In vacuum coating of plastic films, the major section of roll-to-roll vacuum web coating, about 15 billions of square meters per year are presently coated world wide, with a continuous, long-term growth over the last decades. In this area, packaging films today represent about 2/3 of the overall volume. The rest is covered by decorative and technical applications like capacitors. In packaging, the still most important coating material is thermally evaporated aluminium. In addition, a new market perspective is seen in transparent barrier layers on the basis of oxides from silicon and aluminium, today mainly made in Japan. In Europe, the break-through has not been achieved for this kind of layers and mainly test scale coating capacities are in operation.
A lot of challenges and a strong need for technical innovations arise for this sector, mainly driven by the increasing functional demands that are caused by the trend to substitute heavy, but virtually impermeable packaging systems, made from metal and glass, by lightweight and flexible ones, made from film laminates: - To achieve better barrier properties of flexible packaging against the permeation of gases, of water vapour and of flavour substances, for flexible packaging both with barriers from metallic and transparent oxide layers, produced by vacuum coating, - and to allow the use of abundant, less expensive and better recoverable substrate materials like polyolefin's, thereby maintaining superior barrier properties. For those subjects, the basic technical processes have already been tested on the separate steps by different companies, but to achieve the necessary combination of these on the industrial level, the problems in technology transfer are immense. At present, there is a high uncertainty for obtaining a good final result of the process chain and large variations in properties may be observed on most products even in cases where the starting materials are exactly the same. The same is valid for the emerging areas - outside capacitor applications - where vacuum coated layers are used in technical applications. These areas, although characterised by a high added value, show an even higher variety of technical requirements compared to packaging, thus leading to a varying performance of the products available for the related applications.
It is the main goal of the project to coordinate the industrial R&D activities ongoing in different companies and to achieve a better hand shake between industrial partners active along the process line with respect to the following issues: - Film production, pre-treatment, vacuum coating and final lamination of:
- polyolefin films, especially polypropylene, and of;
- other selected polymer films with metallic and transparent barrier layers, for packaging applications. Targets are to enhance the basis of knowledge for all partners and to achieve substantial improvements in the quality of products by simultaneous introduction of process innovations into the whole production chain. Investigation of technical applications outside capacitors, e.g. medical, optical, wearresistance and security applications with their specific requirements toenlarge the knowledge basis also there with respect to process parameters andtheir effects on product performance. - The techniques of measurement andtesting, namely of barrier properties, especially permeability for oxygen, of water vapour and of flavour substances, and of mechanical properties, especially adhesion, for both areas also in dependence on mechanical loadstypical for packaging processes. There is also an important element of prenormative research: To develop industrial testing standards for vacuum coated layers on thin polymer films and, if possible, to introduce themfurther into international standardisation panels.
Funding SchemeTHN - Thematic network contracts
SN2 2QF Swindon
IP24 2QY Thetford
75010 Pisticci Scalo
63667 Nidda - Oberschmitten
7490 AA Delden
DE21 7GY Spndon
OL10 2TL Heywood