Sustainability of BOPET film starts at Lake Constance – Lindauer DORNIER GmbH at Chinaplas/Shenzhen with future-oriented plant solutions

Polyester films made from biaxially oriented PET (BOPET) have got high tensile strength as well as chemical and thermal stability. According to Wood Mackenzie's "BOPET Film Global Supply Demand Report" published in May 2019, this special film records annual growth rates of 6.7% since 2013. In 2018 alone, 5 million tonnes were produced, which corresponds to a turnover of almost 11 billion Euros. In the next five years, another 1.1 million tonnes are to be added. This is a promising market of the future, whose demand is growing considerably, among other things due to its significant role in meeting stricter quality and hygiene requirements worldwide, especially to prevent further pandemics.

As the topic of sustainability is also here increasingly coming to the fore, Lindauer DORNIER will be presenting new approaches for the future-oriented BOPET production in Shenzhen, in order to contribute to answering the question of how the energy and ecological balance of film can be improved by innovative plant technology "made in Germany".

Increasing energy efficiency: Patented air guide with optimized heat recovery
"At DORNIER, sustainability is not a buzzword, but both the basis and the result of a long-term corporate strategy", emphasizes Bernhard Wandinger, Head of the Product Line Specialty Machines. The patented air guiding system in the oven, known as TDO, contributes to higher energy efficiency during transverse stretching of the film. This line component stretches the film, which has a maximum temperature of 240 °C during the production process, in transverse direction to widths of up to 10.6 m – a new world record!

According to the company, the new air guiding system can reduce the consumption of thermal energy in this process step by up to 35 % compared to the previous state of the art. Thereby, the heated air is used several times in the different oven zones while maintaining the temperature requirements. Supplementary, the optimised heat recovery in the TDO provides a further energy saving potential of up to 400 kWh: Previously lost energy is now used for the heating zones in the TDO.

Shrinkage is the trump card
Due to their special properties, BOPET films from DORNIER lines also contribute to the success of the energy revolution and electric mobility, which the innovative MD relax system for the transverse stretching machine proves, says Bernhard Wandinger. With this system, the film shrinkage and especially the shrinkage in machine direction can be optimally adjusted. The dimensional stability of the film achieved in longitudinal and transverse direction, even at high process temperatures, makes it ideally suitable for applications with high heat exposure – for example as separator film in batteries of electric cars or in photovoltaic storage systems.

Keyword innovative clip systems: DORNIER takes another important step towards sustainable stretching with the development of the dynamic chain guide. The patented dynamic chain guide in the outlet stand of the transverse stretching machine significantly extends the lifecycle of the proven and robust SSDC clip system. Supplemented by online monitoring of the clip chain length, this ensures reliable and safe running 24/7. The wear-free measurement in the DORNIER TDO inlet stand is almost free of friction and therefore largely maintenance-free. The chain elongation can be measured more precisely and necessary maintenance work can be planned at an early stage.

As the TDO clip systems, which stretch the film in the area of airflow, can be overhauled many times in the course of their product life, even older systems can be equipped with these new technologies.

The PET cycle is closing
Bernhard Wandinger says that discussions with customers often focus on how to use a higher proportion of recycled material in the future while maintaining the same product quality. We are talking here about so-called recycled PET – in short rPET. A material input of 50 % post-consumer recyclate (PCR) and more is now technically possible. Due to the special properties of the polymer, such as its low foreign substance migration rate, it is even suitable for reuse as film for food packaging. The recyclability of BOPET film itself is increasingly coming into focus. As sustainably thinking family company, DORNIER is confident that polyester films can make a significant contribution to achieving the ambitious goals for the reuse of recycled material for packaging. The special characteristics of PET also play a role here. The film itself has a good intrinsic barrier to oxygen, says Bernhard Wandinger, and with extremely thin coatings of aluminium oxide, the material can be quickly and cost-effectively brought to a level, which even meets ultra-high barrier requirements.

Service 4.0: Digital solutions with added value
The new DORNIER customer portal myDoX^® will also be an important issue at Chinaplas. The portal, which is based on state-of-the-art database technology, provides answers to the question of how the world of a traditional machine manufacturer combines the virtual data volume of its machines and production lines. In addition to digital original parts order processing and as a substitute for omitted customer visits and business trips, Lindauer DORNIER now offers virtual tours. These make it possible to experience machines and production lines digitally live according to customer-specific focal points in the works Lindau and Esseratsweiler: A further essential factor for improving the eco-balance, considering the strong international orientation of the German machinery and plant engineering.

Holistic approaches for thermoplastic composites and three-dimensional preforms
Modern composite lightweight construction is not only geared to the material. In fact, it is about the optimal combination of material, process and application. At Chinaplas, the business unit "Composite Systems" of Lindauer DORNIER, founded in 2014, will give an insight into integral solutions for the economic production of high-quality fiber composite structures with the PROTOS^® and TRITOS^® production systems presented for the first time.