Capillary rheometry

Techniques for evaluating processing stabiHty and mechanochemical effects include using a Brabender torque rheometer (29,30), injection mol ding (26,28), capillary rheometry (26,28), and measuring melt index as a function of residence time (26). 

Capillary Rheometry Galaxy III, V Automated Capillary Rheometers Galaxy I... 

J.L. Leblanc, WaU sUp and compressibiUty like effects in capillary rheometry tests on complex pol3fmer systems, Plast. Rubber Comp., 30(6), 282-293, 2001. 

Capillary rheometry Molecular weight determination and distribution. 

A similar variety of samples was tested for thermal stability by capillary rheometry and TGA. Figure 6.3 shows the viscosity-shear rate dependence for PCTFE homopolymers and one copolymer (Alcon 3000). All materials, save one, showed virtually identical viscosity relationships despite large changes in inherent viscosity. Only the polymers from runs initiated by fluorochemical peroxides (FCP) showed a dependence of molecular weight (as measured by inherent viscosity) upon melt viscosity. 

CALENDER, 144 194 CALIBRATION, 94 377 CAPILLARY DIE, 172 CAPILLARY FLOW, 443 CAPILLARY RHEOMETRY, 252 CAR MAT, 451 CARBON, 316... 

ASTM D5099, 1993. Measurement of processing properties using capillary rheometry. 

Instron Capillary Rheometry. Melt flow rheology was measured according to procedures first proposed by Merz and Colwell (10) and supplied by the Instron Engineering Corp. 

In summary, steady and dynamic simple shear rheometric results are complementary at very low (y) or (co) values they both yield useful macromolecular structure characterization. Moreover, tj (oj) in the range co < 10 s 1 forms an extension of rj(y) obtained by capillary rheometry at y >10 s 1, a range that is relevant to processing. 

The thermal degradation process can be followed by analysis of the colour generated in a static or dynamic environment. The use of capillary rheometry has also been highlighted (105). 

Several different gelation measurement methods have been described in the literature, particularly differential scanning calorimetry (DSC), capillary rheometry, transmission electron microscopy (TEM) and atomic force microscopy (AFM). The gelation level is characterised either by crystallinity related aspects or factors that relate to the development of the three-dimensional network and the corresponding disappearance of the particulate structure (465, a.l). 

It was determined that the shear rate in PVC passing through a copper wire coating die was in excess of 4000000 Is. This resulted in volatilisation of the dioctyl phthalate plasticiser and changes in the polymer molecular structure, as determined by infrared spectroscopy. The flow was studied using capillary rheometry with a die of a 0.15 mm diameter. It was concluded that the change in... 

Funatsu K. and Sato M., "Measurement of slip velocity and normal stress difference of polyvinylchloride, Adv. in Rheol., 4 (Mexico 1984) 465-472. Knappe W. and E. Krumbock, "Evaluation of slip flow of PVC compounds by capillary rheometry," Adv. in Rheol., 3 (Mexico 1984) 417-424. de Smedt C., Nam S., "The processing benefits of fluoroelastomer appUcation in LLDPE," Plast. Rubber Process. Appl. 8,11 (1987). 

Harrison PJ, Newton JM, Rowe RC. The application of capillary rheometry to the extrusion of wet powder masses. Int J Pharm 1987 35 235-42. 

Luukkonen P. Newton JM, Podczcck F, ct al. Use of capillary rheometry to evaluate the rheological properties of microcrystalline and silicified microcrystalline cellulose. Int J Pharm 2001 216 147-57,... 

In Figs. 3 and 4, Eq. 13 is plotted as the heavy full drawn curve. The data used for the variables in Eq. 13 in Figs. 1-4 are shown in Table 1. The data for copolymers of ethylene-propylene copolymers (measured by capillary rheometry) are transplotted from Vinogradov (30). 

Capillary rheometry and parallel-plate rheometry use the fact that wall slip will manifest itself as a geometry-dependent phenomenon. That is, wall slip will appear as a geometric effect on apparent rheological properties. In the capillary-rheometer technique, slip will manifest itself as an effect of capillary diameter ( )) on the shear stress (t, ). Wall slip in capillary rheology can be calculated from an analysis that involves the following ... 

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