US20070272711A1

US20070272711A1 - Squeezable Dispensing Container

Info

Publication number: US20070272711A1
Application number: US10/570,468
Authority: US
Inventors: Andrew MacLeod; Louis Massari
Original assignee: Glaxo Group Ltd
Current assignee: Glaxo Group Ltd
Priority date: 2003-09-05
Filing date: 2004-09-02
Publication date: 2007-11-29
Also published as: JP2007504062A; AR047940A1; TW200522890A; WO2005023660A1; GB0320849D0

Abstract

A container containing an extrudable fluid material content, the container having a wall made of an elastomer material, an extrusion nozzle for the fluid material, being elastically deformable inwardly to extrude the fluid material, being sufficiently resilient to return to its original shape and volume on removal of said external pressure, and being sufficiently robust that it can retain its shape whilst resting on a hard surface. A preferred product contains toothpaste and is substantially spherical.

Description

This invention relates to a novel product comprising a novel container containing an extrudable fluid material content in particular an extrudable dentifrice e.g. toothpaste formulation.
Toothpastes are well known materials, typically comprising a viscous fluid composition which can be extruded onto a toothbrush for use. Alternative dentifrice compositions are also known e.g. extrudable gels.
Typically extrudable dentifrice formulations are provided contained in collapsible tubes for example made from a thin flexible metal such as aluminium alloy, flexible plastics material or flexible laminate, from which the toothpaste content can be extruded by squeezing the tube to thereby expel the content through a nozzle unto an adjacent toothbrush.
Such tubes can look quite unattractive when they are in a partly emptied state and to address this problem an alternative dispenser system is provided by toothpaste pumps which do not steadily collapse as the toothpaste is extruded and retain their outward appearance. In a common type of such pumps such as that disclosed in GB-A-2,152,152 (Realex Corporation) a so called “follower piston” moves internally in the extruding direction along the pump cylinder as the internal volume decreases on expulsion of dentifrice. Other pump constructions are known e.g. from U.S. Pat. No. 5,234,688 (Colgate-Palmolive), WO-A-93/14021, U.S. Pat. No. 5,332,121 and U.S. Pat. No. 3,838,796 in which a flexible collapsible bag containing the dentifrice is enclosed within a semi-rigid outer case so that the bag collapses out of sight within the outer casing as the contents are extruded.
Other types of resiliently collapsible dispensing containers for extrudible materials are known for specific applications such as the multilayered wall container for cyanoacrylate adhesives disclosed in U.S. Pat. No. 6,506,464 (Loctite). Bellows structured containers are also known, e.g. U.S. Pat. No. 4,898,306 (Reseal International), U.S. Pat. No. 3,580,427, U.S. Pat. No. 3,395,836, U.S. Pat. No. 4,516,697, WO-A-00/3923, WO-A-97/29020, WO-A-96/22919 among others. Various other collapsible containers are known from for example US-A-2003/0010844, U.S. Pat. No. 5,649,648, GB-A-854,879 and GB-A-390,816.
Such pump and bellows etc. type containers introduce mechanical complexity and hence cost into a product and therefore there remains a need for a simple, cheap container for extrudible dentifrices that has a externally attractive shape which it retains during use or storage as its contents are progressively extruded. Other objects of the invention will be apparent from the following description.
According to this invention a novel product comprises:
a container containing an extrudable viscous fluid material content,
the container being bounded by a container wall made at least partly of an elastomer material,
the container having an extrusion nozzle through which the extrudable viscous fluid material content can be dispensed for use,
the container wall being elastically deformable inwardly by applied external hand pressure to thereby reduce the internal volume of the container,
the container wall being sufficiently resilient to return to its original shape and volume on removal of said external pressure,
the container wall being sufficiently robust that it can retain its shape whilst resting on a hard surface without deformation under the weight of the container wall and the said contents.
The extrudable viscous fluid material content may for example be a dentifrice composition e.g. a toothpaste or dentrifice gel or dentrifice cream of a generally conventional formulation.
The container wall is preferably made entirely of the said elastomer material. Such a container may be made using an otherwise conventional moulding process. For example the container wall may be blow-moulded, i.e. a process in which an elastomer material pre-form is first made and then expanded within a mould cavity by the introduction of a pressurised gas. Alternatively the container wall may be injection moulded in the form of two or more part container walls which are then fastened together for example by welding, e.g. thermal or ultrasonic welding. Suitable processes are for example known from the art of manufacturing toy balls of rubbery materials.
The extrusion nozzle may comprise a part integrally made with the container wall. For example the container wall may be formed with an integral tubular conduit extending outwardly from the container wall, communicating between the interior and the exterior of the container and along which the content can be extruded toward an exit opening at the distal end of the conduit.
Preferably the nozzle is provided with an openable closure. Such a closure is preferably made of a hard plastics material for example as well known in the toothpaste tube closure art. Preferably the container wall and/or nozzle e.g. the tubular conduit are provided with engagement means to enable such a closure to be connected thereto. For example the tubular conduit may be provided with, e.g. integrally moulded in the shape of, a screw thread which can mate with a corresponding screw thread on the closure. Part of the container wall adjacent to the conduit may be profiled to receive the closure when engaged with the body or to facilitate the seating of the closure thereon.
