From anti-hail nets for agriculture to scaffold sheeting in construction, and geotextiles for infrastructure: marking materials composed of 80% “air” and only 20% solid matter represents an apparent technical paradox. Nevertheless, traceability and branding requirements are non-negotiable. In this context, flexographic printing, embodied by solutions such as Miniflex® 535, stands out as the only truly viable industrial standard.
In the converting sector, printing on continuous films and smooth surfaces is now well-established practice. The real engineering challenge arises when the substrate is discontinuous and consists of an interlacing of filaments, tapes or meshes: nets. Made from plastic polymers (PE, PP), composite materials or metals, these structures exhibit characteristics that rule out most printing technologies, such as inkjet, gravure and offset, effectively leaving flexography as the only technically reliable solution.
The issue of “voids” and the “kiss printing” solution
Why not use inkjet? Inkjet deposition on a mesh substrate leads to a significant portion of ink passing through the openings, resulting in contamination of the equipment and the surrounding environment.
Why not gravure? The process requires high contact pressures, which are incompatible with an open and deformable structure, with the risk of altering the mesh geometry and compromising its mechanical properties.
Flexography prevails thanks to the principle of kiss printing, i.e. controlled light-contact printing. In advanced units such as Miniflex® 535 by Giugni®, the plate is not rigid but consists of an elastic photopolymer matrix. This feature allows the plate to adapt to surface irregularities (knots, intersections, overlaps), transferring ink exclusively onto the raised solid areas without penetrating the voids and without applying pressures that could damage the material structure.
Beyond aesthetics: the strategic drivers of net printing
Once technical feasibility is ensured, it is necessary to analyse the reasons that lead net manufacturers to integrate in-line printing units. Beyond branding, primary functional and regulatory requirements come into play.
- Anti-counterfeiting and quality assurance: in the agricultural and construction sectors, the use of low-quality nets can result in significant economic and structural damage, such as scaffold collapse or crop loss. Periodic marking with the manufacturer’s logo represents the most effective tool to certify product authenticity once installed, distinguishing it from anonymous, low-cost alternatives.
- Regulatory traceability (CE marking): Nets intended for construction and safety applications must display CE marking and mandatory technical specifications. In-line printing enables the permanent and legible application of codes, regulatory references and identification data, ensuring the product’s legal compliance.
- Installation guidance: In many cases, printing serves a technical rather than decorative function, such as overlap lines, directional arrows for installation and cutting indicators. Flexography ensures the geometric precision of such markings even on structurally irregular substrates.
- Outdoor resistance: Nets operate in outdoor environments, exposed to UV radiation, precipitation and mechanical stress. Flexographic technology allows higher ink laydown compared to offset, using highly pigmented formulations with strong weather resistance, ensuring long-term durability and legibility.
“Plug and play” integration
From a production standpoint, net extrusion or weaving lines operate continuously and cannot accommodate dedicated stoppages for marking. The solution must therefore be configured as a compact retrofit system, designed to operate 24/7 in potentially dusty or humid environments.
The compact structure of the Miniflex® 535, in passive configuration, dynamically synchronises with even significantly variable speeds. In this way, an anonymous commodity is transformed, immediately before winding, into a branded, high-value technical product.
Written by Sergio C. | Team Giugni®
