NZ266102A - Plant container has a base and walls of degradable material and an upper opening with a smaller horizontal cross-sectional area than the base - Google Patents

Description

26 6 1 0 2 New Zealand No. 266102 , . International No. PCT/AU94/00250 Priority Date(s): Complete Specification Hied: ...l.dl.sj.S.ht. Class: (6) ....te.e-?.Jp3 | Publication Date: 2 .6 MAR 1996 j •' O. Jo<'• no1 / NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION Title of Invention: Container for plants Name, address and nationality of applicant(s) as in international application form: DULVERRE PTY LTD, of C/- Ernst & Young, 120 Collins Street, Melbourne, Victoria 3000, Australia * Ar% • ;WO 94126092 PCT7AU94/00250 ;1661C ;CONTAINER FOR PLANTS ;Field of the Invention ;The invention relates to containers for plants. ;Background of the Invention ;5 Containers for plants have come in a variety of shapes and sizes and are made from many materials. Typically these containers have either a uniform sectional shape, eg a cylinder, or an increasing cross-sectional shape from the base to an upper opening, eg a truncated cone. These shapes allow the plant to be easily located or removed from the container. ;One common method for growing a plant is to allow the plant or seedling to grow in a 10 container of one size. The plant or seedling is allowed to develop root growth in one container and then is placed in a container with an opening which has a larger horizontal cross-sectional area to allow the plant or seedling to develop an increased root mass. ;Such containers were traditionally manufactured from a suitable clay though in recent times are manufactured from plastics material. ;15 The most popular plant container is plastic and has a conical shape which dimensionally increases from the base to the upper opening. Not only does the shape facilitate the easy removal of plants from the container, it also allows such type of containers to be easily stacked and economically transported. ;However even this popular type of container suffers from certain disadvantages. ;20 The primary disadvantage of such containers is lack of stability where the weight of the plant above the container ex ceeds the weight of the plant within the container. Put another way, once the centre of gravity of plant plus the container is above the container, the combination becomes unstable. The convergent sloping nature of the container wall towards the base restricts the support the container can give to the plant. ;25 Additionally, the shape of these containers discourages plant roots from growing down in the container. When the plant roots reach the walls of these containers they are deflected laterally in a circular direction around the container rather than in a downward direction towards the base of the container. This stilts root growth and generally also causes a smaller mass of roots. This tends to raise the centre of gravity of the plant adding to 30 unstability and the plants commonly need to be staked. ;Further, as the container is made from an impenetrable material such as plastic, the plant roots cannot be given further room to grow without the plant first being extracted from container in which it is planted and transplanted into another. ;WO 94/26092 ;2 ;PCT / AU94/00250 ;In US Patent number 4,019,279 a container is disclosed which prevents the roots of a plani from cracking a nearby sidewalk by having the container buried in the ground. The container has an upper opening and an open base and sidewalls of an impenetrable material, such as plastic, which are divergent. The container is placed below the level of 5 the soil roots are deflected down away from the surrounding concrete. ;Another type of container is disclosed in lapsed Australian patent application number 20947/88. This application discloses a container of the traditional shape described above but uses a rigid degradable material at least partially coated with a degradable substantially water-resistant coating, ;10 Accordingly investigations have taken place to produce a container which can lower the centre of gravity of a plant, whilst permitting healthy growth of plant root systems. ;Description of the Invention ;According to a first embodiment of the invention, a container for a plant is provided having an upper opening to receive a plant, a base and at least one wall extending therebetween, 15 the wall being of degradable material, and the upper opening having a horizontal cross-sectional area which is less than the horizontal cross-sectional area of the base. ;In another preferred embodiment, tht, ontainer wall or walls substantially diverge from the upper opening to the base. ;Such a container exhibits greater stability as the area of the base is greater than that of the 20 upper opening end which provides improved support to the container contents. This arrangement also promotes root growth to extend in a downward and outward direction thereby increasing the root mass of the plants. Additionally, as the wall is degradable over time, after a predetermined time the plant and container can be placed into a larger second container. The original container does not present an impenetrable barrier to the expanding 25 root system. Further as the plant is not removed from its original container there is less likelihood of damage to the root systems of the plant. ;In another preferred embodiment of the invention, the container wall is corrugated with circular or angular ridges. These corrugations extend down the walls towards the base. These corrugations increase the surface area of the container promoting root growth to 30 extend in a downward and outward direction. ;In another preferred form of the invention, the base and upper opening are rectangular and the walls are planar. More preferably the container is a square based frusto-pyramid shape. ;In another preferred form of the invention, the base of the container is made from a rigid degradable material such as a paper based material (eg cardboard). The rigid material may 35 at least be partially coated with a degradable substantially water resistant coating. It will be ;WO 94/26092 PCT/AU94/00250 ;appreciated that the container may have more than one substantially water resistant coating depending on the time period required for the container to remain rigid. The rigid degradable material is both easily removed from the plant without damaging the plant and * degradable over a reasonable period of time (eg twenty-six weeks).

