The invention relates to tanning agents for leather and concerns a zeolite composition suitable as a single tanning agent comprising zeolite, a first weak acid, a second weak acid and optionally a third weak acid. This zeolite composition enables an efficient and effective chrome-free tanning.

The invention relates to tanning agents for leather and concerns a zeolite composition suitable as a single tanning agent comprising zeolite, a first weak acid, a second weak acid and optionally a third weak acid. This zeolite composition enables an efficient and effective chrome-free tanning.

A method of manufacturing at least a part of a footwear in an automatic manufacturing line includes providing a footwear part in the form of a leather base layer, providing a footwear part in the form of a leather attachment layer, automatically stacking the leather base layer and the leather attachment layer against each other with an intermediate application of adhesive between them, automatically activating the adhesive, automatically forcing the leather base layer and the leather attachment layer against each other under a pressure with the adhesive between them, curing the adhesive and thereby bonding the leather base layer and the leather attachment layer to each other thereby providing at least a part of a footwear upper.

A method of manufacturing a footwear includes the steps of providing a leather base layer and providing a leather attachment layer. The leather base layer and the leather attachment layer are fixed against each other with an intermediate application of adhesive between them. The applied adhesive is activated. The leather base layer and the leather attachment layer are forced against each other under a pressure with the adhesive between them. The adhesive is cured and thereby the leather base layer and the leather attachment layer are bonded to each other. The bonded leather base layer and the leather attachment layer are integrated as part of the footwear.

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.

A method for dyeing and/or retanning of leather objects includes providing a leather object. The leather object has been processed by at least a tanning process. The leather object is introduced into a process chamber. The leather object is subjected in the process chamber to a pressurized fluid. The pressure of the pressurized fluid is controlled to reach a supercritical state. The leather object is subjected to a dyeing agent and/or a retanning agent, which dyeing or retanning agent is dissolved and/or transported in the pressurized fluid for at least a predefined period of time while the pressurized fluid is in the supercritical state. The pressure is reduced in the process chamber. The leather object is removed from the process chamber. The pressure reduction is controlled over time.

A method for tanning a hide wherein said method comprises treating a tannable hide with a tanning composition comprising from 25 to 75% by weight (wt. %) of at least one chromium(III) salt; from 5 to 70% by weight (wt. %) of at least one zeolite having the general formula (1): Mx/n [(AlO.sub.2)x(SiO.sub.2)y] wH.sub.2O, wherein M is an alkali metal cation, a bivalent cation, a trivalent cation or a mixture thereof, n is the valence of the cation, w is the number of water molecules per unit cell, y is a number from 0.8 to 50 and the ratio y to x is ranging from 0.7 to 100, treated with at least one acid selected from the group consisting of a monocarboxylic acid and a polycarboxyic acid; and from 1 to 70 wt. % of at least one aluminium(III) salt; wherein all wt. % are relative to the total weight of the composition (T).

A method for tanning a hide wherein said method comprises treating a tannable hide with a tanning composition comprising from 25 to 75% by weight (wt. %) of at least one chromium(III) salt; from 5 to 70% by weight (wt. %) of at least one zeolite having the general formula (1): Mx/n [(AlO.sub.2)x(SiO.sub.2)y] wH.sub.2O, wherein M is an alkali metal cation, a bivalent cation, a trivalent cation or a mixture thereof, n is the valence of the cation, w is the number of water molecules per unit cell, y is a number from 0.8 to 50 and the ratio y to x is ranging from 0.7 to 100, treated with at least one acid selected from the group consisting of a monocarboxylic acid and a polycarboxyic acid; and from 1 to 70 wt. % of at least one aluminium(III) salt; wherein all wt. % are relative to the total weight of the composition (T).

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.

A chrome-free tanning process of an ecological leather is characterized by a TWS+sodium lignosulfonate+TWLZ ternary tanning process system. The sodium lignosulfonate added can not only have a fixation effect on a TWS tanning agent to make the TWS tanning not undergo detanning at a low pH, but also significantly improve the uniformity of distribution of a TWLZ tanning agent in a hide/skin and promote the formation of a stable cross-linked network structure by the TWLZ tanning agent in a collagen fiber, which effectively overcomes the defects of tanning performance of the existing tanning systems to obtain a leather with uniform and sufficient tanning, a high isoelectric point, a strong electropositivity, excellent absorption for post-tanning chemicals, and a prominent softness, and gives a leather a wide use range and a high quality.