Flexography (flexo) and rotogravure (gravure) are both printing processes used for high-volume production of flexible packaging, labels, and other materials, but they have some key differences.
1. Printing method
Flexo printing uses the flexible relief plates which are typically made of rubber or photopolymer materials to transfer ink onto the printing substrate. It’s light pressure printing.
Rotogravure printing uses the cylinder with cells etched or engraved into its surface to transfer ink onto the substrate. It’s heavy pressure printing.
2. Versatility
Flexo printing can be used on a wide range of substrates, including paper, plastic films, labels, aluminum foil and flexible packaging materials. It is particularly well-suited for printing on flexible, shrinkable, super-thin film and non-porous surfaces, such as metallic films. It is also suitable for printing corrugated paper because of its light pressure during printing.
Rotogravure is not suitable for printing corrugated paper because of its heavy pressure. In addition, it’s difficult for rotogravure to print flexible, shrinkable, super-thin film since its instable tension control.
3. Registration precision
Flexo printing has high precision registration which benefits from short distance between each printing unit, no web deformation, stable tension, registration is not influenced when machine speed up or slow down.
On the contrary, it’s difficult for rotogravure printing to control registration precision because it has long distance between each printing unit and is more likely to increase errors, the Web is easy to deform, the tension is unstable, and registration is influenced when machine speed up or slow down.
4. Job changeover
Flexo printing: Job changeover is made easier and faster by the plate cylinder sleeve, anilox sleeve, and closed ink chamber.
Rotogravure printing: Changing the plate manually requires hoisting and takes a longer amount of time.
5. Print speed
Flexo printing achieves a higher printing speed compared to rotogravure presses, with stable printing quality even at high speeds.
Rotogravure printing, due to its lengthy web route and unstable tension, experiences fluctuations in printing quality when running at high speeds.
6. Material wastage
Flexo printing boasts a low wastage rate ranging from 1% to 2%, while rotogravure printing suffers from a high wastage rate of 9% due to low registration precision and an elongated web route.
7. Ink consumption
In flexo printing, ink consumption is 30% lower than in gravure printing for specific regions, concurrently decreasing energy usage for ink drying.
Gravure printing, characterized by high printing pressure and the application of thicker ink, necessitates greater ink consumption, thus demanding additional energy for ink drying.
8. Plate making cycle and cost
In flexographic printing, plate-making is swift and cost-effective, making it suitable for both small and large-scale printing runs.
Contrarily, gravure printing entails a lengthy and expensive plate-making process characterized by its complexity, rendering it unsuitable for small-scale printing projects.
9. Environmental Impact
In flexographic printing, the predominant use of water-based ink makes it an environmentally friendly and sustainable printing method. This makes it particularly well-suited for printing on food packaging, medical packaging, and sanitary packaging. Furthermore, the implementation of closed ink chambers minimizes ink volatilization, contributing positively to both the environment and the health of operators.
Conversely, gravure printing relies heavily on solvent-based ink, resulting in a less environmentally friendly process. The presence of solvent residues renders it unsuitable for printing on food, medical, or sanitary packaging. Moreover, the use of open ink chambers exacerbates ink volatilization, which not only affects ink viscosity but also leads to environmental pollution and poses health risks to operators.
10. Maintenance:
In comparison to a gravure press with an equivalent number of printing units, a C.I flexo press has fewer guide rollers, resulting in reduced maintenance time and costs.
Contrastingly, due to its greater number of guide rollers and mechanical components compared to a flexo press, a gravure press necessitates increased maintenance time and costs.
