Textile & Clothing

Development of heavy metal free tanning and colouring agents and -processes: Producing and characterization of raw materials

As a substitute for chromium, the suitability of herbaceous knotgrass and rhubarb as source materials for the extraction of vegetable tanning agents and dyestuffs has been investigated. The resulting data record describes the entire process, from agricultural production and the characterisation and extraction of constituent materials through to the tanning process itself. 

 

Summary

The use of chrome tanning and synthetic chromium-bearing dyestuffs represents an ecological hazard in the tanning and dyeing of hides.  In an earlier research project, three species of knotgrass (Polygonaceae) have already been analysed as a potential source of raw materials for the extraction of vegetable tanning agents.

This project has involved the more detailed pursuit of this research using herbaceous knotgrass (Reynoutria) and rhubarb (Rheum).  A further key objective has been added, namely, the analysis, extraction and utilisation of naturally-occurring dyestuffs in rhubarb roots as potential substitutes for synthetic chromium-bearing dyestuffs.

Results:

  • Four Rheum genotypes have been identified which are suitable for large-scale cultivation.
  • An in-vitro propagation process for the production of larger quantities of plant material has been developed and successfully tested.
  • Values recorded for the heavy metal content of both raw materials and extracts lay consistently below the limiting values indicated in the literature for the average content of soils.
  • Test data has been used for the preparation of an “Integrated examination of the extraction of tanning agents from rhubarb roots”.  This examination encompasses every stage of the process, from agricultural production and the characterisation and extraction of constituent materials through to the tanning process itself.

More Project Informations

Project title:  Development of heavy metal free tanning and colouring agents and -processes : Producing and characterization of raw materials

Project number:  1481022/8

Project period:  1996 - 1999

Project region:  Germany (Saxony-Anhalt)

Project contact:

Herr Prof. Dr. Schellenberg

This email address is being protected from spambots. You need JavaScript enabled to view it.

+49 (0) 3471 355 1188

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Source: German National Library of Science and Technology Hannover (TIB)