WO2001040140A1

WO2001040140A1 - Composting container

Info

Publication number: WO2001040140A1
Application number: PCT/AU2000/001491
Authority: WO
Inventors: Michael Joseph Morrison
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-12-03
Filing date: 2000-12-01
Publication date: 2001-06-07
Anticipated expiration: 2002-06-03
Also published as: AUPQ446099A0

Abstract

A composting container is disclosed which contain a container body (2) which has a closure lid (13) and sidewalls (3) which define an internal space (7) for receiving material to be composted. An aerator (18) is located in the container for supplying of air into the composting material and a leachate chamber (16) is provided in the bottom of the container (2). The lid (13) has a domed configuration and a periphery which is arranged outwardly of the inner periphery of the container (2) so that condensate which collects on the underside of lid (13) drains to a position outside of the bin (7) and is not returned onto the composting material to form a gas impervious layer on the composting material. The prevention of the gas impervious layer by moisture which drips onto the composting material (50) may also be prevented by a water pervious blanket layer (52) which enables condensate which drips back into the composting material to flow into the composting material (50) without forming a layer on the composting material (50). Thus, air is able to flow and pass up through the composting material (50) to cause aerobic decomposition of the composting material.

Description

COMPOSTING CONTAINER

The present invention is directed to a composting container. It is common practice for households to compost food scraps and vegetative matter in a composting bin. Such bins typically have rigid side walls, an open base and open top, and a lid for the opening. The bin is placed on the ground so that the ground forms the base. During the composting process, heat is generated causing condensation on the underside of the lid which falls back onto the contents of the bin. This has been thought to be desirable as it minimises moisture loss from the container. Moisture is a necessary element for aerobic decomposition. Λ problem with such composting bins is that the supply of air to the composting material can be inadequate to maintain aerobic decomposition, especially if the lid is closed to stop moisture loss from the bin. The applicant has recognised that this problem is exacerbated if condensation that collects on the underside of the lid can fall back to the decomposing material below. If a layer of moisture forms on the surface of the decomposing material, this layer can act as a barrier to rising gases and thereby further restrict airflow. The invention, in a first aspect provides a composting container, including: a container body having an opening and defining an internal space so that material to be composted can be placed in the container through the opening and deposited in the internal space; a closure coupled to the container body and movable from an open position allowing access to the internal space through the opening and a closed position in which the opening is closed by the closure; an air inlet in the container body for allowing air to enter the container body and flow through material deposited in the internal space to facilitate aerobic decomposition of that material; means for preventing a build up of a layer of water on the surface of the composting material which would prevent flow of air through the composting material and prevent aerobic decomposition of the material.

As previously explained the applicant has recognised that if a layer of moisture or water forms on the surface of the decomposing material, the layer of water provides an impermeable barrier which prevents air and other gases from flowing up through the composting material and thereby hampers proper aerobic decomposition of the material in the compost container. The applicant has found that the build up of moisture primarily occurs due to condensation collecting on the closure of the container and dripping back onto the layer of composting material. Because of the high fibrous nature of the composting material, the surface tension of the water which drips back down onto the top of the composting material is sufficient to hold the water in place on top of the composting layer thereby forming the impermeable water layer barrier which prevents flow of air and gases through the composting material. The present invention therefore prevents the build up of the water layer thereby enabling the free flow of gases through the composting material so that proper aerobic decomposition of the material takes place to form compost within the compost container.

In one embodiment of the invention the preventing means comprises a configured closure so that condensate that collects on the underside of the closure is directed to a predetermined location so that it does not drip back onto the top of the composting material to enable the impervious water layer to be formed.

In another embodiment of the invention the preventing means comprises a pervious blanket layer member for location on the composting material, the pervious blanket layer member receiving any condensate which drips from the closure lid, the pervious nature of the layer material being such that the moisture which collects on the layer is able to pass through the layer without collecting as a water barrier layer and then trickle through the composting material. This embodiment of the invention has the advantage that the moisture which leaves the composting material is able to be returned to the composting material thereby obtaining a higher moisture level within the composting material.

In the preferred embodiment of the invention the air inlet includes at least one aerator located in internal space, the aerator communicating with the air inlet so that air can flow through the inlet and into the aerator and then be distributed through the material within the internal space. In the embodiment which includes the configured closure, the closure is configured so that the closure slopes towards the perimeter of the closure, the perimeter of the closure being located outwardly of the container body so that the water drains to a location outside the container body and does not fall onto the composting material.

In other embodiments the closure may be configured so that the water drains to a predetermined point and it is then collected and conveyed to a location outward of the container. In still further embodiments the water can be collected in a reservoir located in the container body, the reservoir being capable of being emptied from time to time.

