Provided is leather spun yarn with improved physical properties of the leather spun yarn by containing leather fibers longer than conventional leather fibers, in which the leather fiber has an average length of 15 mm or more and 40% or more of the content of fibers of more than 15 mm, in the leather fibers for the leather spun yarn contained in the leather spun yarn formed by containing the leather fibers and synthetic fibers.

Provided is leather spun yarn with improved physical properties of the leather spun yarn by containing leather fibers longer than conventional leather fibers, in which the leather fiber has an average length of 15 mm or more and 40% or more of the content of fibers of more than 15 mm, in the leather fibers for the leather spun yarn contained in the leather spun yarn formed by containing the leather fibers and synthetic fibers.

A process for converting post-industrial or post-consumer waste leather materials to leather fibers is disclosed. The process involves obtaining post-industrial or post-consumer waste leather materials with a surface finish, removing the surface finish, reduced the size of the materials to a size between about 0.5 and about 3 inches in length and in width, and adding a surfactant. After the surfactant has been added, the waste leather materials are again reduced in size to between 3 mm and 9 mm in length to form leather fibers, and a humectant and/or lubricant is added to the fibers, optionally after first opening up with steam. FTIR or other analytical chemistry can be used to identify the surface finishes before they are removed, which allows for selection of the most appropriate treatment to remove the finish.

A process for converting post-industrial or post-consumer waste leather materials to leather fibers is disclosed. The process involves obtaining post-industrial or post-consumer waste leather materials with a surface finish, removing the surface finish, reduced the size of the materials to a size between about 0.5 and about 3 inches in length and in width, and adding a surfactant. After the surfactant has been added, the waste leather materials are again reduced in size to between 3 mm and 9 mm in length to form leather fibers, and a humectant and/or lubricant is added to the fibers, optionally after first opening up with steam. FTIR or other analytical chemistry can be used to identify the surface finishes before they are removed, which allows for selection of the most appropriate treatment to remove the finish.

Medical constructs with twisted cables formed from a plurality of collagen fibers twisted together to form strands and those strands twisted together to form cables and relate methods of twisting the collagen fibers to form the medical constructs while holding the fibers and strands of fibers in tension and twisting in a first direction (i.e., in a clockwise direction), then twisting them in a second opposing (counterclockwise) direction for a number of twists per inch.

Medical constructs with twisted cables formed from a plurality of collagen fibers twisted together to form strands and those strands twisted together to form cables and relate methods of twisting the collagen fibers to form the medical constructs while holding the fibers and strands of fibers in tension and twisting in a first direction (i.e., in a clockwise direction), then twisting them in a second opposing (counterclockwise) direction for a number of twists per inch.

Provided is leather fibers for use in yarn. The leather fibers forming the yarn are obtained from cowhide and a thickness index (M) of the leather fibers satisfies Equation 1:

M=D1/D2?60 [Equation 1]

where D1: average thickness of the 10 fibers having the highest thickness in 1 mg of leather fibers, and D2: average thickness of the 10 fibers having the lowest thickness in 1 mg of leather fibers.

Provided is leather fibers for use in yarn. The leather fibers forming the yarn are obtained from cowhide and a thickness index (M) of the leather fibers satisfies Equation 1:

M=D1/D2?60 [Equation 1]

where D1: average thickness of the 10 fibers having the highest thickness in 1 mg of leather fibers, and D2: average thickness of the 10 fibers having the lowest thickness in 1 mg of leather fibers.

Provided is a leather fiber for leather spun yarn with improved physical properties of the leather spun yarn by containing leather fibers with more improved length, thickness, fineness. The leather fiber has an average length of 15 mm or more and 40% or more of the content of fibers of more than 15 mm, in the leather fibers for the leather spun yarn contained in the leather spun yarn formed by containing the leather fibers and natural fibers or/and regenerated fibers.

Provided is a leather fiber for leather spun yarn with improved physical properties of the leather spun yarn by containing leather fibers with more improved length, thickness, fineness. The leather fiber has an average length of 15 mm or more and 40% or more of the content of fibers of more than 15 mm, in the leather fibers for the leather spun yarn contained in the leather spun yarn formed by containing the leather fibers and natural fibers or/and regenerated fibers.