Machine and treatment process via chromatogenous grafting of a hydroxylated substrate

A treatment process via chromatogenous grafting of a scrolling cellulosic material substrate comprising a hydroxylated face, wherein the substrate is paper or cardboard, comprising the following steps:

• (a) application to the hydroxylated face of the cellulosic material substrate of a grafting reagent,
• wherein the grafting reagent is deposited at a quantity of between 0.2 and 2 ml/m2 onto the substrate,
• (b) development of the grafting reaction, one face of the substrate being applied against a heating roller,
• wherein the heating roller is heated to greater than 150° C.,
• wherein a diameter, a temperature and a rotation speed of the heating roller are selected such that a duration of contact of the substrate with the heating roller is a duration that at least 90% of the grafting reaction is complete,
• (c) extraction of the hydrochloric acid emitted during the grafting reaction.

A machine for chromatogenous grafting treatment of a scrolling cellulosic material substrate having a hydroxylated face, comprising:

• a winder for unwinding the cellulosic material substrate,
• an application device of a grafting reagent on the hydroxylated face of the substrate,
• wherein the application device of a grafting reagent is configured to deposit a quantity of reagent of between 0.2 and 2 ml/m2 onto the substrate,
• a heating roller for development of a grafting reaction on the hydroxylated face of the substrate, said roller being provided with a bar-end system for applying a face of the substrate against said heating roller,
• wherein the heating roller is heated to greater than 150° C.,
• wherein the application device and the heating roller are arranged so as the hydroxylated face of the substrate is applied against the heating roller and the surface of the heating roller is provided with roughness to obtain an airgap between the roller and the substrate,
• an extraction device of the hydrochloric acid produced during the grafting reaction, and
• a rewinding device of the treated substrate.