High-speed NMR imaging of capillary action in thin nontransparent porous media

An improved High-Speed NMR profiling method is introduced that enables to measure capillary action in thin, non-transparent porous media. Liquid profiles can be measured as fast as 10 ms with a spatial resolution of 14.5 µm. Capillary absorption of microliter-sized droplets into non-transparent nylon-6,6 porous membranes was studied. In nylon-6...

Failure modes of conducting yarns in electronic-textile applications

Integration of electronic functionalities into textiles adds to the value of textiles. It allows measuring, detecting, actuating and treating or communicating with a body or object. These added values can render the smart textiles very useful, fun, supporting, protecting or even lifesaving. It is, however, important for the comfort, acceptance...

Plasticization lags behind water migration in nylon-6: An NMR imaging and relaxation study

The water sorption mechanism in thin nylon 6 films is studied by 1H NMR imaging and relaxometry. Experiments using D2O and H2O enable identification of polymer and water signal components during the uptake process. Tracking the mobility and size of polymer and water components gives new insights into the water sorption mechanism of nylon 6. 1H...

Migration of divalent ions in nylon 6 films

The migration of ions through a nylon-6 film is studied by MRI. For this study the paramagnetic ions Mn2+ and Cu2+ are used as they act as a contrast agent and are detectable by MRI. The ingress of water and ions in nylon occurs at different rates. First, water is absorbed in the nylon. Second, the ions slowly migrate through the nylon matrix....

The influence of ions on water transport in nylon 6 films

Nylon 6 films are directly exposed to saline solutions containing mono-valent ions and the water uptake is measured with magnetic resonance imaging (MRI). Both the amount of water uptake and the rate of water uptake are studied. First, the films are exposed to solutions with different concentrations of NaCl. Later, solutions of salts such as...

Development of flexible LEO-resistant PI films for space applications using a self-healing mechanism by surface-directed phase separation of block copolymers

Polimide-block-polydimethylsiloxane (PI-b-PDMS) block copolymers have been synthesized from commercially available amino-terminated polysiloxanes with different molecular weights, for use as polymeric materials resistant to the low earth orbit (LEO) space environment. A structural optimization with respect to maximum environmental protection has...

Sepiolite needle-like clay for PA6 nanocomposites: An alternative to layered silicates?

This paper presents a study of polyamide 6/sepiolite clay nanocomposite, obtained by melt compounding in a mini twin-screw extruder, and characterised in terms of morphology (SEM and TEM analysis) and mechanical properties of the composite, along with their crystallinity and crystal structure of the semi-crystalline matrix. The tensile test...

Temperature limit values for touching cold surfaces with the fingertip

Objectives: At the request of the European Commission and in the framework of the European Machinery Directive, research was performed in five different laboratories to develop specifications for surface temperature limit values for the short-term accidental touching of the fingertip with cold surfaces. Methods: Data were collected in four...

Typical diffusion behaviour in packaging polymers - Application to functional barriers

When plastics are collected for recycling, possibly contaminated articles might be recycled into food packaging, and thus the contaminants might subsequently migrate into the food. Multilayer functional barriers may be used to delay and to reduce such migration. The contribution of the work reported here is to establish reference values (at 40°C...

Effects of processing on microstructure and properties of SLS Nylon 12

There currently exists the requirement to improve reproducibility and mechanical properties of SLS Nylon parts for rapid manufacturing (RM). In order to achieve this, further fundamental research is needed and this paper addresses this need by investigating effects of potential sources of the lack of reproducibility and reports effects in...

Benchmarking stiffness of current sprint spikes and concept selective laser sintered nylon outsoles

Stefanyshyn and Fusco (2004) demonstrated that sprint performance can be improved if the stiffness of standard running spikes is increased. The authors concluded that in order to maximise performance individual tuning of the athlete's shoe stiffness to the athlete's particular characteristics is required. Rapid manufacturing processes, such as...

Rumen escape protein in concentrate ingredients determined with the nylon bag and enzymatic techniques

Rumen escape protein (REP) was determined for 26 concentrate feed ingredients using the nylon bag technique and in vitro using a proteolytic enzyme preparation of Streptomyces griseus. In vitro, the samples were incubated for 0, 1, 6 and 24 h. The highest correlation was observed between percentage REP (%REP), determined with the nylon bag...

Temperature limit values for gripping cold surfaces

Objectives. At the request of the European Commission and in the framework of the European Machinery Directive, research was conducted jointly in five different laboratories to develop specifications for surface temperature limit values for the gripping and handling of cold items. Methods. Four hundred and fourteen experiments were run where...

Compatibility testing of energetic materials, which technique?

Compatibility is an important safety aspect related to the production and storage of energetic materials. To test different combinations of materials a simple test method with clear criteria is advisable. At the last ESTAC the use of microcalorimetry and the vacuum stability test for the compatibility testing of propellants were presented. This...

Development of an example flow test object and comparison of five of these test objects, constructed in various laboratories

Doppler test objects are used to characterise Doppler systems, both stand-alone systems and the Doppler part of so-called duplex scanners. The aim of the project partially presented here is the development and validation of an example of a Doppler test object fulfilling the requirements of the IEC 1685. The project has been carried out by nine...

Pain, thermal sensation and cooling rates of hands while touching cold materials

Hand cooling and resulting comfort and pain were studied in 12 subjects, while touching six different materials (polyurethane foam, wood, nylon, rustproof steel, aluminium, and temperature-controlled metal) which were initially at ambient temperature. This was done for three ambient temperatures (-10°, 0° and 10°C), after pre-exposure exercise...

Simulation of hand cooling due to touching cold materials

A simple analytical model has been developed to simulate the cooling of the hands due to touching various types of cold material. The model consisted of a slab of tissue, covered on both sides with skin. The only active mechanism was the skin blood flow. The blood flow was controlled by body core temperature, mean skin temperature, and local...