Degradable Animal Chewing Article Possessing Enhanced Safety, Durability, and Mouth-Feel

Abstract

A chewable, biodegradable article for use as a pet toy comprises a matrix made of a natural polymer, a synthetic organic polymer or a mixture thereof, a natural or synthetic fibrous material that comprises fibers and that is bonded chemically or physically with the matrix material, and, optionally, includes one or more microbe inhibiting agents that inhibit the growth of microbes in or on the article. The presence of the fibrous material inhibits formation of sharp edges upon breakage when the article is chewed, thereby rendering the article safer when used by pets. Also disclosed are processes for manufacturing the above article.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional of U.S. patent application Ser. No. 10 / 249,578, Apr. 21, 2003, now U.S. Pat. No. 6,972,133, issued Dec. 6, 2005, which is a divisional U.S. patent application Ser. No. 09 / 578,199, filed May 24, 2002, now U.S. Pat. No. 6,576,246, issued Jun. 10, 2003, which claims the benefit of U.S. provisional patent application Ser. No. 60 / 135,672, filed May 24, 1999.FIELD OF THE INVENTION [0002] The invention relates to chewable articles intended primarily as chew toys for dogs or other domestic animals. DESCRIPTION OF THE RELATED ART [0003] Chewable animal articles such as artificial bones for dogs have been made of many materials and in many configurations and sizes. These have been made of compressed natural or food materials with a binding agent; some are made of synthetic polymers, as polymers mixed with protein (U.S. Pat. No. 4,681,758), nylon (U.S. Pat. No. 3,871,334) or polyurethane (U.S. Pat. Nos. 4,557,219 a...

AI Technical Summary

Benefits of technology

[0017] wherein, the presence of the fibrous material inhibits formation of sharp edges upon breakage when the article is chewed. The invention provides composite materials for safer and more durable chewable articles for pets.

[0023] In contrast to the '925 patent, the present invention utilizes polymeric materials which are processed in radically different way (polymer melt processing) than are the “biscuits” of the '925 patent (baking). Processing in the present invention involves elevated temperatures, shear rates, and pressures, resulting in final articles with profoundly different microstructural characteristics, such as a, relative lack of correlation in spatial distribution of the fibers (no spanning structures or clumping). Furthermore, the nature of the matrix in the present invention differs fundamentally from that in the '925 patent in that it is self-supporting. Thus, the polymers of the present chewable articles possess great cohesiveness and structural integrity on their own (without added fibers). Fibers (and / or other materials) are added to the articles of the present invention (1) to affect favorably the nature of the breakage processes and (2) to improve the “mouth-feel”, all thee while without sacrificing desirable mechanical properties and degradability.

Problems solved by technology

The durability of such articles is therefore intrinsically limited.

If a chewable article is too soft, it is too easily ripped apart or shredded during use.

On the other hand, if the article is too hard, it may tend to crack, shatter, or splinter.

This tendency to splinter upon breakage or when otherwise structurally damaged is highly undesirable.

Splintering leads to sharp edges that can cause injury and lead serious health problems for the animal, especially if sharp-edged material is swallowed.

Moreover, small pieces breaking from the articles may also be swallowed and contribute to health problems.

Such fibers may or may not be digestible by the animal.