Such a container body is believed to be novel and comprises a further aspect of this invention, viz. a container bounded by a container wall made at least partly of an elastomer material, the container having an extrusion nozzle through which the extrudable viscous fluid material content can be dispensed for use, the container wall being elastically deformable inwardly by applied external hand pressure to thereby reduce the internal volume of the container, and being sufficiently resilient to return to its original shape and volume on removal of said external pressure, the container wall being sufficiently robust that it can retain its shape whilst resting on a hard surface without deformation under the weight of the container wall, the extrusion nozzle and/or an adjacent external part of the container wall being adapted for the engagement and/or seating of the closure on the container wall.
The making of the container wall suitably elastically deformable inwardly by applied external hand pressure to thereby reduce the internal volume of the container, and resilient to return to its original shape and volume on removal of the external pressure, whilst at the same time sufficiently robust that it can retain its shape whilst resting on a hard surface without deformation under the weight of the container wall and the said contents is primarily a matter of selection of a suitable elastomer material and suitable wall thickness.
By “elastomer” is meant a material which is capable of both elastic compression and expansion and which returns to its original shape preferably immediately or quickly on removal of compressive pressure or elastic tension. The material may be natural or synthetic and is preferably thermoplastic to facilitate moulding and any welding.
For use with a dentifrice composition the elastomer must of course be approved for use with e.g. food products, and must be compatible with the ingredients of the composition, i.e. being inert relative thereto such that it does not significantly react with any ingredient, or significantly absorb any ingredient, or significantly allow any ingredient to pass through the elastomer, nor should the elastomer contain any substance which might contaminate the content in contact with the elastomer.
The container wall may be multi-layered, for example comprising an inner layer in contact with the content and a relatively outer layer. Such an inner layer may for example comprise a material selected for suitability for contact with the content, e.g. a thin protective layer. Additionally or alternatively a multi-layered container wall may comprise an outermost layer and a relatively inner layer, for example the outermost layer may comprise a material selected for suitability for contact with the outside environment, e.g. an outer protective layer e.g. resistant to staining or ingress of atmospheric moisture or air etc., being suitable for printing or otherwise labeling, or a layer having physical properties of texture or appearance that render it attractive to the user.
For example a multi-layered elastomer container wall may be made by the so called “sandwich moulding” process also called the “skin/core” method, in which an elastomer material part is formed by an injection moulding process in which at least two materials being respectively the materials of an outer and inner layer, i.e. the “skin” and “core” are injected into a mould cavity simultaneously or successively in such a way that the injected polymer is in the form of an inner core and an outer skin. This process is known from the technical literature. Suitable processes and moulding equipment for such a sandwich moulding process are for example disclosed in U.S. Pat. No. 5,789,033 and U.S. Pat. No. 5,798,069, the contents of which are incorporated herein by way of reference.
In sandwich moulding, a core is introduced into an outer skin component. This process takes place in two or three stages. First the material of the outer skin is injected into the mould cavity to partially fill the cavity with a mass of the material of the outer skin, and then the core component is injected into the mass of introduced skin material to fill and “inflate” the skin material. To finish off, a closure can be produced with the first, i.e. the skin component near the sprue (the point in the cavity at which the materials are injected). This prevents the core material remaining on the surface and at the same time cleans the system for the next shot of polymer to be injected into the mould. U.S. Pat. No. 5,789,033 and U.S. Pat. No. 5,798,069 disclose sandwich moulding processes in which opposed gating injection is used, i.e. the core and skin materials are injected into the mould cavity via respective separate injection nozzles. Sandwich moulding processes are also known in which a single nozzle is used to inject both skin and core materials. Hot runner injection moulding equipment is generally preferred for the sandwich moulding process.
Suitable injection moulding machinery for sandwich injection moulding is available from inter alia Mannesman Demag (Germany). The operating conditions can be determined by practice in the art.
Multi-layered containers can also be made by co-extrusion blow moulding, in which two or more materials are simultaneously extruded to form a tubular parison, then blown into the final container shape. The process is widely practised for the manufacture of food containers where, for example, the contents are sensitive to oxygen and a high barrier polymer is used, or where recycled plastic is used as the core of a three layer wall. The necessary machinery, and principles of selecting polymers for mutual adhesion, are well known to those in the industry.
Suitable elastomer materials for use as the material of the container wall polymer include thermoplastic elastomer (“TPE”) materials, for example compounds based on styrenic block copolymers such as styrene-ethylene-butadiene-styrene (SEBS) copolymers, e.g. the materials sold under the name Thermolast-K™ (available from Gummiwerk Kraiburg GmbH & Co, Germany) e.g. Thermolast-K™ TC7CHT, Thermolast-K™ TA8AAC, Thermolast-K™ 8692-97, Thermolast-K™ 8548-20 and Thermolast-K™ 8706-34; PTS Thermoflex 75 (available from Plastic Technologie Service, DE) having a modulus of elasticity (ISO 178) of 100 MPa and a hardness (ISO 868) of 80 Shore A; and the Evoprene™ materials available from the AlphaGary division of Rockwood Specialties (USA); thermoplastic vulcanisates including polyblends based on EPDM/PP such as the material Sarlink™ (available from DSM Thermoplastic Elastomers NL) and the dynamically vulcanised material Santoprene™ (available from Advanced Elastomer Systems, Ohio); thermoplastic polyurethanes such as Desmopan™ (available from Bayer AG, Germany); thermoplastic copolyesters such as Hytrel™ (available from Du Pont De Nemours, USA); polyether-amide elastomers, such as Pebax™ (available from Atofina, France); and melt processable rubbers, such as Alcryn (available from Advanced Polymer Alloys, USA).
