Abstract: Bonding of leather to leather without the use of any adhesives is achieved by pressing together the two leather portions to be bonded at a pressure of at least about 50 bar and at a bonding temperature of from about 60.degree. to about 200.degree. C. for at least 10 seconds and subsequently cooling them or allowing them to cool while maintaining a pressure of at least about 10 bar at any time during said cooling when the temperature is above about 85.degree. C., the entire process being conducted in an oxygen-poor environment.

Abstract: A novel thermoplastic composition of matter is produced by subjecting leather, especially particulate leather scrap optionally admixed with one or more additives and/or fillers, to the action of a pressure from about 200 to 900 bar, at a temperature from about 50.degree. to about 250.degree. C. in a closed die for a time of at least about 30 seconds.