Bookbinding – a perfectly bound book
Flexible and cost-efficient book spine gluing solutions with Melt-on-Demand technology for highest quality and glue savings up to 50%.
Robatech has set new standards in the bookbinding industry: sophisticated adhesive melting units with Melt-on-Demand (MOD) technology and high–performing hot melt application heads for exceptionally precise and flexible adhesive dispensing for bookbinding. They guarantee highest quality for perfectly bound books. For book spine gluing PUR hot melt is used, processed with a RobaPUR melting unit and a specially designed SpineCoat application head. Book side gluing is done with EVA adhesive processed by a Concept melting unit. The adhesive is applicated with the SideBead application head.
New customer demands challenge the industry for flexible and efficient gluing solutions
In the last decade, declining run lengths and quicker turnaround requirements have left little room for error in the book bindery. Long-standing bookbinding methods have had to evolve because offline production machines and shorter turnaround periods result in expensive short-run applications. Also new technologies, digitalization and new customer demands like Book-on-Demand with variable book dimensions challenge the whole industry.
Robatech solution – SpineCoat and SideBead
To meet today’s challenges, a flexible production with consistent and high quality output is crucial. With the SpineCoat and the SideBead system solutions, Robatech has succeeded in developing two powerful products for a complete bookbinding system designed for your production needs that guarantee the best results with glue savings up to 50% and cost reductions. The Robatech solution in spine gluing has been based on PUR adhesive and for side gluing on EVA to use the characteristics to its full extent. The reliable gluing systems are above all suited for retrofitting existing bookbinding machines allowing a quick ROI. They are designed for precise and clean gluing of spines and sides and can be tailored to the customer's needs.
Robatech is using PUR for the spine gluing process because of its characteristics – excellent binding quality, the resistance to temperature and aging as well as lay flat friendliness.
The geometry of the coating head ensures an even coating across the entire book spine. The side guide guarantees clean gluing for the first and last page and thus prevents these from tearing out. A negatively closing valve also assures a precise and clean cut-off. The PUR hot melt adhesive circulates continuously in the application system. When the adhesive is applied, the valves of the SpineCoat coating application head opens. When no adhesive is applied, the return throttle opens and the PUR hot melt adhesive flows back to the adhesive melter. This guarantees a precise and consistent application from the first book to the last and allows a considerable thinner application, hence saving glue.
The side gluing is done by a fine bead application of EVA hot melt adhesive on both sides of the book spine. The bead length can be set easily for any book length. A precisely applied bead is guaranteed because of the accurate jetting technology. The perfect binding and the downstream triple-cut equipment is prevented from dirt due to the non-contact adhesive application. This results in less system interruptions for cleaning and maintenance. The fine bead application and the adjustable holder assure a very precise and clean glue application with easily changing formats.
Comparison EVA and PUR adhesives
|EVA characteristics||PUR characteristics|
|Coating thickness||0.7 – 1.0 mm||0.3 – 0.5 mm|
|Quantity of glue||40 to 60 % more than PUR||40 to 60 % less than EVA|
|Binding quality||Good||Excellent. Even on difficult to bond substrates|
|Temperature resistance||Not resistant to extreme climate||Resistant to hot and frosty climate|
|Flexibility and aging resistance||Satisfying||Excellent. Durable adhesion|
|Lay flat||Satisfying||Perfectly lay flat (less adhesive)|
|Maintenance & cleaning effort||Normal effort||High effort in open system, less effort in closed system|
|Price||Half the price of PUR||Double the price of EVA|
|Spine gluing||Appropriate but low quality||Recommended due to resistance of temperature, aging and strong binding quality|
|Side gluing||Sufficient as application is less critical than spine gluing. Cost-effective solution with good quality||Can be used but the cost-efficient alternative is EVA which is sufficient for this application|
Melting unit for bookbinding solutions
For a high quality application of PUR the SpineCoat application head is combined with melting units using Melt-on-Demand (MOD) technology, e.g. the RobaPUR 2 MOD unit. It only melts the quantity of adhesive you need, when you need it. Furthermore, the gentle melting and conveying of hot melt adhesive results in less waste and charring. In addition, a well-controlled temperature in the tank guarantees a consistent viscosity. The tank can be filled easily and safe without any system interruptions. This ensures a flexible and consistent production which is of high quality and cost-effective.