You will find that the cove and back’s material is different from the central spine’s, in order to save the material, the file maker often first glue the central spine with the paperboard, then pasting the cover and back paper at the same time, the production difficult point is two pieces of cover material gluing will be at the same time.
In fact, ST Case Making Machine can produce this kind of lever arch file by its unique function, please check on these videos:
Firstly, pasting the central spine material:
Secondly, gluing the cover and back material, two pieces case making at the same time:
In fact, due to the unique function on the level arch file production, ST Case Making Machine is welcome on many contries characteristic stationary, such as Egypt, Poland, Vietnam, etc..