The invention also provides a composting container including: a container body having an opening and defining an internal space; one or more aerators located in said internal space; and a closure for said opening, said closure being configured so that condensate that collects on the underside of the closure is directed to an area that is external to and/or separated from said internal space thereby minimising return of the condensate to the internal space. In one embodiment, at least part of the underside of the closure slopes towards the perimeter of the closure so that condensate runs off towards the perimeter. This sloping surface can have a concave shape. It is further preferred that the closure is a dome-shaped lid. In this embodiment, it is also preferred that the perimeter of the closure extends beyond the opening of the container when the closure is in place to close the opening. A rim may also be located around the opening to the container. The rim assists in preventing condensate that runs to the perimeter of the closure from entering the container through the opening.

It is further preferred that a condensate collecting means be provided to collect the condensate. This may be a channel located adjacent the opening of the container into which condensate can flow. In an alternative embodiment, at least part of the underside of the closure has a convex shape. In this embodiment a condensate collecting means is provided, preferably below the closure. This means defines the area separated from the internal space. Condensate that collects on the underside of the closure runs to the apex of the convex shape and then drops onto the condensate collecting means. The collecting means may be a conduit that extends to the exterior of the container so as to channel condensate to the outside of the container. The convex shape may be formed by a depression in the upper side of the closure. This depression can also be utilised to collect rainwater. In this case a spout may be located at the rear of the closure so that when the closure is tilted, water in the depression is drained out through the spout. It is preferred that the closure be hingedly attached to the container. It is further preferred that the closure be removable so that it can be used as a separate carrying vessel.

The provision of handles is also advantageous to assist the user to open and close the closure and to also carry the closure when it is separated from the container. The condensate that is removed from the container can be reused for a number of purposes, such as irrigation or as drinking water for livestock.

Accordingly, a separate container may be provided into which the condensate is discharged and stored. To assist the flow of air through the container, one or more apertures may be located in the closure. These are preferably 0.5-1.5 mm in diameter and up to five such apertures may be located in the closure.

The closure may be formed from a plastic material which is UV stabilised. Suitable plastics materials include base polymer-polypropylene, high density polyethylene or low density polyethylene. The closure may be manufactured by injection moulding, blow moulding, rotational moulding, vacuum moulding or fabrication and welding of the plastics material.

Preferably the aerator has a body having an internal air chamber and one or more apertures located in the body to permit air inside the air chamber to pass out and into the container. Thus, the aerator assists in the circulation of air through the composting mass placed in the container.

The aerator may have various configurations, and in one embodiment has a column shape. Preferably the upper end of the column is closed so as to prevent the entry of compost material into the aerator. However, apertures of a small diameter may be located in this upper end to assist the airflow.

It is preferred to locate the aerator at or near the centre of the container so that it extends vertically upward through the internal space of the container and is completely surrounded by composting material when placed in the container. The aerator may be constructed using a mesh material, such as a wire mesh which is bent into the shape of a column. The openings in the mesh provide the apertures to the interior of the aerator. In another embodiment, the aerator is formed from one or more interconnecting units, each unit including: an upper end, a lower end, an internal air chamber and an opening at each upper and lower ends to said air chamber; one or more projections extending outward from a side of said unit for contacting material falling onto said unit; and one or more apertures to permit air inside said air chamber to pass through said aerator. The one or more projections contact compost material falling onto said unit to minimise the build-up of this material around the unit. Preferably these projections are angled so that they extend downward and outward from the unit and thereby act to deflect material away from the unit. In a further preferred embodiment these deflecting projections are located at or adjacent the upper end of the unit. There may be present only one such angled projection on each unit, which extends around the unit to form a collar. Alternatively, a series of arms may be located around the unit, each arm extending downwardly and outwardly from the upper end of the unit to provide a number of angled surfaces . The arms may form a star or cross pattern when viewed from above.

Three to six arms are preferably present . Preferably, the angled surface or surfaces extend to 50 to 100 mm out from the side of the unit.

The outwardly extending projections assist in minimising the compaction of material around each unit as an air gap may form below each projection. It is preferred that the one or more apertures are located beneath the outwardly extending projections so as to minimise the possibility that downwardly falling material enters the aerator through the apertures . For example, the apertures may be located in the side of the body of the unit . Alternatively, the apertures may be located in the underside of each projection. The interconnecting units are preferably shaped so that the lower end of one unit can be placed in the upper end of an adjacent unit to provide a contact fit. In this manner, a number of units may be fitted together to form a vertical column. This vertical column will have a series of outwardly extending projections and apertures evenly spaced along its length. This allows a good flow of air into the composting material at appropriate points to optimise aerobic composting and minimises the compaction of composting material. It is preferred that decomposing material in the container body not be able to enter the aerator. Accordingly, where the aerator is formed from interconnecting units as described above, a closure may be provided to close the upper end of the uppermost interconnecting unit. Alternatively, the uppermost unit may differ from the lower units by having an upper end that is closed.

