Abstract: Certain types of lithographic printing plates are activated by preheating while certain other types are post heated to harden the coating. A platen having a large mass compared to the mass of a printing plate is heated and maintained in the exact temperature range to which the printing plate is to be heated. A printing plate is brought into heat exchange contact with the platen for the period of time required to heat the printing plate to the temperature of the platen. The printing plate may be heated while resting in a fixed position on the platen or while the printing plate is carried over the platen by a continuous thin metal conveyor belt in intimate contact with both the platen and printing plate.

Abstract: Certain types of lithographic printing plates are activated by preheating while certain other types are post heated to harden the coating. A platen having a large mass compared to the mass of a printing plate is heated and maintained in the exact temperature range to which the printing plate is to be heated. A printing plate is brought into heat exchange contact with the platen for the period of time required to heat the printing plate to the temperature of the platen. The printing plate may be heated while resting in a fixed position on the platen or while the printing plate is carried over the platen by a continuous thin metal conveyor belt in intimate contact with both the platen and printing plate.

Abstract: A novel method and apparatus for the imaging of a continuous web on an internal drum type imaging device is disclosed. The method and apparatus may further be included in a process to produce punched, imaged sheets. A web is punched with registration holes and imaged in an internal drum-type imager prior to cutting the web into individual imaged plates particularly for use as printing plates. The web with an imageable surface is serially punched, imaged and sheeted with the punched holes being utilized to assure registration and alignment in the imaging operation and in the subsequent use of the plates on a printing press. The imaging station has an arcuate concave imaging platen. The web is advanced under tension and then stopped while a roller on an arm forces the web down into contact with the platen. Vacuum is then used to hold the web on the imaging platen while the web is imaged.

Abstract: A web is punched with registration holes and imaged prior to cutting the web into individual imaged plates particularly for use as printing plates. The web with an imageable surface is serially punched, imaged and sheeted with the punched holes being utilized to assure registration and alignment in the imaging operation and in the subsequent use of the plates on a printing press. The punching and imaging may be performed at separate stations or at a single punching and imaging station. The web is preferably advanced under tension and tension and/or vacuum may be used to hold the web flat on the imaging platen.