Tanning agents that meet high performance and environmental standards

Tanning agents that meet high performance and environmental standards

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After bating, the next stage involves applying the tanning agent to the leather. The tanning agent penetrates the skin, converting its collagen structure to leather. Stahl offers tanning agents that meet high performance and environmental standards. They are part of our Stahl Neo® Portfolio for wet-end and leather finishing, which means that they comply with the ZDHC MRSL.

Learn more about Stahl’s tanning agents by downloading the catalogue.


Feliderm® MGO 

Feliderm® MGO is a special magnesium oxide with a specific particle size distribution. It is used as a safe and effective basifying agent during the chrome-tanning process. Feliderm® MGO contains low levels of impurities and the controlled particle size supports its gradual and controlled dissolution for a slow and controlled basifying action. As a self-basifying agent for chrome tanning, it provides a slow, gentle rise in pH during basification. The carefully controlled particle size distributes the chrome uniformly and it provides a safe and consistent performance. The resulting leather shows a high shrinkage temperature.


Granofin® Easy F-90 Liq 

Stahl’s innovative tanning technologies using Granofin® F-90 help tanners facing today’s challenges: producing premium-quality leathers while efficiently reducing the impact on the environment. Granofin® Easy F-90 Liq is a unique organically based tanning agent. Granofin® Easy F-90 Liq is best suited for use in producing mineral-free leather for automotive, upholstery, shoe upper, or garment. Granofin® Easy F-90 Liq eliminates the need for pickling or basification operations to support a simple and quick tanning process. it further reduces water and energy use, giving it a major environmental and technical advantage. The tannage with Granofin® Easy F-90 Liq is formaldehyde-, heavy-metal- and phenol-free, and shrinkage temperatures of between 70 and 80°c are easy to achieve. Tanning with Granofin® F-90 provides the perfect base for using more sustainable retanning technologies like Stahl EasyWhite TanTM and Stahl EasyBlue TanTM.


Granofin® TA p

Granofin® TA p is a vegetable tanning agent belonging to the pyrogallol group of tannins. It has been specially prepared to include iron complexing agents to reduce the potential for iron staining in the resulting crust leathers. Granofin® TA p has good relative heat and light fastness and comes finely ground, which makes it recommended for soft and milled articles, especially for automotive upholstery.


Imprapel® Supra 

Imprapel® Supra is a specialty bleaching agent based on a chlorine-containing reducing agent which is used for pickle bleaching of pelts. As with all bleaching agents, special care must be taken when using these products. And even when all relevant precaution and safety requirements are met, you should consult your Stahl representative before running any trials, to ensure the most suitable conditions. Imprapel® Supra is used as a pickle bleaching agent on hides, skins or other pelts such are reptile. When used in the pickle, it bleaches any remaining hair roots, pigmentation or other keratinous materials, resulting in a clean pelt. Imprapel® Supra is particularly recommended for use in the production of full aniline, white and pale colored leathers. Imprapel® Supra will improve dye evenness and brilliance. It has a minimal effect on the leather’s strength and structure.


Relugan® GM

Relugan® GM is a new aldehyde tanning agent that is very effective for manu­facturing wet-white. It is a special masked glutaraldehyde derivative that penetrates extremely well through the cross-section of the leather. It also has the excellent tanning action of pure glutaraldehyde. Relugan® GM is fairly insensitive to variations in the processing conditions, and the wet-white is very pale in color. The leather has a full, round handle. It is best suited for the following applications:


Relugan® GT-50

Looking for excellent and effective chrome-free tanning leather and fur? Relugan® GT-50 delivers. It’s also recommended for re-tanning wet-blue to create leather with a low density and a soft, full handle. This product that can be used to manufacture leather to meet high standards of wash fastness and perspiration resistance. Relugan® GT-50 is best suited for the following applications:


Neutrigan® MOS 

If you’re searching for an effective basifying agent for use in chrome tanning, look no further than Neutrigan® MOS. This tanning auxiliary is slow acting: it works continually to ensure that the chrome is evenly distributed in the leather, which gives it a superior grain. It causes a slow, constant increase in the pH of the tanning liquor. If the magnesium oxide is too soluble, the pH undergoes a large initial increase and then decreases towards the end of the tanning process. With Neutrigan® MOS, the final pH is approached gradually, and always from below. This prevents sharp fluctuations in pH.


Sortassist® liq 

Sortassist® liq is a specially developed pigment dispersion used to help in the grading and selection of hides and skins. Sortassist® liq provides excellent definition of all grain faults, is easy to use and the substrate coloration is reversible and so has no residual effect on the color of the crust. The coloration of Sortassist® liq is noticeable above pH 4.0. At a pH of below 4.0, the color is permanently discharged. It is mainly used in the sorting stage of wet-blue leathers. And is applied after the chrome tannage, in the drum. After grading, the resulting coloration (blue) will remain in the wet-blue for up to 24 hours. Sortassist® liq can also be used to sort old and stored wet-blue. For this, the surface pH of the leather is raised above 4.0.


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Tanning agents that meet high performance and environmental standards
David Sabaté
Beamhouse Global Technical Manager