Modular™ 919 allows the printing configuration to be switched between front-side and reverse-side printing (“white and turn”) during production by rotating the printing unit through 180°. This enables the film to follow its existing path through the extrusion line, without requiring the web path to be modified to change the side being printed. The operational outcome depends on the line configuration and production conditions.
In the modern flexible packaging and plastics extrusion industries, integrating flexographic printing directly into a blown film extrusion line is a strategic choice for optimising production workflows.
Printing branding, instructions or graphic elements onto the film as it is extruded eliminates intermediate off-line processing steps, significantly reducing handling time and logistics costs. However, inline printing on an extrusion line presents complex engineering challenges that require advanced mechanical and electronic solutions.
This article examines the use of Modular™ series printing presses in extrusion lines, assessing their advantages and limitations before exploring the performance and unique on-the-fly “white and turn” reversal technology of Modular™ 919.
Integrating Modular™ printing presses into extrusion lines
Installing a Modular™ series flexographic printing press on a blown film extrusion line addresses the need for an integrated and flexible production process.
Advantages
- Process efficiency and cost savings: Converting virgin polymer into printed film in a single continuous production cycle eliminates the need to rewind the material, store unprinted rolls and subsequently process them on dedicated off-line printing presses.
- Compact design and modularity: The vertical, modular stack configuration fits naturally into the film’s upward and downward travel through the extrusion line, minimising the machine’s floor space requirements.
- Graphic flexibility and configuration options: The ability to combine multiple printing units, with six or more colours if required, makes it possible to respond quickly to the varying demands of the packaging market.
Challenges addressed (operational limitations)
- Extrusion continuity: A blown film extruder operates continuously and cannot easily be stopped without generating substantial material waste and incurring downtime during line restart. On conventional printing presses, changing the side to be printed, for example, switching from front-side-only printing to front-and-reverse-side printing, requires stopping the line or using complex web-routing systems.
- Tension and register control: Film during extrusion, particularly at low thicknesses, is elastic and sensitive to tension variations. An excessively long and winding web path through the printing unit increases the risk of both longitudinal and lateral register errors.
The engineering solution: a closer look at the Modular™ 919
Modular™ 919 has been specifically developed to overcome the limitations of inline flexographic printing on extrusion lines, combining high mechanical precision with straightforward operation.
Key technical specifications:
- Maximum web width: 900 mm
- Maximum print width: 800 mm
- Print repeat length: min. 300 mm – max. 700 mm
- Maximum rated speed: up to 100 m/min
- High-efficiency inking system: Enclosed doctor-blade chamber made of Teflon-coated aluminium, featuring ink recirculation and an Ultralox™ anilox roller.
- Independent drive system: Gearless drive technology using dedicated brushless motors for both the Ultralox™ roller and the printing cylinder, with micrometric pressure adjustment via electric cylinders.
- Quick sleeve changeover: Cantilevered design with a pneumatically released mandrel for fast replacement of plate-mounting sleeves.
The automatic “reverse” function: switching between white-and-turn printing configurations without stopping the line
The key differentiating feature of Modular™ 919 is its innovative printing-unit rotation system. This design allows the “white and turn” printing configuration (front and reverse sides) to be changed on the fly, without requiring the operator to stop the extruder or modify the film path.
How printing-unit rotation works
On conventional machines, changing the side of the film to be printed requires redirecting the plastic web through complex mechanical guiding systems, such as diagonal or S-shaped web paths.
Modular™ 919 takes a different approach: the printing unit itself rotates around its own axis.
- Rotating support structure: The printing unit is mounted on a slewing ring or circular guide.
- 180° rotation during production: The entire printing assembly, including the plate cylinder, impression roller, anilox unit and inking system, can rotate through 180°.
- Maintaining a straight web path: During and after rotation of the printing unit, the film continues along its natural, straight vertical path, passing through the gap between the cylinders.
- Integrated drying systems and wiring: The electrical system and connections are designed to rotate together with the unit, while the ventilation ducts for ink drying direct the hot air onto the side of the film being printed.
Operational and economic benefits
- No line stoppages (maximum production continuity): For example, the printing configuration can be switched from 3+0 (all three colours printed on the front side) to 2+1 (two colours on the front side and one on the reverse side) simply by activating the automatic rotation of the selected printing unit while the extrusion line continues running.
- Elimination of material waste: Avoiding the need to cut, rethread or redirect the plastic film can eliminate the hundreds of metres of waste typically generated during each configuration change.
- Excellent print register stability: Keeping the film path as short and straight as possible eliminates the tension fluctuations typically associated with long, additional web-routing systems. This helps maintain stable print registration, even when processing very thin polyethylene films.
- Simplified operation: Automating the white-and-turn reversal reduces the complexity of machine operation, enabling personnel without specialised printing expertise to operate the line more easily and safely.
Combining the Modular™ 919 flexographic printing line with a blown film extruder provides an advanced technical solution for flexible packaging manufacturers seeking maximum flexibility, reduced downtime and high print quality.
With its ability to rotate printing units on the fly and switch between white-and-turn printing configurations while maintaining production continuity, the Modular™ 919 stands out as a solution for optimising industrial extrusion and printing processes.
Written by Gian Pio Giugni – President of Giugni S.r.l., 40 years of expertise in Flexographic Technology | Team Giugni®
Discover more articles by Gian Pio’s on flexographic printing, featuring technical insights, technological innovations and solutions for the industry:
