In-Process R eometry Studies of LDPE Compounds
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A.L. Kelly
Abstract
The initial part of a comprehensive study into the investigation and validation of in-process measurements on a low density polyethylene (LDPE) compound during extrusion is reported. An unfilled, commercial grade of low density polyethylene was processed using fully instrumented, computer monitored, single and twin screw extruders in the Interdisciplinary Research Centre (IRC) laboratories, University of Bradford. Three in-process rheometers were used; a prototype Rosand capillary on-line rheometer (OLR), a four sensor slit die in-line rheometer (ILR) and a six sensor slit die ILR. Off-line comparisons were carried out using a Rosand RH twin bore capillary rheometer. All devices allowed shear ow characterisation at a range of processing rates, and the capillary rheometers also provided a measurement of entry pressure drop through the use of orifice dies. The six-sensor ILR also allowed measurement of entry pressure drop into the slit, although the differences in ow geometry meant these measurements were not directly comparable with the capillary devices, and exit pressures were extrapolated from ILR pressure drops. The in-process devices exhibited very good agreement with measurements made off-line, in both shear ow and entry pressures. In-line slit die measurements were very close to those made using capillary dies, despite the in-line tests being non-isothermal and employing a different geometry of measurement section. Differences in melt rheology between single and twin extrusion were observed, due to the amount of mechanical work input by each extruder. Overall, good agreement was observed from the four different routes to measurement, for the LDPE examined.
© 2000, Carl Hanser Verlag, Munich
Artikel in diesem Heft
- Editorial
- Seventh of a Series: Pioneer of Carbonaceous Pitch Processing Sugio Otani
- Invited Paper
- Injection Blow Molding Technology for Polyethylene Terephthalate
- Screw Extrusion/Mixing
- A New Polymer Processing Technology for Polymer Blends with Unmatched Viscosity: Solid-State Shear Pulverization (S3P)
- In-Line Density Monitoring of Rigid PVC Foam during Extrusion Process
- In-Process R eometry Studies of LDPE Compounds
- In-Process R eometry Studies of LDPE Compounds
- Rheological and Morphological Properties of Immiscible Blends and Microfiber Preparation from the Blends
- Reactive Extrusion
- Development of a Direct Polycondensation Process for Poly (L-lactic acid)
- Fiber and Film
- Radially Dependent Stress and Modeling of Solidi cation in ilament Melt Spinning
- Structure Development in Melt Spinning Syndiotactic Polypropylene and Comparison to Isotactic Polypropylene
- Fibers and Films
- Investigation of Structure and Properties in Biaxially Stretched Poly(butylene terephthalate) Films
- Molding
- Filling and Postfilling Analysis of Injection/Compression Molding
Artikel in diesem Heft
- Editorial
- Seventh of a Series: Pioneer of Carbonaceous Pitch Processing Sugio Otani
- Invited Paper
- Injection Blow Molding Technology for Polyethylene Terephthalate
- Screw Extrusion/Mixing
- A New Polymer Processing Technology for Polymer Blends with Unmatched Viscosity: Solid-State Shear Pulverization (S3P)
- In-Line Density Monitoring of Rigid PVC Foam during Extrusion Process
- In-Process R eometry Studies of LDPE Compounds
- In-Process R eometry Studies of LDPE Compounds
- Rheological and Morphological Properties of Immiscible Blends and Microfiber Preparation from the Blends
- Reactive Extrusion
- Development of a Direct Polycondensation Process for Poly (L-lactic acid)
- Fiber and Film
- Radially Dependent Stress and Modeling of Solidi cation in ilament Melt Spinning
- Structure Development in Melt Spinning Syndiotactic Polypropylene and Comparison to Isotactic Polypropylene
- Fibers and Films
- Investigation of Structure and Properties in Biaxially Stretched Poly(butylene terephthalate) Films
- Molding
- Filling and Postfilling Analysis of Injection/Compression Molding
