| Résumé : |
I have chosen the title "Novel type of finishing technology" as, although we had already started back in the 60s to apply foam finishes to leathers, contrary to today's methods, we then used to work with chemical foams. The making of foam at that time was a relatively simple procedure, as long as you were able to handle the necessary products and technologies. We added to the pigment-binder-mixture a so-called propellant, for example trichlorofluoroethane with a defined boiloing poit of 47.6°C and applied the mixture on normal spraying facilities. During the drying process gas escaped from the mixture, leaving a cell-like structure similar to a foam layer which could then be embossed.
The basic idea is still the same. Due to price pressure and the decreasing quality of available raw material, we apply with a single process an even foam layer. This method results in an upgrading due to the excellent covering powers of the foam which guarantees to cover all faults and defects in the raw material, like thorn scratches, fire-brands and insect bites. The foam method allows us to increase productivity considerably by keeping the sme equipment and manpower level. The embossing of the leathers is superior to any other conventional finish, as they do not harden and keep their soft and natural touch. The leathers, can be milled and at the same time gives very good fastness values. Last but not least, the leathers possess a very good water vapour permeability.
As you will remember, the use of these propellants, however, was limited in the first place and later on forbidden due to effects on the ozone layer and the continuous growth of the so-called ozone hole. These restrictions and environmental issues, inspired us to try to produce foam for leather finishes mechanically. In this connection we would also like to mention that Cliarant GmbH played a pioneer role in the sector of purely aqueous finishing systems. The same applies today for the foam system offered by us ("Melio"), which refers to leather finishing with mechanical foams. |
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Ajouter le résultat dans votre panier Affiner la rechercheFoam systems - A novel type of finishing technology / W. Löbig in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 81, N° 1 (01-02/1997)
