In-Process R eometry Studies of LDPE Compounds
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M. Woodhead
Abstract
The second part of a comprehensive study into the investigation and validation of in-process measurements on a low density polyethylene compound during extrusion is reported. A commercial grade of branched low density polyethylene was used in the study, compounded with various levels of magnesium hydroxide ame retardant filler, up to 0 by weight. In-line and on-line rheometry were used to monitor melt ow behaviour during single screw and twin screw extrusion; off-line capillary rheometry was performed on the compound before and after extrusion, to examine any change in rheology. Morphological observations were made using scanning electron microscopy, and molecular characterisations carried out using gel permeation chromatography. In-process rheometry was found to be able to detect the presence of filler at low and high loadings, but was unable to discriminate between intermediate levels. Off-line rheometry indicated that twin screw extrusion altered the rheology of the compound, and capillary wall slip was found to increase after extrusion. Morphological observation indicated that filler in the compound was better dispersed after extrusion, especially at high volume fractions. Molecular weight and polydispersity of the LDPE were shown to increase after extrusion, more so in the case of low filler loadings. Overall, in-process measurements provided useful rheological data, and the compound was found to exhibit complex, process-dependent rheology.
© 2000, Carl Hanser Verlag, Munich
Articles in the same Issue
- 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
Articles in the same Issue
- 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
