Offset Printing
Up to 30 Percent Increase in Customer Productivity Thanks to Oblong Feeding for Folding
Tuesday 03. November 2009 - Available for buckle plate folders in the Stahlfolder TH and TD series; Optimum folding quality thanks to production at low sheet speed coupled with high cycle rate; Change in folding layout saves both paper and time
Customers now have the opportunity to significantly increase the productivity of their buckle plate folders in the Stahlfolder TH and TD series. This is possible thanks to two new steps introduced by developers at Heidelberger Druckmaschinen AG (Heidelberg) – the sheet to be folded is simply rotated 90 degrees at the feeder and a new pneumatic twin lay system has been implemented before the second folding unit. As a result of the sheet’s shorter feed length at the same press speed, the performance is increased by around 30 percent depending on the sheet format.
Before the new pneumatic twin lay system was implemented, the problem of the extra speed generated by oblong feeding impacted on the second unit. Although the reduced feed length had a positive effect on the feeder and first parallel folding unit, the full feed length still had to be transported at the second unit, which was rotated by 90 degrees. This concept demanded very high speeds at the second unit, which sometimes led to problems with reliability and quality of the folding process.
The pneumatic twin lay system now makes it possible on the second folding unit to align and transport folded sheets in parallel using two side lays. This means that twice as many folded sheets can be transported as before, thus enabling customers to halve the speed of the second unit. Oblong sheet feeding into the first parallel folding unit at the same speed increases productivity significantly and, thanks to the low speed of the second unit, also improves the folding quality, which further improves the reliability of the folding process.
Pneumatic twin lay systems are ideal for use in folders in the TD and TH series. A buckle plate folder that is one format class bigger than the sheet’s format class may be required for the oblong sheet feed process. Pneumatic twin lay systems can be retrofitted on existing folders.
This oblong sheet feed makes it possible to change the folding layout, thus providing opportunities for saving paper and time throughout the production process – from prepress to the finished product.