Shaftless stack flexo printer

In the converting industry, a Stack type flexo printer is widely recognized for its compact footprint and versatile color deck arrangement. The shaftless variant takes this platform further by replacing the common line shaft with independent servo motors on each print station. This upgrade is especially valuable for flexible packaging, labels, and paperboard applications where fast changeover and tight register are critical. A Stack flexographic printer built without a shaft eliminates gear backlash, reduces maintenance points, and supports free-standing deck modules that can be added or removed as production needs evolve. When teams compare a shaft-driven system with a Stack type flexographic printing machine using servos, the difference in job setup time often exceeds 40%. For any operation upgrading from a conventional Stack flexo press, the shaftless configuration delivers consistent print quality at speeds up to 180 m/min while reducing waste during setup and splice events. The platform also allows individual deck phase adjustment for process printing, making it suitable for halftone reproduction and line work on thin films.

The Shaftless stack flexo printer is engineered for converters that require precise register control, rapid deck positioning, and repeatable ink laydown on challenging substrates. Each print deck features a servo-driven plate cylinder and anilox roll, with longitudinal and lateral register adjustments performed through the HMI rather than mechanical stops. The chambered doctor blade system ensures stable ink viscosity and reduces solvent evaporation, while the pneumatic cylinder engagement allows quick sleeve and plate changes. Standard configurations include 2 to 8 color stations, with wider web widths and additional decks available on request. The press handles a broad range of materials, including 15–120 micron polyethylene, BOPP, PET, aluminum foil, and 80–350 gsm paperboard. Dryer options include hot air, infrared, or UV curing depending on ink chemistry and production speed. An automatic web guide system maintains substrate tracking within ±0.1 mm, and optional video inspection supports real-time defect detection at full press speed. The modular frame design simplifies floor layout planning, and the shaftless drive reduces mechanical components that typically require lubrication and alignment. Operators can save job parameters for repeat orders, cutting setup time on returning work to under 10 minutes per color deck. The shaftless architecture also supports quick sleeve technology for plate and anilox changes without removing the mandrel, reducing changeover time by up to 50% compared with shafted systems. Additionally, the press can be integrated with a downstream slitting unit, a sheeting station, or a turret rewinder to create a complete converting line. Closed-loop tension control with load cell feedback maintains consistent web tension from unwind to rewind, preventing wrinkle and misregister on extensible films. The base frame is fabricated from stress-relieved steel and precision-machined after welding, ensuring long-term geometric stability. All electrical cabinets are rated IP54 and feature air conditioning for reliable operation in dusty or hot environments. The user interface includes job recipe storage, remote diagnostics, and multi-language support. Safety features include full guarding, emergency stop circuits, and interlocked doors on each print station. Typical applications include bread bags, frozen food packaging, stand-up pouches, shrink sleeve labels, and paper cups. The machine accepts water-based, solvent-based, and UV-curable inks with an optional corona treater for low-surface-energy films. Below are the main technical parameters and configuration details for the Shaftless stack flexo printer.

• Print width: 600 mm – 1600 mm (custom widths up to 2000 mm)
• Color stations: 2 – 8 (modular, expandable)
• Max mechanical speed: 180 m/min
• Print repeat length: 300 mm – 900 mm
• Registration accuracy: ±0.1 mm longitudinal, ±0.1 mm lateral
• Substrate thickness: 15 μm – 350 gsm
• Unwind / rewind diameter: 1000 mm / 1000 mm (optional 1200 mm)
• Drying system: Hot air, IR, or UV
• Drive system: Independent AC servo motors per deck
• Control system: PLC with 15-inch HMI touchscreen and job memory