Expert knowledge from A-Z
An adhesive tape (to be defined) is used to test the adhesive strength of print areas. The specific adhesive tape can lead to different values, therefore this method can only be used as a guide.
Narrow film tapes that are applied to the packaging film; have an overlapping, free end as a contact point for opening the package. Pulling on the free end of the strip tears open the packaging film. The system must be set up such that the bond of the strip is stronger than the tensile strength of the film.
Error pattern for film rolls that drift to the side on the roll in a funnel pattern—the sideways telescoping of wound foil rolls; the film telescopes out from the original roll width. This error pattern can also occur, for example, if water-absorbent roll centres are stored in an environment that is too moist or the defined moisture content of the roll centres dries out; this can also be caused if the film is too smooth or the winding tension is too low.
Mechanical property, usually specified in the lengthwise and crosswise directions for materials like PP films; the higher the value, the stronger the film.
Thermal transfer printing
The core element of a thermotransfer printer is the thermal print head, which contains many individual heating points, called 'dots', in a row. The thermal transfer ribbon is used as an ink carrier. It is comparable to the carbon ribbon on a typewriter. The difference is that, during thermal transfer printing, the colour is not transferred mechanically, but thermally. When heating the individual dots of the thermal print head, the ink is melted onto the thermal transfer ribbon and remains stuck to the film.
Types of plastic that become soft and fluid at higher temperatures and return to a solid state when cooled off. This process can be repeated multiple times for most thermoplastics.
Materials that cannot be reheated and softened.
Top film of a packaging system consisting of a top and bottom film.
Film coating made of metal using thermal evaporation in a vacuum. A backing film coated with lacquer is metallised on the lacquered side. A laminating process is then used to combine the film to be metallised with the metallised side of the backing film. This creates very high reflectivity and visual effects.
Translucence refers to the (partial) ability of light to pass through a substrate. Wax, human skin, and leaves are examples of translucent materials; they let some light through but are not transparent. Opposite: Opacity.
Measure of the amount of light allowed to pass through a sample. The transparency of the film takes centre stage in many packaging applications. Transparency values are benchmarks for the practical use of films. Definition in accordance with DIN 16544: It is measured as the proportion of transmitted to incident light. Key performance indicator = opacity. See also: High transparency, opaque
Measures the opacity or transparency of films; the scattering or haze of the transmitted light is determined. Low haze values = high transparency. The haze also provides information on the homogeneity or quality of a film. Additives, such as anti-blocking agents, can increase the haze of films.