Preferably, the interconnecting units are made from a plastics material. It is also preferred that the container has an air inlet and that the aerator is in gaseous communication with this air inlet so that air outside the container can enter the air chamber in the aerator and then pass out into the internal space of the container. A conduit may extend from the air inlet to the aerator to provide this gaseous communication.

It is preferred that a platform be located toward the lower end of the container to support material placed therein away from the lower end. A space is thereby created below this platform and if this space is in fluid communication with the portion of the container above the platform, the space can act as a fluid collection chamber for collecting lechate that drains from the compost material placed in the container.

Where the platform creates an air space in the lower end of the container, the air inlet into the container and aerator may connect with this air space so as to provide gaseous communication between the air inlet and aerator. Thus, in this embodiment a conduit is not required. The platform may have an opening into which the lower end of the aerator extends, the lower end having an opening to the internal air chamber.

The container preferably has side walls and a base. It is also preferred that wheels are located at the base of the container and a handle is located at the upper end so that the user can tilt the container onto the wheels to move the container around. Containers having these features are commonly referred to as "wheelie bins".

Decomposing material in the container can be an attractive breeding site for insects. Thus, it is desirable to prevent the entry of insects into the container and this can be achieved by providing filters over all air inlets to the container.

Furthermore, an insecticide may be located in the container and a suitable location for the insecticide is the underside of the closure. A further aspect of the invention relates to a structural panel and a method of forming the structural panel which can be used in a variety of different applications including various components of a composting container, and in particular, panels which are intended to be folded or bent into a curved configuration.

This aspect of the invention provides a method of forming a structural panel comprising the steps of: extruding a plastic panel having a first surface layer, a second surface layer and integral connecting webs interconnecting the first and second surface layer; and scoring at least one of the surface layers in at least one location between adjacent webs to facilitate folding or bending of the structural panel into a curved configuration.

Preferably a plurality of score lines are formed in the said surface layer, each score line being located between an adjacent pair of said webs.

Preferably the score line or lines is formed by a scoring assembly located downstream of a extruder so that the score lines are formed in the board as the board is extruded from the extruder and still in a hot and tacky condition, said score assembly including a plurality of score heads which engage the said surface layer of the panel as the panel is advanced out of the extruder so as to form the score line or lines in the said surface layer of the panel . In one embodiment of the invention punched holes can be formed in the panel so as to extend completely through the panel.

In this embodiment of the invention the punched holes are preferably formed by a roller assembly which is arranged downstream from the scoring assembly and which is rotated by a drive means so as to punch holes in the panel between adjacent score lines formed in the panel.

In other embodiments the panel can be scored by a scoring assembly after formation of the panel and after the panel is cut into discrete lengths and the holes can be punched in the panel after formation of the panel by a flat punch assembly at the same time as or after the panel is cut into discrete lengths.

This aspect of the invention also provides a panel including: a first surface layer; a second surface layer; a plurality of webs interconnecting the first and second surface layers, the first and second surface layers and the webs being integral with one and other and formed in an extrusion process from plastic material; and at least one score line formed in one of the first or second surface layers to facilitate bending or folding of the panel into a curved configuration.

Preferably a plurality of score lines are formed in the said surface layer of the panel between adjacent pairs of said webs.

Preferably the panel includes a plurality of holes extending through the panel.

A further aspect of the invention comprises an aerator for a compost container, the compost container having an interior space and an air inlet for enabling air to flow to the aerator, said aerator including: a peripheral wall of generally cylindrical configuration, said peripheral wall being formed from a panel having a first surface layer, a second surface layer and a plurality of webs interconnecting the first and second surface layer, the first and second surface layers and the webs being integral with one and other and formed from plastics material in an extruded moulding operation; a plurality of score lines running parallel to the webs in the first surface layer so as to facilitate bending of a flat panel into the substantially cylindrical configuration; and a plurality of holes formed through the panel so as to allow air to pass from an interior chamber defined within the substantially cylindrical peripheral wall to the exterior of the aerator so air can be supplied to composting material in the composting bin when the aerator is located in the composting bin.

The aerator may be provided with an end cap for closing an upper end of the aerator a lower end of the aerator may be provided with a reinforcing ring to facilitate coupling of the aerator to a platform within the compost container.

