Described is a method of manufacturing zeolite particles comprising a C1-C4 carboxylate suitable for use in leather tanning, the method comprising the steps of (i) contacting a zeolite particle slurry with a C1-C4 carboxylic acid to increase the acidity of the zeolite particles; and (ii) removing liquid from the slurry to obtain the zeolite particles comprising the C1-C4 carboxylate. Zeolite particles suitable for use in leather tanning, and methods of manufacturing a tanning composition using zeolite particles comprising a C1-C4 carboxylate, are also described.

The invention provides a process for tanning a substrate using at least one ionic liquid. The at least one ionic liquid can be used in at least one of the following tanning steps: tanning, re-tanning, preservation, liming, pickling, impregnation, lubrication, dyeing, fatliquoring or finishing.

A method for antimicrobial protection applied to hides in the tanning process incorporating a biocidal composition and an additive allowing the identification by a luminescent effect, and using luminescence encryption techniques, wherein the composition is added in the tanning process immediately after adding the chromium or titanium salts in an amount between 0.1% and 5% by weight of the material to be tanned and comprises: silver phosphate glass; silicone; aliphatic hydrocarbons; and water, and the luminescent additive is added in an amount between 0.1% and 5% by weight of the material to be tanned and comprises silica; alumina; calcium fluoride; erbium (III) fluoride; ytterbium (III) fluoride; thulium (III) fluoride; and europium (III) fluoride.

A method for antimicrobial protection applied to hides in the tanning process incorporating a biocidal composition and an additive allowing the identification by a luminescent effect, and using luminescence encryption techniques, wherein the composition is added in the tanning process immediately after adding the chromium or titanium salts in an amount between 0.1% and 5% by weight of the material to be tanned and comprises: silver phosphate glass; silicone; aliphatic hydrocarbons; and water, and the luminescent additive is added in an amount between 0.1% and 5% by weight of the material to be tanned and comprises silica; alumina; calcium fluoride; erbium (III) fluoride; ytterbium (III) fluoride; thulium (III) fluoride; and europium (III) fluoride.

An apparatus includes a process chamber, a controllable compressor for pressurizing a fluid, a pressure reducing member, an inlet for a processing agent and a controller. The process chamber is a pressure chamber. The controllable compressor pressurizes a fluid and introduces the pressurized fluid into the process chamber from a source. Further the controllable compressor controls a predefined pressure in the process chamber to reach a supercritical state of the fluid. An inlet for a processing agent facilitates introduction of the processing agent into the process chamber prior to, during, or subsequent to pressurization of the fluid. The pressure reducing member reduces the pressure of the fluid at least to reach a gaseous state subsequent to processing the leather object such that the time for reduction of pressure exceeds a predefined reduction period or the reduction of pressure does not exceed a predefined leather pressure reduction gradient.

There is provided a process for tanning animal hide comprising treating an animal hide with at least one tanning agent and exposing the treated hide to a dose of ionising radiation of from 1 to 500 kJ/kg wherein the ionising radiation is in the form of a charged particle beam.

There is provided a process for tanning animal hide comprising treating an animal hide with at least one tanning agent and exposing the treated hide to a dose of ionising radiation of from 1 to 500 kJ/kg wherein the ionising radiation is in the form of a charged particle beam.