Extruded self-clumping cat litter

Patent metadata

Field	Value
Publication number	US-12550864-B2
Application number	US-202217960125-A
Country	US
Kind code	B2
Filing date	Oct 4, 2022
Priority date	Mar 25, 2015
Publication date	Feb 17, 2026
Grant date	Feb 17, 2026

Abstract

Litter formed of extruded pellets containing water soluble binder sufficient to self-clump when wetted producing pellet clumps having a clump retention rate of at least 90% and which shrink after clump formation during drying producing a clump pulls away from any contacting solid surface minimizing adhesion therebetween. Such clumps preferably also have a crush strength of at least 15 PSI when dry. Pellets preferably contain water-soluble binder formed of starch physically modified during extrusion that solubilizes when wetted to facilitate clumping while opening the interior of the pellet improving absorption capacity. A preferred litter is formed of a mixture of extruded pellets of different sizes producing litter composed of extruded pellets falling within a plurality of different size ranges with the smaller sized pellets being fines that cause horizontally extending clumps to form on top of the litter.

First claim

What is claimed is:

1 . A method of making extruded granular sorbent comprising:
(a) providing a single screw extruder and a starch-containing admixture having a moisture content of no greater than 30% by weight, the starch-containing admixture comprised of at least one cereal grain; (b) subjecting the starch-containing admixture in the single screw extruder to a pressure of at least 1000 pounds per square inch at a temperature of at least 125° Celsius for a residency time within the single screw extruder of no greater than 12 seconds modifying at least some of the starches in the starch-containing admixture into a water-soluble binder; and (c) extruding starch-containing absorbent pellets from the single screw extruder that are each comprised of at least 7.5% of the water-soluble binder by pellet weight.

2 . The method of claim 1 , wherein dextrinization occurs during extrusion of the starch-containing absorbent pellets.

3 . The method of claim 1 , wherein the water-soluble binder is comprised of starch modified during extrusion into having a molecular weight of no greater than 10 6 g/mol.

4 . The method of claim 3 , wherein the water-soluble binder is comprised of starch modified during extrusion into having a molecular weight of no greater than 10 5 g/mol.

5 . The method of claim 1 , wherein the water-soluble binder is comprised of starch that is physically modified during extrusion into having a molecular weight of no greater than 10 6 g/mol.

6 . The method of claim 1 , wherein the water-soluble binder is comprised of starch that is dextrinized during extrusion into having a molecular weight of no greater than 10 6 g/mol.

7 . The method of claim 1 , wherein the water-soluble binder is comprised of starch modified during extrusion into having a degree of polymerization of no greater than 6,000 glucose units.

8 . The method of claim 1 , wherein the water-soluble binder is comprised of starch modified during extrusion into having a degree of polymerization of no greater than 5,000 glucose units.

9 . The method of claim 1 , wherein the water-soluble binder is comprised of starch modified during extrusion into having a degree of polymerization of no greater than 3,000 glucose units.

10 . The method of claim 1 , wherein the water-soluble binder is comprised of starch modified during extrusion into having a molecular weight of no greater than 10 6 g/mol and a degree of polymerization of no greater than 6,000 glucose units.

11 . The method of claim 1 , wherein the water-soluble binder is comprised of starch modified during extrusion into having a mean molecular weight of within ±75% of 504.43708 g/mol.

12 . The method of claim 11 , wherein the water-soluble binder is comprised of dextrin.

13 . The method of claim 1 , wherein the water-soluble binder in each extruded starch-containing absorbent pellet is comprised of a water-soluble amylopectin binder having a molecular weight less than that of the unmodified amylopectin starch of the cereal grain or cereal grains of the starch-containing admixture from which each extruded starch-containing absorbent pellet was extruded.

14 . The method of claim 1 , wherein each extruded starch-containing absorbent pellet is comprised of starch containing at least 70% starch damage as measured in accordance with AOAC: 2002.02.

15 . The method of claim 1 , wherein each extruded starch-containing absorbent pellet has a water activity level of no greater than 0.35.

16 . The method of claim 1 , wherein each extruded starch-containing absorbent pellet comprises a partially dissolving starch-containing absorbent pellet that at least partially dissolves when wetted with water.

17 . The method of claim 1 , wherein a cat litter comprised of the extruded starch-containing absorbent pellets contains no more than 5% dust by weight of the cat litter.

18 . The method of claim 1 , wherein a cat litter comprised of the extruded starch-containing absorbent pellets forms a clump when wetted with 10 milliliters of a 2% saline solution that has a clump retention rate of at least 95%.

19 . The method of claim 1 , wherein a cat litter comprised of the extruded starch-containing absorbent pellets forms a clump when wetted with 10 milliliters of a 2% saline solution that has a clump retention rate of at least 98%.

20 . The method of claim 1 , wherein a cat litter comprised of a plurality of pairs of the extruded starch-containing absorbent pellets forms a flowable adhesive when wetted with room temperature water, the flowable adhesive having a viscosity of at least 200 centipoise within one second after wetting with the water, a viscosity of at least 300 centipoise after one second and within five seconds after wetting with the water, a viscosity of at least 400 centipoise after five seconds and within 10 seconds after wetting with the water, and a viscosity of at least 1000 centipoise after 10 seconds and within 30 seconds after wetting with the water, where the viscosity is measured with a Brookfield DV3T viscometer at a spindle rotation of 50 RPM.

21 . The method of claim 20 , wherein the water-soluble binder in each one of the extruded starch-containing absorbent pellets comprises a cold-water soluble binder that is water soluble at a temperature below 60 degrees Celsius or 140 degrees Fahrenheit.

22 . The method of claim 21 , wherein the water-soluble binder in each one of the extruded starch-containing absorbent pellets comprises a cold-water soluble binder that is water soluble at a room temperature of between 68° F. and 74° F.

23 . The method of claim 1 , wherein during step (b) the starch-containing admixture is subjected to a pressure of at least 1000 pounds per square inch at a temperature of at least 125° Celsius for a residency time within the single screw extruder of between 4-11 seconds.

24 . The method of claim 23 , wherein during step (b) the starch-containing admixture is subjected to a pressure of at least 1000 pounds per square inch at a temperature of at least 125° Celsius for a residency time within the single screw extruder of between 5-10 seconds.

25 . The method of claim 24 , wherein the single screw extruder comprises one of a 50 horsepower and a 100-horsepower single screw extruder.

26 . The method of claim 25 , wherein the starch-containing admixture contains no smectite nor any binder additive.

27 . The method of claim 26 , wherein the starch-containing admixture contains no bentonite.

28 . The method of claim 27 , wherein the starch-containing admixture is comprised of at least one of sorghum, corn, wheat and rice.

Assignees

• Pioneer Pet Products Llc

Inventors

• Lipscomb John M

Classifications

• A01K1/0155 Primary

  comprising organic material · CPC title

• A01K1/0154

  comprising inorganic material · CPC title

• A01K1/0152 Primary

  Litter · CPC title