Preferred embodiments of the invention shall now be described, by way of example, with reference to the following figures which illustrate preferred embodiments of the invention. Figure 1 it; a schematic representation of a composting device of this invention;

Figure 2 is a schematic representation of a composting device of this invention according to another embodimen ;

Figure 3 is a schematic representation of a lower end of a composting device according to this invention showing details of an aerator;

Figure 4 is a view of a second embodiment of the invention;

Figure 5 is a view of a blanket layer member using the embodiment of Figure 4.

Figure 6 is a plan view showing a method of forming panel members from which components of the compost bin can be formed;

Figure 7 is a cross-sectional view along the line

VII VII of Figure 6;

Figure 8 is a cross-sectional view along the line

VIII VIII of Figure 6; Figure 9 shows a portion of a panel member formed in accordance with the method of Figure 6;

Figure 10 shows an aerator formed according to the method of Figure 6 which can be used in the preferred embodiment of the invention; Figure 11 is a view of the lower portion of the compost container including the aerator of Figure 10 and also other structural components formed from panels formed by the method of Figure 6; and

Figure 12 shows one embodiment of a platform section used in the compost container of Figure 11.

Figure 1 is a schematic illustration of a composting container 1 according to this invention. The composting container 1 includes a container body 2 having rigid side walls 3, base 4, wheels 5 (indicated in broken lines), opening 6, internal space 7 and handle 8. Located around the opening 6 is an upstanding rim 9 shown in broken lines. Towards the lower end of the container there is an air inlet 10. A fluid outlet 11 is located at the base 4. Connected to fluid outlet 11 is clear tubing 12. A closure 13 is hingedly attached to the container 2 at handle 8, Hinge pins 14 attach the closure 13 and are removable so as to permit the closure 13 to be separated from the container 2. The closure 13 has handles 36. Located in the internal space 7 of container 2 is a platform 15 located above base 4 so as to create a fluid collection chamber 16 below the platform 15. Platform 15 has central opening 17. Connected to central opening 17 is aerator 18. Aerator 18 has a closed upper end 19, lower end 20 and internal air chamber 21. The aerator 18 is formed from a wire mesh material and therefore has a number of apertures 22 in its side. An air tube 23 extends from air inlet 10 and passes through aerator 18 and continues across the width of the container 2. At the position where air tube 23 passes through aerator 18 the tube 23 has an aperture (now shown) to allow air flow into the aerator 18.

In use, material to be composted is placed in the internal space 7 so that it completely covers aerator 18.

Air from outside the container 2 can enter air inlet 10, pass through air tube 23 and enter air chamber 21. The air can then pass through apertures 22 and into the internal space 7 of container 2. In this manner, a supply of air to the composting material is ensured.

As the material decomposes it will produce heat, and moisture in the material will form as condensate on the underside of domed closure 13. As the closure has a dome shape, condensate will flow to the perimeter of the closure 13 rather than fall back to the decomposing material located in the internal space 7. The closure 13 is shaped so that the perimeter extends outside the rim 9 of the container 2 when the closure is in position to close the opening 6. The rim 9 prevents the entry of the condensate back into the container 2 through opening . A fluid collection channel (not shown) may be located adjacent rim 9 so that condensate may collect in this channel for removal at a later time.

If the condensate were allowed to return to the decomposing material located in internal space 7, it could block the escape of gases from the surface of this decomposing material. This would result in a cut-off of the air flow through the container 2 which would consequently kill off aerobic bacterial activity. The removal of the condensate via the dome lid 13 avoids this problem. Furthermore, if condensate is allowed to drip onto the decomposing material it can cool the material. This can also have a deleterious effect on the decomposition process and this problem is also overcome by domed lid 13.

As platform 15 is located above base 4, a fluid collection chamber 16 is created. Lechate from the decomposing material located above platform 15 can drip into the fluid collection chamber 16. The fluid can then be drained through outlet 11 and tube 12. Tube 12 is transparent so that it may act as a sight glass showing the level of lechate in fluid collection chamber 16.

Domed lid 13 is removable. When removed it can be inverted and used as a carrying vessel. Carrying of the domed lid 13 is assisted by handles 14.

