Solvent exchange by distillation is a common unit operation in active pharmaceutical ingredient (API) manufacturing processes. Either a stepwise solvent displacement mode or a constant volume solvent displacement mode can be used to carry out the solvent exchange. The constant volume mode can be more efficient as the chasing solvent acts as an effective displacer by keeping concentrations of the solvent being displaced at higher levels. As demonstrated during a production application at Abbott Laboratories, the constant volume solvent displacement mode resulted in a 30% reduction in the quantity of displacing solvent, 2-propanol (IPA), when compared with the equivalent process using a stepwise solvent displacement mode. As a consequence, 30% reduction in the waste solvent generation was realized. This mode of operation dose not adversely impact product quality nor process yield.

The thermal conductance and resistance of vertical panels were measured. These panels were representative of wall building panels. Insulations tested included fiberglass, cellulose, rock wool, urea formaldehyde board stock and shredded foam, and polystyrene foam. The thermal resistances of these insula tions in a 3.5 inch vertical cavity has also been determined from these measurements.

A series of measurements of the thermal conduct ance of vertical panels representing building walls have been made. The building panels contained shredded urea-formaldehyde foam at different densities. The results showed a linear decrease in the thermal conductance as the shredded foam density is in creased.

The thermal conductance of vertical panels was measured over a period of months. Urea formaldehyde foam filled the cavities of the panels. The conductance was found to increase with aging. The cause of the increase is due to shrinking and cracking of the foam. The variation of shrinkage and conductance with time are discussed and quantified.

The thermal conductance of vertical panels was measured using the Guarded Hot Box Method in order to compare various forms of urea-formaldehyde foam used to fill the cavities of the panels. These forms included preshrunk and fitted, foamed in place, and shredded and blown. Age studies were performed on the panels with the ureaformaldehyde which was foamed in place. The conductance increased with time for these panels because of shrinkage and cracking of the foam. The panels with the shredded foam showed an increase of conductance as the density of the material decreased. Preshrunk panels that were smaller than the cavity showed the thermal conductance of the panel is dependent upon the placement of the foam. Polyethylene wrapped, preshrunk foam and shredded and blown foam showed excellent thermal insulation characteristics.