AU2016202943A1

AU2016202943A1 - Liquid Storage Container

Info

Publication number: AU2016202943A1
Application number: AU2016202943A
Authority: AU
Inventors: Daniel Carapellotti; Mario Nastri
Original assignee: Class Plastics Aust Pty Ltd
Current assignee: Class Plastics (aust) Pty Ltd
Priority date: 2015-05-08
Filing date: 2016-05-06
Publication date: 2016-11-24
Anticipated expiration: 2036-05-06
Also published as: AU2016202943B2

Abstract

Abstract A liquid storage container having top and bottom ends, and one or more side walls, which collectively define an internal space within which liquid can be stored; a neck 5 that is formed at the top end and defines an opening; and a handle having a first end that is connected to the neck, a second end that is connected to the top end. The neck has a first throughway that extends between the opening and the internal space, a second throughway in communication with the opening, and a bridging formation that extends across the neck and separates the first and second throughways. The handle is hollow so 10 as to form a passageway that extends between the second throughway and the internal space; and a web formation that joins the neck, the handle, and the top end. As liquid flows out of the internal space via the first throughway, air can flow into the internal space via the second throughway and the passageway. The web formation is provided with a frangible path that is arranged to fold and/or break preferentially upon application of an 15 impact force to the liquid storage container that deforms the handle and/or neck. Figure 1 to accompany Abstract. -1116 28 46 46 12 46 ... w IMMIN, mmmm I p Fiaure 1

Description

10095127 1 .Doc - 6/05/2016 - 1 -

LIQUID STORAGE CONTAINER

Field of the invention

The present invention relates to a liquid storage container, and to moulds for use in forming a liquid storage container.

Background

Plastic drums are commonly used for packaging a wide variety of liquids, as plastic materials are lightweight and can be relatively inert with respect to many liquids and chemicals. For this reason, it is known to transport and store liquids, including hazardous liquids, in drums that have a generally rectangular cubic shape, and a volume of between 10 and 40 litres. Using extrusion blow moulding techniques, plastic drums can be formed having a generally cubic shape with an integral handle and a major opening at the top end. In some instances, interfitting shapes are formed on the top and bottom ends, which facilitates stacking the plastic drums.

It is known that pouring liquid out through the major opening can be difficult when the major opening becomes choked by the exiting liquid and there is no opportunity for air to enter drum to compensate for the volume of the discharged liquid. Without a passage for air to enter the drum, the internal volume of the drum decreases with liquid discharge, and this can result in the side walls being drawn inwards. Internal stresses in the drum increase with the reduction in volume, until the drum eventually "sucks" air in through the major opening, which alleviates the stresses. Consequently, liquid flow is at least partially interrupted by the sucking, or "glugging" effect. The consequential varying flow rate of discharging liquid makes pouring liquids difficult, and has the potential to cause injury or damage in the case of hazardous liquids.

Some plastic drums are formed with a neck that provides an air passage that allows air to be drawn into the drum while simultaneously discharging liquid. While this is workable, such drums have a reduced structural integrity. 10095127_1 .Doc - 6/05/2016 -2-

Accordingly, it is desired to address the above, and/or at least provide a useful alternative.

Summary of the invention

The present invention provides a liquid storage container comprising: top and bottom ends, and one or more side walls, which collectively define an internal space within which liquid can be stored; a neck that is formed at the top end and defines an opening, the neck having a first throughway that extends between the opening and the internal space, a second throughway in communication with the opening, and a bridging formation that extends across the neck and separates the first and second throughways; a handle having a first end that is connected to the neck, a second end that is connected to the top end, wherein the handle is hollow so as to form a passageway that extends between the second throughway and the internal space; and a web formation that joins the neck, the handle, and the top end, wherein as liquid flows out of the internal space via the first throughway, air can flow into the internal space via the second throughway and the passageway, and wherein the web formation is provided with a frangible path that is arranged to fold and/or break preferentially upon application of an impact force to the liquid storage container that deforms the handle and/or neck.