Figure 2 is a schematic representation of a composting device 1 of this invention having a lid 13 according to another embodiment. In this embodiment, lid 13 has a depression 24 located in it. This gives rise to a convex surface on the underside of domed lid 13. Condensate from decomposing material in interior 7 of container 2 collects on the underside of lid 13 and runs towards the apex of the convex shape. The condensate then drips onto condensate collecting means 25 which in this embodiment is a tube extending from the interior 7 to outside the container 2. Thus, condensate collecting means 25 defines an area separated from the internal space 7. The condensate can then be collected and used for ether purposes. Lid 13 is hingedly attached to handle 8 by removable hinging pins 1 . When hinging pins 14 are removed the lid 13 can be used as a carrying vessel. The depression 24 in lid 13 is also useful for collecting rainwater. A spout (now shown) can be provided at the rear of the lid 13 so that when the lid is tilted, water in the depression 24 runs through the spout and can be collected in a separate container. In this embodiment there is no air tube 23 connecting air inlet 10 to aerator 18. Rather the lower end 20 of aerator 18 is open to the internal air chamber 21. Air may enter the space 16 below platform 15 through air inlet 10. The air can then pass through the open end 20 of aerator 18 into internal air chamber 21 of aerator 18.

Figure 3 is a schematic representation of the lower end of the container 2 showing details of an aerator according to another embodiment of this invention. In this embodiment, the aerator 18 is formed by a number of modular units 26 which can be stacked one on top of the other to form a column-like structure. In Figure 2, only one modular unit 26 is shown. Modular unit 26 has a body 27 having internal chamber 21, lower end 20 and upper end 19. The lower and upper ends 20 and 19 are open to internal chamber 21. Located towards the upper end 19 is deflecting surface 28. In this embodiment the deflecting surface 28 is a collar that extends around the body 27 of the unit. In other embodiments the unit 26 may have a number of deflecting surfaces formed by two or more arms which extend downward from upper end 19 and outward from body 27. The lower end of each such arm may extend from 5% to 80% of the distance between the aerator and the wall of the container. The collar 28 has an underside 29 and in this underside there are located a series of apertures 22. Each aperture may be about 4 mm in width. Where the deflecting surface is formed by a series of arms, there may be 1-3 such apertures located in the underside of each arm. The lower and upper ends 20 and 19 of unit 26 are shaped so that the lower end 20 of one unit 26 can fit into the opening of an upper end 19 of an adjacent unit 23. Located below the modular unit 26 is a load supporting body 30 having an upper platform 31 and an internal cavity 32. A central opening 33 is located in the platform 31. The lower end 20 of one modular unit 26 extends into opening 33 and is thereby supported in the container 2. In body 30 there is also located an air inlet 34. Support means 35 holds the body 30 above base 4 of container 2. In this embodiment the support means 35 is a set of cross-shaped legs which is separate from body 30. In other embodiments the body 30 and legs 35 could be an integral unit .

The lining bag 36 is located in container 2 around side walls 3 and across the platform 31. At the edges of the lining bag 36 there are located apertures 37. The lining bag 36 has a central opening 38 through which the aerator 18 extends.

In use, air may enter the hollow body 30 through air inlet 16 and aperture 34. Hollow body 30 acts as a bladder and air can pass through opening 33 into the cavity 21 of modular unit 26. The air can then pass into space 7 through apertures 22 located in the underside 29 of modular unit 26. Sloping collar 28 acts to deflect material falling downwards onto unit 26 away from the lower end 20. Thus, an air pocket forms around the lower end 20 so that air may easily pass from internal cavity 21 through apertures 22. As a number of units 26 are interconnected to form a vertical column, a series of deflecting surfaces 28 and apertures 22 will be located at regular intervals along the length of the column. This ensures a good airflow through the aerator

18 into the space 7 and also minimises compaction of composting material.

The lining bag 36 is provided so that when the contents of the container 2 are to be emptied, the lining bag can be lifted out of the container. In this embodiment, the modular units 26 extend through the central opening 38 in the lining bag 36 and can be removed with the lining bag 36. Draining apertures 37 are located in lining bag 36. When fluid contacts the lower end of the lining bag 36, it is directed towards apertures 37 by sloping platform 31. There is a space between the sidewalls 3 and body 30 to allow fluid to pass the body 30 and enter the space below body 30.

Figures 4 and 5 show a second embodiment of the invention. Like reference numerals indicate like parts to those described in the earlier embodiment. In this embodiment of the invention the build up of a layer of water on top of composting material 50 is prevented by a blanket layer 52. The blanket layer 52 is shown in Figure 5 and preferably comprises a layer of TOPTEX (trade mark) material made by Austrusa Inc of the USA. However other material which will provide the same characteristic could be utilised. This material has a generally open weave or cellular structure and thereby provides a pervious layer through which water and air can pass. In this embodiment of the invention the lid 13 can be a conventional flat lid rather than the lid shown in Figure 1 because the build up of a water layer from condensate which drips from the lid 13 will be vented by the blanket layer 52 as will be explained in more detail hereinafter. The blanket layer 52 is preferably dimensioned so that it will fit snugly into the container body 2. Since the container body 2 has a tapered sidewall structure the blanket 52 may be dimensioned so that it will completely cover the composting layer 50 when the container is generally full. When the container is only partially filled the blanket 52 can be located on the composting material and side edges 53 of the blanket layer 52 simply folded up slightly at the walls 3 of the container body 2.

