PUR (polyurethane reactive) glue is the most durable binding glue available, offering design flexibility for any number of applications, including brochures, catalogues, instruction manuals and art books. PUR allows us to successfully bind materials which would not have previously been attempted using conventional EVA (Ethylene Vinyl Acetate) hot melts. PUR adhesives differ from conventional EVA hot melts in that they cure by crosslinking via a chemical reaction with moisture contained in the paper stock or surrounding air. Once cured, the adhesive's higher molecular weight provides a tough, pliable bond that is resistant to temperature extremes.
A common concern with perfect bound books is their stability in extremely hot or cold temperatures. PUR adhesive is impervious to temperature extremes. That means PUR-bound books can be used anywhere – from the hottest summer heat to the most harsh of winter conditions – without unwanted re-melting or cold cracking.
The page pull strength of a PUR-bound book is more than 2.5 times that of a standard perfect-bound book using EVA adhesive. Books bound with PUR adhesive simply will not fall apart, even under heavy usage in the most demanding conditions.
The composition of PUR adhesive enables it to form a strong bond with the paper even in the presence of inks, coatings and varnishes. This is in contrast to EVA perfect binding, where these items must be removed from the spine area prior to binding. Another major advantage of PUR adhesive is its flexibility, once cured.
The cover must be 4mm bigger than the head and the foot of the untrimmed folded text to alow a glue trap
Finished product cannot be opened or used for 12 hours after binding.
Sizes offered by Marvel Bookbinding & Printfinishing:
Minimum trimmed: 105mm x 75mm
Maximum trimmed: 380mm x 300mm
Minimum untrimmed: 140mm x 105mm
Maximum untrimmed: 430mm x 305mm
Minimum spine: 2mm (text)
Maximum spine: 60mm
Minimum cover size: 145mm x 220mm
Maximum cover size: 440mm x 630mm
Maximum cover for gate fold: 1000mm x 440mm