Achieving design and function in a single molding cycle
- Plastics Processing
Leonhard Kurz integrates surface decoration and the PolyTC® touch functionality from PolyIC into the injection molding process.
The coating specialist Kurz has developed an integration technology that allows both functional films for touch sensors and decorative coatings to be applied concurrently to a component while it is being injection molded. This integration of functionality and decoration occurs in a process that combines Inmold Labeling (IML) with Inmold Decoration (IMD). First individual inmold labels of the printed films with touch functionality are produced and then inserted into one half of the mold and bonded to the rear of the plastic part through back injection.
Concurrently, using IMD technology, a carrier foil with a decorative coating is fed through the second half of the mold, and the coating is released from the carrier and bonds to the front side of the component as it is injection molded. In order to implement both these film application processes within a single injection molding cycle, it was necessary to develop a specialized mold technology. A special-purpose functional film that is suitable for use in an IML process was also required.
Sensor films from PolyIC
These IML-capable functional films have the trade name PolyTC® and were developed by PolyIC, a KURZ subsidiary. PolyTC® are transparent films with a high sensor sampling rate, signal quality and electromagnetic immunity thanks to their metallic conductivity. These films enable the production of very thin, flexible and transparent touch sensors that can be easily integrated into many applications and can be controlled using conventional electronic components. PolyTC® films are produced in a roll-to-roll manufacturing process that enables a high production capacity.
Design freedom for sensor controls
The decisive advantage of using this novel Kurz technology to manufacture transparent touch displays is that it enables the touch functionality to be integrated directly into the part by means of inmold labeling. When used to manufacture touch control panels for electrical or electronic appliances, for example, this process allows a uniform and elegant surface design to be achieved, while at the same time offering unlimited scope for varying the appearance and quality level of the product depending on the particular IMD foil selected.
Kurz's IMD designs come in a wide variety of colors, patterns and structures, for example with a realistic wood, marble or carbon look. A broad range of true metal coatings are also available. These can be produced in bright metallic colors, with a variety of gloss levels or with a sandblasted or brushed surface appearance. All of these designs are available for use when decorating appliances with touch sensor panels. To enable these buttons to be capacitively controlled, so-called NCVM (Non Conductive Vacuum Metallized) coatings are used in the manufacture of these metallic designs. This design freedom opens up new surface design possibilities for automotive interiors and telecommunication, household or entertainment appliances.
The combined IML and IMD process delivers not only design, but also cost advantages because it provides an especially efficient method for achieving both part decoration, and integration of the touch functionality, within a single injection molding operation. You can assess for yourself the success of this process by visiting the Kurz booth A19 in Hall 5 at K 2013.
- Martin Sedláček