Perfect Binding machines use two types of glue to bind covers and pages: PUR and EVA. For a long time, EVA was the only gluing option for perfect binding machines.
PUR (Polyurethane Reactive) glue was developed in the 1989 and quickly proved superiority over EVA (Ethylene Vinyl Acetate.) PUR required less heat, required less glue per book and was dried completely transparently. PUR glue permanently bonds the paper without cracking or melting. If you’ve ever opened a book that lays flat it was most likely bound with PUR instead of EVA.
This machine, the 2011 Bourg / NewBind Adventure-PA Single Clamp perfect Binder uses the PUR gluing system. The single-clamp binder comes up from a cold start within 13 minutes to produce books up to 2 inches thick with spine lengths from 4.7 inches to 17.7 inches at up to 200 cycles per hour.
PUR takes a lot longer to cure than EVA, sometimes up to 24 hours, but once it does the bond is stronger and more likely to withstand moisture and heat. EVA cures quickly and makes for an easier cleanup. This glue can be re-melted over and over again which may be a downfall in warmer climates. In colder climates it has been known to crack.
Although PUR is a more expensive option than EVA, most printers agree that it results in a far superior end product. WireBids auctions perfect binders featuring both types for either preference.