Aqueous processing method for flexographic printing plates

A method for processing a photosensitive flexographic printing plate having a latent image formed by image-wise exposure of an aqueous-processable photopolymer, comprising:

• using a main processing unit to develop the latent image into a relief image by removing unexposed photopolymer from the photosensitive flexographic printing plate by contacting the photosensitive flexographic printing plate with an aqueous processing solution including a first dispersing agent while the photosensitive flexographic printing plate is being subjected to mechanical cleaning, wherein the aqueous processing solution is supplied to the main processing unit from a processing solution tank, and wherein used aqueous processing solution containing the removed photopolymer is returned from the main processing unit back into the processing solution tank;
• using a secondary processing unit to wash the developed relief image with a secondary aqueous processing solution including a second dispersing agent to remove debris from the developed relief image, wherein unused secondary aqueous processing solution is provided to the secondary processing unit, and wherein used secondary aqueous processing solution containing the removed photopolymer is directed from the secondary processing unit into the processing solution tank;
• and
• removing a portion of the aqueous processing solution from the processing solution tank to keep a volume of aqueous processing solution in the processing solution tank below a predefined maximum volume;
• wherein a concentration of photopolymer in the aqueous processing solution in the processing solution tank is maintained below a predefined maximum photopolymer concentration.