Roll-to-roll processes have uses in rapid, cost-effective electronic parts manufacturing, and have long been involved in electrical engineering, micro-production, and solar technology. Conventional and other laser-based manufacturing processes have already been incorporated in roll-to-roll manufacturing, but attempts to integrate direct structuring operations conducted using pulsed lasers have so far met with little success. Until now, these processes have failed because of inadequate repetition frequency and low pulse energy, as well as the lack of speed and precision of the beam deflection.
Recognizing this, the Fraunhofer Institute for Production Technology (IPT; Aachen, Germany) is collaborating with the Fraunhofer Institute for Environmental, Safety and Energy Technology (UMSICHT; Oberhausen, Germany) and partners from industry to develop a module capable of direct laser microstructuring in a roll-to-roll process. The aim of the project, dubbed PoLaRoll, is to produce a sieve-like metal foil to serve as a demonstrator that will be used to protect glass facades from the effects of the sun. Their special geometry will lower the impact of solar radiation, thereby reducing the amount of energy required to cool and ventilate the building.
In this project, Fraunhofer IPT is responsible for developing the laser structuring process as well as the measuring and systems engineering. In addition, the industrial partners will refine two pivotal components: a femtosecond laser with high power output coupled with an extremely high pulse repetition rate and an innovative, dual polygon scanner system, whose purpose will be to ensure swift and accurate beam deflection. Fraunhofer UMSICHT is developing a new chromate-free, environmentally compatible coating that will be cured via UV lithography. It will ultimately be possible to structure both sides of the metal foil simultaneously using a laser.
|Laser structuring of metal foil. (Photo: Fraunhofer IPT)|
Fraunhofer IPT is currently developing an inline measuring system for the polygon scanner that will permit coating removal via the femtosecond laser to be measured and any processing faults in the material to be measured in real time along with the form and position of the micro-structures. They will also develop a system-based solution which will permit high-speed synchronization of the laser source and the polygon scanner, allowing the beam path to be split, for example, and moved in both directions.
It is anticipated that the new module with its femtosecond laser and the polygon scanner system will be integrated in a roll-to-roll process chain to bring together new, interdisciplinary developments from industry and research. These, in turn, will be integrated within a high-speed structuring operation using a pulsed laser to achieve efficient, environmentally compatible industrial high-volume manufacture.
The Horizon 2020 program will grant €3.5 million (around $4 million) to fund the project from October 2016 until September 2019. The total cost is expected to amount to approximately €4.4 million (about $5 million).
Participating industrial partners are Amplitude Systèmes (France), D'Appolonia (Italy), Laser Engineering Applications (Belgium), LUNOVU Integrated Laser Solutions (Germany), Micrometal (Germany), and Next Scan Technology (Belgium).
For more information, please visit www.ipt.fraunhofer.de.