GB2254769A

GB2254769A - Animal bedding materials

Info

Publication number: GB2254769A
Application number: GB9203490A
Authority: GB
Inventors: Donald Henry Wall
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-02-19
Filing date: 1992-02-19
Publication date: 1992-10-21
Anticipated expiration: 2012-02-19
Also published as: GB9203490D0; GB9103442D0; GB2254769B

Abstract

An animal bedding material comprises a plurality of irregular shaped pieces 1 of cardboard having feathered edges 2 which are formed as by tearing or shearing rather than as by cutting. The provision of such feathered edges 2 avoids sharp edges which might cause injury or discomfort to an animal, and renders the material particularly absorbent. The pieces 1 of cardboard may be crimped to render the bedding material more compressible, resilient and comfortable. The animal bedding material may be mixed with animal excrement, and optionally also woodchips, to form a compost or mulch. A machine for tearing sheets of cardboard into the irregularly shaped pieces is also described. <IMAGE>

Description

"Animal Bedding Materials This invention relates to animal bedding materials and methods of production of such materials.

There is an increasing need for alternative forms of bedding material for horses to replace straw which is conventionally used for this purpose. Not only is straw often costly and difficult to obtain but also it is considered by many to be a less than ideal bedding material. Also straw when cut may be contaminated with chemicals which have been applied by the farmer.

There are a number of alternative forms of horse bedding material which are currently used, all of which make use of waste products and all of which suffer certain disadvantages in use. For example use has been made of shredded newspaper for horse bedding material. However not only is shredded newspaper a relatively unsuitable material for this purpose because of its low absorbency, but also it necessarily has a high proportion of its surface area covered in ink, and it is believed that the chemical reaction of such ink with horse urine may give rise to substances having harmful effects on horses or people handling such material. The use of recycled newspaper for this purpose is considered to be even more unsatisfactory because of the tendency for such recycled newspaper to produce fungal growths which might again be harmful to the horse.Another type of horse bedding material currently used is wood shavings. However the use of wood shavings as a bedding material is relatively costly, and there has also recently been concern expressed over the effects of chemical reactions occurring between substances in the wood shavings and horse urine.

It has also been proposed to use cardboard which has been cut into thin strips by a shredding machine as a horse bedding material. However the use of such shredded cardboard as a bedding material has not found favour for a number of reasons of which the main one is that the cut edges of the strips tend to cause discomfort, or even injury, to the horse.

It is an object of the invention to provide an improved animal bedding material which can be produced from biodegradable waste materials and which is therefore particularly advantageous from an environmental point of view.

According to the present invention there is provided animal bedding material comprising a plurality of irregularly shaped pieces of cardboard having feathered edges.

In this context the expression "feathered edge" denotes an edge formed as by tearing or shearing, as opposed to a sharp edge formed as by cutting.

The provision of such feathered edges has the advantage that it avoids sharp edges which might be a source of discomfort or injury to an animal, and that it renders the material particularly absorbent.

It is preferred that the pieces of material are crimped so that a mass of the material occupies a greater volume for a given weight of material than would a mass of material consisting of substantially flat pieces of cardboard. This renders the material more compressible and more resilient, and thus provides a more comfortable bedding material for the animal.

The pieces of cardboard have maximum dimensions which are preferably in the range of 20 to 100 mm, and most preferably in the range of 30 to 60 mm. The mean value of the maximum dimensions of the particles is typically in the range of 40 to 50 mm.

Preferably, the bedding material is substantially dust free, and the amount of dust present in the bedding material is at least small enough to avoid irritation to an animal using the bedding material, and to avoid harmful effects to the animal's respiratory system during normal use of the bedding material.

Furthermore the pieces of cardboard may be formed from waste cardboard having no more than 5% of its surface area printed with ink.

The invention also provides a method of producing animal bedding material comprising tearing a plurality of irregularly shaped pieces from a sheet of cardboard.

