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John Duffy
Dr. John Duffy is Sector Marketing Manager - Industrial at Malvern Instruments and is based at the company’s headquarters in the UK. He has a PhD from the University of Nottingham where his research in the school of chemical and environmental engineering involved rheological studies of the microstructure of molten coal. John received the Vernon Harrison award in 2009 from the British Society of Rheology for this work. This is an annual award based on the most distinguished PhD thesis on the subject of rheology. Previously he worked with both Boots and Unilever and has a wide experience of the role of rheology in household and personal care products.

Mastersizer, Morphologi, Tech Talk »

[28 Nov 2018 | ]

Additive manufacturing (AM), also commonly referred to as 3D printing is the process of building a three dimensional structure or component from the ground up, usually layer by layer. There are seven main categories of additive manufacturing processes, as defined by the ASTM Committee F42 on Additive Manufacturing Technologies. One of the fastest growing AM processes is powder bed fusion in which a powder layer is deposited on a building platform and a laser or electron beam is used to selectively melt or fuse the powder. After melting, the platform …

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Malvern Panalytical Events, Tech Talk »

[9 Nov 2018 | ]

About Sanjeeva Murthy and the New Jersey center for Biomaterials at Rutgers University
Sanjeeva Murthy is an Associate Research Professor at the New Jersey Center for Biomaterials (NJCBM), Rutgers University. He is a Materials Scientist with expertise in polymers, biomaterials and biological structures.  The NJCBM was founded in 1991 by Dr. Joachim Kohn with a mission to improve patient care and public health through the development and commercialization of future generations of biomaterials. Current activities in the laboratory include synthesis and characterization of new polymers for regenerative medicine, and fabricating them …

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Kinexus, Meet the Experts, Rheology, Rheometry »

[4 Oct 2018 | ]

The most common approach for measuring time-dependent viscoelastic properties of a material on a rotational rheometer is to perform small amplitude oscillatory shear (SAOS) over a range of oscillation frequencies – commonly referred to as a frequency sweep – where the sample is oscillated back and forth with a given stress or strain. Here the oscillation frequency, measured in rad/s, is equivalent to 1/t, with t the deformation time of the material.
Let’s consider a sample of Play Putty which is a viscoelastic material. At short deformation times (high frequencies) Play …

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Kinexus, Meet the Experts, Rheology, Rheometry »

[9 May 2017 | ]

Controlling the performance of an ink is a complex optimization challenge. Understanding how features of the system, the dispersed particle size in particular, impact stability and behavior during each stage of the printing process is crucial for effective formulation.
Over the past 30 years, the use of commercial and industrial inks has changed substantially. In particular, the maturation of inkjet technology has revolutionized printing. From office printers through to industrial coding and marking systems, inks are now required to meet demanding performance targets, for a wide range of different applications.
Inks are …

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Meet the Experts »

[21 Dec 2016 | ]

Our festive webinar was a real success and so much fun! Boys and girls, we invited you to send in your questions, comments, feedback and wish lists for Father Characterization to answer.  He received lots and lots of letters and was able to get through a selection during the webinar. Luckily, Father Characterization has zillions of little elf and pixie helpers all over the world.
Letters to Father Characterization:
Q: Dear Father Characterization, As an independent consultant, I would like to be a good consultant in the upcoming year. Can you teach me how …

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Malvern Panalytical Events, Rheology »

[7 Aug 2016 | ]

We have been waiting four years for this global event to return but it’s finally here. No, not the Olympics but the 17th International Congress of Rheology!
Like the Olympics this event is held every four years with the last one being held in Lisbon, Portugal in 2012 and this time in Kyoto, Japan. The event starts on 8th August and runs until the 13th August and brings together the world’s leading rheologists to present the latest advances and developments in this expanding field.
There are 19 sessions, covering both pure and applied …

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Rheology, Tech Talk »

[9 Jun 2016 | ]

Using rheology for faster, smarter material formulation
Rheology is often perceived as a theoretical, highly mathematical discipline but in fact it has very practical relevance in defining the behaviour of a wide range of materials including cement, asphalt, cosmetics, foods, paints, inks, blood and much more. Rheology is all around us and we are constantly performing rheological testing every time we apply a force to one of these materials in order to deform it or make it flow at the desired rate, be it squeezing toothpaste, spreading cement, or chewing food.  The …

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Kinexus, Tech Talk »

[20 Aug 2015 | ]

There is often a necessity to measure, or at least estimate, true viscosity values using non-standard measuring systems on a rotational rheometer. This may be to replicate a mixing or manufacturing process on a lab scale, to keep a sample dispersed and uniform during a measurement or to measure some rheological property that would be difficult or impossible with a standard configuration such as ‘cone and plate’ or ‘concentric cylinders’.
While non-standard measuring systems can be used on our Kinexus rotational rheometers (such as custom made systems attached via our universal …

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Customer experience, Malvern Panalytical Events, Microrheology, Particle size, Rheology, Tech Talk »

[2 Feb 2015 | ]

Last year at Malvern we put a lot of emphasis on inkjet ink technology due to the scale of growth in this area and the analytical benefits our products can bring when characterizing these inkjet inks.
To try to assist current and potential users in this sector our team of technical experts in particle characterization and rheology joined forces to deliver a three part webinar series (see Related Resources below) showing how their respective technologies could be used to help characterize and optimize inkjets inks in terms of pigment composition, ink …

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