The present invention also provides a liquid storage container comprising: top and bottom ends, and one or more side walls, which collectively define an internal space within which liquid can be stored; a neck that is formed at the top end and defines an opening, the neck having a first throughway that extends between the opening and the internal space, a second throughway in communication with the opening, and a bridging formation that extends across the neck and separates the first and second throughways; a handle having a first end that is connected to the neck, a second end that is connected to the top end, wherein the handle is hollow so as to form a passageway that extends between the second throughway and the internal space; and a web formation that joins the neck, the handle, and the top end, wherein: 10095127_1 .Doc - 6/05/2016 -3- the thickness of the web formation is varied such that the web formation includes at least one or more thick portions, and at least one thin portion, as liquid flows out of the internal space via the first throughway, air can flow into the internal space via the second throughway and the passageway, and an impact force applied to the liquid storage container that causes the handle and/or neck to deform can cause the web formation to fold within the at least one thin portion.

In certain embodiments, the web formation includes one or more thick portions that extend along at least some of the peripheral edges of the web formation. Preferably, the web formation includes a first thick portion that extends along the peripheral edges of the web formation, and the thin portion is spaced internally of some, or all of the peripheral edges of the web formation.

Alternatively or additionally, the web formation includes a second thick portion that is located centrally within the web formation. Preferably, the thin portion encircles the second thick portion.

In some embodiments, the web formation is joined to the portion of the external surface of the neck that forms the first and second throughways, and the bridging formation.

Preferably, the web formation is coplanar with a moulding seam formed in the liquid storage container during the moulding process.

In at least some embodiments, the liquid storage container defines a hand throughway that is surrounded by the handle, the web formation, and a portion of the top end.

In some embodiments, portions of the top and bottom ends have complementary interfitting shapes to facilitate stacking of a plurality of like liquid storage containers. 10095127_1 .Doc - 6/05/2016 -4-

The present invention also provides a set of moulding components for use in forming a liquid storage container as previously described, the set of moulds comprising: a pair of opposing moulds that are shaped to define external surfaces of the top and bottom ends, the side walls, the outer surface of the neck, the handle, and the web formation; and an air tube having an external surface that is shaped to define the inner surface of the neck, and includes a first projection that forms the internal surface of the first throughway, a second projection that forms the internal surface of the second throughway, and an intermediate portion that forms the internal surface of the bridging portion, wherein the air tube further comprises a primary air channel that extends from a first air inlet through the first projection to a first air outlet, and a secondary air channel that extends from a second air inlet through the second projection to a second air outlet.

The present invention also provides an air tube for use in blow moulding a liquid storage container as previously described, the air tube comprising: an external surface that is shaped to define the inner surface of the neck, and includes a first projection that forms the internal surface of the first throughway, a second projection that forms the internal surface of the second throughway, and an intermediate portion that forms the internal surface of the bridging portion; a primary air channel that extends from a first air inlet through the first projection to a first air outlet; and a secondary air channel that extends from a second air inlet through the second projection to a second air outlet.

In some embodiments, the maximum air flow through the secondary air channel is less than the maximum air flow through the primary air channel. Preferably, the diameter of the second air outlet is smaller than the diameter of the first air outlet.

The secondary air channel can include a rearward portion having a first diameter that extends from the second air inlet, and a forward portion having a second diameter that is less than the first diameter and that extends from the rearward portion to the second air outlet. 10095127_1 .Doc - 6/05/2016 -5-

In certain embodiments, the air tube includes a cooling liquid circuit that includes a liquid inlet, a liquid outlet, and an annular channel that surrounds a portion of the primary air channel. Preferably, at least part of the secondary air channel is positioned adjacent the annular channel, whereby heat from air passing through the secondary air channel is transferred to cooling liquid in the cooling liquid circuit. More preferably, a part of the forward portion of the secondary air channel is positioned adjacent the annular channel.