Such tearing may be effected by projecting teeth on a rotating mechanical head. Preferably the teeth have rounded edges so as to avoid cutting the cardboard.

Furthermore each of the teeth may have a tearing surface having the general shape of a square having rounded edges.

Each side of the square preferably has a length of 20 to 40 mm, most preferably about 30 mm.

The method of the invention preferably includes the additional step of forcing the irregularly shaped pieces of cardboard through an apertured screen of sufficiently small aperture size to cause crimping of the pieces of material. Each aperture of the apertured screen may have the general shape of a square having rounded edges, each side of the square preferably having a length of 20 to 40 mm, most preferably about 30 mm.

The method of the invention advantageously includes the further step of removing dust laden air from around the pieces of cardboard of the bedding material after effecting said tearing. If the method of the invention includes the additional step of forcing the pieces of cardboard through the apertured screen, the dust laden air may be removed before and/or after performing the additional step of forcing the pieces of cardboard through the apertured screen.

If the animal bedding material produced by the method of the invention comprises pieces of cardboard having maximum dimensions both greater than and less than about lOmm, the method of the invention may also include the step of separating the pieces of cardboard having maximum dimensions of less than about lOmm from the rest of the pieces of cardboard. It has been found that these smaller pieces of cardboard make an excellent bedding material for small animals, such as, for example, rabbits and hamsters.

The invention also provides a machine for forming animal bedding material, comprising feed means for feeding sheets of cardboard into the machine, and tearing means for tearing a plurality of irregularly shaped pieces from the sheets of cardboard to form the animal bedding material.

The tearing means is advantageously a rotary mechanical head having projecting teeth.

The machine preferably also includes an apertured screen through which the irregularly shaped pieces of cardboard are forced to cause crimping of the pieces.

The machine advantageously further comprises dust extraction means for removing dust from the irregularly shaped pieces of cardboard.

The invention also provides a compost or mulch formed from a mixture of such animal bedding material and animal excreta, and optionally also wood chips.

In order that the invention may be more fully understood, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 shows pieces of material produced in accordance with the invention; Figure 2 is a schematic diagram of a machine in accordance with the invention; and Figures 3 and 4 show details of the machine of Figure 2.

More particularly Figure 1 shows five irregularly shaped pieces 1 (actual size) of animal bedding material which has been produced from cardboard by a method described below so as to have feathered edges 2 and crimped portions such as 3. The feathered edges 2 are produced by a tearing action which breaks the bonds between the fibres of the cardboard, rather than by cutting through the cardboard fibres. Thus the feathered edges 2 are not only uneven but also, on a microscopic scale, have a series of individual projecting fibres along the edge. The provision of such feathered edges 2 both avoids sharp edges and improves the absorption of each piece 1 of material. Also the fact that each piece 1 of material has portions such as 3 which are crimped to a greater or lesser degree, that is which are folded or bent out of the plane of the surface on which the pieces lie, means that a mass of the material will be rendered generally more compressible and more resilient than would otherwise be the case, this clearly being desirable to provide a more comfortable bedding material.

It has been found that, when the bedding material is used as a horse bedding on stable floors, the bedding does not need to be fully replaced for some considerable time, unlike conventional beddings formed from straw, paper or woodchips which need to be fully replaced at least once a month and usually once a week.

It has been found that, so long as the parts of the cardboard bedding material which have become soiled with horse excrement or urine are removed and replaced by new bedding at regular intervals, there is no need to replace the entire bedding for at least six months. Furthermore, unlike bedding materials formed of straw, paper or woodshavings, the cardboard bedding material does not form bare, uncovered patches on the stable floor due to the movement of the horse's feet.

The animal bedding shown in Figure 1 has been produced by a method, which will be described below, which ensures that it is virtually dust-free. This is particularly important to avoiding damage to the animal's respiratory system caused by the inhalation of dust, and also to avoiding irritation of the animal during use of the bedding material.

