Product category:
Gauges, Indicators and Instruments
News Release from: Celsum Technologies | Subject: Precision extrusion dies
Edited by the Engineeringtalk Editorial
Team on 14 July 2004
Extrusion dies aid materials testing
Celsum Technologies can supply a wide range of precision extrusion dies for laboratory rheometers and extrusion lines, as well as for pilot extrusion plants.
Celsum Technologies can supply a wide range of precision extrusion dies for laboratory rheometers and extrusion lines, as well as for pilot extrusion plants Recently, Celsum has provided a set of complex dies with bi-hyperbolic profiles (ie hyperbolic profiles on the entry and exit section of the die), and with a subminiature pressure transducers only 3mm in diameter embedded in the die wall
This article was originally published on Engineeringtalk on 10 Jun 2003 at 8.00am (UK)
Related stories
Wireless links aid sensor acquisition
Licence-free radio telemetry instruments allow remote strain-gauge-based sensors to be monitored without the need for expensive cabling.
Straightforward reliable temperature controller
The EC4-173 single-channel PID thermoregulator accepts both Type K and J thermocouple inputs, has an output to drive a solid-state relay, and operates from a nominal 230V AC supply.
These are being used to study the flow behaviour of muds and slurries in a specially built rheological test rig.
Celsum has also supplied regular hyperbolic-profile dies for a range of commercially available capillary extrusion rheometers, where they are useful for analysing the elongational or extensional flow properties of materials.
Such materials include polymer melts, rubbers, ceramic pastes, pharmaceuticals, foods, cosmetics, explosives, and others, although the latest batch of dies are being used to optimise processing geometry for polymers filled with wood-flour in a major recycling project aimed at developing the next generation of building materials.
Celsum also supply regular parallel-profile precision dies for laboratory rheometers including its own BFR 2100 and Eta 2100 instruments, in a range of materials including tungsten carbide, tool steel and stainless steel.
Typically, a set of dies with the same diameter bore but different bore lengths is used to determine the "Bagley end correction", by plotting the pressures required to maintain extrusion at a series of constant extrusion rates.
When extrapolated to zero length, there is still a finite residual pressure, and this is used to correct the shear stress values (the Bagley correction).
This zero-length pressure is used also in most analyses, such as Cogswell's and Rides', to estimate the extensional viscosity of the fluid - ie the viscosity when considered in tension rather than in shear.
Materials with similar shear viscosities can have widely different extensional viscosities, which can cause severe processing difficulties.
Celsum is always happy to look at special or modified dies and instruments to suit customers' specific requirements. Request a free brochure from Celsum Technologies ...
• Celsum Technologies: contact details and other news
• Email this article to a colleague
• Register for the free Engineeringtalk email newsletter
• Engineeringtalk Home Page
Search the Pro-Talk network of sites