In certain embodiments, the forward portion of the secondary air channel includes: a first section that extends longitudinally with respect to the air tube from the rearward portion; a second section that extends radially inwardly from the first section; a third section that extends longitudinally with respect to the air tube from the second section; a fourth section that extends radially outwardly with respect to the air tube from the third section; and a fifth section that extends longitudinally with respect to the air tube from the fourth section and to the second air outlet.

Brief description of the drawings

In order that the invention may be more easily understood, embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1: is a perspective view of a plastic drum in accordance with a first embodiment of the present invention, together with a screw cap; Figure 2: is an enlarged view of region A in Figure 1;

Figure 3: is a side view of the plastic drum of Figure 1;

Figure 4: is a top view of the plastic drum of Figure 1;

Figure 5: is a partial perspective showing the neck and handle of the plastic drum of Figure 1;

Figure 6: is a partial cross section of the plastic drum, as viewed along the line X-X in Figure 4; -6-

Figure 7: Figure 8 Figure 9: Figure 10: Figure 11: Figure 12: Figure 13: Figure 14: Figure 15: Figure 16: 10095127_1 .Doc - 6/05/2016 is an enlarged view of region B in Figure 6; is a cross section of the plastic drum, as viewed along the line Y-Y in Figure 4; is an enlarged view of region C in Figure 8; is an enlarged schematic view of region D in Figure 9; is a schematic cross section of the plastic drum, as viewed along the line Z-Z in Figure 10; is a schematic view of a set of moulds in accordance with a second embodiment of the present invention, together with an air tube in accordance with a third embodiment of the present invention; is perspective view of the air tube in accordance with the third embodiment of the present invention and as shown in Figure 12; is an enlarged perspective view of the air outlet end of the air tube of Figure 13; is a partially transparent view of the air tube of Figure 13; and is a longitudinal cross section of the air tube of Figure 13.

Detailed description

Figures 1 to 11 show a liquid storage container, in accordance with a first embodiment of the present invention, and which in this embodiment is in the form of a plastic drum 10. The plastic drum 10 has a top end 12, a bottom end 14, and side walls 16, which collectively define an internal space 18 within which liquid can be stored. A neck 20 is formed at the top end 12 and defines an opening into the internal space 18. As will be appreciated by the person skilled in the art, the plastic drum may have other openings, for example in one of the side walls for a bung or tap. As shown most clearly in Figure 4, the neck 20 has a first throughway 22 that extends between the opening and the internal space 18. When pouring liquid out of the drum 10 from within the internal space 18, liquid will pass through first throughway 22 to exit the opening defined by the neck 20. The neck 20 also has external threads to enable a cap C to be secured onto the drum 10 to close the opening. 10095127_1 .Doc - 6/05/2016 -7-

The neck 20 also has a second throughway 24 that is in communication with the opening, and a bridging formation 26 that extends across the neck 20 and separates the first and second throughways 22, 24. The drum 10 has a handle 28 with a first end that is connected to the neck 20, a second end that is connected to the top end 12. A person can grasp the handle 28 to lift the drum 10. As shown in Figures 8 and 9, the handle 28 is hollow so as to form a passageway 30 that extends between the second throughway 24 and the internal space 18.

In instances where liquid being poured out (in other words, flowing out) through the opening in the neck 20 chokes the first throughway 22, air can readily flow into the internal space 18 via the second throughway 24 and the passageway 30. Consequently, liquid can be poured from the plastic drum 10 in a smooth, continuous flow, while air to replace the volume of the discharging liquid flows into the internal space 18 via the second throughway 24 and the passageway 30. Thus, the air flow through the passageway 30 obviates, or at least substantially reduces, the glugging effect while pouring liquid from within the plastic drum 10.

In the illustrated embodiment, the bridging formation 26 extends transversely across the neck 20 with respect to an elongate direction of the handle 28. Further, the second throughway 24 is disposed between the first throughway 22 and the handle 28.

