Optimized film processing through infrared heat

Infrared heat helps in the processing of plastic films, for example in the drying of coatings. Infrared emitters make heating processes for plastic films more efficient and save energy and costs.

Plastic films are used in many different ways, for sealing roofs, as food packaging, as decorative or functional films in car interiors. The films are painted, printed, embossed, laminated or laminated and all of these processes benefit from innovative infrared systems. Very thin films are a challenge for heating processes. Infrared emitters have proven to be very effective here, as plastics absorb medium wavelengths particularly well and convert them quickly into heat. The infrared emitters and systems from Excelitas Technologies can be precisely matched to the plastic material and process. This makes heating processes more efficient and helps to save energy and costs.

Conventional heating methods quickly reach their limits when it comes to increasing the process speed when processing films. Large rollers weighing several tons have to be heated up for a long time, cool down only slowly if the belt stops unexpectedly and can therefore cause problems. Hot air causes the films to flutter and the heat transfer is not optimal, so hot air ovens are very large if higher belt speeds are to be achieved.

In contrast, infrared radiation transfers energy contact-free and very efficiently. Carbon infrared emitters emit medium wavelengths and thus heat the films, especially on the surface. They can be controlled very well because they react within seconds. This minimizes damage in the event of a sudden belt stop.

If coating or printing on films is to be dried efficiently, it often turns out that hot air ovens are not an option for the thin films. Infrared drying with medium-wave infrared emitters provides a remedy here. Short-wave radiation simply radiates through a film, while medium-wave radiation heats films very efficiently, especially on the surface. Carbon infrared emitters combine medium-wave radiation with very short reaction times, which helps to minimize damage in the event of an unexpected belt stop. Doors, center consoles or instrument panels of a car consist of carrier parts that are covered with a film. This is often done using lamination technology. The adhesive system is applied to the film or carrier part in advance.

In contrast to conventional quartz emitters, Noblelight infrared emitters offer enormous advantages when heating TPO and PVC films. They heat the films faster, reduce cycle times and at the same time save energy because they do not have to be kept on standby all the time. Infrared emitters are only switched on when heat is required.

Decorative strips in cars, switches with a metal look or high-gloss fittings are made from injection-molded plastic and coated on the outside. This is often done using the IMD process, known as in-mold decoration or film back injection molding. In this process, a carrier product with decorative coating is placed inside the injection mold. While the mold is filled with plastic, the lacquer or paint adheres to the surface of the plastic cast parts. When the mold is opened, the paint detaches from the carrier and remains on the plastic part. The coated part can now be removed and the entire process benefits from IR technology. The coated transfer product can be processed much better if it is preheated by infrared radiation and thus becomes malleable. Excelitas offers infrared systems that are precisely adapted to the product and process. This saves space, effort and costs. (OM-9/24)