The Introduction of Polyurethane Reactive (PUR) in Printing
Moving towards the present day, advances in perfect binding came one after another and once more towards the end of the 1980’s, technologies in bookbinding took another dramatic leap upwards with the advent of PUR.
PUR is the shorthand name for the more recently introduced binding option polyurethane reactive.
Polyurethane reactive is unique in that it will bond to many types of coatings and films as well as paper and superior to other hot-melt adhesives with its ability to allow a book to lie flat whilst open- the benefits of which shall be discussed in a little further detail later on.
The latest PUR adhesives as modern binding mediums are highly versatile, with the changes in paper weight and inks along with the various coatings used by today’s printing industry posing it little challenge. Additionally, with traditional adhesives when the migration of inks into a book’s gutter can bring about binding issues, PUR adhesives are said to remain virtually unaffected.
When applied at its recommended thickness – ~0.01 inches, polyurethane reactive is considerably more flexible than standard ethylene vinyl acetate hot-melts. This characteristic allows PUR-perfect bound books to lie flat on their own whilst open, a useful trait which enables hands free reading.
An example of the benefit of this is in user guide/manual manufacture; have you ever tried holding the instructions for a new piece of kit open whilst trying to configure your new toy? Not an easy task, if I might say so myself- and now a task which is no longer necessary. Thanks to this attribute, according to National Adhesives, both the world’s largest software seller and a Texas based computer manufacturer chose PUR for all their instruction manuals several years ago.
This is the third and penultimate part in a short series detailing the evolution of traditional bookbinding up to the modern day and a short insight into developments made in the field of perfect binding. Check back a week today for the final part in this series, an overview in the many developments and improvements in PUR.
