Smart Conveying Optimizes Digital Book Print Line

  • October 19, 2011
  • Case Study

By Jim McMahon

Capable of digitally printing and finishing over 1,000 paperback books per hour, Harlequin Distribution Center in Depew, New York utilizes advanced conveying technology – such as Slip-Torque low-backpressure accumulation conveyors, buffer conveyors, and Star Rollers from Shuttleworth – to minimize product damage and finishing downtime, and maximize throughput.    Given that the latest digital printers of paperback books are much less the cause of production hold-ups compared to downstream finishing processes, most book publishers that print digitally separate their printing and finishing lines to eliminate the risk of downstream jams in folding, stacking, binding and cutting from influencing the print cycle. If not, such jams, if only for a few minutes, could back-up and impede printing, causing further production interference. But recent technical developments in conveying systems have enabled digital printing and downstream finishing processes to coexist in one continuously-integrated inline system without printing interruption, despite what downstream hold-ups may occur.   One book publisher that has employed this unique system of integrated inline throughput with its digital printing and finishing processes is Harlequin, the world’s largest publisher of fiction romance novels. Harlequin set-up its in-house digital paperback book printing line to support its short-run printing needs. With a capability of printing and finishing more than 1,000 paperback books per hour, and printing production uninfluenced from downstream jams, the system is a model of efficiency in inline print-and-finish processes for short-run digital book publishing.   Harlequin’s Need for Short-Run Digital Printing With such bestselling romance authors like Debbie Macomber, Susan Wiggs, Linda Lael Miller, Sherryl Woods, Gena Showalter and 1,100 other contributing writers, Harlequin commands an awesome array of talent to produce its 130 million books annually in North America alone, all of this flowing through its 400,000 square-foot distribution center in Depew, New York (Another 120 million books annually are distributed from international sources). The publishing company manages over 2,000 title configurations each year for the North American market in paperback format, trade size and hard cover. Its selling channels include retail, book club and Internet.   Since the mid-1990’s, markets have gone from being predictable to unpredictable in order volume. To ensure inventory, Harlequin printed additional copies (offset), much of which never left its warehouse. For a number of years prior to setting up its short-run digital printing, this additional copies averaged 7.5 million units per year. Even with this overproduction, production calls were not always adequate and offset reprints took too long to satisfy market timelines.   Harlequin outsourced all of its printing prior to its digital set-up. If it ordered 50,000 copies of a title, but needed 51,000, the cost to order 1,000 additional books from its offset printer was quite expensive. So, in some cases, Harlequin would just not capture those sales.   “For some time we had been looking at ways to print some of our books digitally,” says John Reindl, General Manager of Harlequin Distribution Center. “The technology finally got to a point where the digital printers could support the type of paper that we use. We wanted to mimic the print quality of offset so that the consumer would not notice the difference.”   “We also wanted a solution that we could set-up in our own distribution center,” explains Reindl. “So our approach was to bring in digital printing to facilitate our short-run printing needs, which is anywhere from 500 to 4,000 copies of any one title to top off the main offset runs. But we still planned to out-source the bulk of our printing to our offset printer.”   “With 95 percent of our books in the same format, and few changeovers associated with our production process, we felt we could target a higher degree of automation and inline processing than we had seen elsewhere,” Reindl adds. This vision was put into place by Harlequin’s Vice President of Operations, Jim Robinson, who was responsible for the design of the company’s inline digital printing process.   Printing to Finishing in One Integrated Online System Harlequin selected an Océ VarioStream high-volume continuous-feed printer, a toner-based solution that digitally prints almost 10,000 books in an eight-hour shift. The printer is not the limiting factor, however, some of the back-end finishing processes limit capacity, like the stacker that takes printed signatures and stacks them into book blocks.   Basically, after printing, the paper is cut and folded into 16-page signatures. These then go through a folder and stacker to create book blocks. Then these book blocks go to the binder, and into a three-knife cutter (trimmer) before they exit as finished books.   “Many digital printers print the books and then do the finishing off line,” says Reindl. “We wanted to do it differently, with all of our production inline. Meaning we would literally start with a roll of paper on one end, and a finished product would come out the other end. To do this inline we needed a solution that would allow us to move book blocks from one part of the production process to another. But the book blocks are still loose signatures. The importance of getting the book blocks out of the folder and to the binder without the book blocks tipping over, and maintaining their stability, was a critical part of the process. We searched and found only one solution that would allow us to do this.”   