The present invention relates to a polyamide fiber with enhanced dyeing properties. The polyamide fiber is suitable for low-temperature dyeing and shorter dyeing cycle. The present invention also discloses a method for obtaining such a fiber. The polyamide fiber is obtained by blending at least a polyamide 5.X, X being an integer from 4 to 16 with an aliphatic polyamide during the melt-spinning extrusion of the polyamide fiber. The blended polyamide fiber and articles made therefrom can be dyed at a lower temperature than the usual boiling temperature, and the dyeing time is half of the time of a normal dyeing cycle. The dyed polyamide fiber and article also show enhanced fastness to washing and perspiration.

A polyurethane is dyed with an aqueous solution of an acid dye compound, a quaternary ammonium compound selected from soluble tetrabutylammonium compounds and tetrahexylammonium compounds, and, optionally, an water-soluble organic solvent.

Disclosed are a composition and process useful for the trichromatic dyeing of polyamide textile fibers. The composition has a yellow component, a red component and a blue component and wherein the red component includes the mixture of Acid Red 361 and Acid Red 419.

A method is provided for treating the surface of a shaped melded part produced with a plastic having ester, ketone and/or ether bonds. The plastic is selected from the group including a polymer, copolymer, polymer blend and combinations of the same. The method includes a pretreatment step for cationically modifying the surface of the melded shaped part. The cationic modification is carried out with a reactant dissolved in a solvent and having one or more amine, imine and/or amide groups.

A method for dyeing a hook-and-loop fastener strap is disclosed. The hook-and-loop fastener strap continuously passes through a basic or neutral dyeing solution in a dyeing device. The dyeing solution attaches itself to the hook-and-loop fastener strap. The dyeing solution has a dye that binds to the hook-and-loop fastener strap only when the dyeing solution is in an acidic state. After passing through the dyeing device, the hook-and-loop fastener strap with the deposited dyeing solution is passed through a damper, causing the dyeing solution to become acidic. The dye adheres to the hook-and-loop fastener strap to dye the hook-and-loop fastener strap. A dyeing system for implementing the method is also disclosed.

Fibers including a polyurethane or a protein polyurethane alloy. The fibers include a core defined by the polyurethane or the protein polyurethane alloy. The fibers including a protein polyurethane alloy include a protein dissolved within a polyurethane. In some embodiments, the fibers can be made by wet spinning a blended mixture of the polyurethane or protein polyurethane alloy and an organic solvent. In alternative embodiments, the fibers can be made by wet spinning a blended mixture of the polyurethane or protein polyurethane alloy and an aqueous polyethylene oxide solution.

Provided are methods of continuously imparting a desired characteristic, optionally color, to a linear polymeric substrate with reliability and reproducibility. According to some aspects, a method of continuously bonding an active agent to or into a polymeric substrate may include contacting an active agent solution with a polymeric substrate. Contacting the active agent solution with the polymeric substrate may occur at a treatment temperature and for a treatment time. The active agent solution may have been prepared from a method including diluting the treated active agent precursor solution to form the active agent solution.