April 16, 2003 -- Thanks to the installation of a high-performance Corona C15 perfect binding system from Muller Martini at the end of 2001, Clays has set new performance standards in paperback production. And, somewhat surprisingly, this is achieved with rather small runs of 7,000 to 8,000 books per title and with up to 12 format changes per shift! Record-breaking To date, over 100 million books have already been produced and between 6,500 and 7,000 format changeovers carried out. That has to be a record! Depending on the number of signatures and the run length, production output varies between 12,000 and 15,000 cycles/hour, which results in a net output of 18,000 to 22,000 books per hour (or 9,000 to 11,000 books in two-up production). Special equipment The Corona C15 is equipped with a special twin milling station and three separate backbone preparation stations, as well as two hotmelt spine glue stations and a hotmelt side gluing unit. Three 160-liter (42.2) premelters are used to preheat the glue for the spine glue station and a 30-liter (7.9) premelter for the side gluing unit. An extraordinary requirement of this configuration is that two 160l premelters are needed to feed the second spine glue station. This is because of the high level of glue consumption at these extremely high production speeds with book thicknesses up to 60 mm (2 3/8"). Maximum speed Clays operates three shifts a day, five or six days a week. The main objective of this system is to run at the maximum binder speed of 15,000 cycles per hour whenever possible. And in order to achieve this output, the system is equipped with four three-knife trimmers. This means that it is still possible to run at full capacity even if one of the three knife trimmers is being changed over, has a malfunction or is out of service. The master downstream processing control system continuously monitors how many books are being processed by the three-knife trimmers and determines the binder speed from this information.