Fleming PTC and Malvern Instruments Unique Approach Accelerates Co-Extrusion Process Development


18 June 2010: Malvern, UK: Recent polymer co-extrusion studies demonstrate the value of a unique die developed by Fleming Polymer Testing and Consultancy, for use with the Rosand capillary rheometer from Malvern Instruments. In combination the die and rheometer generate all the data needed to develop and validate co-extrusion process models, reducing the need for pilot scale studies. Small-scale experimentation coupled with process modelling gives detailed insight and reduces the time and expense associated with process optimization.

Polymers are co-extruded to form composite products that exploit the properties of different materials. A prime example is multi-layer films which incorporate different materials to individually impart properties such as strength, printability, permeability. The development of successful co-extrusion systems demands careful control and matching of the constituent polymers, ideally at an early stage of the development process. Research shows that good rheological data allow highly effective simulation of co-extrusion processes, providing models for system optimisation.

The Fleming PTC die exploits the design features of the Rosand rheometer to provide an integrated solution for the small scale study of co-extrusion behaviour. Accurate measurement of the pressure drop across the flow channel, at controlled polymer flow rates and temperature, produces the shear stress, shear rate and shear viscosity data needed for modelling. The geometry of the die can be altered to manipulate shear rates using a series of inserts. The position of the resulting interface in a two-polymer system can be determined both by visual examination of the samples produced and prediction via flow simulation. In this way, the predicted interface position can be validated by practical observation together with assessment of the physical compatibility of the two polymers being coextruded.

A model that accurately describes the co-extrusion process is an extremely valuable tool for full-scale process optimization. It can be used to target and reduce pilot studies, cutting development time and expenditure.

To download details of the system, and an experimental study, visit www.malvern.com/coextrusion

To find out more about Malvern rheology products see www.malvern.com/rheometers

For more about Fleming Polymer Testing and Consultancy go to http://www.flemingptc.co.uk/

About Malvern Instruments

Malvern Instruments is a market leader in measuring performance controlling material properties. These include particle size, particle shape, zeta potential, molecular weight, size and conformation, rheological properties and chemical distribution. Malvern delivers the systems, support and expertise that ensure the analytical integrity and productivity needed to drive research, development and manufacturing.

Malvern's measurement solutions for scientists, technologists and engineers advance continually through customer collaboration. Complementary materials characterization systems deliver inter-related measurements that reflect the complexities of particulates and disperse systems, nanomaterials and macromolecules. Combining intelligently implemented technologies with in-depth industry applications knowledge and support, Malvern provides customers with the competitive advantage they demand.

Headquartered in Malvern, UK, Malvern Instruments has subsidiary organizations in all major European markets, North America, China, Korea and Japan, a joint venture in India, a global distributor network and applications laboratories around the world. www.malvern.com

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