Sheet-fed offset inks for printing of food packages 

The legal requirements for food packages are very high .They must be designed in such a manner that they do not release -on normal or foreseeable use conditions-,components on food ,which could potentially;
-Endanger human health
-Cause an untenable change of composition of the food
-Cause an impairment of the organoleptic characteristics of the food

(except from article 3 of the framework regulation (EEC) NR. 1935/2004 of the EUROPEAN PARLIAMENT AND THE ADVICE of the 27.10.2004 )

The entire package,(consisting of printing substrate,ink,varnish,and possibly refinement components) is always the focus of the legislator.Measurement and limit values do not always refer to the individual components ,but to the total product.

In order to manufacture a package which conforms to these guidelines,the use of tested ,highly pure materials is necessary 

The Migration-reduced ink system guarantees the manufacturer of food packages,the fact that from the ink sşde,all legal requirements are complied with ,and makes problem-free printing possible for the printer.

An ink system must fulfil ,apart from good printing properties the following three requirements.

-Scent reduction
-Swelling reduction
-Migration reduction

Scent Reduction :

For many years,a limited number of raw materials were evaluated for the Migration-reduced product line,which does not exert perceptible influence on the filling material or the food because of their degree of purity.Above all,aldehydes are considered to be odour causers ,which can impair the filling material.Beside the well-known Robinson test,the gas chromatography analysis has been proven to be a recognized effective analytic tool.

All Migration-reduced basic inks are submitted to a production-accompanying gas choromatography examination.(as example see appendix 1 )

Swelling Reduction :

A further requirement,especially from the cigarette industry,is apart from the harmlessness requirement,the swelling reduction of sheet-fed offset inks.By swelling,one understands a rejecting of foils,which can results among other things,from the penetration of componets from the inks or varnish film into the foil side facing the printed product.The mechanical stress which arises thereby leads to the fact that the foil no longer rests falt and waves.In the past,this problem was attributed to the mineral oil Migration-reduced inks are therefore mineral oil-free.
The swelling test was in the past afflicted with large problems,especially regarding the reproducibility.During a one year project together with a leading cigarette manufacturer,a gas chromatography method was developed in order to determine the swelling behaviour.For evaluation ,the choromatogram is divided into three regions:

-Very short polar molecules,short non-polar hydrocarbons
-Polar organic substances with medium polarity,longer chain hydrocarbons
-Long chain of hydrocarbons (e.g. highly boiling minerals oils,large strong polar compounds)

sum and tested according to the limit values specified for each region (paramater A<0,4,B<0,1 und C <1,25).(As example see appendix 2).This kind of test is to date unique in the printing ink industry.An appropriate quality test certificate is a firm component of the delivery agreement between the company Epple and its customers in the cigarette industry.

Migration Reduction :

Migration reduction demanded by the legislator is examined by means of the Tenax method (EN 14338 , guideline 82/711/EWG).All package migrating components on the inside of the package are absorbed by a synthetic powder (Tenax).Subsequently ,the entire migrate is evaluated gravimetrically,respectably through gas chromatography.

An entire migration of 60 ppm is kept problem- free with Migrationreduced inks.
(further information regarding migration is to be inferred from the lecture -migration reduced inks-which can be requested under info

The Migration-reduced ink system combines all these characteristics in only one ink system,and this makes the production of law-conformal food packing possible.

In addition,the Migration-reduced ink system is characterised by good runnability and ink/water stability.

Besides the scale,a high-pigmented ,mono pigmented ink mixing system is at the customers diisposal with a Migration-reduced basis (appendix 3 )which covers all ink nuances necessary in the package printing.