Royaltan is a highly astringent vegetable extract from Tanac which can used for tanning or retanning. It has a high tannin content and provides a very special green-yellowish shade. It has a remarkable organic acidity and good ratio of tannin to non-tannins. Royaltan provides good tannin fixation, an increased leather firmness and a low water uptake.
For heavy hides and sole leather Royaltan provides good fibre compaction and outstanding yield. It can be used alone or compounded with other vegetable or synthetic tanning materials, which is useful when producing sole or vachetta leathers. Articles with a fine, tight grain and excellent fullness have been produced when Royaltan is used as a retannage with chrome tanned leathers.
This product is a dark brown, hygroscopic, dedusted powder which is free of PCP and contains a minimum of 74% tannin content. The extract has a pH (in 20% solution p/v) of 2.5-3.2 and packed moisture content of 4.5-6.5%.
Royaltan is soluble in tap and hot water and has a very high resistance to iron preventing spots and staining during processing. When used as a retannage it provides the leather with excellent printing, polishing, burnishing and embossing characteristics, good buffing properties and a tight grain. It can also aid water resistance.
Tanac recommend the following applications: 25-30% of Royaltan for tanning vachettas; 40-45% for sole leather – based on limed weight; 5-15% Royaltan for retanning chrome leather – based on shaved weight.