As is most evident from Figures 6 to 10, in the illustrated embodiment the bridging formation 26 rises upwardly from the top end 12 to inhibit liquid flowing into the second throughway 24. In addition, the neck 20 is formed to a first side of the top end 12, and the handle 28 joins the top end 12 at the opposite side of the top end 12. Thus, when liquid is being poured from the plastic drum 10, liquid is inherently away from the exhaust end of the passageway 30.

The plastic drum 10 includes a web formation 32 that joins the neck 20, the handle 28, and the top end 12. The web formation 32 is provided with a frangible path that is arranged to fold and/or break preferentially upon application of an impact force to the liquid storage container 10 that deforms the handle 28 and/or neck 10. 10095127_1. Doc - 6/05/2016 -8-

The web formation 32 of this embodiment is shown in detail in Figures 9 to 11. The thickness of the web formation 32 is varied. In this embodiment, the web formation 32 includes a first thick portion 34 that extends along the peripheral edges of the web formation 32, a thin portion 36 is spaced internally of the peripheral edges of the web formation 32, and a second thick portion 38 that is located centrally within the web formation 32. As is evident from Figures 10 and 11, the thin portion 36 encircles the second thick portion 38. In addition, the first thick portion 34 encircles the thin portion 36. Thus, in this particular embodiment, the frangible path is provided by the thin portion 36.

An impact force that is applied to the plastic drum 10 on the handle 28 and/or neck 20 can cause the handle 28 and/or neck 20 to deform. If this impact force is of sufficient magnitude, the web formation 32 will fold and/or break within the at least one thin portion 36. This has the advantage of absorbing impact energy, and preventing the plastic drum 10 from splitting, which could release the liquid contents of the drum 10.

The web formation 32 is coplanar with a moulding seam that is formed in the plastic drum 10 during the moulding process.

The Australian Code for the Transport of Dangerous Goods by Road & Rail, Seventh edition, Version 7.3, August 2014, published by the National Transport Commission sets out requirements for the construction and testing of packages, including for plastic containers that are intended to contain liquids. One of these requirements is that such plastic drums must pass a drop test before being used for transport. The drop test procedure for plastic drums, such as the drum 10, requires that six drums be filled with liquid, closed with appropriate closures, and dropped onto a hard, horizontal surface from a height (of between 0.8 m and 1.8 m). The test requires three of the plastic drums of this type be dropped diagonally onto an edge (such as between the side walls and bottom end), and that the other three of the plastic drums be dropped onto the weakest part, such as the closure or the moulding seam. The test is only successfully passed if all six drums are dropped without rupturing.

Drop tests of plastic drums made in accordance with the first embodiment have successfully passed a drop test. 10095127_1 .Doc - 6/05/2016 -9-

As is evident from Figures 8 to 10, the web formation 32 joins to the external surface of the neck 20 that forms the first and second throughways 22, 24, and the bridging formation 26. The handle 28, the web formation 32, and a portion of the top end 12 together define a hand throughway 40.

As is particularly evident from Figures 3 and 8, portions of the top and bottom ends 12, 14 have complementary interfitting shapes to facilitate stacking of multiple plastic drums 10. To this end, the bottom end 14 has a concave section 42 that is to be received on a complementary convex section 44 formed in the top end 12 when plastic drums 10 are stacked. In addition, the top end 12 has a set of upwardly projecting studs 46 that are to be received in corresponding concave wells (not shown) formed in the bottom end 14 when plastic drums 10 are stacked. The handle 28, neck 20 and cap C (when screwed onto the neck 20) either fit within the concave section 42, or would locate beneath the bottom end of a plastic drum 10, when stacked.

