Cooler spray
Cold spray (also ice spray ) is a liquid gas filled into a spray can that is used to cool objects or body parts. Temperatures of −25 to −55 ° C are usually reached. Different gases and gas mixtures are used, whereby the lowest possible temperature and flammability are the main criteria for differentiation.
I.a. flammable hydrocarbons such as propane , butane , pentane or mixtures of these substances are used, as well as the non-flammable 1,1,1,2-tetrafluoroethane ( R 134a ). In medicine, the combustible chloroethane is mainly used. All of these materials may only be used in well-ventilated rooms and away from open flames.
Examples of application areas for cold sprays are cold anesthesia in medicine, troubleshooting in thermally sensitive electronic components and the assembly and disassembly of components .
In dentistry , cold spray is used to test the sensitivity of the teeth.
Cold spray in electronics / electrical engineering
In the field of electronics, cooling spray is used for troubleshooting (temperature-dependent errors) or for testing temperature sensors.
It can be problematic that the contents of the spray can lead to electrostatic charging, which can possibly cause ESD damage to the components or assemblies .
A major hazard potential when using electronic assemblies is ignition of the aerosol by external ignition sources and arcs or voltage flashovers, such as those caused by e.g. B. can occur on high voltage or hot components. For this reason, cold sprays that are used on electronics in operation must demonstrate a safety test in accordance with the aerosol directive 75/324 / EEC. This test is also necessary for use in explosion protection areas. Primarily inexpensive cold sprays do not meet this requirement .
Web links
Individual evidence
- ↑ Technical data sheet Kälte 75 Super - Kontakt Chemie. CRC Industries Deutschland GmbH, December 24, 2003, accessed May 30, 2017 .
- ↑ Bernd Engels, Carsten jewelry, Reinhold Fink, Tanja Schirmeister: Chemistry for medical professionals . Pearson Deutschland GmbH, 2008, ISBN 978-3-8273-7286-4 , p. 93.
- ↑ Boris Zernikow: Pain therapy for children, adolescents and young adults . Springer-Verlag, February 21, 2009, ISBN 978-3-540-74065-0 , pp. 233–.
- ↑ Wilm-Gert Esders: Rational workflows in the dental practice . Georg Thieme Verlag, 2007, ISBN 978-3-13-132261-6 , p. 17.
- ↑ Radio Electronics Show 1975.