by Danny Mertens
Durable labels used in washing machines, PCs, cars , machinery, refrigerators etc. are intended to last several years. They are often subject to extreme conditions, such as high or low temperature, excessive exposure to UV light or contact with chemicals. In order to meet the end user’s and the brand owner’s expectations, the labels must be durable as well. For these ends, UV inkjet is the perfect technology.
1) Temperature and mechanical stress
Dry and liquid toner images are polymers fused to the substrate, so when heated, they can melt again. Applying heat-resistant lamination remedies this issue. UV-curable and water-based inkjet are heat resistant: the polymers formed after the complete curing of the UV-curable inkjet have a high melting point. In water-based inks, the concentration of polymers on the substrate surface is too low for the ink to melt and become sticky. Moreover, UV inkjet inks are resistant to mechanical stress after being exposed to UV light.
2) Chemical resistance of durable labels
Cross-linked inks/toners are generally highly resistant to chemicals, which explains the performance of UV-curable inkjet inks compared to that of liquid or dry toner: the resins in toner are mostly not cross-linked. Applying chemically-resistant lamination remedies this issue but comes with a cost.
3) UV sunlight and durables
Lightfastness is critical for high quality labels. It is a measure of how well a printed image resists discoloration or fading as a result of exposure to light over time. Products sitting on a store shelf or in a warehouse are often exposed to direct sunlight for hours on end. The UV affects the color pigments, causing the image to lose its brightness over time. It is a natural process which can be slowed down by adding protective UV layers on top of the label (varnish or laminate). From the start, Xeikon invested in high quality toners, UV inks with great lightfastness scores without any additional protective finishing.
Without applying any additional protection, liquid toner and water-based inkjet achieve a very poor result.
Durables, which typically have a fairly long shelf life, require labels that can stand the test of time. They must often endure extreme temperatures, mechanical stress, exposure to chemicals and UV light. For all these conditions, digital label printing combined with UV inkjet is the best technology.
The Xeikon PX3000 combines our trademark quality, versatility and speed with the possibilities of inkjet.
|End-use label application||Dry toner||UV inkjet|
|Beverage||xx (offset quality)||xx (tactile look and feel)|
|Wine & Spirits||xx||too challenging a material|
|Pharma||xx (finest detail in print)||Xeikon CX3|
|Durable / Industrial||Varnish or lamination required||xx (durability)|
|Health & beauty||xx (offset quality)||xx (tactile look and feel)|
|Chemical||Varnish or lamination required||xx (durability)|
Download white paper
More on food label printing? Would you like a more in-depth look at the different digital printing technologies?
- Download our white paper ‘Digital label printing technologies: No one size fits all’
- or get in touch
For our complete digital label press line-up, visit our label pages.