Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Rheologica acta 37 (1998), S. 424-429 
    ISSN: 1435-1528
    Keywords: Key words Interfacial flow hysteresis ; wall slip ; self oscillation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Abstract When a stick-slip transition of an extremely large magnitude occurs in capillary flow of a highly entangled melt, a significant flow can be generated in the barrel. At a constant piston pressure, this barrel flow reduces the actual pressure available at the die entry that produces the capillary flow in the die. Experiments on linear monodisperse polybutadienes (PBd) show that a significant correction due to this barrel flow must be made to obtain a reliable characterization of the interfacial stick-slip transition. The interfacial flow discontinuity transition exhibits hysteresis behavior similar to that of linear polyethylenes. When a large pressure loss occurs in the barrel due to a massive stick-slip transition, the die wall stress may drop below the hysteresis loop, causing a new self-regulated flow oscillation to take place at a constant applied pressure.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Rheologica acta 36 (1997), S. 128-134 
    ISSN: 1435-1528
    Keywords: Stick-slip transition ; wall slip ; surface effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Abstract Effects of surface topology and energy on the stick-slip transition were studied in capillary flow of highly entangled polyethylene (PE) melts. Surface roughness was shown to increase the critical stress of the stick-slip transition because of the increased resistance to interfacial disentanglement. Lowering the surface energy of a smooth die wall by treatment with a fluorocarbon completely eliminates the stick-slip transition and produces massive interfacial slip at PE/wall boundary down to a stress level of 0.05 MPa. On the other hand, considerable roughness on the same low energy surface can produce a stick hydrodynamic boundary condition and restore the stick-slip transition despite the weak PE/wall interfacial interactions. Additionally, a slip-slip transition was found in the die with a nearly non-adsorbing wall that appears to involve a secondary chain-debonding process.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...