Suitable elastomers have a surface which is smooth to the touch. Preferably the elastomer material has a modulus of elasticity less than 500 Mpa, preferably less than about 300 Mpa. Suitably the elastomer material has a hardness between about 30 Shore A to 75 Shore D, inclusive.
Thermolast-K™ TA8AAC has the advantage that it is adapted for blowmoulding and is easily paintable and printable. Thermolast-K™ TC7CHT has the advantage that it is adapted for injection moulding and blowmoulding.
Selection of a suitable container wall thickness is dependant upon both the elastomer material used, and the dimensions and the shape of the container. Although normally for dentifrice compositions typically the above-described prior art tubular containers have been used, the container of the invention, excluding any above mentioned tubular conduit, is preferably substantially spherical or ellipsoidal. For example a substantially spherical container may have X (horizontal):Y (horizontal perpendicular to X):Z (vertical perpendicular to X and Y) axis dimension ratios in the range 1-1.5:1-1.5:1-1.5. For example a substantially ellipsoidal container may have major:minor:minor axis dimension ratios in the range 2-1.5:1-1.5:1-1.5. For a typical dentifrice container of this invention of a substantially spherical shape, made of the above-mentioned elastomer, with a substantially spherical or ellipsoidal shape to enclose ca. 75-150 ml, a wall thickness of 1-3 mm, preferably 1.5-3 mm appears to be suitable.
The container of the invention is preferably shaped externally so that it can rest stable on a flat surface e.g. a bathroom surface. For this purpose, although of a substantially spherical or ellipsoidal shape the container may be externally provided with feet or a flat bottom.
The extrudible viscous material content of the product of the invention is typically a dentifrice e.g. toothpaste material. Such materials are well known in the art, for example from WO-A-95/17158.
The construction and use of the invention will now be described by way of non-limiting example only with reference to FIGS. 1, 2 and 3.
FIG. 1 shows a longitudinal section through a product of this invention.
FIG. 2 shows an external view of a product of the invention.
FIG. 3 shows an external view of another product of the invention.
FIG. 4 shows an external view of another product of the invention.
FIG. 5 shows the product of the invention in use.
Referring to FIGS. 1 and 2, a product 10 overall comprises a container bounded by a container wall 11. The container wall 11 is substantially spherical, having a spherical radius ca. 3 cm, i.e. enclosing ca. 100-120 ml. The container contains an extrudable fluid material 12, being a toothpaste material of a generally conventional formulation. Part 13 of the container wall 11 is integrally formed as an integral tubular conduit extending outwardly from the container wall 11, communicating between the interior and the exterior of the container and having an exit opening 14 at its end distal from the interior of the container. This conduit 13 comprises an extrusion nozzle along which the material 12 may be extruded. For convenient extrusion of the said toothpaste material 12 with a viscosity typical of such materials a conduit length of ca. 0.5-1.5 cm e.g. ca. 1 cm and a cross section of 0.3-0.8 cm, e.g. ca. 0.5 cm is found suitable.
The conduit 13 is formed externally with screw thread 15, with which is engagable an openable closure 16 generally, comprising a lower part 17 having a corresponding screw thread, and a generally conventional flip-cap 18 hinged at 19 to the lower part 17. This closure is made of a hard plastics material.
To enable the product 10 to rest stable on a flat surface (not shown), in the embodiment seen in FIG. 2 the container wall 11 is formed with a flat bottom 110 on which it may stand.
The container wall 11 and conduit 13 are integrally made of an elastomer material. A suitable elastomer material is Thermolast-K™ TA8AAC or Thermolast-K™ TC7CHT. To provide a container wall which is both elastically deformable inwardly by applied external hand pressure to extrude the material 12 through conduit 13 and sufficiently resilient to return to its original shape and volume on removal of external pressure, whilst being sufficiently robust that it can retain its shape whilst resting on a hard surface without deformation under the weight of the container wall and its contents 12, a wall 11 thickness of ca. 1-2 mm is found to be suitable. The container wall 11 is made using an otherwise conventional blow- or injection-moulding process.
Referring to FIG. 3 an alternative construction of the product of this invention is shown, in which the lower part of the container wall 11 may be formed with integral bulges 111 acting as feet for the container wall 11 to stand upon. Four such bulges 111 are shown. A minimum of three appears to be advisable for stability, but there may be more than four bulges 111.
Referring to FIG. 4 a modification of the container wall 11 of FIG. 3 is shown in which the conduit 13 is wider in cross section than that of FIG. 3, i.e. ca. 25 mm in internal cross section to facilitate extrusion of the toothpaste contents, and provided with screw thread 15 for a correspondingly larger cap 16 (not shown).
Referring to FIG. 5 the product 10 is shown in use. Conveniently the product 10 is inverted so opening 14 is downward, closure 18 is flipped open, remaining open by friction or a snap action, and by applying hand pressure in the direction of the arrows toothpaste content 12 is extruded out onto the bristles 21 of a toothbrush 20. When sufficient toothpaste 12 has been applied to the bristles 21 the pressure is released, allowing the wall 11 to return to its initial spherical form, and closure 18 is shut again. The product 10 may then be stored e.g. on a bathroom shelf standing on its feet 111.

