Arctic Materials

Printing Inks

Arcova RT Retort Gravure Inks

Two-component polyurethane gravure inks for reverse-printed retort pouches sterilised at 121 – 135 Â°C.

Ink technology

Solvent-based, 2K polyurethane

Printing process

Rotogravure

Key substrates

Retort-grade PET, nylon and aluminium foil

Primary end use

Reverse print — retort pouches

Product description

Retort sterilisation is the most severe process a printed laminate meets: superheated water or steam at 121 Â°C to 135 Â°C for up to an hour, under pressure, with the pack full. A standard lamination ink will hydrolyse, lose bond and delaminate.

Arcova RT is a two-component polyurethane system supplied with a separate hardener. Cross-linking after printing produces a thermoset ink film with the hydrolysis resistance and bond retention that a retort structure requires. Because it is two-component, pot life must be managed on press.

Key features

  • Two-component polyurethane system with separate hardener
  • Formulated for sterilisation at 121 – 135 Â°C
  • Hydrolysis resistance and bond retention after full retort cycle
  • Suitable for foil-containing and transparent retort structures
  • High colour strength and clean process reproduction
  • Delamination and tunnelling resistance after processing

Product suitability

Arcova RT is intended for reverse-printed retort pouches and lidding for ready meals, curries, pet food and other sterilised products, laminated with a retort-grade two-component polyurethane adhesive. The complete structure — films, ink, adhesive and sealant — must be qualified together through a full retort cycle before commercial production.

Arcova RT is not suitable for:

  • direct food-contact applications
  • use without the specified hardener, or after the stated pot life has expired
  • structures that have not been qualified through a full retort validation

Substrates

SubstrateRequirementRemarks
Retort-grade PET, primedPrint on the primed sideUse retort-grade film only; standard PET will not survive
Nylon (BOPA) filmPer film supplierControl moisture pickup before printing
Aluminium foil, primedPrint on the primed sidePrimer type to be confirmed with our laboratory

Each substrate and structure must be evaluated for adhesion and end-use properties before commercial printing.

Technical specifications

The figures below describe the typical operating window for this range. Confirmed values for a specific shade or batch are issued with the Technical Data Sheet and Certificate of Analysis by our laboratory.

Binder systemTwo-component polyurethane, supplied with hardener
Printing viscosityTypically 16 – 20 s, Ford Cup B4 (4 mm) at 25 Â°C
Retort window121 – 135 Â°C, validated per structure
Pot lifeLimited once catalysed — confirmed on the Technical Data Sheet
AdhesiveRetort-grade 2K polyurethane, mandatory
FlammabilityHighly flammable liquid — see Safety Data Sheet
Shelf life12 months from manufacture, unopened, components stored separately

Colour range

Arcova RT is available as a finished ink range and as a concentrate system of pigment bases and technology varnishes for in-house dispensing. A full range of heavy-metal-free organic and inorganic colours is offered, together with opaque whites and a reducing medium.

Special shades, brand colours and Pantone® matches are formulated against a reference sample. Please contact us for the current Arcova RT shade card and product codes.

Standard pigments are not intended for prolonged exposure to direct sunlight. For outdoor or high-exposure applications, specify high-light-fastness pigments at the time of ordering.

Printing and application guidelines

Cylinder and engraving. Cell depth and screen ruling set the transferred ink film weight and therefore colour density. Confirm the engraving specification with our laboratory for each new job: a deeper cell increases density and opacity, while fine process and vignette work needs a shallower, finer engraving.

Doctor blade. Set blade angle and pressure to the lightest setting that wipes the land area cleanly. Excess pressure scores the cylinder and accelerates blade wear without improving print.

Viscosity and solvent. Stir thoroughly until homogeneous before reducing, and reduce in small steps, re-checking after each addition. Dedicate one clean viscosity cup to each printing unit and record viscosity at the start of the run and at intervals. Always select the fastest solvent blend consistent with clean printing and the drying capacity of the press — retained slow solvent is the most common cause of blocking, odour and poor bond development downstream.

Drying. The ink dries by solvent evaporation. Set dryer air temperature and volume to give a dry, non-tacky film at the rewind without distorting thin films, and check the printed reel for retained solvent before release for conversion.

Storage, handling and shelf life

Classified as a highly flammable liquid. Observe suitable precautions to avoid ignition sources; warehouses must be approved and equipped accordingly. Store in tightly sealed original containers between 5 Â°C and 35 Â°C away from direct sunlight and heat; for optimum stability, 10 – 25 Â°C is recommended.

Waste disposal. Handle inks, coatings and printing residues in accordance with normal standards of industrial hygiene and good manufacturing practice, and dispose of them observing all applicable regulations. Refer to the Safety Data Sheet for specific handling advice.

Health, safety and regulatory compliance

Formulated in accordance with the current CEPE / EuPIA guidelines and the EuPIA Exclusion Policy for printing inks and related products. The formulations exclude:

  • substances classified as carcinogenic, mutagenic or toxic for reproduction (CMR categories 1A and 1B) or as acutely toxic under Regulation (EC) No 1272/2008 (CLP);
  • pigments based on compounds of antimony, arsenic, cadmium, chromium VI, lead, mercury and selenium;
  • dyes, solvents, plasticisers and other materials listed in the Exclusion Policy. A copy of the supporting declaration is available on request.

All Arctic Materials products are designed with end-use safety built in and must not be mixed with products from other manufacturers.

Indirect food-contact applications. It is the responsibility of the food packer to ensure the packed food is safe, and of the converter and packer/filler to ensure that migration does not exceed applicable legal or industry limits. Under a mutual non-disclosure agreement, Arctic Materials will provide a Statement of Composition detailing any potentially migratable components in its products.

Documents

Technical Data Sheets, Safety Data Sheets, Statements of Composition and regulatory declarations for this range are issued by our technical department on request.

The Safety Data Sheet, Statement of Composition, EuPIA Exclusion Policy declaration and heavy-metal / regulatory declarations for this range are issued on request by our technical department, and the Statement of Composition is released under a mutual non-disclosure agreement.

These products are suitable only for use on the non-food-contact side of food packaging, applied under Good Manufacturing Practices and in accordance with the recommendations of the Technical Data Sheet. Printers, converters and packer/fillers carry the legal responsibility to ensure the finished article is fit for its intended purpose and that ink components do not migrate into food above legal and industry limits. Consult the Safety Data Sheet before use.

The information on this page is a guide only and describes properties achieved under laboratory conditions. Arctic Materials recommends that users satisfy themselves as to the suitability of the product by carrying out their own trials under commercial conditions. Because conditions of use and the quality of substrates are outside our control, we cannot guarantee performance and do not accept liability for loss, damage or injury resulting from use, except as required by law. Contact our laboratory to discuss any requirement not covered here.