Special film lamination

Metallic foils, diffraction foils, film structure (Forchheim films)

Metallic and diffraction foils are used as pure surface of a book or brochure covers as well as a base for a then-applied pressure image (text and images). In the second case, different effects can be achieved that are of particular interest to commercial printing such as very fast-acting metal gloss pictured cars or other objects that exist in the reality of metal.

The film structure (Forchheim film) offers a much higher level of protection against wear and contamination of the printed product as a matt or gloss film.

It has a fine linen texture and is with her about twice the film thickness (compared with normal PP films) very durable. This ensures increased resistance to chemicals, dirt and moisture to ordinary matt or gloss films. Suitable it is therefore for all products that are subject to regular and laying claim to use, e.g. covers for school books and maps, as well as ring binders or menus.

Other imprints such as leather grain, "Pearl" structure are possible in a film structure.

Technical background

Textures can be applied as a pre-embossed film to the substrate. Here, a variety of structures are possible, the natural structures are modeled, such as linen.

You can also first apply a film and the structure then subsequently with a textured roller imprint(structure embossed foil lamination). This is recommended especially for long runs, because it is then less costly than the first method.

Effect

Most metallic and diffraction foils can be overprint offset or screen printing, this can be made translucent or opaque. Every color normally act metallic luster, the screen printing process, this effect can, however, be much weaker. If opaque white has been applied before, the film can also be re-printed with natural color effect.

These sheets are best printed with UV offset printing process, since the inks dry by UV radiation and do not require chip off.

Although textures cannot be printed, but partial coatings can be applied that emphasize the underlying print image effectively or can act completely independently. Partial coating and foil stamping are also possible with printed products with metallic and diffraction foils.

Application possibilities

Metallic foil has an evaporated under high vacuum metal layer; the standard models are silver and gold, but also other metallic shades are possible, as well as a pearly effect.

Diffraction foils are also metallized, usually silvery stamping foils. They have a changing with the light colors in the rainbow colors(as in a prism). Various diffraction patterns are available. Diffraction means "diffraction" and occurs when light passes by a sharp edge or through one or several narrow gaps by running. The light undergoes little lateral deflection - it is diffracted. Add or subtract the diffracted light waves against each other in multiple columns. This effect is called interference. Certain light waves(colors) are weakened by mutual cancellation or subtraction, other amplified by addition or summation of the waves. The light is decomposed into its spectral components.

In opto-mechanical means are films can be produced that contain such diffraction grating. You can disassemble the light impinging into its spectral components and thus shimmer in rainbow colors. In holography, this effect is further exploited considerably: Pictures may look three-dimensional on a two-dimensional support. Custom embossed holograms, for example, important security features on bank notes or tickets.

For the lining, not all papers that are used for the gloss or matt foil lamination. This must be agreed in individual cases with the respective finishing service.

When structure embossed foil lamination only papers of 80 g/m2 to about 450 g/m2 are used.

Limitations

All special films except the structure films are not very abrasion resistant and susceptible to scratches. The solution here is an additional gloss film lamination or a little less durable, but more cost-effective, transparent protective coating. However, the latter method is used in transparent hologram film is not considered, because thereby the hologram is destroyed.

For metallic and diffraction foil act colors to be printed, otherwise; for example, seems a darker red. These color changes must be considered and planned for image reproduction in the precursor. Must be tested under certain circumstances, the adhesion on the film, which may be somewhat limited case by case basis.

Costs

Diffraction foil is expensive because of their relatively complex manufacturing, metallic films are a lot cheaper.

Sources and additional literature

see film lamination

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