ZIB

Hits per page

hits 1 - 2 | 2 hits

Sorting

Electronic Resource

Untersuchungen zum Wandgleitverhalten von plastifiziertem Hart-PVC (1981)

Hegler, R. -P. ; Mennig, G.

Springer

Rheologica acta 20 (1981), S. 553-560

add to mindlist on the mindlist

Details

ISSN: 1435-1528

Keywords: Wall slip ; PVC ; capillary rheometer ; flow profile

Source: Springer Online Journal Archives 1860-2000

Topics: Chemistry and Pharmacology , Physics

Description / Table of Contents: Summary Wall slip of rigid PVC has been studied in a capillary rheometer with two pistons by a previously used visual measuring method. For quantitative evaluation of the results a method was developed based on the usual assumption of a simple superposition of slip and shear flow. It was found that wall slip increases with increasing wall shear stress and decreasing temperature. There was no pronounced influence of surface roughness of metal walls and of hydrostatic pressure. In the region where slip gradually develops into wall stick a flow profile was observed which did not coincide with the mentioned simple assumption but indicates a more complicated phenomenon particularly in the boundary layer.

Notes: Zusammenfassung Zur Untersuchung des Wandgleitverhaltens von plastifiziertem Hart-PVC in einem Rheometer mit Zwei-Kolben-Anordnung wurde zu einer schon früher benutzten visuellen Meßmethode eine Auswertemethode auf der Basis der Modellvorstellung der linearen Überlagerung von Gleiten und Scherfließen entwickelt. Solcherart ausgewertete quantitative Versuchsergebnisse zeigen eine Zunahme des Gleitens mit steigender Schubspannung und sinkender Temperatur. Ein ausgeprägter Einfluß der Oberflächenfeingestalt der Rohrwand und des hydrostatischen Drucks konnte nicht festgestellt werden. Es zeigte sich weiter, daß im Übergangsbereich von Gleiten zu Haften offenbar eine von der angenommenen einfachen Modellvorstellung abweichende Strömungsform vorliegt, die auf kompliziertere Vorgänge in der Randschicht hindeutet.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF01502962

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Phase separation effects in processing of glass-bead- and glass-fiber-filled thermoplastics by injection moldingPresented in part at the Conference on Engineering Reheology, Imperial College of London(September 19-23, 1983). (1985)

Hegler, R. P. ; Mennig, G.

Stamford, Conn. [u.a.] : Wiley-Blackwell

Polymer Engineering and Science 25 (1985), S. 395-405

add to mindlist on the mindlist

Details

ISSN: 0032-3888

Keywords: Chemistry ; Chemical Engineering

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics

Notes: Dumb-bell specimens and rectangular boxes were used to study phase separation effects occurring in injection molding of glass-bead and glass-fiber-filled thermoplastics. The separation effects were more pronounced with beads than with fibers and they increase with increasing bead diameter. The filler distribution is further influenced by mold geometry, filler concentration, matrix material, and processing conditions. If the use of fillers, which promote inhomogeneity, is unavoidable it is possible to improve the distribution of the rigid phase by a favorable choice of injection speed and melt temperature. With the theories available at present a qualitative interpretation of the origin of the observed separation phenomena is feasible.

Additional Material: 13 Ill.