Not Turned Off by Offset
Despite the dramatic improvements in flexography, some carton manufacturers still prefer offset printing. This may be due in part to the dramatic strides offset has made as well. Two carton manufacturers explain why.
"With today's automation (auto preset, auto wash devices, auto plate loading, fully computerized density control, etc.), offset printing is highly competitive for both small and long runs. With maximum speeds of 15,000 sheets per hour on 40-in. format and quick make-ready features, it is difficult to surpass offset's performance.
"High-speed offset presses are often combined with high-speed die-cutters, overcoming some of the challenges faced by other printing processes. Our new flatbed die-cutting equipment now registers with the print and not the edge of the sheet, ensuring a print-to-cut tolerance unmatched by web process. With blanking capabilities running at a maximum speed of 12,000 sheets per hour, it is now highly competitive.
"There is almost no limit in the graphic reproduction of waterless printing. It is now possible to print with 200- or 300-line screen resolution, and more if needed. Not often used for pharmaceutical carton applications, such resolution can be used to improve graphic quality and act as a good anticounterfeiting feature to avoid unauthorized duplication. As well, UV ink technology or conventional ink systems will enhance the carton's design."
Director, Technical Services
Alcan Packaging, Margo
Baie d'Urfé, QC, Canada
"Generally speaking, a folding carton in six colors and with a UV coating in a run quantity of 300,000 or less can be run more economically on an offset press and platen die cutter/ blanker than on a web-fed flexo. Of course, the size of the carton has a lot of influence. But the actual converting time (including set-up time) on the flexo is usually not enough to absorb the extremely high cost of tooling. At CCC, we have modern Iberica die-cutters/blankers and all tooling for them, including cutting dies, blanking tools, and stripping boards, are manufactured in-house. This saves our clients a great deal of money. The Iberica die-cutters have a top speed of 9,100 sheets per hour, and the blankers are rated for 8,100 sheets per hour. With the make readies done off-line, we have very little machine downtime on the Ibericas.
"We also manufacture the printing plates in house. In October, we will install a new KBA seven-color Rapida, and this will have a major impact on reducing time cycles. We are planning to cut our press make-ready time in half and increase our average running speed by 40–50%. The top speed on the new Rapida is 15,000 sheets per hour, but we are planning to have running speeds between 10,000 and 13,000 sheets per hour."
Colonial Carton Co.