Figure 12 shows a set of moulding components for use in forming a liquid storage container, such as the plastic drum 10. The set of moulds includes a pair of opposing moulds 60, 62 that are each shaped to define opposing halves of the external surfaces of the top and bottom ends 12, 14, the side walls 16, the outer surface of the neck 20, the handle 28, and the web formation 32. In addition, the set includes an air tube 64 having an external surface that is shaped to define the inner surface of the neck 20. The air tube 64, which is shown in further detail in Figures 13 to 16, has a first projection 66 that is shaped to define the internal surface of the first throughway 22, a second projection 68 that is shaped to define the internal surface of the second throughway 24, and an intermediate portion 70 that is shaped to define the internal surface of the bridging portion 26. A primary air channel 72 extends from a first air inlet 74 at the rear end of the air tube 64, through the first projection 66, and to a first air outlet 76. Similarly, a secondary air channel 78 extends from a second air inlet 80 on a side of the air tube 64, through the second projection 68, and to a second air outlet 82. 10095127_1 .Doc - 6/05/2016 -10-

The opposing moulds 60, 62 and air tube 64 are suitable for use in an extrusion blow moulding process that forms the plastic drum 10. In this process, a tube of mouldable plastics material is extruded, typically in downward direction, such that the "free" end of the extruded tube surrounds the air tube 64. The opposing moulds 60, 62 are then closed onto the circumferential wall of the extruded tube, with the air tube 64 positioned between the parts of the moulds 60, 62 that are to form the neck 20 in the plastic drum 10. Air is then injected into the internal space of the extruded tube via the primary and secondary air channels 72, 78. The injected air expands the extruded tube into the mould cavity to form the plastic drum 10. Once the formed drum is released from the moulds, excess material is torn away from the top and bottom ends 12, 14, and the plastic drum 10 is formed.

The maximum air flow through the secondary air channel 78 is less than the maximum air flow through the primary air channel 72, which ensures that sufficient material surrounds both the internal cavity 16, and the passageway 30 in the handle 28. To facilitate providing the appropriate air flows through the air channels, the diameter of the second air outlet 82 is smaller than the diameter of the first air outlet 76, as shown in Figures 14 and 16.

As shown in Figures 15 and 16, the secondary air channel 78 of this embodiment includes a rearward portion 84 that extends from the second air inlet 80, and a forward portion 86 that extends from the rearward portion 84 to the second air outlet 82. The diameter of the secondary air channel 78 in the rearward portion 84 is less than the diameter of the secondary air channel 78 in the forward portion 86.

The air tube 64 includes a cooling liquid circuit that has a liquid inlet 88, a liquid outlet 90, and an annular channel 92 that surrounds a portion of the primary air channel 72. As shown in Figures 15 and 16, part of the secondary air channel 78 is positioned adjacent the annular channel 92, such that heat from air passing through the secondary air channel 72 is transferred to cooling liquid in the cooling liquid circuit.

In this particular embodiment, the forward portion 86 of the secondary air channel 78 includes: 2016202943 06 May 2016 5 10095127 1 .Doc - 6/05/2016 -11 - • a first section 94 that extends longitudinally with respect to the air tube 64 from the rearward portion 84; • a second section 96 that extends radially inwardly from the first section 94; • a third section 98 that extends from the second section 96 in a longitudinal direction with respect to the air tube 64; • a fourth section 100 that extends radially outwardly from the third section 98; and • a fifth section 102 that extends from the fourth section 100 and to the second air outlet 82, and in a longitudinal direction with respect to the air tube 64.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated integer or step or group 15 of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

Claims

CLAIMS:

