Articles - Leather Technology Magazine Nº74
New Micro-sphere Application in the
Leather Industry
Authors: Leandro del Frate
LANXESS S.A. |
New Micro-sphere Application in the
Leather Industry
Work presented at the 2nd National Technical Symposium
of the Tanning Industry, Buenos Aires, November 21st,
2008
ABSTRACT
The upgrade of lower quality hides or skins in order to
produce a good quality leather article with acceptable
yield and performance is one of the most value adding
opportunities for a tanner. A new, innovative wet end
technology based on expandable
Micro-spheres is being introduced to the leather industry.
Tanned leather is treated during the retanning step with
a customized penetrating polymer dispersion containing
compact micro-spheres. These Micro-spheres have a
diameter of 5 - 20 µm and are small enough to migrate
into the collagen structure; they are filled with a liquid gas,
and can expand through a heat treatment process, up to
40 times of their original size to a much larger, resilient
Micro-cell. During the wet end process the polymer
together with the micro-spheres penetrate into the leather.
After a conventional retanning and drying process the
dried crust is then be subjected to a special steam treatment
where the Micro-spheres inside the leather are expanded
and transformed into larger Micro-cells.
This operation results in a dramatic upgrade of the internal
structure of the leather, and in turn the grain surface
appearance and uniformity, too. The loose areas, blood
vessels and other voids in the corium layer are selectively
and permanently filled while keeping the leather light and
soft. Several applications have already been studied and
the feasibility of the technology has been proven, but this
new system further opens up a variety of completely new
opportunities for the leather industry.
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