Tips and tricks for processing foil inscriptions
Material – Application - Processing
Inscriptions are among the most well-known areas of application for foils. Depending on the purpose of the application, they are available unicolored or structured, matt or glossy, reflective, transparent, translucent or even phosphorescent and specular. As inscriptions are often used outdoors, UV and weathering resistance are usually imperative requirements. The foils themselves as well as the adhesive layer and the ink of the print must meet these required properties.
For this reason the foils of the inscription segments are generally made of PVC. Normally a difference is made between hard PVC-U (unplasticized) and soft PVC-P (plasticized) that is made more elastic by the addition of softeners. This plastic is found more and more frequently in the advertising industry, where it is used for decorative and inscription foil. Foil inscriptions are found on shop windows, for example, or as wall stickers and privacy shields, as labels or used for the lettering on vehicles. In the broadest sense foils in this segment also include those used as stencils for paintwork, for the painting of aircraft, for example.
Cutting plotters, with knife inserts for example, are very often used to cut inscription foil. The advantage here is that processing is relative economic and flexible. Various shapes, logos or lettering can be cut very quickly. However, CO2 laser systems are also suitable for cutting such foils. There is no tool wear with laser in contrast to cutting with knives. Nevertheless, attention must be paid to the material of the foil when laser is used. Although PVC can in fact be cut with laser, the thermal process produces hydrochloric acid and toxic fumes. For this reason we advise you not to use laser for cutting PVC in order to prevent corrosion of your laser system and to ensure the safety of the machine operator. Instead we offer systems in which knife tools can be installed parallel to the laser in order to ensure the most flexible use of materials.
The cutting system should be equipped with a camera recognition system when cutting printed foils. Fiducial marks are printed between the individual images and these are detected by a CCD camera. This is installed directly in the processing head and scans the defined fudicial marks on the workpiece at the start of the machining process. The connected software calculates the exact position of the foil sheet and compensates print deviations, even automatically if required. This ensures that the cuts are always absolutely accurate along the print contour. Punching tools are only suitable for inscription foils if the costs of producing the tools (punching dies) are offset by high volumes.