Full Record for Micrograph 585
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- Micrograph no
- 585
- Brief description
- Internal surface of blow-moulded HDPE
- Keywords
- blow moulding , bottle, catspaws, HDPE, parison , polyethylene (PE), polymer , surface
- Categories
- Polymer
- System
- High density polyethylene (HDPE)
- Composition
- Not specified
- Standard codes
- Reaction
- Processing
- A 'parison' (tube) is continuously extruded into a mould which periodically closes together with a knife, to cut suitable lengths which are then expanded to fill the mould
- Applications
- Blow moulding is a continuous process used in the manufacture of bottles as well as sheets, bags, and tubes.
- Sample preparation
- The specimen has been sputter-coated with gold, to give a conducting surface
- Technique
- Scanning electron microscopy (SEM)
- Length bar
- 6 μm
- Further information
- The surface shows ~5 micron periodic ridges which are indicative of flow instability and a periodic slipping of the melt at the die wall. On a finer scale are catspaws of submicron polymer, drawn up by the 'wind' in the blowing process.
- Contributor
- J A Curran
- Organisation
- Department of Materials Science and Metallurgy, University of Cambridge
- Date
- 03/10/02
- Licence for re-use
- Attribution-NonCommercial-ShareAlike 4.0 International
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