Doctor-blade process

J. C. Williams, "Doctor-Blade Process," in F. F. Y. Wang, ed.. Treatise on Materials Science and Technology, Vol. 9, Academic Press, New York, 1976. 

As for all conjugated molecules, the insolubility of para-phenylenes longer than five phenyl rings poses a severe obstacle to easy solution processing and film fabrication via simple drop, dip, or spin-casting as well as doctor blade processing. However, there are several strategies widely used to circumvent this problem ... 

Williams, J.C. Doctor-blade process. In Treatise on Materials Science and Technology, Wang, F.F.Y., Ed. Academic Press New York, 1976 Vol. 9, 173-198. 

Band casting and the doctor-blade process are other names. 

The mechanical setup of the doctor blade tape casting process is shown in Figure 4.7. In this process, the slip is deposited in excess on the carrier surface, typically in a confined reservoir. The carrier surface is then moved under the doctor blade, which wipes the excess material back into the reservoir, leaving a thin layer of fluid on the carrier. The mechanics of the doctor blading process are, in theory, quite simple. In practice, however, controlling all of the variables to... 

For the production of fuel cell electrodes via a doctor blade process, a Newtonian behavior of carbon-based inks is very desirable. This means, that the viscosity is not changing, no matter what shear stress is applied on the ink or slurry, what is leading to the fact, that the ink or slurry can be pumped from a storage vessel to the doctor blade with low changes in viscosity. The low change of viscosity leads to a very constant flow of ink to the doctor blade. 

The doctor blade process consists on the applying of the catalyst slurry on a wet-proofed GDL. One possible way to design the doctor blade process is shown in Fig. 15.4. 

Usually, just the ink viscosity and particle size are limiting parameters at doctor blade processes. At not absorbing materials, liquids with viscosities between 100 and 50,000 mPa s can get applied with ink loadings from 10 up to 1250 g m GDL. By coating of porous materials... 

This manufacturing process can be used for coating of whole MEA rolls. This fits continuous production in best way. Via the CCM process, the catalyst ink is applied directly via a spray or doctor blade process on the polymeric membrane. Due to the swelling and shrinking behavior of the membrane when in contact with liquids, this process causes high mechanical stress during the application of the catalyst ink on the membrane, in special... 

Interference pigments based on liquid crystalline materials are prepared by a doctor-blade coating of the polymers in the liquid or liquid crystalline state on an even surface. The doctor-blade process leads to a thin film wherein a homogeneous orientation of the molecules takes place. It is only after this orientation process that the film shows an interference color. The films are then cured and crushed by special techniques to yield platelets of liquid crystalline polymers showing interference effects. 

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