The sizes of the irregularly shaped pieces of cardboard forming the bedding material vary according to the type of animal for which the bedding is produced. A bedding suitable for horses might be formed from pieces of cardboard having maximum dimensions of around 45mm, whereas the maximum dimensions for a bedding suitable for hamsters, rabbits or other small animals might be up to about lOmm.

The method used to produce the material shown in Figure 1 is such that the pieces 1 formed have many different sizes and shapes. Thus, for example, the piece 4 in Figure 1 is relatively large and relatively uncrimped, whereas the piece 5 is relatively small and highly crimped so that parts of the piece are folded over on one another. The pieces 1 can be formed from a variety of thicknesses and grades of cardboard, although it is preferred that as far as possible the cardboard used has little or no printing on it, and that little or none of the cardboard has a white facing incorporating kaolin. It is preferred that no more than 5% of the surface area of the cardboard used should be coated in ink, and in addition cardboard should not be used in which the maize starch used for gluing together parts of the cardboard, as in cardboard boxes, incorporates a formaldehyde additive.

Cardboard produced for the packaging of food for human consumption has been found to be particularly suitable. Of course, the cardboard used will generally have the conventional cardboard structure comprising one or more laminar layers separated by one or more corrugated layers.

Referring to Figure 2 the apparatus used for forming the bedding material comprises a feed station 10 for feeding sheets of cardboard in the direction of the arrow 11, a rotary mechanical tearing head 12, an arcuate crimping screen 13 and a scraper conveyor 14. Feed station 10 consists of two parallel rollers 15 and 16 having intermeshing teeth which are rotated in synchronism by means of a drive and suitable gearing so as to advance the cardboard towards the tearing head 12.

Alternatively, the cardboard may be advanced towards the tearing head 12 by means of a linearly reciprocating ram (not shown). The tearing head 12 is provided with 82 tearing teeth 16 which are arranged in a double helical layout on the cylindrical outer surface of the head 12 so that 41 of the teeth 16 are regularly spaced apart along a right handed helix on one axial half of the head 12 and 41 of the teeth 16 are regularly spaced apart along a left handed helix on the other axial half of the head 12. The double helical arrangement of the teeth 16 has the general effect of tending to bias the cardboard towards the mid point along the axial length of the head 12.

The tearing head 12, which is rotated by a suitable drive and gearing in the direction of the arrow 12A, tears the cardboard into the required pieces and forces these pieces through the apertures 17 which are regularly spaced apart in the arcuate crimping screen 13 which has generally the shape of an elongate trough having five arcuate strengthening ribs 18 spaced apart along its length. A serratted edge 21 cooperates with the outer surface of the tearing head 12 and the teeth 21 to tend to prevent larger pieces of cardboard being drawn beyond the edge 21. The cardboard pieces which have been crimped by being forced through the screen 13 then fall onto a flat surface 19 along which they are conveyed in the direction of the arrow 20 by the scraper conveyer 14 towards a loading point at which the pieces are loaded into suitable receptacles, such as bags.

It will be appreciated that during the tearing of the cardboard by the tearing head 12 substantial quantities of dust may be formed. The dust may be removed from the bedding material by removing dust-laden air from around the pieces of cardboard during the production of the bedding material, and passing the dust-laden air through a suitable dust extraction system. To this end, one or more dust extraction vents (not shown) may be provided above the tearing head 12 and/or between the tearing head 12 and the scraper conveyor 14 for removing dust laden air, thus ensuring that the animal bedding material produced by the apparatus is substantially dust free.It will be appreciated that dust extraction vents provided above the tearing head 12 and between the tearing head 12 and the scraper conveyor 12 remove dust laden air from around the pieces of cardboard before and after the pieces of cardboard are forced through the screen 13 repectively.