1. A liquid storage container comprising: top and bottom ends, and one or more side walls, which collectively define an internal space within which liquid can be stored; a neck that is formed at the top end and defines an opening, the neck having a first throughway that extends between the opening and the internal space, a second throughway in communication with the opening, and a bridging formation that extends across the neck and separates the first and second throughways; a handle having a first end that is connected to the neck, a second end that is connected to the top end, wherein the handle is hollow so as to form a passageway that extends between the second throughway and the internal space; and a web formation that joins the neck, the handle, and the top end, wherein as liquid flows out of the internal space via the first throughway, air can flow into the internal space via the second throughway and the passageway, and wherein the web formation is provided with a frangible path that is arranged to fold and/or break preferentially upon application of an impact force to the liquid storage container that deforms the handle and/or neck.
2. A liquid storage container comprising: top and bottom ends, and one or more side walls, which collectively define an internal space within which liquid can be stored; a neck that is formed at the top end and defines an opening, the neck having a first throughway that extends between the opening and the internal space, a second throughway in communication with the opening, and a bridging formation that extends across the neck and separates the first and second throughways; a handle having a first end that is connected to the neck, a second end that is connected to the top end, wherein the handle is hollow so as to form a passageway that extends between the second throughway and the internal space; and a web formation that joins the neck, the handle, and the top end, wherein: the thickness of the web formation is varied such that the web formation includes at least one or more thick portions, and at least one thin portion, as liquid flows out of the internal space via the first throughway, air can flow into the internal space via the second throughway and the passageway, and an impact force applied to the liquid storage container that causes the handle and/or neck to deform can cause the web formation to fold within the at least one thin portion.
3. A liquid storage container according to claim 2, wherein the web formation includes one or more thick portions that extend along at least some of the peripheral edges of the web formation.
4. A liquid storage container according to either claim 2 or 3, wherein the web formation includes a first thick portion that extends along the peripheral edges of the web formation, and the thin portion is spaced internally of the peripheral edges of the web formation.
5. A liquid storage container according to any one of claims 2 to 4, wherein the web formation includes a second thick portion that is located centrally within the web formation.
6. A liquid storage container according to any one of claims 2 to 5, wherein the thin portion encircles the second thick portion.
7. A liquid storage container according to any one of claims 1 to 6, wherein the web formation joins to the external surface of the neck that forms the first and second throughways, and the bridging formation.
8. A liquid storage container according to any one of claims 1 to 7, wherein the web formation is coplanar with a moulding seam formed in the liquid storage container during the moulding process.
9. A liquid storage container according to any one of claims 1 to 8, wherein the liquid storage container defines a hand throughway that is surrounded by the handle, the web formation, and a portion of the top end.
10. An air tube for use in blow moulding a liquid storage container according to any one of claims 1 to 9, the air tube comprising: an external surface that is shaped to define the inner surface of the neck, and includes a first projection that forms the internal surface of the first throughway, a second projection that forms the internal surface of the second throughway, and an intermediate portion that forms the internal surface of the bridging portion; a primary air channel that extends from a first air inlet through the first projection to a first air outlet; and a secondary air channel that extends from a second air inlet through the second projection to a second air outlet.
11. An air tube according to claim 10, wherein the maximum air flow through the secondary air channel is less than the maximum air flow through the primary air channel.
12. An air tube according to either claim 10 or 11, wherein the diameter of the second air outlet is smaller than the diameter of the first air outlet.
13. An air tube according to any one of claims 10 to 12, wherein the secondary air channel includes a rearward portion having a first diameter that extends from the second air inlet, and a forward portion having a second diameter that is less than the first diameter and that extends from the rearward portion to the second air outlet.
14. An air tube according to any one of claims 10 to 13, further comprising a cooling liquid circuit that includes a liquid inlet, a liquid outlet, and an annular channel that surrounds a portion of the primary air channel.
15. An air tube according to claim 14, wherein at least part of the secondary air channel is positioned adjacent the annular channel, whereby heat from air passing through the secondary air channel is transferred to cooling liquid in the cooling liquid circuit.
16. An air tube according to either claim 14 or 15, wherein a part of the forward portion of the secondary air channel is positioned adjacent the annular channel.
17. An air tube according to any one of claims 13 to 14, wherein the forward portion of the secondary air channel includes: a first section that extends longitudinally with respect to the air tube from the rearward portion; a second section that extends radially inwardly from the first section; a third section that extends longitudinally with respect to the air tube from the second section; a fourth section that extends radially outwardly with respect to the air tube from the third section; and a fifth section that extends longitudinally with respect to the air tube from the fourth section and to the second air outlet.
18. A set of moulding components for use in forming a liquid storage container according to any one of claims 1 to 9, the set of moulds comprising: a pair of opposing moulds that are shaped to define external surfaces of the top and bottom ends, the side walls, the outer surface of the neck, the handle, and the web formation; and an air tube according to any one of claims 10 to 17.