Professional Polymer Technology
E-mail : firstname.lastname@example.org
Adhesive bonding is one of the most elaborate processes […]
Adhesive bonding is one of the most elaborate processes in the post-press world. There are hundreds of adhesive formulations to choose from, choosing the right one for a particular project is a chemistry course related to graphic arts. All adhesives need to be strong enough to connect the books together for years and have sufficient flexibility to open them thousands of times. There are three main series of adhesives: EVA hot melt, animal based cold application and PUR. Each has a unique feature that makes it suitable for certain applications.
EVA and PUR adhesives are the three most popular and versatile, so we will focus on these two adhesive grades: EVA is a "standard" binder for perfect bonding that can be used in many different formulations The As the name implies, EVA adhesives are heated during construction. EVA adhesives are of sufficient versatility and can be used for both coated and uncoated raw materials and can be used not only for perfect combination. For example, you can use the "round" hot melt adhesive to create a circular spine on a Smyth sewing book. The pressure-sensitive hot melt formulation can be used as a side glue for filling and covering the hinges.
PUR adhesive is the strongest adhesive that is available. PUR adhesives were originally designed for use in furniture and automobiles, subject to heat and extreme temperatures. It applies to all raw materials and coatings, including synthetic and ultraviolet. PUR is much more flexible than EVA adhesives, making it a common choice for paving adhesive applications. Finally, the PUR adhesive application is thin and helps to prevent wave pattern and other adhesive build-up problems.
Unlike other adhesives, PUR adhesives require at least 24 hours to fully cure. Be sure to keep this in mind when planning your PUR adhesive project. Paint and paint should be knocked out from the spine area on books that bind to EVA or cold binders. These elements affect adhesion when they penetrate into the bound area, reducing the strength of the bond and the life of the book. Although we still recommend knocking out, the PUR adhesive will form sufficient adhesion even if the ink and coating are creeping into the spinal area.