Slot-die coating

There are three basic slot-die orientations die facing upward, horizontal, and downward. With the die face pointing upward, coating can be problematic, especially with thin or low-viscosity slurries, since slurries can flow backwards down the web toward the die. The tendency for slurries to back flow on the web can be reduced by changing the orientation of the die to either horizontal or facing downward. The horizontal position also provides the best combination of air purging at start-up, clean operation, and the finest degree of operator adjustment. 

One advantage of slot-die coating is the low contamination of the coating layer. 

The entire slurry flow path is sealed against the environment until the slurry reaches the aluminum foil. Wear in a slot-die system is also very low in comparison to most other coating methods. This further reduces contamination of a coated product. 

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Krebs, F.C. (2009) Polymer solar cell modules prepared using roll-to-roU methods knife-over-edge coating, slot-die coating and screen printing. Sol. Eneigy Mater. Sol. Cells, 93 (4), 465—475. 

Introduction of microgravure and slot die coating heads on tape casting equipment in Japan to produce precision thickness in thin tape-cast materials. 

Figure 55 Cartridge style coater showing a slot die coating cartridge - mainly used for water based PSA adhesive (source FAUSTEL Inc. USA).

Krebs PC, Fyenbo J, J0rgensen M (2010) Product integration of compact roll-to-roU processed polymer solar cell modules methods and manufacture using flexographic printing, slot-die coating and rotary screen printing. J Mater Chem 20(41) 8994-9001... 

Traditionally, screen printing has been used for the manufacture of biosensor platforms as the printed substrates can be easily modified (metal fllrns, conducting polymers, nanoparticles and other nanostructured composites) for the recognition of different analytes. However, the biological molecules (enzymes, DNA, antibodies) are usually dispensed in some other way (Gonzalez-Macia et al., 2010 Mistry et al., 2014 Taleat et al., 2014). Slot-die coating and drop deposition are two of the conventional... 

Vacuum adjustment Coating roll Figure 28.2 Schematic of slot-die coating. 

In one report, a ZnO nanopartiele layer, P3HT PCBM and a PEDOTrPSS layer were slot-die coated sequentially onto ITO-PET, and the performance of the device fabricated by the slot-die coating system exhibited around 2% PCE (the module area was 96 cm ). ... 

In one report in the literature, the performance of a device fabricated by the gravure printing system exhibited around 0.6% PCE (the device area was 4.5 mm ). Typically, P3HT PCBM and PEDOT PSS layers are slot-die coated sequentially onto the ITO-PET. 

J. Alstrup, M. Jorgensen, A. J. Medford and F. C. Krebs, Ultra Fast and Parsimonious Materials Screening for Polymer Solar Cells Using Differentially Pumped Slot-Die Coating, ACS Appl Mater. Interfaces, 2010, 2, 2819-2827. 

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