Applications of Tape Technology

As we mentioned in the Foreword, the uses for tape casting as a fabrication tool have advanced well beyond the scope envisioned by the pioneers in the field some 50 years ago. In this chapter we will review some of the standard applications as well as some uses that are only beginning to be recognized as potential applications for this unique fabrication technology Almost everyone involved with ceramic processing knows that thin, flat sheets can be produced using this technique, but how many ceramists appreciate the fact that 1.2 x 2.5 m (4 x 8 ft.) sheets that are 0.5 to 0.76 mm (0.020 to 0.030 in.) thick are produced by tape casting for use in the manufacture of molten carbonate fuel cells These are some of the diverse applications that we will discuss in the sections that follow. 

---

Section IV deals with the application of electrochemical technologies to magnetic-storage devices. In the field of magnetic information storage, hard discs, floppy discs, and tape drives are widely used. Electrochemical deposition techniques are essential in their production and this is the raison d etat for its inclusion in this chapter. 

In another application of electroluminescent technology, the Light Tape company produces light sources in the form of tape which, for example, is available in a 25 mm wide, 0.5 mm thick, format in lengths of up to 90 m with a power consumption of 0.004/cm. Consequently, this 90 m tape will consume less energy than a 100 W incandescent light bulb. The tape is designed to be powered either by a 3 V to 12 V DC supply or variable AC whose frequency is adjustable between 200 Hz and 2000 Hz and which is fed by a 90 V-260 V power supply. 

For technological applications it is highly desirable to be able to design self-assembling systems to have particular physico-chemical properties under a given set of experimental conditions. Using computer simulation, it is possible to construct an atomistic model of tapes, ribbons and fibrils to study all of the interatomic interactions within the system in a quantitative manner. Figure 13 shows atomistic... 

Langmuir-Blodgett films may have value in many applied areas of traditional interest to the industrial chemist, such as adhesion, encapsulation, and catalysis. The permeability characteristics of monolayer assemblies may also find application as synthetic membranes for ultrafine filtration, gas separation, and reverse osmosis. For example, Albrecht et al. (44) proved the eflSciency of polymeric diacetylene monolayers on semipermeable supports in reducing the flow of CH4. One interesting possibility lies in using LB monolayers as lubricants in magnetic tape technology. Unpublished reports have indicated that frictional coeflScients can be reduced markedly when the tape is coated with a few monolayers. In applications such as those listed previously, difiSculties may well be encountered with the mechanical stability of the films. To date, relatively little research has been carried out in this area. 

The most important application of cubic ferrites, quantitywise, is the manufacture of coil- and transfomier-cores. In terms of numbers, recording and erasure heads for tape recorders, ferrite antennae for the frequency range 0.5 to 1.5 MHz and other components for high frequency technology are also important. 

An ideal bond coat should have several characteristics that include uncompromised biocompatibility, good adhesion to both the metal substrate and the osseoconductive top coat, and a well-defined melting point to allow application of thermal spray technology. The adhesive function of the bond coat has been loosely compared to the action of a double-sided adhesive tape. 

---