AU636601B2 - Animal litter and a method for its manufacture - Google Patents

Abstract

The invention relates to a new process for producing animal litter, using fillers and additives which react with water. These fillers are obtained from a fraction from household, industrial and similar waste and/or from paper sludge. The fraction obtained from the waste is pulverised and mixed with the additives, the mixed product is adjusted to a given moisture content and then granulated, and the resulting granulate grains with a specified particle size are separated out. The animal litter produced according to the invention ensures a high deodorising level, high absorbency and has low bulk weight. <IMAGE>

Description

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class 63660 Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Applicant(s): Organ-Faser Technology Company N.V.

de Ruyterkade 62, Curacao, Antilles, THE NETHERLANDS Address for Service is: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Complete Specification for the invention entitled: ANIMAL LITTER AND A METHOD FOR ITS MANUFACTURE Our Ref 166536 POF Code: 1329/58348 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): 6006 6006 TITLE OF THE INVENTION Animal Litter and a method for its manufacture.

TECHNICAL FIELD OF THE INVENTION The invention relates to animal Litter in a solid, granulated form which ensures a high degree of odour retention, has high absorbing power and low apparent density, and a method for its manufacture.

BACKGROUND OF THE INVENTION AND PRIOR ART The known materials for the manufacture of Litter for animals are essentially natural products of mineral origin such as pumice stone, bentonite, clay minerals, for example sepioLite, diatomite, or of organic origin such as wood flour, sawdust and peat which, because of their porous structure, have the property of absorbing liquids in their pores.

For yeas granulated drying and/or absorbing agents have bee'i used for keeping household pets c lean, especially in densely populated urban and suburban areas.

Such products are mostly bought and used in large quarti ties by owners of small animals, in particular cats.

Nowadays a variety of products with very different properties is marketed under the name "cat litter". The majority of these products, as already mentioned above, are manufactured on a mineral basis.

An animal litter of this kind is known, for example, from DE-PS 31 21 403, which is made using a porous inorgani ma terial with a pore s tructure. The porous material used here consists of calcium silicate gr,.nulate and/or calcium si licate powder which has a pH-va lue )between about 5.8 and 6.2.

The known animal litter made from calcium silicate 39 granulate having a pore radius of Less than 500 nm retains its shape and consistency and is bactericidal.

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However, after prolonged use of such materials an unfavourable smell develops so that the animal Litter often has to be changed even though the absorbing power of the material is by no means exhausted.

The afore-mentioned animal Litter products with their different characteristics do, however, have further disadvantages. Their high specific gravity causes great practical problems in the supply and transportation of the packaged product. Some of the animal litter preparations consist of sharp-edged in particular broken stones, which leads pawed animals to avoid the sharp granules.

In relation to the weight of the product the take-up of liquid in many known products is very small. After reaching their absorptive capacity these products tend to swell and thus form clumps. This effect is still more marked in the case of diatomite, which becomes very sticky, greasy and even pasty. These disadvantageous properties necessarily lead to difficulties in handling such products. Because of these product characteristics the litter must also be changed often and as a result more is used.

In the manufacture of these animal litter iiaterials a large proportion of fine dust is formed as a result of the way they are crushed, and by abrasion in the drums or other containers during storage, transport and hindling between the manufacturer and consumer. Handling the open container in the pet owner's home raises a great deal of dust, especially when changing the Litter in the boxes.

In addition this high proportion of fine dust is bad for the animals, since they inhale the dust when s.,ratching in such products.

After use, such water-insoluble stone and/or mineral animal litter products can only be disposed of as or with domestic waste. This causes the waste disposal plants to be burdened with a not insignificant amount of such waste products. In Switzerland and in the Federal Republic of Germany, for example, about 40,000 tons and 500,000 tons respectively of waste consisting of this kind of product accumulates each year. This shows that the market for such (albeit improved) animal litter products is very large, especially in densely populated urban and suburban areas.

OBJECT OF THE INVENTION An object of the invention is to provide a novel animal litter which, by reducing or eliminating one or more of the disadvantages of the prior art, ensures a high degree of odour retention and high absorbing power. A further object is to provide a new method for the manufacture of animal litter.