It has been found that small pieces of cardboard, if present in bedding material used for horses are capable of causing discomfort and possibly injury to a horse if inhaled by the horse. Such small pieces of cardboard, typically having maximum dimensions of up to about lOmm, may be removed from the bedding material by forming small holes (not shown) in the flat surface 19 through which the small pieces of cardboard may drop as the animal bedding material is conveyed along the surface 19 by the scraper conveyor 14. Circular holes of about lcm diameter, spaced apart by about 1cam, have been found particularly suitable for removing the small pieces of cardboard. Furthermore, the small pieces of cardboard removed in this may have been found to make an excellent bedding for smaller animals such as hamsters, rabbits and cats etc.The method of producing the bedding material is thus particularly efficient and advantageous from an environmental point of view because the smaller pieces of cardboard are not allowed to go to waste.

The general form of the cutting teeth 16 is shown diagrammatically in Figure 3 from which it will be seen that each tooth 16 consists of a fixed part 22, which has the shape of a cylinder having a cross-section in the form of a square having rounded corners, disposed within a groove 23 in the cylindrical surface of the tearing head 12 extending generally in the circumferential direction 24 and welded in place by welds 25 on the two sides of the part 22. Furthermore each tooth 16 has a replaceable part 26, which again has a cross-section in the form of a square having rounded corners, bolted to the leading face of the fixed part 22 by a bolt 27 having a head 28 and extending through a bore in the part 22 into a screwthreaded bore 29 in the part 26. It is important that all the edges of the leading face of the part 26, which are responsible for the tearing action, are rounded (typically having a radius of about 5mm) so as to avoid imparting a cutting action to the cardboard. Furthermore the generally square cross-section of each tooth 16 preferably has a side length of about 30 mm.

Figure 4 shows a detail of the crimping screen 13 from which it will be seen that each of the apertures 17 has generally the shape of a square having rounded corners and having a side length of about 30 mm. The rounded corners typically have a radius of about 5 mm, and the apertures are typically spaced apart in the screen 17 by about 11 mm. The apertures 17 are regularly spaced apart in this manner both in the axial direction and in the circumferential direction of the screen 13, except where interrupted by the ribs 18 along the axial length of the screen 13.

Although the description of the material and its method of production set out above refers to the use of the material as animal bedding, it should be appreciated that the invention also contemplates using the same material for other purposes. For example, the material may be used in various horticultural or agricultural applications, such as for a compost or mulch. It is particularly convenient to use the material in such applications after it has been used as a bedding material as the material will then be mixed with animal excreta.

The large amount of moisture absorbed by the material will render the material particularly suitable as a mulch, and it is believed that the material would be suitable for use as a fire break to be laid along the sides of roads, for example in areas which are liable to bush fires.

It has been found that a compost or mulch formed from a mixture of the animal bedding material with horse excrement, formed for example by use of the animal bedding material in stables, is particularly effective as a soil conditioner and has a good nitrogen content, being about 25 mg/l. Furthermore, the potassium and phosphate contents of the mixture are also high, being about 0.93t and 0.35% respectively. The nitrogen content is about 29.3t, and the dry matter content is about 29.3%. In general terms the mixture is slightly basic, having a pH of about 8.09.

Animal bedding material which has been used for animal bedding, and therefore contains animal excrement, may be allowed to rot down to form a compost or mulch.

Additionally or alternatively, the mixture could be passed through a mixing or shredding machine in order to form a finer mulch. The mixture is particularly suitable for use as a compost or mulch when mixed with wood chips, which could be produced by passing wood through a chipping machine. Such mixing of the animal bedding material with the wood chips can be obtained by passing a mixture of the two materials through a machine broadly similar to that described above. This not only thoroughly mixes the two materials but also has the effect of causing moisture to penetrate the wood chips themselves, thus increasing the moisture retaining properties of the product.

Claims

1. An animal bedding material comprising a plurality of irregularly shaped pieces of cardboard having feathered edges which are formed as by tearing or shearing.

2. An animal bedding material as claimed in Claim 1, wherein the pieces of material are crimped so that a mass of the material occupies a greater volume for a given weight of material than would a mass of material consisting of substantially flat pieces of cardboard.

