Method and apparatus for fixing a binding agent

An apparatus for the thermal treatment of a web of material in a closed chamber for the polymerization of the binding agent of a dyestuff on the web of material, the apparatus comprising:

• a closed chamber;
• the chamber having an inlet;
• first driven means for feeding the web into the chamber via the inlet at a predetermined velocity;
• the chamber having an outlet;
• second driven means for discharging the web from the chamber via the outlet, also at a predetermined velocity;
• a polymerization zone in which the binding agent may be polymerized, and comprising an endless belt for receiving the web thereon and located in the chamber between the inlet and the outlet, third drive means for driving the belt, at a lower velocity than the predetermined velocities of the first and second driven means for feeding and discharge of the web, for promoting a tension-free formation of loops of the web on the belt;
• the second driven means being located downstream of the endless belt in the path of travel of the web;
• a heatable, nonmoving plate within the chamber and positioned between the endless belt and the second driven means in the path of travel of the web, the plate having a convexly curved surface with respect to the travel of the web along its path of travel, web guiding means prior to the heatable plate in the path of the web of travel and located for pulling the web against the surface of the plate toward one end of the curved plate surface and the second means being located for pulling the web against the surface of the plate toward the other end of the curved plate surface, whereby the web is moved by the second drive means, and the web is guided by the web guiding means and the second driven means over and along the convexly curved surface of the plate with tensile stress for smoothing the web prior to discharge thereof.