Methods are directed to the use of a supercritical fluid for performing a dyeing of a material such that dye from a first material is used to dye a second material. A supercritical fluid is passed through a first material in a pressurized vessel. The supercritical fluid transports the dye from the first material to at least a second material causing a dye profile of the second material to change as a result of dye from the first material perfusing the second material.

A machine for dyeing reels of yarn and textile fibers wound on packages, including: a structure delimiting a chamber partially or fully filled with a dyeing fluid; a support immersed in the dyeing fluid; a plurality of reel-holder rods that communicate via the fluid with the support to allow the dyeing fluid to pass the support; first and second recirculation mechanisms associated with the structure, to initiate transit of the dyeing fluid in accordance with at least one set route is described. The first recirculation mechanism interposed between the chamber and the support induces the dyeing fluid to pass through the reel-holder rods and includes a pump and respective selection mechanisms to intermittently channel the dyeing fluid through the support, the reel-holder rods, and the respective reels. The second recirculation mechanism induces transit of the dyeing fluid within the chamber in accordance with at least one closed route.

A machine for dyeing reels of yarn and textile fibers wound on packages, including: a structure delimiting a chamber partially or fully filled with a dyeing fluid; a support immersed in the dyeing fluid; a plurality of reel-holder rods that communicate via the fluid with the support to allow the dyeing fluid to pass the support; first and second recirculation mechanisms associated with the structure, to initiate transit of the dyeing fluid in accordance with at least one set route is described. The first recirculation mechanism interposed between the chamber and the support induces the dyeing fluid to pass through the reel-holder rods and includes a pump and respective selection mechanisms to intermittently channel the dyeing fluid through the support, the reel-holder rods, and the respective reels. The second recirculation mechanism induces transit of the dyeing fluid within the chamber in accordance with at least one closed route.