When we think of flexographic printing, our minds immediately turn to the converting and packaging industries: rolls of flexible plastic film running at high speeds, folding cartons made from solid board, corrugated cardboard packaging and rolls of enhanced self-adhesive labels.
Over the years, flexographic printing has established a strong position in these traditional sectors thanks to consistent print quality, fast drying times and unrivalled hourly productivity. However, limiting flexo to the world of packaging alone means overlooking one of its most valuable assets: the remarkable mechanical and fluid-dynamic versatility of ink transfer.
Taking an established technology beyond its traditional “comfort zone” requires in-depth expertise in fluid dynamics, kinematics and consumables chemistry. This is where the engineering excellence of specialised manufacturers comes into play, re-engineering the fundamental principles of flexographic printing to address demanding industrial challenges in operating environments that conventional systems were never designed to handle.
From rotary printing to cutting-edge applications: the challenges of specialised marking
In demanding production processes, printing cannot rely on the ideal operating conditions of a conventional flexographic press: there is no controlled web tension, no perfectly flat surfaces, and the surrounding environment may be characterised by low temperatures, saturated humidity or dust.
Transferring a sharp, fast and permanent mark onto non-absorbent materials or biological substrates requires three essential capabilities:
- Micrometric ink metering: preventing smearing, dripping and ink build-up through specifically engineered anilox rollers.
- Three-dimensional adaptability: handling organic, irregular or oscillating surfaces without distorting the printing plate or damaging the substrate.
- Resistance to intensive washing and sanitisation cycles: compliance with the strictest hygiene standards (IP55 or higher, stainless steel construction and tool-free quick-release components).
A clear example of this technological frontier is direct marking within the meat processing and slaughtering industry.
Application case study: traceability and direct carcass stamping in industrial slaughterhouses
In the meat processing industry, traceability is not optional; it is a strict regulatory requirement established by European legislation, including Regulation (EC) No. 853/2004 and subsequent health and hygiene provisions. Each animal carcass side or quarter (beef, pork or sheep/goat) must bear a clearly visible and indelible health mark identifying the slaughterhouse’s unique approval number and the relevant commercial classification.
Traditionally, this operation was performed manually using ink-pad stamps. This method was not only slow and potentially hazardous for operators working alongside overhead conveyor systems, but also prone to errors, smudging and inconsistent marking.
Implementing continuous or intermittent flexographic marking directly onto the carcass appeared to be an almost impossible challenge due to several constraints:
- Wet, fatty, concave and convex surfaces;
- Carcass sides suspended from continuously moving overhead conveyor chains and subject to natural oscillations;
- Strict hygiene and food safety requirements: the use of food-grade, non-toxic inks formulated without harmful volatile solvents and capable of drying instantly on the rind or muscle tissue;
- Cold working environments and high-pressure washdown conditions.
The engineering solution: Flexo Printer 397
To meet the requirements of large-scale slaughterhouses, Giugni S.r.l. developed the Flexo Printer 397, a marking machine that incorporates the conventional architecture of a flexographic inking system into a highly responsive electro-pneumatic assembly.
1. Three-roller flexographic inking system with integrated anilox roller
The heart of Flexo Prinetr 397 inking unit replicates the fluid-dynamic precision of an industrial flexographic press:
- A rubber pickup roller draws food-grade ink from a constant-level ink tray, continuously supplied by an independent bottle-type reservoir fitted with a compensation valve;
- An Anilox roller, driven by an adjustable-speed pneumatic motor through a toothed belt transmission, removes excess ink and ensures uniform volumetric distribution;
- A movable rubber transfer roller picks up the correct amount of ink from the anilox roller and moves upwards to ink the printing plate/stamp mounted on the plate holder.
