Shearing equipment technology

Figure 5-27. Shear rate is a function of velocity gradient. By permission, Lightnin Technology Lightnin Technology Seminar, 3rd ed., 1982, Lightnin (formerly Mixing Equipment Co.), a unit of General Signal, p. 1, Section 2A [27].

The TurboVap Concentration Workstation series, which includes models II, LV, 500 and 96, all of which are equipped with shearing technology and differ mainly in the number of samples they can handle simultaneously. 

Another type of material optimization software is a technology that develops shearing patterns to produce rectangular parts of varying width, length, and demand from an inventory of available master sheets. The software analyzes part requirements, equipment and material constraints, and available master sheets. The software automatically develops the optimal shearing patterns and generates reports for production. 

Most companies are attracted to the optimization technology by the quick return on investment and bottom-line benefits. By using this technology, a company will typically reduce their scrap by 30-60% and reduce the number of master coil/sheet sizes by 20-50%. Additionally, the software can be used to assist with equipment purchases or to evaluate the impact of equipment that is not performing to specification. Performing some what-if studies can quickly determine what size cut-to-length line or shear is the best for a particular manufacturing demand. 

Equipment for manufacturing transparent soap can have very different specifications where translucency is achieved by applying the right amount of mechanical work on the soap mass within a narrow range of temperature. The actual technology used to achieve translucency varies from manufacturer to manufacturer, but the principle of shearing/mechanical work that leads to phase transformation and translucency remains similar. Besides having extruded transparent soaps with... 

Another consideration in the selection of technology platform is the polymer chosen for the amorphous solid dispersion formulation. The fact that many pharmaceutical polymers degrade, crosslink, or lose functionality at high temperatures has already been discussed. However, the melt viscosity of a polymer is critical to the ability to extrude the amorphous solid dispersion within the capabilities of the extrusion equipment. The melt viscosity as a function of temperature and shear rate varies considerably across pharmaceutical polymers (Chokshi et al. 2005). Formulation melt viscosities in the range of 10-100,000 Pa s are generally acceptable for HME, although the range depends heavily on the torque limit capability of the particular extruder. 

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