Leather Tanning Robot: From Tan Vats to ABB Arms

Turning a raw hide into leather means hauling wet, heavy skins through pits, drums and machines, and people still do much of that hauling. This post traces the leather tanning robot from colonial tan vats and the motor-driven drums of the early 1900s to the finishing lines where robots now spray color onto whole hides. It ties that history to what tanners showed at Simac Tanning Tech in Milan this September, looks at where ABB paint and handling robots could fit, and explains why most tanneries have not automated yet. Money is part of it, but so are corrosive drum rooms and hides that never come in the same shape twice.

Workers handling hides among the dye and tanning vats of the Chouara tannery in Fez, Morocco, 2024. Photo: Jorge Franganillo / Wikimedia Commons (CC BY 2.0)

How tanneries worked hides by hand

In 1761 the Moravian settlers of Bethlehem, Pennsylvania, built a limestone tannery beside Monocacy Creek. Its tanners worked about 3,000 hides a year into shoes, boots, saddles, harnesses and fire buckets. Historic Bethlehem describes a process that could take up to two years from raw hide to leather: rinsing in the creek, then long soaks in tannic acid in wooden vats. It is the only 18th century Moravian industrial building still standing anywhere, and in early October 2026 the National Park Service awarded nearly $700,000 toward preserving it.

The Moravian Tannery of 1761 beside Monocacy Creek in Bethlehem, Pennsylvania, photographed in 1968. Photo: Jack Boucher / Wikimedia Commons (public domain)

By the First World War American tanneries had become factories, but the work was still physical. Photographs taken in 1918 at the Kistler Lesh and Co. Burke Tannery in Morganton, North Carolina, show the bean house, where men fed hides into unhairing, graining and fleshing machines one at a time. Chestnut wood and oak bark were ground on site for tannin. Machines did the scraping that used to be done with a knife over a beam, but people still lifted every wet hide in and out of them.

The bean house at Kistler Lesh and Co.'s Burke Tannery in Morganton, North Carolina, with unhairing and fleshing machines, 1918. Photo: Kistler Lesh Co. / NARA via Wikimedia Commons (public domain)

Rotating drums changed the timing of the trade. Photographs from the Pfister and Vogel Leather Company in Milwaukee, taken during the same war, show large tan drums turned by electric motors behind wire mesh guards, with locking devices to make loading and unloading safer. Chrome tanning, which tanners took up after doctors started soaking gut sutures in chromium salts in the 1840s, went well with drums and now accounts for 85 to 90 percent of leather made. It cut tanning from months to days. The hides still had to be lifted in and out by hand.

Motor driven tan drums with a mesh guard over the drive at the Pfister and Vogel Leather Co. in Milwaukee, around 1918. Photo: F. A. Vogel / NARA via Wikimedia Commons (public domain)

Tanneries short of hands and the robots on show

The labor problem is now the main reason tanners talk about robots. La Conceria, the Italian leather trade paper, reported on 1 October 2026 that several companies at the latest Simac Tanning Tech showed machines with artificial intelligence designed to take over manual work. Cesare Dal Monte and Laura Beschin of Ger Elettronica told the paper that "know-how is at risk of being lost" as older workers retire. Cristiano Paccagnella of Omac pointed out the other side: in developing countries, machines need to be simple and cheap enough to cope with fast staff turnover.

White tanned hides inside an open tanning drum. Photo: Mirko Müller / Wikimedia Commons (CC BY-SA 3.0)

Finishing is where robots have gone furthest. The Italian machine builder Barnini sells RoboSpray, a six-axis robot that sprays color onto a whole hide with a two-circuit spray tool and can handle leather panels with a suction gripper. Fratelli Carlessi built Spray Lab, a robot paired with a drying tunnel and run by the company's own software; its XL model is 1,200 mm wide and takes half hides or small skins. A robot like this lets a tanner repeat the same finish exactly from one batch to the next. The shoe manufacturing post picks up the story once that leather reaches the cutting table.

Freshly tanned hides stacked on a wall in Marrakech, 2005. Photo: Donar Reiskoffer / Wikimedia Commons (CC BY 3.0)

I have not found a tannery that names ABB as its robot supplier, so what follows is a possibility. ABB's IRB 5500 paint robot is designed for the explosive air of a spray booth and could carry a spray gun over hides on a conveyor. A larger arm such as the IRB 6700 could lift stacks of wet blue or move hides between a drum, a sammying machine and a shaving machine. Programs for spray paths are usually built offline in RobotStudio, which matters here because a tanner cannot stop a finishing line every time the leather article changes.

An ABB IRB 5500 paint robot, a design built to work in explosive paint booth air. Photo: ABB

Where tannery automation goes from here

The next problem is the hide itself. Every one is a different size and shape, with scars, thin spots and brands. Vision systems that scan a hide and plan a spray path for that exact outline are what make a robot useful on mixed batches. The same scan could grade the hide and send the best areas to car seats and the rest to smaller goods. Some of this already exists on cutting tables; joining it to the drum room and the finishing line is the harder part.

An ABB IRB 6700 lifts a solar module for a folding roof at dhp technology, a flat load much like a stack of hides. Photo: ABB

Conditions in the wet end are hard on any machine. Drum rooms are full of water, salts, chrome and fat liquors, and hides come out heavy and slippery. That is why handling there is still mostly done by people, and why rooftops in places like Dharavi in Mumbai are still covered with drying hides. Home buyers will not see a tanning robot, but they may notice the result in more even color across a sofa or a car seat, and in finishing that uses less spray and less solvent.

Hides laid out to dry on a factory rooftop in Dharavi, Mumbai, 2006. Photo: Everhard van Eimeren / Wikimedia Commons (CC BY-SA 4.0)

Cost is the biggest barrier. Many tanneries are small family firms, and the La Conceria piece notes that technology is welcome where wages are high and less needed where they are low. Safety is another: robots near open drums and slippery floors need guarding or collaborative arms such as ABB's GoFa and PoWa cobots, which stop when they sense contact with a person. Then there are skills. Someone in the tannery has to learn to program and maintain the cell, and the older tanners who know how a hide should look have to pass that judgment on before they retire.

An engineer hand guiding an ABB PoWa cobot. Photo: ABB

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