Foil and film laminates
To attain specific properties, paperboard is combined with various plastics, films, foils or other additional paperboard layers. Complete descriptions of the product can be acquired by studying the specifications of the laminate together with the specifications of the paperboard product. The choice of material is determined by the desired properties. These can be barriers against moisture and grease, heat tolerance, strength or combinations of these functions.
Iggesund Paperboard representatives often participate in customers’ packaging development, thereby acquiring a broad overview of packaging solutions. Their knowledge can help determine the best solution for the product’s journey through the distribution system from manufacturer to consumer. In addition to what is presented in the catalogue, there are other products and combinations available. Contact your local Iggesund Paperboard representative for more information.
The surface finish of a foil or film laminated printing surface is determined by the smoothness of the baseboard, and by the amount of plastic applied. A smooth baseboard together with a high gloss chill roll and plastic results in a smooth printing surface. The surfaces are subjected to chemical modifications to achieve good ink wetting. The finished surface can be damaged by handling, friction, high stacking, fingerprints, etc. When printing on a foil or film laminated surface special inks are required. You should consult your ink supplier.
The finish on the reverse side of plastic coated products is NSO (non-set-off). This means that the plastic surface has small elevated spots. This is achieved by the use of a chill roll with a special surface. The resulting point contact with the underlying sheet ensures low friction and facilitates quick drying and avoids set-off. For plastic grammages below 15 g/m², the function of the NSO finish is successively reduced. To minimise the risk of blocking in printing and converting processes, avoid plastic grammages below 15 g/m² on the reverse side of products coated on both sides. One-side plastic coated board is usually corona treated to improve the sealing characteristics and to permit gluing with waterbased adhesive. If the reverse side is plastic coated, please consult the information in the respective specification.
Immediately after being manufactured, the finished paperboard is packed in a moisture-proof wrapper. The wrapper offers satisfactory protection against moisture changes, but only as long as it is left on intact. Leave the moisture-proof wrapping on until the paperboard is to be converted. Two-side plastic coated board will tend to stick together if exposed to high pressure and/or temperature, leading to friction blocking problems. If the corona treatment is damaged reduced wetting with printing inks may result. Since the corona treatment is influenced by handling and storage conditions we recommend that the material is used within six months after production.
Foil and film laminates are used on paperboard to provide protection against wet or aggressive products and to provide a barrier against moisture loss and gas transfer. The construction of the package and its closures are in many cases the factors which limit the total protective function of the package.
The shelf life of the packed product depends on parameters such as:
- Quality and geometry of the product
- Filling level in the package
- Exposed area of the product
- Chemical properties of the product
- Storage conditions
When selecting a suitable protective plastic barrier it is necessary to refer to previous experience with similar packing requirements and also to consider the specific barrier. Typical values for our most common plastic coatings are tested according to ASTM F-1249/ DIN 53122 (water vapour permeability) and ASTM D-3985/DIN 53380 (oxygen permeability).
Typical barrier values
||23°C, 50% RH
||38°C, 90% RH
||23°C, 50% RH
||38°C, 90% RH