2. Two-stage pneumatic kinematics with mechanical contact sensing
The real innovation of the Flexo Prinetr 397 lies in the way the printing head approaches the carcass suspended from the overhead conveyor:
- Phase 1 (Detection and preparation): the first photocell detects the arrival of the carcass side on the conveyor. The pickup roller and anilox roller start rotating, while the movable roller transfers ink onto the stamp.
- Phase 2 (Approach and extension): the second sensor detects the carcass body. The long-stroke positioning cylinder moves the entire stamping head into its advanced standby position.
- Phase 3 (Compensated dynamic marking): a front-mounted contact sensing roller physically engages with the moving carcass side. As soon as the sensor detects contact with the surface, regardless of the carcass dimensions or oscillations, the short-stroke cylinder is activated, applying the printing plate with a preset force.
3. Micrometric adjustment and substrate protection
Transfer precision is ensured by 10:1 ratio graduated adjustment indicators: each turn of the adjustment knobs allows extremely fine calibration, with a resolution of 0.02 mm per graduation. This ensures that the stamp contacts the rind with only the pressure required to transfer the ink, without tearing the meat or damaging the polymer printing plate.
4. Tool-free maintenance and sanitisation
In compliance with HACCP procedures and the strict hygiene requirements of food processing facilities, the Flexo Prinetr 397 stamping unit is designed to enable rapid end-of-shift cleaning. The ink tray can be released using quick-release levers and washed with water; printing plates mounted on removable bases can be replaced and realigned quickly, while the pneumatic assembly features a sealed construction.
Competitive advantages: precision, automation and full compliance
Introducing specialised flexographic technology into the slaughterhouse production line offers immediate advantages over traditional marking methods:
| Aspect | Traditional manual stamping | Automatic flexographic marking (Mod. 397) |
| Production rate | Up to 10–15 carcasses per minute, with operator fatigue risks | Continuous in-line synchronisation (one printing cycle every 15 seconds per channel) |
| Print quality and legibility | Variable, with frequent smudging or incomplete impressions | Consistent, with uniform and controlled anilox ink metering |
| Operator safety | Operators working close to heavy moving loads | Fully automated process, with remotely positioned emergency stop controls |
| Inks and traceability | Risk of contamination or dripping | Compliant food-grade inks, no harmful emissions and immediate ink setting |
The Giugni® vision: flexographic printing as a tailor-made solution
The Mod. 397 printing unit demonstrates that flexographic technology is not limited to converting applications. When mechanical expertise is combined with pneumatic precision, flexo becomes an ideal solution for marking wood, profiled metal sections, extruded plastic pipes and even complex organic substrates.
At Giugni S.r.l., we combine over fifty years of Made in Italy mechanical engineering expertise with applied engineering, developing both standard and customised solutions to meet the most demanding flexographic printing challenges on your production line.
Frequently asked questions (FAQ)
How does flexographic printing ensure compatibility with food safety standards?
In the Flexo Printer 397, the inking process uses non-toxic formulations certified for direct food contact, without harmful volatile solvents. The controlled closed-loop system prevents external contamination and ensures immediate drying on muscle tissue or the rind.
How does the machine prevent the stamp from being damaged when contacting a moving carcass?
The machine uses an intelligent combination of contact sensing rollers and cylinders with different strokes. The sensing roller detects the actual position and profile of the carcass, cushioning the contact and allowing the short-stroke cylinder to apply only the calibrated pressure required to produce the impression.
Can the machine print variable codes, or is it limited to fixed stamps?
The mounting base is designed to accommodate polymer printing plates or interchangeable numbering units and character sets. This allows health marks, batch numbers, slaughterhouse identification numbers and commercial classification codes to be updated according to the production schedule.
Model 397 demonstrates how flexographic technology can be adapted to complex production environments, ensuring marking precision, operational continuity, and reliability in food supply chain traceability processes.
To learn more about the technical features and specifications of the Flexo Printer 397, consult the corresponding product datasheet.
Written by Andrea Giugni – Specialized PLC Programming and Automation Technician | Team Giugni®
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