Fixation of the Printed Fabric

Depending on the layout of the printing plant, the printed fabric may go through the fixation process immediately following drying or it may be held to go to fixation later. The type of colorant and production issues of the printing operation dictate the choice. Fixation can be accomplished through several different heating mechanisms such as atmospheric steaming, high-temperature steaming, or curing, also known as baking. 

For dyes, fixation normally incorporates an atmospheric steamer with specified moisture content and a nominal temperature of 212 degrees Fahrenheit or 100 degrees Celsius. With certain dyes, an auxiliary chemical may be necessary as an extra additive to the print paste. For example, reactive dyes require additional alkali for complete fixation. In the case of vat dyes, reducing agents are necessary. For pigments on all fibers and disperse dyes for polyester or nylon, only high temperatures are necessary. For the binder to polymerize and form a film trapping the pigment on the fabric, the water must be removed from the printed fabric. This is usually accomplished with dry heat in a curing oven or a finishing tenter frame oven. The key issue for pigments is reaching an appropriate temperature for the particular synthetic binder which is usually between 150 and 163 degrees Celsius. Disperse dyes require energy in the form of heat to move from the surface of the fiber into the core of the fiber where they are trapped. This energy can be in the form of dry heat or superheated steam.