3. An animal bedding material as claimed in Claim 1 or 2, wherein the pieces of cardboard have maximum dimensions which are in the range of 20 to 100 mm.

4. An animal bedding material as claimed in any preceding claim, wherein the pieces of cardboard have maximum dimensions which are in the range of 30 to 60 mm.

5. An animal bedding material as claimed in any preceding claim, wherein the mean value of the maximum dimensions of the particles is in the range of 40 to 50 mm.

6. An animal bedding material as claimed in any preceding claim, which is substantially dust free, and in which the amount of dust present is at least small enough to avoid irritation to an animal using the bedding, and to avoid harmful effects to the animal's respiratory system during normal use of the bedding material.

7. An animal bedding material as claimed in any preceding claim, wherein the pieces of cardboard are formed from waste cardboard having no more than 5% of its surface area printed with ink.

8. A method of producing animal bedding material comprising tearing a plurality of irregularly shaped pieces from a sheet of cardboard.

9. A method as claimed in Claim 8, wherein the tearing is effected by projecting teeth on a rotating mechanical head.

10. A method as claimed in Claim 9, wherein the teeth have rounded edges so as to avoid cutting the cardboard.

11. A method as claimed in Claim 8 or 9, wherein each of the teeth has a tearing surface having the general shape of a square having rounded edges.

12. A method as claimed in Claim 11, wherein each side of the square has a length of 20 to 40 mm.

13. A method as claimed in Claim 11 or 12, wherein each side of the square has a length of about 30 mm.

14. A method as claimed in any one of claims 8 to 13, which includes the additional step of forcing the irregularly shaped pieces of cardboard through an apertured screen of sufficiently small aperture size to cause crimping of the pieces of material.

15. A method as claimed in Claim 14, wherein each aperture of the apertured screen has the general shape of a square having rounded edges.

16. A method as claimed in Claim 15, wherein each side of the square has a length of 20 to 40 mm.

17. A method as claimed in Claim 15 or 16, wherein each side of the square has a length of about 30 mm.

18. A method as claimed in any one of claims 8 to 17, which includes removing dust laden air from around the pieces of cardboard of the bedding material after effecting said tearing.

19. A method as claimed in Claim 18 and in any one of claims 14 to 17, wherein dust laden air is removed before performing the additional step of forcing the pieces of cardboard through the apertured screen.

20. A method as claimed in Claim 18 or 19, and in any one of Claims 14 to 17, wherein dust laden air is removed after performing the additional step or forcing the pieces of cardboard through the apertured screen.

21. A method as claimed in any one of claims 8 to 20, which further includes, if the animal bedding material produced by the method comprises pieces of cardboard having maximum dimensions both greater than and less than about lOmm, the step of separating the pieces of cardboard having maximum dimensions of less than about lOmm from the rest of the pieces of cardboard.

22. A machine for forming animal bedding material, comprising feed means for feeding sheets of cardboard into the machine, and tearing means for tearing a plurality of irregularly shaped pieces from the sheets of cardboard to form the animal bedding material.

23. A machine as claimed in Claim 22, wherein the tearing means is a rotary mechanical head having projecting teeth.

24. A machine as claimed in Claim 22 or 23, which includes an apertured screen through which the irregularly shaped pieces of cardboard are forced to cause crimping of the pieces.

25. A machine as claimed in any one of claims 22 to 24, which further comprises dust. extraction means for removing dust from the irregularly shaped pieces of cardboard.

26. A compost or mulch formed from a mixture of animal bedding material as claimed in any one of claims 1 to 7, and animal excreta.

27. A compost or mulch as claimed in Claim 26, which further comprises wood chips.

28. An animal bedding material substantially as hereinbefore described with reference to Figure 1 of the accompanying drawings.

29. A machine for forming animal bedding material, the machine being substantially as hereinbefore described with reference to any one of Figures 2, 3 and 4 of the accompanying drawings.