The conveying solution that Harlequin embraced was a multi-faced, integrated conveying approach designed and built by Shuttleworth, Inc., specifically for conveying cut-paper products. The design incorporated the following systems:   Star Rollers – As the book blocks exit the stacker toward the binder they travel on a 15-foot long conveyor equipped with very unique Star Rollers.   These Star Rollers, developed by Shuttleworth, were employed to eliminate shingling or creeping of the bottom layers of paper when stacks are transported and accumulated on the conveyors. The Star Roller profile (shaped like a star) enables loose stacks of paper to be conveyed and accumulated between the stacker and the binder without disrupting the integrity of the stacks, because only the points of the star touch the stacks. Regular rollers would push the bottom sheets back, and end up with a shingled stack, and belt conveyors are incapable of accumulating stacks of paper.   Slip-Torque Conveyor Technology – This conveyor is also outfitted with Slip-Torque Technology, also from Shuttleworth. Slip-Torque employs polished stainless steel shafts individually powered by a continuous chain. These stainless steel shafts are covered with segmented, loose-fit rollers (Star Rollers), which form the conveyor surface. ”It is the weight of the products being conveyed, combined with the coefficient of friction between the shafts and the inside diameter of the rollers that provides the driving force,” says Ralph Matchett with Shuttleworth. “As the weight of the product increases, there is a corresponding increase in the driving force supplied. As products stop, the segmented rollers beneath them also stop, creating very low backpressure accumulation and significantly reducing product damage.”   Slip-Torque provides the gentle handling needed for transporting Harlequin’s book blocks from the stacker to the binder.   Buffer Accumulation Conveyor – If the line is running normally, there will be no accumulation of book stacks on the conveyor. The stacks would just be flowing through to a blade stop before entering the binder, which indexes one stack at a time into the binder. But if the binder were to go down, then the book stacks are diverted into a buffer conveyor, (also Slip-Torque enabled) which can accept up to 85 stacks (5 minutes worth of throughput) – predictably enough time to dislodge the binder jam-up. Once the binder is cleared, the book stacks will automatically feed into the binder.   The buffer conveyor reduces total line delays by allowing the printer, folder and stacker to continue production for a cost-effective period of time when the binder is down. This gives greater productivity, and reduces product damage and operating time.   “We thought we would have some downtime with the binder and the cutter, so we built in a buffer conveyor,” explains Reindl. “If the binder goes down, we have the buffer that allows us to accumulate the book stacks until the binder comes back up and then it feeds them automatically right back into the binder. We haven’t had to use it much, but when we have had to it has worked quite well.”   In-House Print-and-Finish-on-Demand Improves Inventory With its streamlined digital printing and finishing capability, Harlequin can now cost-efficiently print and finish in-house whatever overages are needed – above its initial offset runs – for any title on a just-in-time production model.   It can now also print and finish short runs for select titles that require, initially, very small quantities. Previously, these would be sent out for offset printing with a minimum order of 5,000 required, even if only 3,500 copies were needed.   The new print and finish line has significantly improved Harlequin’s inventory load, resulting in a 15 – 20 percent reduction in titles held in stock.   “The key value of the conveying system is that it supports our inline process, which is critical to the success of the system,” says Reindl. “Our print and finish system would not have been possible if we did not have a solution that allowed us to maintain stable book blocks coming out of the stacker and going into the binder, and a back-up solution to keep the print and finish throughput operational in the event of binder malfunction.”   About Harlequin Harlequin Enterprises Limited is the global leader in series romance and one of the world's leading publishers of books for women. The Toronto-based company publishes over 110 titles a month in 28 languages and in 114 international markets. These books offer women a broad range of reading from romance to psychological thrillers to relationship novels.    About Shuttleworth Since 1962, Shuttleworth has served as a leading designer, consultant and manufacturer of product handling conveyor automation worldwide. As a conveyor solutions provider, Shuttleworth specializes in accumulation conveyors, product diverters, multi-lane conveyors, servo-controlled machine in-feeds, and high-speed sorters and combiners. Shuttleworth leads the industry in gentle product handling using its unique Slip-Torque® technology.     

Learn More

Did you enjoy this great article?

Check out our free e-newsletters to read more great articles..