AND METHOD OF MAKING SAME

Background of the Invention

This invention relates to the provision of hydrophobic material manufactured from scrap waxed cardboard and/or a combination of the waxed cardboard and waste paper. Two products have been invented, one a kitty litter product and the other a product which absorbs oil.

The invention relates to the ongoing search to recycle materials and to provide means for cleaning oil waste such as in garages and plants using heavy machinery and the like.

The invention deals particularly with waxed boxes of the type used for meat and poultry as well as of the type used for vegetables and fruit. Generally, waxed cardboard is of two types. Curtain coated cardboard is commonly used in boxes for meat and poultry wherein meat juices and the like would soak through unwaxed cardboard. To preserve the strength of the cardboard, a heavy wax coating in the form of a curtain is laid onto the cardboard, hence the name curtain coating. This type of cardboard box may be curtain coated on one or on both sides. The other type of waxed cardboard commonly used is saturated cardboard which is commonly used for fruit and vegetable boxes where the amount of moisture encountered is less. The oil absorbing product of this invention may be made with either or both of the curtain coated or saturated cardboard whereas the kitty litter product hereinafter described must be made with at least a certain amount of curtain coated waxed cardboard.

The invention consists of certain novel features and a combination of parts hereinafter fully described, and particularly pointed out in the appended claims, it being understood that various changes in the details may be made without departing from the spirit, or sacrificing any of the advantages of the present invention.

Summary of the Invention

It is an object of the invention to provide an oil absorbing material made from waste waxed cardboard.

It is another object of the invention to provide methods of manufacturing both the oil absorbing material and the kitty litter material.

Description of the Preferred f_nbn .τn__nt

The highly oil absorbent material hereinafter described is made principally from waxed cardboard and may be made from any combination of single or double sided curtain coated cardboard or saturated cardboard. The material in its final form is a fluffy slightly hydrophobic and hydrophilic cellulosic material having wax distributed or bonded throughout the fluffy cellulose fibers. The oil absorbing material is made by introducing the feedstock of curtain coated or saturated wax cardboard into a hammer mill. The product which comes out of the hammer mill is physically altered and perhaps chemically altered in the sense that the waxed cardboard entering the hammer mill is slightly hydrophilic but the material which exits the hammer mill is slightly hydrophobic. It is believed that during the processing operation the wax is somehow distributed throughout and perhaps chemically bonded to the cellulosic fibers, thereby accounting for the change from slightly hydrophilic to slightly hydrophobic and hydrophilic characteristics. In addition, when wax is attempted to be dissolved from the final product, very little of the wax was dissolvable by a solvent from the hammered product whereas considerably more wax was dissolvable from the initial waxed cardboard. It may be that during the process the wax is melted and a chemical reaction takes place between the cellulose fibers and the melted wax, but this is not presently known. What is apparent is that the product coming out of the hammer mill or in the preferred method two successive hammer mills each operating at about 3600 rpm is physically altered and perhaps chemically altered in the sense that the product exiting the second hammer mill is slightly hydrophobic whereas the material entering the first hammer mill is slightly hydrophilic. The term "cellulosic fibers having wax distributed throughout" as used herein means the product from the hammer mill, whether or not there

is both a physical and chemical alteration or only a physical.

In the oil absorbing material of the present invention, waste or scrap waxed cardboard is torn, cut or shredded into smaller pieces and introduced into one of two serially connected hammer mills each operating at 3600 rpm. The material exits the first hammer mill and is introduced into a second hammer mill for further processing. When the product enters the second hammer mill, it is passed through a 3/8" mesh screen after which the product is in its final fluffy slightly hydrophobic condition. The material may be then packaged in a variety of configurations and used to absorb oil in garages, machine shops and the like. The material may be used as a loose fill or it may be packaged in cylinders such as a tube sock and used for dams in oil spills on oceans or lakes. The product is extremely oil absorbent.

The kitty litter product is an improvement over present kitty litter products which are made of fullers earth because fullers earth is not combustible and thereby presents an environmental disposal problem not encountered with the present product. In order to make a kitty litter product according to the present invention, curtain coated waxed cardboard must be used rather than the saturated material previously discussed. The curtain coated waxed cardboard is mixed with normal waste paper which may be newspaper, any other waste paper available, magazine slicks or any combination thereof. A disadvantage with magazine slicks is that they contain fullers earth and so to a small degree there will be a residue remaining whereas except for the fullers earth present in magazine slicks, the material is completely combustible in any commercial incinerator.

The mixture which is fed to the hammer mill as previously described is paper and waxed curtain coated cardboard present in an amount not less than about 1% by weight and preferably about 5% by weight. The preferred mixture is 95% by weight paper and 5% by weight curtain coated cardboard which is fed into successive hammer mills.

The product in the second hammer mill is then forced through 3/8" screen and is transported therefrom to a machine which is used to form a dense solid product such as a pellet. When a pellet is preferred for the kitty litter product, a normal extrusion die is used to produce, for instance, a 5/16" diameter by 1" long pellet. It is understood that pellets of various lengths and diameters may be used as desired. In addition, briquettes may be formed of the material which is forced through the 3/8" screen and this may also be advantageous for the kitty litter product.

The kitty litter product of the present invention in the form of 5/16" x 1" pellets is advantageous because the material is slightly hydrophobic and retains its integrity in water. When used as a kitty litter, this means that the cat urine will seep farther down into the kitty litter before being absorbed while the feces remains at or near the top even after being buried by the animal. Because it is the contact of the urine with the feces which produces an offensive "cat box" odor, this kitty litter is advantageous over presently available kitty litters in that the subject invention serves to separate the urine from the feces. In addition, as before stated, another advantage to the present invention is that the kitty litter formed from this invention is completely combustible in a commercial incinerator thereby leaving no residue for disposal. The material will retain its integrity even when exposed to urine or water and will not disintegrate as will newspaper when wet. Even though the product may be from 95% to 99% paper, it sill retains its form and shape upon exposure to moisture.

It is clear from the foregoing, that two products have been produced from waste waxed cardboard and a mixture of waxed cardboard and waste paper, both products being environmentally safe and providing advantages in that materials normally discarded can now be used for beneficial products.

It is clear that various additives may be included with the kitty litter such as perfumes, or other additives.

Tests with the kitty litter have shown that the pellets can be produced as dense solids having a density in the range of from about 2 lbs. per cubic foot to about 14 lbs. per cubic foot. Further, it should be noted that products with varying moisture content may be produced and it is well within the scope of this invention to produce products with predetermined moisture content.

While there have been disclosed herein solid kitty litter pellets and briquettes, it should be understood that various other forms such as granulated material can be made by a variety of compacting or extruding processes, all well known in the art.

While there has been disclosed what is considered to be the preferred embodiment of the present invention, it is understood that various changes in the details may be made without departing from the spirit, or sacrificing any of the advantages of the present invention.