Full Record for Micrograph 595

[99 KB]

View micrograph
.. in new window

View micrograph and record
.. in new window

You can also view and download the micrographs on Flickr

Micrograph no: 595
Brief description: Thermoset case of an electrical plug
Keywords: electrical, formaldehyde, injection moulding , network, plug, polymer , thermoset, urea, urea formaldehyde
Categories: Polymer
System: Urea formaldehyde
Composition: Not specified
Standard codes
Reaction
Processing: Reaction injection moulding
Applications: Thermosets are cross-linked networks; hard but unprocessable after the initial reaction. They are used as adhesives, composite matrices, and to make casings for electrical equipment.
Sample preparation: A cross-section has been cold-mounted and stained with dye to highlight the filler material
Technique: Reflected light microscopy
Length bar: 100 μm
Further information: The microstructure revealed by the dye consists of seams of filler material (flour or wood-pulp) which is introduced to the melt in a 2:1 ratio part way through the moulding process. Urea thermosets are used because they are hard, inexpensive, and have good resistance to electrical arcing. An additional benefit of a thermoset as opposed to a thermoplastic in this application is that should a failure occur, it will fail in a safe mode (charring, but retaining it form, rather than melting).
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