Advanced manufacturing

Manufacturing in the UK is changing rapidly, moving into and dominating the 'high value manufacturing' sector. Productivity has doubled since 1997; 75% of R&D spend is in manufacturing; it contributes £150 billion annually to the economy, over 50% of the UK's exports and more foreign direct investments than any other country apart from the USA.

Developing economies are growing at twice the rate of developed economies. Rising energy and materials cost see the introduction of new and innovative low carbon technologies. Advanced economies need to exploit technology to increase productivity and enhance national competitive advantage.

NPL has a critical role in supporting the manufacturing sectors' metrology needs, providing unique capability, guidance, solutions and collaborative innovation to ensure that they combat these pressures. Some manufacturing examples of NPL's thermal imaging metrology support are given below.

1.  Wetsuit development

NPL performed laboratory and field-based tests for UK wetsuit manufacturer, Spartan, to help further their knowledge of how wetsuits keep people warm.

Spartan is a UK wetsuit manufacturer, who specialise in wetsuits for the wind sports market (i.e. wind-surfing, kite-surfing and sailing). They are based in Essex, UK, and have been making wetsuits since 1958.

There is surprisingly little scientific research into how wetsuits keep people warm. As such, there is very little data that can help manufacturers improve their product design. Spartan were particularly interested to find out how to improve their windsurfing wetsuits, as these are designed to keep windsurfers warm whilst they are standing up on their board (as opposed to surfers' wetsuits, which are meant to keep them warm whilst underwater).

Spartan and NPL set out to perform some detailed measurements of wetsuits' thermal function, using NPL's sophisticated measurement equipment. Measuring a wetsuit's thermal function helps manufacturers understand how a wetsuit really works, and therefore allows them to make informed decisions about what materials and construction methods to use.

Spartan's Mark Minter and John Morgan, and pro-windsurfer Chris Murray, donned their wetsuits and joined NPL's Dr Richard Dudley and Dr Rob Simpson on a chilly day in March 2010 to test the wetsuits in their natural habitat - the sea - and on the beach.

"NPL's wetsuit testing has really helped us gain a better understanding of the technical side of wetsuit design. We are now focused on improving our suits by using the correct materials and fully testing everything before production. Neoprene suppliers send us samples with subjective claims as to a material's suitability for our needs, rather than objective data about its thermal performance. NPL's testing has highlighted the need to research the correct new material and has saved us producing whole ranges of suits (saving us at least £100K) that would effectively be next to useless for the colder northern European countries we sell to."
- Mark Minter, Spartan

Watch YouTube video: Wetsuit testing with Muzza - Field testing wetsuits in March 2010 at Clacton-on-Sea

Read more: Keeping you warm

2.  Intelligent textile testing

Intelligent Textiles is a UK SME that designs and manufactures polymer-based heating elements and sensors that are integrated into the fabric of products such as gloves, boots, clothing, bandages and heating pads for hospital patients.

As the textile is in close contact with the skin, it is obviously essential that the heating elements incorporate fail-safe mechanisms and are assessed to ensure they do not exceed a given maximum temperature.

'Hot spots' or failed elements in the fabric are currently identified by a time consuming manual process. However, if a technique based on thermal imaging could be developed to monitor temperature over the whole area of the fabric, it could potentially lead to considerable improvements in the product, online quality control and product assurance.

The company approached NPL for advice and a four-day consultancy was set up. The practicality of the technique of thermal imaging on textile samples was investigated and the causes of failure of the heating elements examined. The uniformity and stability of a number of the company's products were measured under normal conditions of use. As a result Intelligent Textiles gained a good understanding of the potential capabilities of thermal imaging as applied to their range of products, although further work would be required to develop the technique into an acceptable quality assurance procedure. This will be explored further in tandem with the products themselves as they proceed towards manufacture, with the continuing advice of NPL.

"Our NPL consultancy not only gave us access to the most advanced equipment, but more importantly let us discuss our results with highly capable and erudite experts. In the event, this work has advanced understanding across our entire supply chain, from our clients down to our raw material manufacturers."
- Dr Stan Swallow, Director, Intelligent Textiles

Read more: Too hot to handle

3.  Spacecraft testing (European Space Agency)

The European space agency (ESA) approached NPL to assist them with the incorporation of thermal imaging into the 'large space simulator' (LSS) testing facility - a house sized liquid nitrogen cooled, evacuated spacecraft test chamber, where a sun simulator is used to test the craft under anticipated solar conditions.

Specifically NPL and ESA together have:

• Assessed the potential for quantitative temperature measurement using thermal imaging in LSS environments
• Successfully performed two LVAF (small vacuum chamber) feasibility trials
• Produced a radiosity model developed for thermal imaging use in the LSS (large space simulator)
• Implemented the capability (GAIA spacecraft testing) in LSS

Healthcare

In medicine, thermal imaging is used in rheumatology; dermatology, drug therapy; diagnostics; monitoring; and surgical applications. In medicine, body temperature measurements are expected to have an absolute accuracy of ± 0.2 °C, with most thermal imaging systems having specified uncertainties of ± 2 °C, or ± 2 %, whichever is higher. Achieving this required accuracy is challenging.

NPL in collaboration with a number of UK clinical centres (Royal Free, Ninewells Hospital / University of Dundee, University of Glamorgan) and instrumentation manufacturers (Isothermal Technologies Ltd, Land Instruments) have improved calibration and validation facilities for diagnostic thermometry - developing first a laboratory based variable temperature standard (TIBB - Thermal imaging blackbody). Then a range of novel, robust and portable 'fixed-point' in-field of view validation blackbodies (TIVS - Thermal imaging validation system).

Energy

Rising energy and raw material costs, carbon reduction requirements and climate change are driving a focus of research and development in these areas NPL along with several collaborators in academia and industry have been working together on the measurement challenges behind new energy and efficiency systems.

Thermal shock of SOFC (solid oxide fuel cells)

Temperature gradients across SOFC are a major cause of failure. Thermal imaging presents unique advantages (non-contact, in situ, high spatial and dynamic resolution and response).

Standard flame burner performance

Measuring accurately the temperature of a flame possess significant challenges. The assessment of a 'standard flame' burner profile and response to differing burn regimes.

Contact

For further information, please contact Dr Rob Simpson