SUMMARY OF THE INVENTION According to the present invention, there is provided animal litter in a solid, granulated form comprising substantially dry, hard granules having an absorbent organic fibre component, derived from organic waste material, and an absorbent inorganic component, the relative proportions of said organic component and said inorganic component being such as to impart to said animal litter high absorbency and a high degree of odour retention.

The present invention also provides a method for the manufacture of animal litter having an organic component and an inorganic component, said method comprising: pulverising an organic fibre and/or granular fraction obtained from domestic, industrial and other similar waste, mixing the pulverised organic fibre and/or granular fraction with inorganic materials and water, adjusting the mixture from step to a specific moisture content, forming the adjusted mixture into granules, and separating out the granules having a predetermined particle size range as said animal litter, 4 -3 wherein, the relative proportions of said organic component and said inorganic component are such as to impart to said animal litter high absorbency and a high degree of odour retention.

The novel and advantageous properties are bestowed upon the animal litter according to the invention, in particular by the choice, preparation, composition, mixing and processing of the starting material.

For the first time a new animal litter can thus be provided which consists of a granulate having an organic fibre basis, prepared from waste materials and additional materials. For this a precrushed fibre and/or granulate fraction obtained from domestic, industrial and similar waste could be used, which can be manufactured according to DE-PS 31 05 597.

The spherical animal litter granulate according to an embodiment of the invention has the following specification: The (i c r i cwi~ a granulate has a particle size in the range of 1 to 10 mm diameter and is spherical. In the finished animal Litter product spheres of all sizes are advantageously mixed together. In this product, however, the preferred particle size range is from 2 to 5 mm diameter. The granulate also has, according to the invention, an apparent density in the range of 200 to 700 kg/m 3 advantageously in the range of 300 to 500 kg/m 3 The colour of the animaL i tter product according to the invention is greyish to brownish, and can to a large extent be adapted to the desires of the consumer.

The animal litter according to the invention is particularly useful as litter for cats.

Compared with known animal litter products the product manufactured according to the invention has the following advantages. The new litter according to the invention is very easy to handle in comparison to known litter products because it has a low apparent density.

In addition, the product according to the invention does not have a fine dust fraction and is abrasion-free according to the abrasion classification (modified SHELL- Index). Owing to its high absorbing power the litter according to the invention does not need to be changed frequently and thereby reduces use of large amounts so that a longer life or period of use are ensured. The product according to the invention can advantageously be disposed of down the drains or by domestic compost preparation.

To LM tup the n.i M t. i tAo according to the invention has, compared with the known animal li Iter products, the great advantage that with the super ior ab';orp tion or adsorption capacity (high absorbing power) of the granules according to the invention having an organic fibre basis, prepared from waste and used materials with the addition of diverse materials, such as time, calcium hydroxide, gypsum and similar materials and _'4 a certain amount of residual moisture, it not only, as already mentioned, retains its shape and consistency but is also odour-retaining, bactericidal and easy to dispose of.

The invention further relates to a new method for the manufacture of animal. Litter by using a fibre and/or granulate fraction obtained from domestic, industrial and other similar waste. This fraction can be produced according to DE-PS 31 05 597. In this way waste and used materials and/or secondary materials can be used therewith to a great extent. The method according to the invention makes it possible to manufacture the new animal litter mechanically and economically. In this new method it is possible in part to use a known technique (rotating granulating drum) which can also be employed to manufacture other granuLated products, such as ferti lizer, chemical materials, foodstuffs, etc.

BRIEF DESCRIPTION OF THE DRAWING The invention will now be described in more detail with reference to the accompanying drawing, in which Fig. 1 shows a flow diagram of the manufacture according to the invention of an animal litter according to an embodiment of the invention.

DTFAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE

INVENTION

By way of example, the mnanufacture according to the inven ion of the new animal litter having a precrushed organic fibre basis, prepared from waste materials was carried out as fol lows, with reference to Fig. 1.

The following starting matr.rials were used: approx. 60 organic fibres, prepared from waste and used materials (according to DE-PS 31 05 597), approx. 32 Lime or calcium hydroxide or gypsum, approx. 8 water.