When the lid is closed and condensate collects on the underside of lid 13 the condensate will drip back onto the blanket layer 52. Because of the open cellular weave structure of the blanket 52 the surface tension of the water is not sufficient to hold the water on the blanket 52 and the water is able to pass through the blanket 52 back to the composting material 50. Thus, the build up of the impervious water layer is prevented by the blanket 52. The water which passes through the blanket 52 is also able to flow into the composting material 50 and does not build up or form a layer between the composting material 50 and the blanket 52 for several reasons. Firstly, because of the location of the blanket 52 on top of the composting material 50, the surface of the composting material 50 is maintained at a higher temperature than would be the case if the blanket 52 is not used. This enables the complete composting layer 50 to properly decompose thereby changing the fibrous nature of the upper surface of the composting material 50 into a much more friable material so that the water can easily penetrate and pass through that material. Furthermore, the flow of water through the blanket 52 is somewhat slowed down so a relatively large volume of water is not applied to the top of the composting material in a short time period. This increases the ability of the water to be absorbed into the composting material before an impervious layer of water can build up between the blanket 52 and the upper surface of the composting material 50.

Air which enters the composting material 50 from the aerator 18 and gases which are generated during decomposition of material are able to flow up through the composting material and through the pervious blanket layer 52. Thus, good airflow and proper aerobic decomposition of the composting material 50 can take place.

When it is desired to remove composted material from the container or add further material into the container for composting, the blanket 52 is removed and then relocated in place so that composting of the material within the container can continue.

Figures 6 to 11 show a further embodiment of the invention which relates to the manner in which various panel components of the compost container can be formed. It should be understood that the panel components formed according to the method described with reference to these figures also has application in other environments in which structural panels may be required and, in particular, in which structural panels having a curved contour and which are formed from a generally panel sheet are required.

According to this embodiment of the invention the aerator 18 and the platform 15 which divides the lechate chamber 16 from the interior 7 of the compost container 2, are formed from PAKFLUTE (trade mark) corrugated plastic board manufactured by Nylex Industrial Products Pty Ltd of Melbourne Australia.

With reference to Figure 6 corrugated plastic board is formed in an extrusion moulding process from an extruder 100 so as to produce the board 110. The manner of producing the board 110 is conventional and therefore full details need not be described in any detail hereinafter. A cross-sectional view of the board 110 is shown in Figure 7 and the board 110 comprises upper surface layer 112 lower surface layer 114 and interconnecting ribs 116 which extend between the layers 112 and 114.

According to the preferred embodiment of this aspect of the invention, the board 110 is modified by scoring the board so as to produce regions of weakness extending in a longitudinal direction of the board so that the board can then be easily bent or curved into a curved configuration as shown in Figure 9. In the preferred embodiment of the invention a scoring assembly 120 is provided downstream of the extruder 100. The scoring assembly 120, as best shown in Figure 8, include a support member 122 from which extends downwardly projecting scoring heads 124. The number of scoring heads 124 can vary depending on the degree of curvature the board is required to have and therefrom particular applications to which the formed corrugated board will be used. In the preferred embodiment of the invention a score is to be formed between adjacent ribs 116 of the board 110, and therefore a number of scoring heads 124 are provided, one corresponding to each of the spaces defined by adjacent webs 116. In the preferred embodiment, the heads 124 are arranged so that they will score the board 110 at mid points between adjacent webs 116. When the board 110 leaves the extruder 100 it is still in a hot and semi-set state. The assembly 122 is adjusted so that the scoring heads 124 project down into the upper surface layer 112 but not fully through the surface layer 112 so that as the board 110 is advanced in the direction of arrow A in Figure 6 the scoring heads 124 score channels 126 in the upper surface 112.

As is best shown in Figure 9 the scoring of the upper surface 112 to form the channels 126 enables the board 110 to be easily bent into a curved configuration and, if desired, into a cylindrical configuration.

