Interchangeable adhesive-applying apparatus

A method and an operator interchangeable apparatus with fast warm up time for coating flowable and pasty materials onto a workpiece, especially for the application of glue and other adhesive substances to the back of signatures in bookbinding and the like, uses a first internally heated rotating roller for applying the material which is partly immersed in a bath thereof and a second internally heated roller to smooth and doctor the adhesive on clamped stacks of pages that have passed over the first roller. Production rates suitable of in-line use with reproduction equipment are achieved with no buildup on the edges. The relative velocity of the surface of the adhesive on the first roller is maintained at the same velocity as the clamped stack of pages. A mechanical adjustment device and method that provides for ease of interchangeability. A control device for proportioning the electrical power to the heating elements for the two rollers. Wattage of these heating elements is matched to each roller's heating requirements.