Claims

1. A product comprising:

a container containing an extrudable viscous fluid material content,

the container being bounded by a container wall made at least partly of an elastomer material,

the container having an extrusion nozzle through which the extrudable viscous fluid material content can be dispensed for use,

the container wall being elastically deformable inwardly by applied external hand pressure to thereby reduce the internal volume of the container,

the container wall being sufficiently resilient to return to its original shape and volume on removal of said external pressure,

the container wall being sufficiently robust that it can retain its shape whilst resting on a hard surface without deformation under the weight of the container wall and the said contents.

2. A product according to claim 1 wherein the extrudable viscous fluid material content is a dentifrice composition.

3. A product according to claim 1 wherein the extrusion nozzle comprises a part integrally made with the container wall.

4. A product according to claim 4 wherein the container wall is formed with an integral tubular conduit extending outwardly from the container wall, communicating between the interior and the exterior of the container and along which the content can be extruded toward an exit opening at the distal end of the conduit.

5. A product according to claim 1 wherein the container wall and/or nozzle are provided with engagement means to enable a closure to be connected thereto.

6. A product according to claim 1 wherein the container wall is multi-layered comprising an inner layer in contact with the content and a relatively outer layer.

7. A product according to claim 6 wherein the container wall is made by co-extrusion blow moulding, in which two or more materials are simultaneously extruded to form a tubular parison, which is then blown into the final container shape.

8. A product according to claim 1 wherein the elastomer material of the container wall is a thermoplastic elastomer material.

9. A product according to claim 8 wherein the thermoplastic elastomer material is a compound based on a styrenic block copolymer and selected from Thermolast-K™, Thermolast-K™ TC7CHT, Thermolast-K™ TA8AAC, Thermolast-K™ 8692-97, Thermolast-K™ 8548-20, Thermolast-K™ 8706-34, PTS Thermoflex 75 and Evoprene™.

10. A product according to claim 8 wherein the thermoplastic elastomer material is a thermoplastic vulcanisate selected from Sarlink™ and Santoprene™.

11. A product according to claim 1 wherein the elastomer material has a modulus of elasticity less than 500 Mpa.

12. A product according to claim 11 wherein the elastomer material has a modulus of elasticity less than 300 Mpa.

13. A product according to claim 1 wherein the elastomer material has a hardness between about 30 Shore A to 75 Shore D, inclusive.

14. A product according to claim 1 wherein the container is substantially spherical or ellipsoidal.

15. A product according to claim 14 wherein the container has X:Y:Z axis dimension ratios in the range 1-1.5:1-1.5:1-1.5.

16. A product according to claim 14 wherein the container is substantially ellipsoidal with major:minor:minor axis dimension ratios in the range 2-1.5:1-1.5:1-1.5.

17. A product according to claim 1 with a substantially spherical or ellipsoidal shape to enclose ca. 75-150 ml, and a wall thickness of 1-3 mm.

18. A product according to claim 1 wherein the container wall is integrally formed into plural feet to facilitate the product resting stable on a flat surface.