SubscribeThe conventional methods used to manufacture cast PP films are well known. For films having a thickness of 15 - 250 µm, cast-film lines are used, while for the range from 450 µm - 2.2 mm, sheet-extrusion lines are the state of the art. Yet, under this concept, compromises need to be made as to the film's optical and mechanical properties, especially in the case of thickness close to the processing window between these two ranges.
Cast films from 200 µm, but also extremely thin sheet-extruded films from 450 µm, lose in transparency and gloss, and their printability decreases as well. SML's engineers have now devised a method that produces cast films of unprecedented quality with thickness ranging from 100 µm – 400 µm. This procedure is referred to as "Sleeve Touch Technology".
Originally, Sleeve Touch Technology had been a Japanese/European idea which, however, had not been practicable in terms of costs, handling, and maintenance. In recent years, the development department at SML, as worldwide licensee, refined this technology to a point where the result in terms of output, flexibility, and not least quality meets the demands of the European market.
"One of SML's foremost objectives is the continued further development of existing technologies and ideas, there by satisfying the ever-changing requirements of the market. The development of Sleeve Touch Technology from the mere idea to full market maturity, however, constitutes a milestone for the entire industry and, for me personally, is something to be proud of", says Dr. Bruno Haider, reflecting on SML's world novelty for the market of filmmakers.
The sleeve components are conveniently small and therefore ensure excellent handling. Operation and maintenance of the sleeve elements of a cast-film line are so cost-effective that, meanwhile; Sleeve Touch Technology can be regarded as full-fledged alternative to cast-film and sheet-extrusion lines and has in fact already been positioned successfully in the market.
But how does Sleeve Touch Technology work? Generally, it is quite simple. The film is not cooled at one point of the roller, as is the case in cast-film or sheet-extrusion systems, but at the so-called sleeve, i.e., a metal strip, over a distance of up to 15 cm. In the production of packaging materials, Sleeve Touch Technology has the potential for opening up new dimensions even in two directions.
On the one hand, the new SML method can be used to seriously enhance the quality of known applications such as barrier films, films for the office segment, but also shrink films and folded boxes, while, on the other hand, Sleeve Touch Technology also adds new dimensions for manufacturers of materials (granulate). Here, the aim is to create new granulate mixtures in order to improve the quality of previous applications. Yet, Sleeve Touch Technology also harbors a potential for reducing the amount of raw materials used and thus helping lower manufacturing costs while at the same time protecting natural resources.
Furthermore, new granulate mixtures, processed by means of Sleeve Touch Technology, can be used to develop entirely novel applications. Sleeve Touch Technology is of special significance for the Asian market. "To Asian consumers, the transparency and gloss of a packaging film is of enormous importance. In Asia, many items, especially in the segment of packages for cosmetics that in Europe come packaged in cardboard boxes, are marketed in "folded boxes" only.
And it is exactly this range of applications where we are the only ones in the world to offer a cost-effective alternative for quality enhancement in cast-film production in the form of our Sleeve Touch Technology", says DI Rupert Becker, Product Manager at SML, who is convinced that SML now services a previously untapped market niche in the production of films for high-quality packaging.