GPL SERIES INKS

TECHNICAL INFORMATION

GPL is an ink series for the reverse gravure and flexo printing of flexible films. It is suitable for lamination use with water based, solvent based and solventless adhesives.

APPLICATION:

The GPL series can be used for in-line lamination with a wide range of printing speeds. GPLcan also be used for out-of-line lamination. The formulation has been adjusted for medium speeds (150-200m/min) and electronically engraved cylinders. For the use of GPL at other speeds or gravure conditions, please contact your local Technical Department. The GPL series covers the general applications in packaging printing. It is recommended for printing on different types of lamination structures (chips, snacks, etc) which may or may not need pasteurisation or sterilisation (depending on the pigments used, contact your local Technical Department).

SUBSTRATES:

The following substrates may be printed using GPL:

  • Bi-oriented polypropylene**

  • Co-extruded polypropylene**

  • PVdC polypropylene

  • PVOH polypropylene

  • XS Cellophane

  • Chemically treated polyester

  • Corona treated polyester

  • PVdC polyester

  • Orientated polyamide*

* Due to the features of these substrates, in-line corona treatment is recommended.

** Needs addition of adhesion promoter The appropriate ink adhesion is always obtained with correct corona treatment.

A film is considered correctly treated when its minimum surface tension is 38-42 dynes/cm. Due to the great variety of polyesters and polyamides in the market, it is recommended that laboratory trials are done prior to the industrial printing of these substrates. To print on substrates not on this list, please contact your local Technical Department.

RESISTANCE PROPERTIES:

  • Blocking (in normal printing conditions) - None

  • Oil and vegetable fat resistance: Good

CHARACTERISTICS:

Odour: the odour level and solvent retention level are good. In correct application conditions (curing and ventilation in machine), it can be between 2-4 mg/mē for a 200% printed surface (depending on the substrate used).

REDUCTION:

Reduction must be done with a mixture of alcohol: ester, usually in a ratio of between 4:1 and 2:1 depending on application/drying speed. For slower drying, ethyl acetate can be replaced with N-propyl acetate. Use of 96° alcohol should be limited to 20%. Methoxy-propanol for gravure and ethoxy-propanol for flexo may be used as retarders, if a 90/10 blend of alcohol/acetate is still too fast. The retarder addition can increase the solvent retention. Our Technical Department can adapt the formulation to your printing conditions to avoid excessive use of retarder. The use of alcohols with a high water content or the excessive use of retarder affect the curing of the laminating adhesive negatively, thus giving poor lamination bond strengths.

IMPORTANT NOTICE:

  1. Ethyl alcohol must not contain a denaturant which could give residual odour.

  2. With metallic inks, lamination bond strengths are lower.

PRINTING MACHINE DRYING:

Please note that, under all circumstances, drying conditions of the printing machine are very important. The drying capacity (air volume, air temperature, recirculation etc) must be as high as possible. If this condition is not complied with, there can be negative consequences on odour (food products) or web blocking (printing of large coinciding backgrounds).

COLOUR RANGE:

GPL is available in a wide colour range only occasionally limited by selecting pigments suited to the requirements of lamination. The pigments have reasonable lightfastness but may not be suited to extended exposure to direct sunlight. If this property is required it should be requested on ordering and pigments of appropriate lightfastness will be selected. It should be noted that laminate bond strengths may vary from colour to colour. BCF These inks have been formulated in accordance with the recommendations of the British Coatings Federation (which incorporates the Society of British Printing Ink Manufacturers).

WASH UP:

TSDA: acetate blends.

Note:

This information has been carefully compiled from experience gained in field conditions and detailed laboratory testing. However, the product's performance and it's suitability for the customer's purchase depend on the particular conditions of use and the material being printed. We recommend that customers satisfy themselves that each product meets their requirements in all respects before commencing a print run. Since we cannot anticipate or control the conditions under which our products are used, it is not possible to guarantee their performance. We would point out that the information provided here is only a recommendation, and may need to be altered to suit the conditions and efficiency of the equipment employed. Coates Lorilleux ink products are not designed for use in conjunction with those of any other ink-maker or similar supplier unless agreed to in writing.