The organic fibres, prepared from mixed domestic, industrial and other such waste which can be manufactured according to DE-PS 31 05 597, are stored in a storage bin 1. The pre-crushed organic waste materials are withdrawn in measured amounts from this bin 1 and delivered to a pulverizer 3.

Position 3 then pulverises these materials to dust and the powder made in this way is transported pneumatically (not shown) to a metering bin 4.

This position 4 then conveys the powder, metered by weight, to a mixer 6. The additional materials (lime, calcium hydroxide, gypsum or similar materials) are then metered from a storage bin 4 according to a special formula and sequence and are likewise supplied to the mixer 6.

Water metered from a device 5 is then conveyed to the mixer. This mixer (position 6) can be a known cyclic batch mixer, having the function of mixing the components according to a special program. A conveyor (not shown) conveys the finished mixture to a mixture metering device 7. This mixture metering device has the following functions: a) Storing the mixture and b) metering the mixture.

A mechanical conveyor (not shown) then transports the mixture meter d from the mixture ieotering device 7 to a granulating device 8. The function of the granulating device 8, which in an embodiment of the invention comprises a rotating drum, is to spheroidise the mixed material. The speed, inclination and residence time of the mixture are important for determining its shape. The granulating device can alternatively comprise a plate or 3q a worm.

The shaped pieces obtained are conveyed from position 8 (granulating device) directly to a prescreening device 9. This pre-screening device 9 separates the oversized shaped pieces from those with the maximum final size (10 mm diameter). A conveyor (not shown) transports the oversize pieces back to the mixture metering device 7.

The shaped pieces of litter are then conveyed to a secondary treatment device 10 by a conveyor (not shown).

The function of the secondary treatment device (position 10) is to dust the shaped pieces of litter with a mineral powder. A conveyor (not shown) then transports the dusted shaped pieces to a drier 11. This drier 11 comprises a rotating drum with a heating device (not shown) arranged before it. The function of position 11 is to dry the shaped pieces at a specific temperature, while continually moving and rolling them, from about to 70% water content to a maximum water content of 8 without the shaped pieces being damaged or deformed. At the end of this drying phase hard granules are formed which are conveyed directly to a separating housing 12.

The separating housing (position 12) comprises a settling chamber and a granule discharge outlet and separates the granules from the steam-air mixture that has been formed during drying.

The granules are then taken by a conveyor (not shown) from the outlet of the separating housing 12 rnd transported to a fractionating device 13. This position 13 (fractionating device) separates the granules into two grain sizes. In the method according to the invention the fine grain material, advantageously less than 1 mmi diameter, is supplied to the mixer 6 for recycling by a conveyor (not shown).

The product (granulate) obtained is supplied to a cooling/dust-removing device 14 Likewise by a transporting unit (not shown).

The function of this position 14 (cooLi,ng/dustremoving devi ce), in which there are bui It-in fan~s, is to cool the product, which is still hot, to room temperature and simultaneously remove t>p dust. The cooled product is then conveyed directly to a deodorizing device Posi tion 15 (deodori zing devi ce) comprises a swinging container with a pneumatic injection device and its f unicti on i s to spray the product uniformly wi th the preset fragrance note.

A transporter (not shown) conveys the fini shed animal Litter product to a porti on dispensing device 16.

This dispensing device 16 divides the product stream into portions of the predetermined commercial size and passes these directly to a pack agi.ig device 17. Posi tion 17 (packaging) takes the portions and fi lls them into bags, which are then sea Led immediately and stacked in a con ta i nr.