Curvature of the board into a curved configuration enables the board to be used in environments where the board is required to form a structural component which has a curved configuration. In the preferred embodiment of the present invention the board is used to form the aerator 18 used in the compost container 2. According to this embodiment of the invention the board 110 is further processed, as is shown in Figure 6, before it is bent in the curved configuration by forming holes 130 in the board. As shown in Figure 6 a roller 131 which has a plurality of punches 133 on its outer surface is arranged across the board 110 after it has been scored by the scoring assembly 120. The roller 133 is rotated by a drive assembly (not shown) so as to punch holes 130 in the board 120 between the score lines

126. The punch holes extend all the way through the board 110 so that when the board 110 is bent into a cylindrical configuration as shown in Figure 10 the holes 130 pass right through the peripheral wall of the cylindrical configuration which will form the aerator 18 according to this embodiment of the invention. Edges 140 and 141 of the panel 110 which abut one and other when the panel is bent into the cylindrical configuration as shown in Figure 10 can be connected together by welding or any like method. Thus, this embodiment of the invention forms an aerator 18 which is a cylindrical configuration and which is formed from corrugated plastic board which has good structural rigidity. The holes 130 provide communication between the interior of the aerator 18 and the interior of the compost bin so air can flow up through the aerator 18 and out through the holes 130 into the composting material in the same manner as previously described.

Figure 11 shows a view of the compost container 2 including the aerator 18 of Figure 10. In this embodiment of the invention the platform 15 which divides the interior 7 of the compost bin from the lechate chamber 16 is formed from corrugated plastic board of the same type as described with reference to Figure 6, except that the board need not be scored or holes punched in it other than a central hole 145 which is intended to receive a lower end of the aerator 18. According to this embodiment the platform 15 is formed from a laminate of two or more sheets of the corrugated board which are arranged so that the webs 116 of each sheet run in directions which are perpendicular to one and other. That is, in the case of the upper board 110a in Figure 8 the webs 116 run into and out of the sheet of the paper in Figure 11 and in the case of the lower board 110b in Figure 11 the webs run from left to right. Thus, a strong laminate is formed which can provide the platform 15. As previously mentioned, the platform 15 is provided with a central hole 145 and the end of the aerator 18 locates in the central hole so as to communicate the aerator 18 with the lechate chamber 16. A hole 10 is formed in the sidewall 3 of the compost as in the previous embodiments so that air can enter the lechate chamber 16 and then pass into the aerator 18.

In one alternative embodiment of the invention the hole 10 can be provided in registry with the panel 110b so that the space in the panel 110b between adjacent webs 116 acts as a channel to convey air from the opening 110 to a hole 130 of the aerator 18 so air can flow into the aerator 18 and then up through the aerator 18 to be dispersed out through other holes 130 into the composting material.

In the embodiment shown in Figure 11 a support 150 is provided for supporting the platform 15. The support 150 may be formed from a short length of the cylindrical aerator 18 formed with reference to Figure 10. The support 150 is preferably glued to the platform 15 in registry with the opening 145. In other embodiments, the aerator 18 could pass through the platform 15 and be glued to the platform 15 so that the portion of the aerator 18 which extends below the platform 15 acts as the support 150.

In the embodiment of Figure 11 the platform 15 is formed from completely overlapping boards 110a and 110b which have an outer periphery which matches the circumferential dimension of the container 2 at the location where the platform 15 is to be located.

In the embodiment of Figure 12 the platform 15 is formed from two sheets 110c and llOd of the corrugated plastic board which simply form a cross configuration. A hole 160 is formed for receiving the aerator 18. In this embodiment of the invention an additional panel or baffle can be used in combination with the platform 15 so as to prevent composting material from dropping into the lechate chamber 16. However, this embodiment may also be used with a liner bag which is intended to receive the composting material so that the liner bag will prevent the composting material from passing into the lechate chamber 16.

It should be appreciated that various modifications may be made to the composting container as described above without departing from the spirit of the invention.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A composting container, including: a container body having an opening and defining an internal space so that material to be composted can be placed in the container through the opening and deposited in the internal space; a closure coupled to the container body and movable from an open position allowing access to the internal space through the opening and a closed position in which the opening is closed by the closure; an air inlet in the container body for allowing air to enter the container body and flow through material deposited in the internal space to facilitate aerobic decomposition of that material; means for preventing a build up of a layer of water on the surface of the composting material which would prevent flow of air through the composting material and prevent aerobic decomposition of the material.

2. The container of claim 1 wherein the preventing means comprises a configured closure so that condensate that collects on the underside of the closure is directed to a predetermined location so that it does not drip back onto the top of the composting material to enable the impervious water layer to be formed.

3. The container of claim 1 wherein the invention the preventing means comprises a pervious blanket layer member for location on the composting material, the pervious blanket layer member receiving any condensate which drips from the closure lid, the pervious nature of the layer material being such that the moisture which collects on the layer is able to pass through the layer without collecting as a water barrier layer and then trickle through the composting material.

