04 Mar Shredding of tannery waste for the leather industry

Industrial shredders are employed in many industries, yet their contribution is not always adequately valued. A strategic sector for our country’s economy is the Made in Italy. This article illustrates a customized shredding solution that directly involves this market type.

The customized installation described below consists of a 50 HP dual-shaft shredder working in concert with another 125 HP three-shaft shredder through a conveyor belt system. The application is very specific but allows addressing, albeit tangentially, a very important issue: the ecological impact of Italian manufacturing.

Italian Tannery: A Prime Market

In Italy, one of the industries of excellence is the tannery. Leather is a material widely used in Fashion: bags, footwear, and small leather goods are among the healthiest sectors of the entire manufacturing industry.

The sector, as a whole, produced a turnover of 68.5 billion euros in 2023, an increase of 5.8% compared to 2022. Exports rose by 6.3%, and Italy is the world’s second-largest exporter of leather goods, after China.

In our country, there are over 1,200 companies dealing with the leather industry. They are concentrated mostly in Veneto, Campania, and especially Tuscany, where the historic Leather District of Santa Croce sull’Arno is located. The sector is not experiencing a crisis: Tuscan leather has seen a doubling of exports in the period 2007-2023, going from 1.8 to 4.3 billion euros.

Such an important market represents an asset for the entire nation. However, in addition to the merits of a unique industry in the world, it is also necessary to look at the responsibilities that follow such a primacy. Indeed, if we boast about production, we must not forget the correct disposal of tannery waste. From a circular economy perspective, understanding how to reduce the environmental impact of an industry is the first step towards optimizing processing, reusing materials, and reducing waste.

Leather Processing and Treatment: An Environmental Impact Not to Be Underestimated

Leather and hide are naturally biodegradable materials. However, the tanning process makes them more resistant and difficult to dispose of. But not only that: during tanning, toxic chemical components and a large amount of water are used.

Since leather and hide require processing with a high carbon footprint, proper disposal, but above all, the reuse of these materials, are fundamental from a sustainability perspective. #Shredding, therefore, is an indispensable step in reducing waste, recovering not only the finished product but also all the semi-finished products discarded during production.

The processing process that leads from raw leather to the finished product produces various by-products: wastewater, solid waste, fats, chemicals. It is essential to identify processing methods with minimal resource consumption and emissions. The leather industry also moves a market that involves not just leather goods but also sectors like furniture and automotive.

Dual Industrial Shredding Line for the Tannery Industry

In specialized plants for the tannery industry, shredders play an important role. An example is the management of tannery waste trimmings, i.e., the non-conforming parts of the leather removed during the early stages of production, treated by an Italian company leading the world in transforming these processing residues into biostimulants for agriculture.

This is precisely the purpose of the two twin shredding lines composed of two shredders that work 24/7: one dual-shaft and one three-shaft connected by multiple conveyor belts, remotely controlled in a completely automatic manner. The control panels with #PLC Siemens, equipped with connection for remote management both #Profinet and #Profibus, are equipped with remote assistance. The supplies comply with the latest Industry 4.0 requirements.

The first material pass is carried out by a medium power dual-shaft shredder model of 37 kW (50 HP) with 1 beak blades of 50 mm thickness. The second pass by a three-shaft shredder of 93 kW (125 CV), with 5-1 beak blades with a thickness of 50 mm and discharge grids with hexagonal holes. The two machines are connected to each other by a 10 mt conveyor belt.

Exiting the three-shaft shredder, the material is collected by a 2 mt horizontal weighing belt which conveys it to a second 4.5 mt conveyor belt equipped with an Overbelt. After discharging ferrous material from the line, a third 5 mt belt takes the material to a hydrolysis tank.

Our commercial team is at your disposal to provide you with further information and introduce you to our wide range of industrial shredders available and support you in any waste shredding issues.