Paste extrusion of polytetrafluoroethylene: Temperature, blending and processing aid effects

Ochoa, I; Hatzikiriakos, SG; Mitsoulis, E

dc.contributor.author	Ochoa, I	en
dc.contributor.author	Hatzikiriakos, SG	en
dc.contributor.author	Mitsoulis, E	en
dc.date.accessioned	2014-03-01T01:24:50Z
dc.date.available	2014-03-01T01:24:50Z
dc.date.issued	2006	en
dc.identifier.issn	0930-777X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/17459
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-33751012993&partnerID=40&md5=a1a69f2cad22b1dd1a26be554d534004	en
dc.subject.classification	Engineering, Chemical	en
dc.subject.classification	Polymer Science	en
dc.subject.other	SURFACE-TENSION	en
dc.subject.other	PTFE	en
dc.subject.other	VISCOSITY	en
dc.title	Paste extrusion of polytetrafluoroethylene: Temperature, blending and processing aid effects	en
heal.type	journalArticle	en
heal.language	English	en
heal.publicationDate	2006	en
heal.abstract	Blends of different PTFE fine powder resins have been prepared and extruded in an attempt of improving the PTFE paste extrusion process and/or the extrudates. The extrusion pressure and the mechanical properties of the extrudates were found to fall between those exhibited by the pure components. While this is an expectable behavior, it offers opportunities for controlling the degree of fibrillation needed in the final products by mixing highly fibrillated with low fibrillated PTFE resins. Boron nitride and organically modified montmorillonite clays (solid lubricants) are also tested as additives to the lubricants used in the PTFE paste extrusion in order to identify enhanced processing aids. It was found that the addition of boron nitride and clays increase the extrusion pressure but at the same time improve the mechanical properties of the final extrudates in most cases. This again offers possibilities for controlling the final mechanical properties by controlling the degree of fibrillation, i. e., by adding a small amount of solid lubricants to adjust pressure, fibrillation, and thus the final mechanical properties. Finally, it is shown that fibrillation depends on temperature. Moreover, the mechanical properties of extrudates increase as the temperature goes through its two transition temperatures of 19°C and 30°C that render PTFE particles more deformable and prone to fibrillation. © Hanser Publishers.	en
heal.publisher	CARL HANSER VERLAG	en
heal.journalName	International Polymer Processing	en
dc.identifier.isi	ISI:000241804600009	en
dc.identifier.volume	21	en
dc.identifier.issue	5	en
dc.identifier.spage	497	en
dc.identifier.epage	503	en