A method of dyeing collagen fiber includes providing collagen fiber and dyeing the collagen fiber.

An animal leather fiber bundle, yarn, core-spun yarn and products with nanoscale branches is disclosed. The animal leather fiber bundle with nanoscale branches has an animal leather fiber body, which is a spinnable animal leather fiber body. The animal leather fiber body has nanoscale branches, the yarn is formed of animal leather fiber bundles with nanoscale branches, the core-spun yarn has a core yarn and a skin layer, the skin layer has animal leather fiber bundles with nanoscale branches, and the product is made of any one of the above. The disclosed structure has independent and separated nanoscale branches.

An animal leather fiber bundle, yarn, core-spun yarn and products with nanoscale branches is disclosed. The animal leather fiber bundle with nanoscale branches has an animal leather fiber body, which is a spinnable animal leather fiber body. The animal leather fiber body has nanoscale branches, the yarn is formed of animal leather fiber bundles with nanoscale branches, the core-spun yarn has a core yarn and a skin layer, the skin layer has animal leather fiber bundles with nanoscale branches, and the product is made of any one of the above. The disclosed structure has independent and separated nanoscale branches.

Methods of using of natural or engineered proteins such as collagen to form tanned and/or crosslinked fibers suitable for a wide range of textile manufacturing processes, including non-woven, woven and knitted fabrics. In particular, described herein are methods of forming collagen fibers formed from cell-cultured materials by forming a solution of collagen, tanning agent and in some variations cross-linker, and shortly thereafter, extruding collagen fibers. Also described herein are collagen fibers formed by these methods.

Provided are leather fibers for yarn. The leather fibers forming the yarn are obtained from cowhide. An amount of the leather fibers having an H value of 30 or more is 30% by weight or more of a total leather fibers contained in the yarn. The H value is defined by the following Equation 2: [Equation 2] H=L/D where L: leather fiber length, and D: leather fiber thickness. A thickness index (M) of the leather fibers satisfies Equation 1: [Equation 1] M=D1/D2?60 where D1: an average thickness of 0 fibers having a highest thickness in 1 mg of leather fibers, and D2: an average thickness of 10 fibers having a lowest thickness in 1 mg of leather fibers.

Provided are leather fibers for yarn. The leather fibers forming the yarn are obtained from cowhide. An amount of the leather fibers having an H value of 30 or more is 30% by weight or more of a total leather fibers contained in the yarn. The H value is defined by the following Equation 2: [Equation 2] H=L/D where L: leather fiber length, and D: leather fiber thickness. A thickness index (M) of the leather fibers satisfies Equation 1: [Equation 1] M=D1/D2?60 where D1: an average thickness of 0 fibers having a highest thickness in 1 mg of leather fibers, and D2: an average thickness of 10 fibers having a 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, and the like 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.

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, and the like 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.

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, and the like 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 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, and the like 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 natural fibers or/and regenerated fibers.