25 Unique Approach Accelerates Co-extrusion Process Development
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 optimisation.
Polymers are co-extruded to form composite products that exploit the properties of different materials. 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.
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ADVERTORIAL Nano Spray Dryer – A World Novelty In Laboratory Scale – Experience Submicron Spray Drying
Büchi's latest instrument generation – the Nano Spray Dryer B-90 – revolutionises spray drying with an innovative technology for particle creation down to the submicron and even nanometre range from minimal sample quantities at highest yield. Spray drying becomes more and more important in drug development, pharmaceutical formulation and particle design as a gentle, easy to control, continuous and scalable drying process to convert liquid formulations directly into dry powders. The Nano Spray Dryer B-90 is especially designed for the early stages of product development. The modular glass assembly enables a visible spray process and a quick and gentle drying of various applications in small scale, ideal for feasibility studies in R&D laboratories to dry only a few millilitres of substance.
The Nano Spray Dryer B-90 meets the requirements of the pharmaceutical, biotech, medical, food ingredient, chemical and advanced material industry as well as in the nanotechnology. New application trends focus on effective formulation of complex pharmaceuticals and nanomaterial substances for novel drug delivery systems, like inhalable powder drugs. Typical applications are spray drying of aqueous or solvent based solutions, nanoemulsions, nanoparticle suspensions, structural transformations or nanoencapsulations.
The droplet generation is based on a piezoelectric driven actuator, vibrating a thin, perforated membrane in a small spray cap. The membrane features an array of micron-sized holes. The actuator is driven at ultrasonic frequency, causing the membrane to vibrate, ejecting every second millions of precisely sized droplets with very narrow droplet distribution. Different spray caps with 4.0, 5.5 and 7.0 micron hole sizes are available to achieve a precise droplet size between 8 to 21 microns. A unique heater technology based on porous metal foam provides a laminar gas flow in the drying section. Optimal energy input guarantees fast heat-up times up to 120°C for very gentle drying of heat-sensitive materials. The fine spray dried particles are separated by an electrostatic particle collector, a novel technology in laboratory scale. The electrostatic particle collector offers excellent particle recovery rates for samples in the milligram range. It enables an easy collection of small powder amounts of high value materials at high yields. The integrated LCD display ensures easy process control. The PC software provides comprehensive data acquisition, storage and export capabilities. The transparency from spray head to particle collector due to the glass assembly and the very short set-up times enable an easy cleaning and even a sterilisation.
Produce finest particles of 300 nm to 5 micron size with very narrow size distribution, dry samples in the milligram range, profit from minimal product loss due to uniquely high yields up to 90%, save process time thanks to quick assembly, easy cleaning and fast product change
Since 1979, BÜCHI Labortechnik AG offers the Mini Spray Dryers B-190, B-191 and B-290 and is the worldwide market leader in laboratory scale spray dryers. Over 2900 units have been installed at universities, R&D centres and powder specialists around the world.
Visit our free on-line Spray Dryer Application Database at
www.buchi.com and be inspired by the wide variety of applications! Circle no. 76
1 µm
The Nano Spray Dryer B-90 is the ideal laboratory spray dryer for new breakthroughs in R&D: Invest only a minimal sample amount to receive powder quantities of <100 mg Produce submicron – or even nanoparticles of 300 nm to 5 µm size with very narrow size distribution Profit from minimal product loss due to uniquely high yields up to 90%
Visit our detailed Spray Dryer Application Database on
www.buchi.com and be inspired from the variety of applications!
BÜCHI Labortechnik AG 9230 Flawil / Switzerland T +41 71 394 63 63
www.buchi.com
Quality in your hands Circle no. 77
INTERNATIONAL LABMATE - AUGUST/SEPTEMBER 2010 - LABORATORY PRODUCTS
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