Tensile

Thermoplastic Elastomers 2011 - Brussels

 Linkam equipment on display at TPE 2011

Last week, I again delved into the world of Polymer science when I attended the 14th International Conference on Thermoplastic Elastomers (TPE's) which was held at the Sheraton Hotel in Brussels.

The main focus of the two day event was on how this innovative class of speciality engineered materials can be used in various different applications. These materials provide a hybridity between plastic processing and elastomeric functionality which has lead to an increase in market demand within the medical, industrial, electrical fields, just to name a few. The variety of applications for TPE's was highlighted by the diversity in the contents of the talks; which ranged from the use of TPE's in athletic footwear to how they can be used to reduce the cost of baby diapers.   

There was a lot of interest from the delegates in our Linkam stages and there was much intrigue in regards to the TST350 (Tensile Stress Testing Stage) and CSS450 (Optical Rheology Stage) which were being exhibited at the conference. 

It was a thoroughly enjoyable few days, not least for fantastic Belgian chocolate shop located right opposite the hotel! I would like to thank Helen and Sharon at iSmithers Rapra for their hospitality and for putting on such a great show. 

Posted by Ricky Patel

Advancing Medical Research with the TST350

Test cells subjected to cyclic stress for 7 days on the TST350

Tendons are susceptible to injury or tendinopathies due to many stressors including age, body weight, nutrition, excessive loading or forces, poor training techniques and environmental conditions. Tendons connect muscle to bone and passively modulate forces during locomotion to provide additional stability by their ability to stretch under tension.

Healthy tendons are composed of parallel collagen molecules which form fibrils. These fibrils then assemble into fascicles, which in turn make up the tendon fibre. The orientation of the collagen molecules is important because it is this alignment that gives the tendon its mechanical properties such as tensile strength.

At the University of Liverpool Senior Research Assistant, Dr Caroline Smith and her colleagues are working to advance the treatment of tendon injuries by using a Linkam TST350 stage.

To understand the development of orientated collagen under stress Dr. Smith is using the optical technique of reflection anisotropy spectroscopy to study mouse fibroblast cells subjected to regular uniaxial stress.

Mouse fibroblast cells were cultured on specially designed small wells fabricated from polydimethylsiloxane (PDMS) and were subjected to cyclic stress for 7 days. After this the cells could be investigated under the microscope.PDMS wells used to test mouse fibroblast cells

There are many conflicting opinions on how best to heal a tendon injury, and when is a tendon healed sufficiently to begin exercising it. This is crucial in accident rehabilitation as currently a severe injury can end a sportspersons career.  

This is an ongoing topic of research where developments are occurring every day. Our new stage has helped scientists push forward medical research and has opened up a whole new way of looking at how the collagen cells react to mechanical stress.

By Caroline Feltham

 

Thin Film Tensile Testing App Note


We have received a couple more great application notes involving our Tensile Testing Stage the TST350.

These two come from the folks at the Ecole Polytechnique Federale de Lausanne (EPFL) in Switzerland.
Here's the 'Introduction' from the App Note,
'Fragmentation Test Method for Adhesion Analysis of Coatings In Situ in a Microscope'.
You can read the full application note on our website.
'Mechanical integrity is a key attribute of coatings, which should not crack and delaminate during processing and during service life. Numerous methods are available to determine the adhesion of coatings, including tape and pull-out tests, and indentation and scratch techniques. The accuracy of these methods is however compromised by the presence of 'third body interactions', such as indenter-coating friction in case of scratch and indentation tests, or adherent-coating traction in case of peel and pull-out tests. The fragmentation test method detailed in the present note is free of third-body interactions. It enables quantifying the cohesive properties (which control cracking) and the adhesive properties (which control delamination) of coatings on high-elongation substrates. The method has been used to analyze a broad range of coating/substrate combinations, including inorganic coatings on polymers [1-3] and steel (e.g, [4]) and organic coatings on polymers (e.g., [e.g, [5]). The following section introduces the theory of coating fragmentation and calculation of the adhesive strength. The experimental conditions are detailed in a further section. Finally two application examples are given to illustrate the method, with focus on adhesive strength of an organic coating on a PET substrate, and a transparent electrode on a PEN substrate.'
With Thanks to Dr. Manfred Feustel of Resultec Analytical Equipment for his collaboration.