Migration in Packaging Printing

"... undesirable ingredients, decreasing print runs, fast finishing ..." Packaging printers are all too familiar with all these terms. Every day printers face these challenges, and every day they are glad to have reliable suppliers as partners at their side.

Food Packaging
The migration of ink components is more relevant than ever. LMI-series (Low Migration Inks) are now a must-have for every ink manufacturer.
Jänecke + Schneemann do their part to ensure product safety and compliance. J + S were able to transfer the knowledge gained from the development of LMI-offset inks into the areas of UV flexo and, quite recently, tin printing. Moreover, corresponding basic colour mixing systems have been developed for each application area in addition to the standard colour scale. These mixing systems are based on 15 basic colours from which the entire range of Pantone colours can be assembled. J + S also offer LMI supplies and chemistry for the conventional offset range. The goal is to ensure the highest possible quality and highest process safety along the production line.

Can UV inks be used in the printing of food packaging?
The awareness of UV technology in the field of food packaging has changed very much over time. Especially in the field of photo-initiators, further developments have taken place and continue to do so. The possibility of rapid processing, the enormous resistance to physical stress, and the possibility of producing high-quality visual and sensory effects have made the UV technology increasingly attractive. All relevant legislation is, of course, adhered to whenever inks are being developed and enhanced.

What actually migrates?
To answer this question, the structure of the various ink systems has to be considered.


With regard to UV inks, special attention is paid to the photoinitiators which are decomposed by the action of UV radiation and may possibly not be integrated into the ink film in the case of insufficient cure. The respective printing ink binder base can be a carrier of potential migrants, either by contamination or by non-integrated monomers. Considering the facts relating to the raw materials, substances of low molecular weight show a stronger migration potential. In the UV range, for example, the photoinitiators are divided into very small fission products. J + S have developed specific approaches to meet these risks of migration.

Carcinogenic and mutagenic substances are excluded from production. In the field of conventional offset printing, heavy metal driers are not used. Through careful research and selection of raw materials, oils and resins have been found and are employed that do not form fission products. With similar stringent care only suitable pigments have been selected. Careful evaluation has revealed fatty acid esters that can be safely used.

In UV technology, high molecular weight photoinitiators and, alternatively, self-initiating binders can be used. In UV systems used for food packaging, only extensively cleaned binders are used; furthermore, the proportion of monomers in the binder complex is also reduced to a minimum.

Components with Migration Potential

Conventional Offset

UV Offset


Insufficient ink film adhesion


Decomposition on exposure to UV rays,

Insufficient ink film adhesion

Oils and fatty acid esters

Insufficient drying


Contamination by acrylic acids and solvents,

Not fully embedded monomers


Contamination by heavy metals


Contamination by heavy metals

What DOES the packaging printers have to do
The selection of a suitable substrate and the use of a low migration ink alone are not foolproof. Accordingly, there are other details which have to be considered with regard to processing. The risk of contamination, for example by an unsuitable cleaning agent, is high. Therefore, only LMI aids and cleaning agents should be applied. J + S, as already mentioned, offer their contribution to safety along the entire production line. Needless to say, thorough cleaning of the machine is a basic requirement. Maximum attention should always be paid to the printed products in the sheet delivery. Migration happens mostly via wiping contact. Here, it is especially important to observe the pressure and temperature in the stack. With increasing values, these two factors are highly conducive to migration. Moreover, the time until further processing should be as short as possible.