Finishing & Screen Printing

Südostschweiz Presse und Print AG, Chur: Increase Added Value with PUR Extension

Monday 26. May 2014 - PUR is all but indispensable for high-quality softcover products today, which is why perfect binding lines set up for hotmelt are often retrofitted with PUR, just like the Pantera from Muller Martini at Südostschweiz Presse und Print AG in the Swiss city of Chur.

Since only hotmelt production was possible on the Starbinder from Muller Martini, Südostschweiz Presse und Print AG had to outsource production of all PUR-bound products until just under a year ago. According to Lorenz Cajochen, Director of Technology/Printing Production for Customers at the company in Chur, that had two consequences: “First, demand for PUR among our customers of high-quality company brochures and annual reports increased owing to the better layflat behavior of the print products. Second, we didn’t have the entire value chain in-house.” In order to close that gap, Südostschweiz Presse und Print AG installed a secondhand Pantera to replace the Starbinder. “It suits our job structure perfectly, fits our limited space exactly in terms of layout, and the price was also right,” says Cajochen, explaining the decision to invest in the perfect binder from Muller Martini.
Three-Knife Trimmer Upgraded Too
Since the Pantera, which was manufactured in 2008, was originally designed only for hotmelt production, it was retrofitted for PUR after the move to Chur under the MMUptodate label. “Of course you need to calculate precisely whether to buy a new system or a used one with additional functions,” says Cajochen. The Pantera with PUR extension was just the right solution for our budget. Südostschweiz Presse und Print AG now binds all its products using the PUR process, which removes the need to keep cleaning the glue pot.
The increase in quality of the softcover books and brochures produced in Chur
following commissioning of the Pantera, which is coupled with a 14-station gathering machine (with Asir 3 automatic signature image recognition) is also a result of the new three-knife trimmer. Südostschweiz Presse und Print AG decided to invest in a secondhand Zenith, rather than using the system of its predecessor. It ensures a clean three-side trim, after which the products are stacked in the CB 16.
The Muller Martini technicians also made various adjustments, such as to the scoring rollers at the cover feeder, and replaced some wear parts.
PUR is Crucial for Photo Books
The extension of existing perfect binding lines for production with polyurethane adhesives is not only due to pressure from publishing companies and their end customers, but also in some countries, especially in warmer climates, because of statutory regulations. The Brazilian government, for instance, requires that school textbooks be PUR-bound to improve durability. The thermal stability guaranteed by PUR (in terms of both heat and cold) is required, for instance, for brochures placed in cars such as manuals or guide books.
And PUR is essential when it comes to softcover products with coated paper or paper with few wood fibers. “Production with photo paper isn’t possible without PUR,” says Rudolf Graf, Product Manager at Muller Martini Bookbinding Systems. “Our customers who order the production of prestige books, such as those in the automobile or watch industries, require good pull values, which can be achieved far better with the thinner glue application that is characteristic of PUR. Shorter-lived products, on the other hand, such as weekly or monthly magazines are mostly bound with hotmelt.”
Nozzle System as Catalyst
The popularity of PUR has grown since it was introduced in the 1990s, not least because the adhesives have kept on improving. The nozzle systems, which Muller Martini also offers for its perfect binders, acted as a PUR catalyst. “They have several benefits,” says Graf. “They are ideal for thin and even glue application. The viscosity always remains the same. Cleaning is far quicker because after switching off the machine, there is no glue pot with residual adhesive film, which means no waste. The closed-loop system ensures high production speed and prevents the escape of steam. Bookbinders save costs because setup times are shortened so that productivity rises and less glue is used.”
Retrofitting with PUR is relatively easy according to Graf: “Muller Martini provides the new PUR equipment, and the PUR pot and the nozzle are inserted into the base-unit of the perfect binder. Then come the premelter and the pre-heating station. The new installation typically takes us two days, followed by training, if necessary.”
The dimensions of the perfect binding line remain the same, except for the cooling section. Around 90 seconds are needed for PUR, compared to 60 seconds for hotmelt. To extend the cooling section, where required, either the belts need to be lengthened or the production speed reduced. It is not possible to generalize about how quickly PUR extension of an existing line provides return on investment compared to a new investment, says Graf. “That has to be calculated on a case-by-case basis, depending on the perfect binder type or job volumes.”