The Stack Press

The Stack Press

A stack press arranges individual color stations, also known as sections or decks, vertically on one or both sides of a main press frame. Gear trains supported by this central frame drive each station. These presses are manufactured with one to eight color stations, with the six-color configuration being the most prevalent.

Stack presses offer three primary operational benefits. First, the operator can typically reverse the web path, enabling both sides of a substrate to be printed in a single pass. Various threading arrangements allow for complete ink drying before the reverse side is printed, assuming sufficient drying capacity is integrated between the stations. The second advantage is the high degree of color-station accessibility, which simplifies changeover and wash-up procedures. The third benefit is the press's capability to print large repeats.

While the stack press has proven useful across numerous applications and can print on almost every substrate type, it does possess limitations for certain uses. When printing extensible substrates or materials of extremely thin gauges, the stack press is generally restricted to color registrations with an accuracy no greater than ±0.0312". However, when printing heavier gauge materials like papers and laminated film structures that tolerate higher web tension, the press can produce commercially acceptable registered products.

This press design is well-suited for integration with other machinery in an in-line production process. Common add-ons include extruders, bag machines, sheeters, and laminators.

Specialized color-station designs enable 360° register control on each unit and independent engaging and disengaging, allowing the rest of the machine to continue operating. The stack press also serves effectively as a coating and tinting machine. Because each color station operates independently, various rotations of the inking parts can be mechanically arranged. The web lead can also be altered to flood coat a sheet or apply coatings in a standard fashion. These techniques are frequently applied in the preprinting of corrugated liner material.

Looking ahead to 2026, stack presses continue to be a relevant technology within a broader printing industry focused on automation and sustainability. Their mechanical simplicity and adaptability support integration into streamlined, automated production lines. Furthermore, their efficiency in single-pass printing aligns with ongoing efforts to reduce material waste and energy consumption.