Tape casting machines

In an attempt to simplify the geometiy of the tape casting machine, the zone between the bottom of the flat tape casting blade and the moving belt surface is isolated for analysis. In this zone, shown in Figure 13.8(b), a momentum balance is performed, giving... 

R.B. Runk and M.J. Andrejco, A precision tape casting machine for fabricating thin, organically suspended, ceramic tapes. Am. Ceram. Soc. Bull, 54 (1975) 199. 

FIGURE 27.4 Example of an industrial tape casting machine. 

First work and first tape casting machine designed and built at Fort Monmouth Signal Laboratory, Fort Monmouth, New Jersey. 

Tape casting machines, like doctor blades, come in as many sizes and shapes as there are companies and designers producing them. They range from simple laboratory-scale machines to large production-scale machines with a wide variety of carrier transport and chamber designs. Examples of several of these machines are shown in Figures 4.11 to 4.16. 

Fig. 4.13 Dielectric ceramic tape casting machine. Photograph courtesy of A.J. Carsten Co., Ltd. Powell River, BC, Canada.

Fig. 4.14 Pro Cast tape casting machine. Photograph courtesy of Unique/Pereny Division of HED Industries, Ringoes, NJ, 08551.

All fans used on or near the tape casting machine should be explosion-proof if volatile, flammable solvents are being used in the process. On many of the laboratory-scale machines this problem is eliminated by the use of "house air" provided by a remote compressor. On these systems, the airflow through the machine is controlled by the use of flow meters and the cross-sectional geometry of the drying chamber itself. 

Tension control works in concert with the speed control on a tape casting machine. A wide variety of tension control mechanisms are used, ranging from a very simple spring-loaded frictional strap on the... 

This section will describe some of the other options that are sometimes included on tape casting machines. The options in some cases are more expensive than the machine itself. All of the options described in the following paragraphs are usually found on large-scale production machines, where tight control of the process is required or where there is a concern about the volume of solvent (s) being generated in the exhaust stream. 

The photopolymer mixed with the initiator polymerizes when exposed to the UV radiation, and the ceramic particles are entrapped in the polymeric matrix. Herein lies one of the advantages of UV-cured tape casting a much shorter tape casting machine can be used since there is no long-term evaporative drying involved. Also, the elimination of solvent (s) means that solvent recovery or burnoff systems are not needed. 

At this point the slip is ready to cast. Casting is done on a silicone-coated Mylar carrier in a continuous tape casting machine. The doctor blade gap setting, speed of casting, etc. are determined by the tape thickness desired as an end product. 

Cold trap A device that lowers the temperature of a gas, forcing the condensation of solvent (water or other) vapor. This can be used to reclaim solvents from the tape casting machine s exhaust. 

R. B. Runkand M. J. Andrejco, A Precision Tape Casting Machine for Fabricating Thin Ceramic Tapes , Ceramic Bull., Vol. 54, No.2, (1975) pp. 199-200. 

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