embodiment the divider walls do not have surface to surface contact with the printing screen but have only linear contact therewith due to their circular configuration as shown in fig4 it is also possible to removably mount the divider walls 50 on the rod 51 and to fix them in place by the use of suitable nuts or the like and in such a manner that their spacing from one another can be varied the purpose of this would be to conform the moving means 5 to the foam use requirements of a particular application in this embodiment the divider walls 50 have u shaped cutouts 150 for convenient displacement and also for the replacement or removal of individual walls for example in the event of breakage or damage the moving means 5 need by no means be only of the type illustrated in the drawing for example it may be in form of a screw which may be provided with a reciprocatory rack and pinion drive so that it alternately turns to the right once and then to the left once to ensure that the screw threads do not always transport the foam to one side of the printing screen 1 but transport it back again it is also possible to replace the rod 51 which in these embodiments is located centrally of the walls 50 with mounting means located at the upper edges of the walls 50 so that these walls then.