner-most wall or coating to said container which is soluble only in aqueous wash liquid.
• Figure 1 is a cross-sectional view of a container in a mould
• Figure 2 is a cross-sectional view of the wall of a container
• Figure 3 is an additional cross-sectional view of the wall of a container
• Figure 4 is a cross-sectional view of the base of a container
• Figure 5 is an additional cross-sectional view of the base of a container;
• Figure 6 is a cross-sectional view of a vacuum dispensing container;
• Figure 7 is a cross-sectional view of a container containing a formulated chemical
• the container 1 is illustrated while inside the mould 4 in which the co-extrusion or co-injection blow moulding operation takes place.
• the mould 4 is formed in two halves 4a, 4b, and the layers of molten plastics materials are extruded or injected from tubes 5 placed one inside the other inside the mould 4. During extrusion or injection air is blown into the inner space 6 pushing out the layers to the shape of the mould 4.
• the container is formed with an outer shell 2 which is rigid or semi-rigid according to the users' requirements and to achieve this may be made up of layers of different plastics materials.
• the outer shell 2 has an inner wall or coating 3.
• Figures 2 and 3 demonstrate single and multi-layer outer shells respectively, with an inner wall or coating 3. Multi-layer outer shells may require an adhesive tie layer 7 between two layers of thermally incompatible materials.
• the inner wall 3 is a single layer of a solulisable material. When the extrusion or injection process is complete, the two halves of the mould 4, 4a are separated to reveal the container 1.
• Figure 4 shows the base of the container 1 in greater detail. Where the two halves of the outer shell 2 meet at the pinch 8 these are unable to weld because of the inner wall or coating 3. Thus when ejected from the mould 4, the container 1 is open at the base 9 of the outer shell 2.
• Figure 5 demonstrates a method of overcoming the inability to weld the base 9. In this case the inner wall or coating 3 is 'pushed' back into the outer shell 2 and the opening is welded as a separate operation, for example, by the application of heat or ultrasonic welding.
• Figure 6 illustrates a vacuum dispensing container 1 which has an inner collapsible bag 11.
• the outer shell 2 has several layers the innermost of which 10 is thermally incompatible to and not adhesive tie bonded to the rest.
• the inner wall or coating 3 is found on the inside of the inner collapsible bag.
• a suitable pump 12 for vacuum dispensing is provided on the neck 13 of the container 1.
• the inner collapsible bag 11 is drawn away from the outer shell 2 to ensure full evacuation of the container 1.
• the bag 11 itself could be formed from the inner wall or coating 3.
• Figure 7 illustrates a finished container 1 containing a formulation of a chemical 13.
• the container 1 is provided with a cap (not shown) and optionally with a seal 14 which is made of a suitable material such as plastics or metal foil.
• a 1 litre polyethylene terephthalat ⁇ bottle (formed by injection stretch blow moulding technique) was coated on the inner wall with 2 grams of Mowiol (Grade 383) PVOH.
• the coating was applied by putting a solution of Mowiol 383 in water in the bottle and swirling the solution around until a film covered the entire inner surface of the bottle.
• the bottle was dried in a air oven.
• the thickness of the resultant film was 20 microns thick.
• the bottle was filled with an 2.5% emulsion concentrate formulation of lambda-cyhalothrin (insecticide) and left in storage for 1 week at 40°C and 90% relative humidity and 1 week at 23°C and 50% relative humidity. After storage the contents were decanted.
• the solvent from the formulation was allowed to evaporate off the inner PVOH film surface and then the bottle was cut in half horizontally.
• the inner lining of PVOH film was separated from the polyethylene outer shell. The film had retained its flexibility.
• the detached PVOH film was immersed in a 1 litre glass beaker of tap water at approximately 20°C. Rapid dissolution of 75% of the film occurred within 30 seconds. The remainder of the film dissolved within a further 90 seconds with gentle agitation of the water.
• the containers are provided with an inner wall or coating of a suitable poly- vinyl alcohol.
• the examples serve to illustrate the invention and the containers described may suitably be provided with any of the coating materials mentioned herein.
• This example demonstrates a number of different plastics for containers made of a single material and provided with an inner wall or coating of polyvinyl alcohol.
• glycol modified polyethylene terephthalate (f) glycol modified polyethylene terephthalate (g) high density polyethylene
• This example demonstrates materials for co-extruded multilayer plastic containers provided with an inner wall or coating of polyvinyl alcohol.
• the 1st layer is the outermost layer.
• This example demonstrates the diversity of materials which can be used for containers and in each example the container is provided with a coating of polyvinyl alcohol.
• laminar technology concentrates such as nylon
• a coupling agent are blended with polyolefins, such as high density polyethylene to produce containers with a layered structure.
• polyolefins such as high density polyethylene
• This example demonstrates bag-in-box designs.
• the container is provided with a liner which is detached from the wall of the container and the liner is provided with the inner wall or coating or
• the inner wall or coating is detachable from the container and serves as the liner.
• Each of the following examples is provided with an inner coating of polyvinyl alcohol.
• This example demonstrates materials which can be used for drums provided with an inner wall or coating of polyvinyl alcohol.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Ceramic Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Details Of Rigid Or Semi-Rigid Containers (AREA)
• Containers Having Bodies Formed In One Piece (AREA)
• Glass Compositions (AREA)
• Laminated Bodies (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10666105

Family Applications (1)

Country Status (11)

Cited By (9)

Families Citing this family (5)

Citations (7)

Family Cites Families (12)

• 1989
  • 1989-11-10 GB GB898925472A patent/GB8925472D0/en active Pending
• 1990
  • 1990-10-25 IE IE385090A patent/IE903850A1/en unknown
  • 1990-10-26 GB GB9023338A patent/GB2237790B/en not_active Expired - Fee Related
  • 1990-10-29 EP EP90916084A patent/EP0500600A1/en not_active Ceased
  • 1990-10-29 WO PCT/GB1990/001654 patent/WO1991007240A1/en not_active Application Discontinuation
  • 1990-10-29 KR KR1019920701081A patent/KR920703222A/ko not_active Application Discontinuation
  • 1990-10-29 BR BR909007820A patent/BR9007820A/pt unknown
  • 1990-10-29 JP JP2514844A patent/JPH05503485A/ja active Pending
  • 1990-10-29 AU AU66304/90A patent/AU643470B2/en not_active Ceased
  • 1990-10-29 CA CA002069862A patent/CA2069862A1/en not_active Abandoned
  • 1990-10-31 ZA ZA908753A patent/ZA908753B/xx unknown
  • 1990-11-08 PT PT95828A patent/PT95828A/pt not_active Application Discontinuation

Patent Citations (7)

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