4. The container of claim 1,2 or 3 wherein the invention the air inlet includes at least one aerator located in internal space, the aerator communicating with the air inlet so that air can flow through the inlet and into the aerator and then be distributed through the material within the internal space.

5. The container of claim 2 wherein the configured closure, the closure is configured so that the closure slopes towards the perimeter of the closure, the perimeter of the closure being located outwardly of the container body so that the water drains to a location outside the container body and does not fall onto the composting material .

6. A composting container including: a container body having an opening and defining an internal space; one or more aerators located in said internal space; and a closure for said opening, said closure being configured so that condensate that collects on the underside of the closure is directed to an area that is external to and/or separated from said internal space thereby minimising return of the condensate to the internal space.

7. The container of claim 5 wherein the underside of the closure slopes towards the perimeter of the closure so that condensate runs off towards the perimeter.

8. The container of claim 6 wherein this sloping surface has a concave shape.

9. The container of claim 7 wherein the closure is a dome-shaped lid.

10. The container of claim 5 wherein the perimeter of the closure extends beyond the opening of the container when the closure is in place to close the opening.

11. The container of claim 5 wherein at least part of the underside of the closure has a convex shape, a condensate collecting means is provided below the closure, and wherein condensate that collects on the underside of the closure runs to the apex of the convex shape and then drops onto the condensate collecting means.

12. The container of claim 5 wherein the aerator has a body having an internal air chamber and one or more apertures located in the body to permit air inside the air chamber to pass out and into the container.

13. The container of claim 10 wherein the aerator is constructed using a mesh material.

14. The container of claim 10 wherein the aerator is formed from one or more interconnecting units, each unit including: an upper end, a lower end, an internal air chamber and an opening at each upper and lower ends to said air chamber; one or more projections extending outward from a side of said unit for contacting material falling onto said unit; and one or more apertures to permit air inside said air chamber to pass through said aerator.

15. The container of claim 11 wherein the container has an air inlet and that the aerator is in gaseous communication with this air inlet so that air outside the container can enter the air chamber in the aerator and then pass out into the internal space of the container.

16. A method of forming a structural panel comprising the steps of: extruding a plastic panel having a first surface layer, a second surface layer and integral connecting webs interconnecting the first and second surface layers; and scoring at least one of the surface layers in at least one location between adjacent webs to facilitate folding or bending of the structural panel into a curved configuration.

17. The method of claim 16 wherein a plurality of score lines are formed in the said surface layer, each score line being located between an adjacent pair of said webs.

18. The method of claim 16 or 17 wherein the score line or lines is formed by a scoring assembly located downstream of an extruder so that the score lines are formed in the panel as the panel is extruded from the extruder and still in a hot and tacky condition, said score assembly including a plurality of score heads which engage the said surface layer of the panel as the panel is advanced out of the extruder so as to form the score line or lines in the said surface layer of the panel.

19. The method of claim 16, 17 or 18 including the step of forming punched holes in the panel which extend completely through the panel.

20. The method of claim 19 wherein the punched holes are formed by a roller assembly which is arranged downstream from the scoring assembly and which is rotated by a drive means so as to punch holes in the panel between adjacent score lines formed in the panel.

21. A panel including: a first surface layer; a second surface layer; a plurality of webs interconnecting the first and second surface layers, the first and second surface layers and the webs being integral with one and other and formed in an extrusion process from plastic material; and at least one score line formed in one of the first or second surface layers to facilitate bending or folding of the panel into a curved configuration.

22. The panel of claim 18 wherein a plurality of score lines are formed in the said surface layer of the panel, each score line being located between an adjacent pair of said webs.

23. The panel of claim 21 wherein the panel includes a plurality of holes extending through the panel.

24. An aerator for a compost container, the compost container having an interior space and an air inlet for enabling air to flow to the aerator, said aerator including: a peripheral wall of generally cylindrical configuration, said peripheral wall being formed from a panel having a first surface layer, a second surface layer and a plurality of webs interconnecting the first and second surface layer, the first and second surface layers and the webs being integral with one and other and formed from plastics material in an extruded moulding operation; a plurality of score lines running parallel to the webs in the first surface layer so as to facilitate bending of a flat panel into the substantially cylindrical configuration; and a plurality of holes formed through the panel so as to allow air to pass from an interior chamber defined within the substantially cylindrical peripheral wall to the exterior of the aerator so air can be supplied to composting material in the composting bin when the aerator is located in the composting bin.

25. The aerator of claim 24 including an end cap for closing an upper end of the aerator.