Method of making a lithographic printing plate

1. A method of making a lithographic printing plate, the method comprising the steps of:

image-wise exposing a lithographic printing plate precursor including a support including a hydrophilic surface or a hydrophilic layer and, a light or heat sensitive coating including a photopolymerisable composition containing a polymerisable compound, that is polymerisable by exposure to light or heat, on the support;

processing the precursor, consecutively, with a first solution and a second solution to remove the coating from the support at non-printing areas;

the first and second solutions are provided by a cascade system such that the second solution overflows into the first solution and the first solution overflows into a container to be treated as waste;

the second solution is regenerated by adding a replenishing solution or a mixture of replenishing solutions at a rate of at least 5 ml/m 2 of treated precursor and at most 100 ml/m 2 of treated precursor;

the first and second solutions are circulated respectively by a first and second liquid conveying system;

the first solution in the first liquid conveying system has a volume of at least Vmin and at most Vmax, respectively, defined by formula 1 and formula 2:

V min=[ A +(processing width/0.95 m)]·liter  (formula 1)

V max=[ B +(processing width/0.95 m)]·liter  (formula 2)

Vmin and Vmax represent, respectively, a minimum and a maximum volume in the first liquid conveying system, each expressed in liters;

A represents a constant value of 2 and B represents a constant value of 15, 10, 8, or 6; and

the processing width represents a width, expressed in m, inside a processing unit, perpendicular to a processing direction of the precursor.

2. The method according to claim 1 , wherein the second solution is regenerated by adding a replenishing solution or a mixture of replenishing solutions at a rate of at least 20 ml/m 2 of treated precursor and at most 85 ml/m 2 of treated precursor.

3. The method according to claim 1 , wherein the second solution is regenerated by adding a replenishing solution or a mixture of replenishing solutions at a rate of at least 50 ml/m 2 of treated precursor and at most 75 ml/m 2 of treated precursor.

4. The method according to claim 1 , wherein the second solution in the second liquid conveying system has a volume of at least Vmin and at most Vmax, respectively, defined by formula 3 and formula 4:

V min=[ A ′+(processing width/0.95 m)]·liter  (formula 3)

V max=[ B ′+(processing width/0.95 m)]·liter  (formula 4)

Vmin and Vmax represent, respectively, a minimum and a maximum volume in the second liquid conveying system, each expressed in liters;

A′ and B′ represent a constant value of respectively 2 and 15;

the processing width represents a width, expressed in m, inside the processing unit, perpendicular to the processing direction.

5. The method according to claim 1 , wherein a volume of the second solution in the second liquid conveying system is a same as the volume of the first solution present in the first liquid conveying system.

6. The method according to claim 1 , wherein the first solution is regenerated by adding a replenishing solution or a mixture of replenishing solutions or water.

7. The method according to claim 1 , wherein the first and second solutions are a gum solution such that the precursor is developed and gummed in one single step.

8. The method according to claim 7 , wherein the second solution is regenerated by adding fresh gum solution.

9. The method according to claim 1 , wherein the light or heat sensitive coating on the support includes an image recording layer and, optionally, a top layer on top of the light or heat sensitive coating.

10. The method according to claim 9 , wherein the light or heat sensitive coating on the support includes an intermediate layer between the support and the image recording layer.