Hot melt glue is expensive and hard to use, setup and control (not to mention the safety side of things).
What we are doing is creating an adhesive or glue ink solution that is jettable from a ink-jet printing head.
This is cheaper than buying a hot melt solution, just run our "ink" into the printhead and setup your job to jet the ink out where you need it and pass the paper under the head. You also do this on the matching (or mating) surface and press it together - done.
Contact us for more information: james [dot] worrell [at] phoenix-digital-solutions.co.uk