Open bath

H. J. Kammeyer, K. U. Maske, and G. Pugh, Open-Bath Production ofFerrochromium in a DC Plasma Furnace, Paper in Proceedings of the 5th International Ferroalloys Congress, New Orleans, La., Apr. 23—26, 1989, Ferroalloys Association, 1989, pp. 95—102. 

Some weak correlation between fihn morphology and resistivity was noted for films, deposited from a pH 9.5 bath Films deposited from a closed system (no evaporation or loss of ammonia) were more uniform and had somewhat lower (two to three times) resistivity (ca. 1.5 X 10 O-cm) than films deposited from an open bath [43]. 

The whole dilatometer is immersed in an open bath thermostat, and the temperature is kept constant within =t0.05°C. The position of the motor buret syringe is converted into an electrical signal and scanned by a millivoltmeter installed in a neighboring laboratory (Siemens Kom-pensograph, maximum deflection 250 mm. with a signal of 5 mv.). When the pen reaches full deflection, the meter is compensated automatically back to zero, there resuming scanning. Thus, a considerable ordinate expansion can be achieved. 

Figure 10.41 Hood for extraction above an open end of a furnace or above an open bath. Source Reprinted from Daly BB, Woods Practical Guide to Fan Engineering, Woods of Colchester (a GE Company) Sheffield 1973, ed., 72, 1992. By kind permission of Flakt Woods Ltd 2004.

Different stages of the pultrusion process (a) creel and mat racks for fibre handling (b) orifice plate (c) open bath (courtesy of ALTO) (d) preforming guides (e) cutting system (courtesy of Strongwell). 

An important consideration about the pin transfer technique is that it requires an open bath of the adhesive or flux. Adhesives readily absorb water from the air. Fluxes lose vehicle (water or alcohol) and possibly other constituents through evaporation. By either mechanism, the material properties change, which affects the quantity of fluid retained on the pin and deposited at the site (including the fhp-chip process previously described). Adhesives must have sufficient wet strength, and the fluxes must have enough tack to hold the component in place for the duration of component placement activity as well as subsequent handling of the circuit board on its way to the curing oven or reflow oven. 

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