RAWHIDE ANIMAL CHEW INCLUDING MICROPORES FILLED WITH CHITOSAN
A microporous animal chew comprising a rawhide sheet having a thickness in the range of 0.1 millimeters to 3.0 millimeters and a plurality of micropores extending through said rawhide sheet at least partially filled with chitosan. The rawhide sheet provides a digestible yet chewable and durable animal chew.
1 . A microporous animal chew comprising:
a rawhide sheet having a thickness in the range of 0.1 millimeters to 3.0 millimeters;
a plurality of micropores in said rawhide sheet, wherein said micropores exhibit a longest linear dimension across a cross-section of said micropores in the range of 1 micrometer to 2,000 micrometers, are present at a density of 1 to 100 pores per square centimeter; and
wherein said micropores are at least partially filled with chitosan.
2 . The microporous animal chew of claim 1 wherein said rawhide sheet has two sides and said micropores are present on one side of said rawhide sheet.
3 . The microporous animal chew of claim 1 wherein said rawhide sheet has two sides and said micropores are present on both sides of said rawhide sheet.
4 . The microporous animal chew of claim 1 wherein said chitosan is present as a film layer in said micropores.
5 . The microporous animal chew of claim 1 wherein said plurality of micropores are completely filled with chitosan.
6 . The microporous animal chew of claim 1 wherein said plurality of micropores extend partially through said rawhide sheet.
7 . The microporous animal chew of claim 1 wherein said plurality of micropores extend completely through said rawhide sheet.
8 . The microporous animal chew of claim 1 wherein said micropores have a penetration depth in said rawhide sheet of 0.1 millimeters to 3.0 millimeters.
9 . The microporous animal chew of claim 1 wherein said rawhide sheet includes a surface region between said micropores and said surface region includes a layer of chitosan.
10 . The microporous animal chew of claim 1 , wherein said rawhide sheet is in the form of a roll, ring, pretzel, stick, braid, chip or knotted to assume the general geometry of a bone or a knotted bone.
11 . The microporous chew of claim 1 wherein said chew has a water content of 1% to 20% by weight.
12 . A method of forming a microporous animal chew, comprising:
providing a wet rawhide sheet having a thickness in the range of 0.5 millimeters to 4.0 millimeters including water present at 60% to 80% by weight of the total weight of the rawhide sheet or greater;
piercing said rawhide sheet with pins and forming micropores in said rawhide sheet, wherein said micropores have a largest linear cross-sectional length in the range of 1 micrometer to 2,000 micrometers and are arranged to provide a pore density in the range of 1 to 100 pores per square centimeter;
partially filling said micropores with chitosan; and
drying said rawhide sheet, wherein said rawhide sheet includes 1 to 20% by weight water of the total weight of the rawhide sheet.
13 . The method of claim 12 , further comprising removing a portion of water present in said rawhide sheet prior to drying.
14 . The method of claim 12 , further comprising stretching said rawhide sheet prior to drying.
15 . The method of claim 10 , wherein said rawhide sheet is provided between a carrier plate and a receiving plate, wherein said carrier plate carries said pins, and piercing said rawhide sheet includes forcing said plates together.
16 . The method of claim 15 , wherein said receiving plate includes holes to receive said pins therein.
17 . The method of claim 15 , further comprising compressing said rawhide sheet between said plates to remove at least a portion of water present in said rawhide sheet.
18 . The method of claim 10 , wherein said rawhide sheet is fed into calender rollers, wherein one of said rollers includes said pins and said pins pierce said rawhide sheet as said pins bear against a bearing roll.
19 . The method of claim 18 , further comprising compressing said rawhide sheet between a squeeze roll and said bearing roll and removing a portion of said water present in said rawhide sheet.
20 . The method of claim 19 , further comprising stretching said rawhide sheet prior to drying by passing said rawhide sheet between tenter rolls.
21 . The method of claim 10 , further comprising filling said micropores with a support additive prior to drying.
22 . The method of claim 10 , wherein said pins pierce said rawhide sheet at an angle α relative to a surface of said rawhide, wherein α is in the range of 10 to 80 degrees.
23 . The method of claim 22 , wherein said micropores exhibit a length that is greater than the thickness of said rawhide sheet.
24 . The method of claim 12 wherein said wet rawhide sheet includes a rawhide resin composition.
25 . The method of claim 10 wherein said dried rawhide has a thickness of 0.1 millimeters to 3.0 millimeters.