Undulation

As undulation (derived from lat. Anda 'wave', or French. Onde 'wave'), the artificial introduction of curls or waves into the head or facial hair , respectively. For this purpose, curling irons are used , for example . The curling iron is heated, the hair is then pressed into shape with the curling iron. The process was developed by Marcel Grateau in 1872 and is also used in wig making. The curling tongs were later replaced by electrically operated curling rods. In 1906 Karl Ludwig Nessler invented the first permanent condulation (hot wave) by means of chemical and thermal treatment. Such procedures are now known as permanent waves . The different types of undulation can damage the hair.

Fiber deflection in tissues

The term also describes the deflection of fibers within fabrics, for example in the case of fiber composites . If fiber bundles are interwoven and held together by a warp thread, the fiber bundles may deviate, which is caused by the warp threads. The undulation leads to a decrease in the strength of the tissue parallel to the fibers.

Web links

Wiktionary: undulating  - explanations of meanings, word origins, synonyms, translations

Individual evidence

1. ↑ Hans W. Kern: The techniques of hair work . Reinhard Welz Vermittler Verlag eK, 2004, ISBN 978-3-937805-50-4 , p. 215 ( limited preview in Google Book search).
2. ↑ Dermatocosmetics . Springer, 2009, ISBN 978-3-7985-1546-8 , pp. 201 ( limited preview in Google Book search).
3. ↑ Wolfgang Raab: Hair diseases in dermatological practice . Springer DE, 2012, ISBN 978-3-642-20527-9 , pp. 103 ( limited preview in Google Book search).
4. ↑ Christoph Mersmann: Industrializing machine vision integration in fiber composite lightweight construction . Apprimus Verlag, 2012, ISBN 978-3-86359-062-8 , pp. 24 ( limited preview in Google Book search).