The average material parameter values, of the animal L lt ter granu Les obtainted according to the ivninwr as follows: apparent densi ty approx 400kg/m3 moisture/liquid take-up Capaci ty between 90 and 12~0 9 water! '100 g Litter p itr ti c t e 5)i 7 v in the range of L' to mm co Lour Light grey water conitont 7 (it 1,011 heat 56.100, 301 Ab r as i on 1 .3 '/00 at 4 kgco- (mrod. 3H1NL- Inldex) T li pr odu e t s manu f aetur(ed in t his~ way aet o rd ri nt to thte methodi or theo inventiot-I ano having an organic f Ibre basi se p r ep a red from waste and used ma ten a Is, c: a n b v 3 used wi th advantage, as ani mat Litter, in part icu tAr a s Li tter for Cats. AS rshown, above the product according to the invention is superior to known commercial products in respect of apparent density, absorption of moisture/Liquid and abrasive behaviour. Since the new product according to the invention is also superior to known commercial products in respect ot odour-retaining power and in the other ways mentioned above it is suitable as a superior animal Litter, in particular as litter for cats.

Claims (15)

1. Animal litter in a solid, granulated form comprising t-S-C\ e n- substantially dry, hard granules having an, organic §component, derived from organic waste material, and an /inorganic component, the relative proportions of said organic component and said inorganic component being such as to impart to said animal litter high absorbency and a high degree of odour retention.

2. The animal litter according to claim 1, wherein said granules have a particle size in the range of 1 to

3. The animal litter according to claim 1, wherein said granules have a particle size in the range of 2 to

4. The animal litter according to any one oL claims 1 to 3 wherein said granules have an apparent density in the range of 200 to 700 kg/m 3 The animal litter according to any one of claims 1 to 4, wherein said granules have an apparent density in 3 the range of 300 to 500 kg/m 3

6. The animal litter according to any one of claims 1 to 5, wherein said granules have been freed from dust and deodorized.

7. The animal litter according to any one of claims 1 to 6, wherein said absorbent inorganic materials are selected from the croup consisting of lime, calcium hydroxide, gypsum and similar materials.

8. The animal litter according to any one of claims 1 to 7, wherein said litter consists of: a) 55 to 65 of said absorbent organic waste mat-rials, b) 30 to 34 of said absorbent inorganic materials selected from lime, calcium hydroxide, gypsum and similar 10 materials, c) 6 to 10 water.

9. The animal litter according to any one of claims 1 to 7, wherein said litter consists of: a) about 60 wt% of said absorbent organic waste maierials. b) about 32 wt% of said absorbent inorganic materials selected from lime, calcium hydroxide, gypsum and similar materials, c) about 8 wt% water. The animal litter according to any one of the preceding claims, which has a moisture/liquid take-up capacity between 90 and 120 g water/100 g litter.

11. A method for the manufacture of animal litter having an organic component and an inorganic component, said method comprising: pulverising an organic fibre and/or granular fraction obtained from domestic, industrial and other similar waste, mixing the pulverised organic fibre and/or granular fraction with inorganic materials and water, adjusting the mixture from step to a specific moisture content, forming the adjasted mixture into granules, and separating out the granules having a predetermined particle size range as said animal litter, wherein, the relative proportions of said organic component and said inorganic component are such as to impart to said animal litter high absorbency and a high degree of odour retention.

12. The method for the manufacture of animal litter according to claim 11, wherein said shaped pieces undergo a secondary treatment having the following steps: adding dust to and then drying the shaped pieces, repeated fractionation of the resulting granules 11 into the predetermined particle size range, cooling and removing dust from the granules.

13. The method for the manufacture 'of animal litter according to claim 1.2, wherein said secondary treatment further includes the step of deodorizing the cooled and dust-free granules.

14. The method for the manufacture of animal litter according to any one of claims 12 or 13, wherein in the drying step the shaped pieces are dried in a rotating drum at a specific temperature from 40 to 70% water content to a maximum water content of 8%.

15. The method for the manufacture of animal litter according to any one of claims 11 to 14, wherein, after the separation, the remaining shaped pieces are returned to the mixture.

16. The method for the manufacture of animal litter according to any one of claims 12 to 15, wherein fine grained material, having a particle size less than said predetermined particle size range, obtained by the fractionation is added back to the mixture.

17. The method for the manufacture of animal litter according to claim 16, wherein the fine grained material has a particle size smaller than Imm diameter. DATED: 11 August 1992 PHILLIPS ORMONDE FITZPATRICK 4 Attorneys for: ORGAN-FASER TECHNOLOGY COMPANY N.V. 3195Z 12