Typically for an extrusion rheometry test, a material is extruded at the same temperatures through a set of dies of the same diameter but of different bore lemghts
Celsum Technologies is supplying extrusion dies for laboratory applications such as extrusion rheometry.
Celsum's MD, Roy Carter, says: "We have many years experience in the design, manufacture and application of materials testing instruments, especially those for rheology and small-scale extrusion.
"We have identified a need for a versatile service to supply precision extrusion dies in a range of materials such as tungsten carbide and stainless steel, and in a range of geometries to suit our clients' requirements.
"We offer a tailor-made extrusion die service for many laboratory instruments and pilot plant processes".
Typically for an extrusion rheometry test, a material is extruded at the same temperatures through a set of dies of the same diameter but of different bore lengths.
For each extrusion speed, extrapolation of a plot of extrusion pressure against, in effect, bore length gives a positive pressure at zero bore length; mathematical analyses take this offset value into account in correcting for shear flow behaviour (the Bagley end correction), and the offset value is also the source data for the estimation of the extensional or elongational flow properties of the material, which are vital to processes such as extrusion, bottle blowing, rotational moulding and coating operations. Additionally, the choice of die can affect the extent to which the material swells after extrusion, and this die swell may be measured by the Cads non-contacting optical micrometer system, available also from Celsum.
Also, Celsum Technologies can supply extrusion dies with non-linear profiles, for example hyperbolic geometry.
A current project involves the supply of profiled extrusion dies with embedded miniature pressure transducers to allow pressure within the die to be monitored.
All of the dies supplied by Celsum Technologies are precision made and may be supplied with certificates of metrology if required.
