Articles - Leather Technology Magazine Nº72

Decrease in leather water resistance due to dry cleaning

Toshinori INATSUGI ¹, Kyoji SATO ¹, Masashi NAKAMURA ², Hidehiko NAKANO ³, Tohei YAMAMOTO ^3
1Leather Test Centre. Industrial Technology Research Institute of Osaka. 1-18-13 Kishibenaka, Suita, Osaka, Japan (ZIP: 564-0002) ² Leather Consumption Sciences Association 1-18-13 Kishibenaka, Suita, Osaka, Japan (ZIP: 564-0002)
³ Materials Engineering Area. School of Engineering Graduates, University of Hyogo. 2167 Shosha, Himeji, Hyogo, Japan (ZIP: 671-2280)

Decrease in leather water resistance due to dry cleaning

Work published in the Magazine of the Japanese Leather Chemists Association: Leather Science, Vol. 54, No. 2, pp. 90-97 (2008)

ABSTRACT

As leather garments change their shape or texture easily when they become wet with water, they are usually dry cleaned. However, it is a well known fact that dry cleaning causes the water resistance of leather garments to decrease significantly.
The present studies were carried out with the objective of determining the factor which produces this reduction in leather water resistance. To that aim, highly water-resistant leathers were first prepared and then used to perform a dry cleaning according to JIS test procedures. The leather water resistance was obtained from the critical values of surface tension forces (Xc) measured by dynamic impermeability tests and using the flotation/immersion methods.
The results of the studies confirm in principle that dry cleaning causes a reduction in leather water resistance. The adsorption of tensoactive agents onto leather is the factor that produces this decrease. In particular, it was established that anionic tensoactive agents have a greater influence on the decrease than non-anionic ones.
In addition, in order to clarify this adsorption behaviour of tensoactive agents, the amount of tensoactive agents adsorbed in non-aqueous media was measured by using chrome-tanned leather powder. It was verified that the maximum amount adsorbed tends to increase as its chrome content increases. Furthermore, it was found that leather dynamic impermeability decreases at values of adsorbed tensoactive agents as small as approximately 0.3 mmol/g.