Clevertex - Grado Zero Espace Srl

hexadecane 16.2 18.5 57
Table 2 Different paraffin waxes used in microcapsules
However, in general, the changing of the phase occurs within a temperature range in the vicinity of the
body temperature. Therefore, the main function of the PCM will be to minimise the heat flow between
the human body and the outside environment thus maintaining the skin temperature relatively constant
and at a level considered to be comfortable.
In order to prevent the substances in the liquid state from flooding, it is necessary to capture them in a
microcapsule, which is resistant against mechanical action, temperature and different chemicals.
Microcapsules are integrated either into an acryl fibre (during spinning) and produced by Accordis, a
coating or foam [3].
Fig. 96 Working principle of PCM
Source: Merck
The American Society for Testing and Materials (ASTM) developed an approved standard test
procedure to measure the amount of latent energy in textile materials, the first “Test Method for
Steady State and Dynamic Thermal Performance in Textile Materials” (ASTM D7024). The method
was developed with the help of Outlast ® Technologies, Inc., and the Colorado State University.
A study carried out by researchers of the EMPA in Switzerland showed that the heat conduction of the
microcapsules containing paraffin wax is better in the liquid state of the wax than in the solid state.
2.4.3 Applications in the clothing sector
PCM technology was originally developed in the 60's for use in NASA space suits. With the successful
introduction of micro-encapsulated PCM (mPCM), this technology became available to the consumer
and industrial markets.
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