Roll-to-roll process
The roll-to-roll process ( R2R process for short , English roll-to-roll ) represents a possibility in the production of flexible printed electronics , flexible electronic components, printed on a web of flexible plastic or metal foils, inexpensive and quick to manufacture. Other areas of application of the R2R process can be found in the field of coating and normal printing of substrates . For this purpose, the starting material on a roll is unrolled, processed and finally rolled up again.
Printing process in the R2R
Depending on the requirements for the printed layers (e.g. degree of flexibility), the properties of the printed materials and economic aspects, mass printing processes such as gravure , offset and flexographic printing are mostly used in the R2R process . The advantages of the R2R process are:
- inexpensive production
- high working speed (manufacturing)
- low material consumption
- Low temperature process
- flexible substrates
- proven printing technology
- existing printing techniques can be easily integrated
- cost-effective, through time and material savings
In addition to mass printing processes, printing processes such as inkjet or screen printing are also used.
Gravure printing
In the gravure printing process ( direct printing process ), the information to be printed is available as depressions (cells) in the printing form cylinder. In doctor blade gravure printing, the printing forme cylinder consists of four individual steel cylinders for four-color printing.
Part of the printing forme cylinder is located in the ink tray and receives the material / color to be transferred in the depressions. Excess material picked up is removed with the help of a doctor blade . The substrate runs between the printing cylinder and the printing forme cylinder and absorbs the material / color due to the greater adhesive forces and the high contact pressure.
Offset printing
In offset printing (indirect printing process), the printing cylinder and substrate do not come into direct contact. The ink or the material is first transferred from the impression cylinder to the blanket cylinder and then onto the substrate. Thus on the one hand the printing plate and on the other hand the substrate are protected. The general structure of the printing cylinder can be divided into printing and non-printing areas. While the printing areas are hydrophobic , the non-printing areas are hydrophilic. The printing form is treated with the help of the dampening unit , so that no dampening solution collects on the hydrophobic areas, but does collect on the hydrophilic areas. These properties are used to transfer paint or material. While the paint / material adheres to the hydrophobic areas, it does not adhere to the hydrophilic areas and a targeted transfer of color can take place.
Flexographic printing
Flexographic printing is also characterized as a letterpress process, as the printing areas ("image-bearing") are higher than the non-printing areas. In general, the image information is transferred to the printing cylinder via a colored anilox roller and from there to the substrate with the aid of an impression cylinder.
R2R for printed electronics
The developments in the electronics and photovoltaics sector in recent years show that there is an increasing trend towards light, flexible and inexpensive (mass printing) produced electronic components. In view of these requirements, the R2R process is very well suited for the production of thin layers on flexible substrates. The printed materials range from metallic to organic to dielectric or semiconducting. The thickness of the printed layers range from micrometers to nanometers. Areas of application for this technology can be, for example:
- flexible thin-film solar cells and organic photovoltaics
- flexible LED / OLED lighting and display technologies
- Medical technology
- Semiconductor industry
- Microsystem technology
- RFID
- printed electronics
The R2R process is still in development. The aim is to produce semiconductor components in the mass printing process at a fraction of the production time and costs.
Individual evidence
- ↑ Anne Blayo, Bernard Pineaux: Printing Processes and Their Potential for RFID Printing. In: Proceedings of the 2005 Joint Conference on Smart Objects and Ambient Intelligence: Innovative Context-Aware Services: Usages and Technologies. , ACM, New York, NY, USA 2005, ISBN 1-59593-304-2 , pp. 27-30 doi: 10.1145 / 1107548.1107559 .
- ↑ Archived copy ( memento of the original from March 6, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ a b Handbook of Print Media PCK Technologies and Production Methods . Springer-Verlag, Berlin / Heidelberg 2001, ISBN 3-540-67326-1
- ↑ http://www.wellpappe-wissen.de/wissen/wellpappen-verpackung/verpackungsproduktion/flexodruck.html
- ↑ Joachim Böhringer, Peter Bühler, Patrick Schlaich: Compendium of media design: Production and technology for digital and print media . Springer, 2008, ISBN 978-3-540-78528-6 .
- ↑ Archived copy ( memento of the original from August 20, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
