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United States Department of Agriculture

Agricultural Research Service

Research Project: Environmentally Friendly Processes and New Applications for Animal Hides and Leather

Location: Biobased and Other Animal Co-Products

Project Number: 8072-41440-019-00
Project Type: Appropriated

Start Date: Jun 24, 2010
End Date: Jun 23, 2015

Objective:
1. Develop commercially viable hide preparation and leather processing methods that are environmentally friendly while maintaining and improving the quality and/or value of hide products. 1A: Develop computational and laboratory models for predicting the effectiveness of new chrome-free tanning agents. 1B: Develop improved environmentally friendly processes for hide preparation. 2. Create commercially viable hide-quality sensing technologies that are more rapid, accurate, precise, nondestructive, and cost-effective than current systems. 3. Develop technologies that enable new products from hides such as green composites (reinforced with hide fibers), nonwoven fabric filters, and new fillers and coatings for leather. 3A: Develop green composites and fibrous materials from hides. 3B: Develop new applications for tanning waste.

Approach:
To develop a basis for designing or selecting effective chrome-free tanning agents, the results of studies of the interactions between collagen and current or proposed tanning processes will be integrated to give the best overall evaluation. The ERRC computational molecular model of collagen will be used to predict how the secondary or tertiary structure of collagen might be affected by a proposed modification. The model can predict if the modifier will fit into the structure, and how likely is the modifier to attach to telopeptide residues or form bonds with sidechains in the end-to-end gap between triple helices. Bench scale experimental model systems using collagen at different stages of molecular complexity (soluble collagen, milled collagen or powdered hide) will be used to evaluate by physical, chemical and biochemical methods the effect of these modifications on collagen. The development of effective and eco-friendly methods for removal of manure and other organic contaminants from animal hides will build on the incorporation of glycerol or biosurfactants or combination of both. Methods to enhance hide preservation using less salt or salt-free alternatives will also be developed. Environmental and economic concerns in terms of obtaining better quality hides and higher returns are the major criteria for developing and accepting new and alternative cleansing and preserving techniques. The goal is to not completely remove all of the manure prior to processing but to achieve a state where the manure/hair adhesion can be broken by a mechanical removal process without removing the hair at the root or tearing the grain. The advanced evaluation technology for the detection of hide defects and the evaluation of hide quality will be developed by incorporating airborne ultrasonic (AU) technology. Green composites will be designed and prepared with gelatin as the matrix reinforced with collagen fiber networks. Both components will be derived from hides. In addition, new fibrous products such as filters having a nonwoven fibrous structure will be prepared from fine diameter collagen fibers (fibrils). Collagen fiber networks will be obtained from split hides that have been processed to remove the noncollagenous materials. The use of chemical and biochemical techniques for enhancing the properties of tanning byproducts will proceed concurrently with the work on tanning. To demonstrate a potential role for protein recovered from leather waste, used alone or in conjunction with other renewable agricultural resources, model systems will be developed, in which these renewable resources will be treated with known chemoenzymatic crosslinking agents to determine functional properties. Effects then will be made to establish if these products would be appropriate to be used in leather processing, for example as potential fillers, coatings and encapsulating agents. Aqueous gelatin will also be combined with fibrous protein waste products, such as chrome shavings, buffing dust, feathers, and meat & bone meal, and then the mixture will be modified with enzyme to prepare products, such as films, with unique functional properties.

Last Modified: 11/23/2014
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