Alfalfa used in the treatment of leathers as a renewable retanning agent?
The challenges of the Italian tanning industry
The leather processing cycle still involves many substances classified as dangerous for both the worker and environment. The safety in handling these substances upstream, the effects that they can cause for the user of the leather product downstream and the quality of pollutants that they release into the environment do not give the complete picture of their ecological footprint. In addition to the efforts required for the disposal of waste and residual sludge from processing, a more complete picture includes the degree of sustainability of a product with the lowest possible consumption of non-renewable resources. This is increasingly important in order to create an increasingly sustainable process.
In leather retanning phase there are still many oil products that are used to make the most varied leather articles because of their valuable organoleptic characteristics and consistent results. Their disadvantage is undesired substances detected in the finished products such as hexavalent chromium, formaldehyde and phenols.
Alfalfa as an alternative?
The project “Development of an innovative retanning agent for leather from the reuse of waste vegetable fibers of alfalfa” presented by IKEM last summer 2017, won the public bid for support for projects developed by business combinations provided by the Veneto Region in scope of the “POR FESR 2014-2020” plan.
The project is consistent with creative industry: it involves two tanning companies in the Vicenza tanning district and a chemical company.
The project plans to adopt innovative solutions reusing waste materials (fibrous residue from the splitting of alfalfa to its green state) aimed at the improvement of traditional productions. In particular, the leathers treated with the new “green” retanning agent should make it possible to obtain items for footwear, furniture and clothing with characteristics similar to current quality standards but with a significant increase in environmental sustainability. By using the fibrous residue coming from the splitting of the alfalfa to the green state,
our company makes efficient use of natural resources.
Recovery, recycling and biodegradability
This proposed innovation aims to replace synthetic substances used in retanning with innovative non-toxic biopolymers derived from waste from the agricultural industry. A new retanning agent would therefore be placed in a circular economy perspective, with a double value:
- recovery and reuse of waste materials or low-value by-products of the primary sector, which would be used as raw material in the production of the new retanning agent;
- obtaining leather articles free from dangerous substances and therefore easily recyclable at the end of their life cycle.
The development of innovative retanning agents and its integration into the leather production process also offers a tangible advantage to the purification plants. By aiming to replace the chrome, the waste-to-energy treatment of sludge would be drastically better. Aiming to replace other retanning agents, however, waste and sewage sludge would still be more easily processed. The biopolymers are in fact more biodegradable than common synthetic or vegetable tannins by at least 50%.
Once industrialized the new biopolymers can possibly limit the cost of some chemical products currently used in retanning thanks to the lower cost of raw materials for their creation. The leathers developed with this new technology could allow tanning companies to conquer new market shares, especially in the creative industry of high fashion, where the retail customer today asks for a pleasant product with a higher environmental sustainability.
In conclusion this research project aims to innovate through creativity and environmental sustainability.
For more information, please do not hesitate to contact us.