Method and device for continuously coating at least a metal strip with a crosslinkable polymer fluid film
AssigneeSollac
InventorsThierry Soas, Claude Bonnebat, Frédéric Jenny
Life of this patent
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Abstract
A method and device for continuously coating at least a metal strip (1) with a crosslinkable polymer fluid film which is free of non-reactive solvent or diluent, and which has a softening temperature higher than 50° C. The method includes the steps of: continuously unwinding the metal strip (1) on at least a back-up roll (30); forming, by forced flow on an applicator roll (20) having a deformable surface, a layer of the crosslinkable polymer; and forming on the applicator roll (20) the crosslinkable polymer film and transferring the film from the applicator roll onto the metal strip. The device implements this method.
Claims29
Process for the continuous coating of at least one metal strip (1) with a fluid film (31) of crosslinkable polymer containing neither non-reactive solvent nor diluent, the said film (31) having a thickness of less than that of the metal strip (1), characterized in that:
- the metal strip (1) is made to run continuously over at least one back-up roll (3);
- a sheet (30) of the said crosslinkable polymer is formed, by forced flow at a temperature above the softening temperature of the crosslinkable polymer, on an applicator roll (20) having a deformable surface, the said crosslinkable polymer having a melt viscosity greater than 10 Pa.s under the conditions of formation of the said sheet, the temperature of formation of this sheet (30) being below the crosslinking onset temperature of the crosslinkable polymer and the said applicator roll (20) being driven, in rotation in the opposite direction to the direction in which the metal strip (1) runs at a point of contact between the applicator roll and the metal strip;
- the crosslinkable polymer film (31) is formed 25 on the applicator roll (20);
- the film (31) is transferred, thicknesswise, from the applicator roll onto the metal strip (1), by compressing this metal strip between the back-up roll (3) and the applicator roll (20), in order to obtain a coating of homogeneous thickness.
Apparatus for the continuous coating of at least one metal strip (1) with a fluid film (31) of crosslinkable polymer containing neither non-reactive solvent nor diluent, the said film (31) having a thickness of less than that of the metal strip (1), characterized in that it comprises:
- means for continuously driving the metal strip (1);
- at least one back-up roll (3) supporting the metal strip (1);
- means (11, 12) for forming, on an applicator roll (20) having a deformable surface, by forced flow at a temperature greater than the softening temperature of the crosslinkable polymer, a sheet (30) of the said crosslinkable polymer having a melt viscosity greater than 10 Pa.s under the conditions of formation of the said sheet, the formation temperature of this sheet (30) being below the crossslinking onset temperature of the crosslinkable polymer, and the said applicator roll (20) being driven in rotation, in the opposite direction to the direction in which the metal strip (1) runs at a point of contact between said applicator roll and said metal strip, and forming the crosslinkable polymer film (31);
- and
- means for compressing the metal strip between the back-up roll (3) and the applicator roll (20) in order to completely transfer, thicknesswise, the said film (31) from the applicator roll (20) onto the metal strip (1) and to obtain a coating of homogeneous thickness.
Dependencies are inferred from the claim text.