Tanning Materials

Tanning Materials


plant parts or extracts containing tannins, which are used in leatherworking to tan hides.

Among the main tanning materials are the wood of the oak and chestnut (together with the bark); the bark of the willow, larch, and fir; and certain roots (knotweed, rhubarb, and thrift). In the oak, the tannins occur in all parts of the plant, but only the stumps and the wood and bark of the trunk and large branches, which are not suitable for use as lumber, are used as tanning materials. The quantity of tannins in oak varies from 4 to 6 percent, depending on the species and the region and time of procurement; for chestnut it varies from 7 to 8 percent; and in willow, larch, and fir tannides are found in the bark (8-20 percent). The possibilities for annual procurement of fir and larch bark are virtually unlimited. The content of tannins in root tanning materials is as much as 22 percent in knotweed, 14.5 percent in rhubarb, and 11-21 percent in thrift.

In addition to the plant tanning materials mentioned above, factories sometimes process valonia, quebracho, acacia, mangrove, myrobalan, and gallnuts. Valonia (the cups of acorns from oaks growing mainly in Asia Minor and southern Europe) contains an average of 23.5 percent tannins, and the scales that cover the acorn cup contain as much as 45.5 percent; therefore, they are separated out and marketed in the form of a separate tanning material known as trillo. Quebracho wood contains about 19 percent tannins; acacia bark, an average of 31.5 percent; mangrove bark, 14-48 percent; myrobalan fruit, 35-50 percent; and gallnuts, 19-77 percent, depending on the species.

Tanning materials have not been used in leather production for the layer tanning method in the USSR since the early 1930’s. With the development of the Soviet tanning-extract industry, all tanning materials are processed to make extracts.


References in periodicals archive ?
2 (provisional) for the previous month due to lower price of tanning materials (35 percent), fodder (10 percent), raw rubber, raw silk and raw jute (four percent each), skins (raw), castor seed and soyabean (three percent each), mesta and coir fibre (two percent each) and safflower (kardi seed), guar seed and hides (raw) (one percent each).
Scrape the entire hide so the thin membrane layer is broken up and can absorb the tanning materials.
In turn, India can import phosphate fertilisers, phosphoric acid, zinc, asbestos, dying and tanning materials, newsprint and precious chemicals.
We found the decision to do the former very difficult to make, as we had built an intensely vertically-integrated organization in Zlin that sourced hides and tanning materials from all over the world, but manufactured the shoes out of a single integrated operation.
Furthermore, LANXESS will be presenting a comprehensive range of proven inorganic and synthetic tanning materials, preservatives, fatliquoring agents, dyestuffs, tanning and finishing products.
At this site, the group operates a highly modern plant, that mainly produces Sodium Dichromate which is further processed into chrome tanning materials for the global leather industry.
The easy-to-use kit also includes the chrome-free tanning material X-Tan, the highly concentrated, eutectic preservative U-Tec G for wet blue, wet white and vegetable-tanned leathers, and retanning materials from the Levotan X-Biomer line.