Such a container is particularly suited to commercial growers of plants, cuttings and seedlings. These persons usually grow plants from seed and have a need to move the seedling plant from smaller to larger containers. By selecting appropriate paper based material and sizes of containers according to this invention, it is possible to provide an appropriate range of sizes. Additionally, by selecting the degradable substantially water 10 resistant coating and then the number of such coatings, the grower is able to select a container which will degrade appropriate to the time a seedling or plant will stay in the container. This will considerably simplify the current labour intensive growing method of moving a plant from one size plastic pot to another.

In another preferred form of the invention, the container includes two parts with a first part 15 having an open base, the upper opening and the wall and a second part having the base to cover the open base of the first part.

Description of the Drawings The invention now will be further illustrated with reference to the drawings in which: Figure 1 is a perspective view of one form of the container of the invention; Figure 2 is a plan view of the container of Figure 1; Figure 3 is a perspective view of another form of the container of the invention; Figure 4 is a plan view of the container of Figure 3; Figure 5 is a perspective view of the container of Figure 1 with a plant in place; Figure 6 is a front partial cross-section of the container of Figure 5; Figure 7 is a perspective view of another form of the container of the invention where the walls are corrugated circular ridges; Figure 8 is a sectional view of the container in Figure 7; Figure 9 is a perspective view of another form of the container of the invention where the walls are corrugated to form angular ridges; and Figure 10 is a section of the perspective view of the container of Figure 9.

Figure 11 is a perspective view of the container of Figure 1 having two parts.

Figure 12 is a perspective view of the container of Figure 3 having two parts. 4 As shown in Figures 1 & 2, plant container 1 has an upper opening 2 and a base 3. Diverging walls 4 extend from base 3 and define upper opening 2. The base 3 is a regular rectangle whilst the walls 4 are of irregular rectangular shape.

Ar .more particularly shown in Figure 2, the cross-sectional area of the upper opening 2 is 5 smaller than the area of the base 3 and provides additional stability to the container 1.

Figures 3 & 4 depict an alternate shaped container according to the invention. Plant container 5 has an upper opening 6 and a base 7. A diverging wall 8 extends from base 7 and defines upper opening 6. The base 7 is a circular and with the wall 8 define an open frusto-cone.

As was the case with Figure 2, the cross-sectional area of the upper opening 6 is smaller than the area of the base 7 and provides additional stability to the container 1.

Figure 5 shows container 1 with a sizeable plant 9 located in it. Base 3 is very stable as it provides a significant surface area which would need to be tipped if the plant is to fall over.

Figure 6 shows the path of roots when the plant 9 is located in container 1. The root path is 15 out and down similar to the root structure that would occur if the plant was located in the ground. This further consolidates the plant in container 1 to provide additional stability.

Figure 7 shows a container where the diverging wall 4 has corrugations 10. These corrugations are more particularly shown in Figure 8 and are formed from a sheet folded to form circular ridges. Figure 9 also shows a container 1 with diverging walls 4 where the 20 diverging walls 4 are corrugated. However the angular ridges 11 have a triangular cross-section. In both cases the circular ridges 10 or angular ridges 11 of the corrugated diverging walls 4 improve the direction of the roots of a plant in an outward and downward direction.

Figures 11 depicts a plant container 1 with two parts, the first part 12 having an upper 25 opening 2, the open base 3 and a wall 4, the second part 13 having a base 14 to cover the open base 3 of the first part.

Figure 12 depicts a plant container 5 with two parts, the first part 15 having an upper opening 6, the open base 7 and wall 8, the second part 16 having a base 17 to cover the open base 7 of the first part.

The container may be manufactured from known paper based sheet material such as corrugated cardboard or formed by molding paper based material, these techniques will be readily known to those skilled in the art.

Claims (5)

The claims hereinafter defining the invention are as follows.

1. A plant container having a rectangular upper opening to receive a plant, a rectangular base, and four walls extending between the base and the upper opening, the base and the walls being of degradable material; the upper opening having a horizontal cross-sectional area which is less than the horizontal cross-sectional area of the base; the wails diverging from the upper opening to the base, the walls having vertically extending corrugations on an inner surface thereof.

2. A plant container according to claim 1, including a first part having an open base, the upper opening and the at least one wall, and a second part having the base to cover the open base.

3. A plant container according to claim 1 or claim 2. wherein the degradable material is a paper based.

4. A plant container according to any of the previous claims, further including a water resistant coating on the base and/or the walls.

5. A plant container substantially as hereinbefore described with reference to the drawings.