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Extrusion process stability

Use Varnish and lacquer drier, high-pressure lubricants, lubricant in extrusion processes, stabilizer for vinyl polymers, corrosion inhibitor for petroleum, component of greases, waxes, and paints. [Pg.748]

The extrusion process frequently results in realignment of disulfide bonds and breakage of intramolecular bonds. Disulfide bonds stabilize the tertiary structure of protein and may limit protein imfolding during extrusion (Taylor et al., 2006). Flow and melt characteristics were improved when other proteins were extruded with disulfide reducing agents (Areas, 1992), which indicates that disulfide bonds adversely affect... [Pg.181]

Third, the pronounced difference in stability between the naphtho[2,3-sulfur extrusion processes. In contrast to the substantial instability of 116, the increased stability of 114 may be due to the energy required to convert two aromatic rings into the o-quinoid form in 114a. [Pg.61]

To verify that the cooling water was the root cause for the flow surging, the cooling water flow was turned off and on several times. As expected, the stability of the extruder was acceptable when the cooling water was on and unacceptable when it was off. The line was operated for about a month with the cooling water on, and the line has operated stably. Thus, the level of cooling for this system was acceptable and major modifications to the extrusion process were not required. [Pg.586]

Costabilizers. In most cases the alkyltin stabilizers are particularly efficient heat stabilizers for PVC without the addition of costabilizers. Many of the traditional coadditives, such as antioxidants, epoxy compounds, and phosphites, used with the mixed metal stabilizer systems, afford only minimal benefits when used with the alkyltin mercaptides. Mercaptans are quite effective costabilizers for some of the alkyltin mercaptides, particulady those based on mercaptoethyl ester technology (23). Combinations of mercaptan and alkyltin mercaptide are currently the most efficient stabilizers for PVC extrusion processes. The level of tin metal in the stabilizer composition can be reduced by up to 50% while maintaining equivalent performance. Figure 2 shows the two-roll mill performance of some methyltin stabilizers in a PVC pipe formulation as a function of the tin content and the mercaptide groups at 200°C. The test formulation contains 100 parts of PVC (Fikentscher K = 65), 1.2 parts of paraffin wax, 0.6 parts of calcium stearate, and 0.4 parts of methyltin-based stabilizers. [Pg.548]

All six candidate compounds provide better process stability than BHT when evaluated alone after 5 extrusions. In conjunction with phenolic AO-1, all six compounds exhibit superior synergism and provide better process stability and color than ]) and (8) during multiple extrusion. [Pg.354]

Some of the test methods being used to measure the processing stability of polypropylene include melt flow drift measurements at elevated temperatures using an extrusion plastometer (melt indexer), melt viscosity retention measurements using a torque rheometer, retention of melt flow after repeated extrusions, and injection molded spiral test measured by the flow in inches at various temperatures and the retention of melt flow of the injected spirals. The nine commercial resins were evaluated by these methods. [Pg.248]

Extrusion Stability (20). Processing stabilities were also determined by six succesive extrusions of the resins through a 1-inch extruder and measuring the change in melt flow (ASTM D 1238-65T, Condition L) after each extrusion. The data shown in Figure 7 indicate that Resins C, E, and I are least stable and G, A, and D are the most stable. [Pg.249]

Mahungu, S.M. Diaz-Mercado, S. Li, J. Mschwenk, M. Singletary, K. Faller, J. 1999. Stability of isoflavones during extrusion processing of com/soy mixture. J. Agric. Food Chem. 47 279-284. [Pg.20]

Extrudates Flavour composition encapsulated in high-molecular weight matrix by extrusion process Good oxidative stability of encapsulated flavour Stable particles (Very) large particle size Tunable release profiles... [Pg.404]

These polymers are subjected to high temperatures, ca 300 °C, during extrusion and injection molding. Processing stabilizers are used to decrease both the change in viscosity of the polymer melt and the development of color. A phosphite, such as tris(2,4-di- / -butylphenyl)phosphite (25) or bis(2,4-di-/ butylphenyl)pentaerythtitol diphosphite [26741-53-7] , in combination with a phenolic antioxidant such as octadecyl... [Pg.228]

Sheets of PVC/ABS blends are often used for thermoforming large parts such as automotive or aircraft interiors. These blends have also been formed by molding and extrusion processes as low cost alternatives to flame-retarded ABS. The low thermal stability of PVC requires strict control of the processing conditions. [Pg.734]


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Extrusion process

Process stability

Processing extrusion

Processing stabilizers

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