Silkworm Farming: Robot Silk Factories and ABB

It takes more than 100 kg of mulberry leaves to produce 1 kg of raw silk, and about 70 percent of the world's silk comes from China. For thousands of years silkworm farming meant picking those leaves and spreading them over trays by hand. Now factories in Zhejiang and Hunan raise silkworms year-round on artificial feed, with robot arms moving the trays. This post covers how sericulture worked before machines, the science and mills that changed it, today's silkworm factories and smart rearing rooms, where ABB robots could fit, and the open problems.

Feeding silkworms with mulberry leaves on round trays in Suzhou, Jiangsu, 1987. Photo: Lorenz King, Matti&Keti / Wikimedia Commons (CC BY-SA 4.0)

How silkworms were raised by hand

Sericulture has existed for at least 5,000 years in China; a ceramic silkworm found in Nancun, Hebei, in 1977 is 5,400 to 5,500 years old. The larvae eat only mulberry leaves through five instars, and after the fourth moult they climb a twig and spin their cocoons. In Japan the work happened on trays in farmhouses: a photo published in 1911 shows girls spreading fresh mulberry leaves over one of 16 bamboo trays taken down from its rack. In 1803 Uegaki Morikuni published Yōsan Hiroku, a rearing manual that Philipp Franz von Siebold took to Europe, where it appeared in 1848.

Japanese girls spread fresh mulberry leaves over a bamboo tray of silkworms, from a book published in 1911. Photo: unknown photographer via Wikimedia Commons (public domain)

Science reached the rearing room in the 19th century. In 1840 Nakamura Zen'emon adapted the thermometer for silkworm rooms, which helped farmers replace guesswork with temperature control. Disease forced the next change: pébrine cut France's cocoon output from 26,000 tons in 1853 to 5,500 tons in 1865. Louis Pasteur showed that examining the mother moths stopped the spread, and the rule still holds: eggs from infected moths have to be ruled out by checking the moth's body fluid under a microscope. Around 1900 Japan overtook China as the world's largest exporter of raw silk.

Silkworm rearing in Yatsuo, Toyama Prefecture, Japan, in 1936. Photo: Port and Harbour Association committee, Toyama via Wikimedia Commons (public domain)

Machines came first to the mills. Japan's government opened the Tomioka Silk Mill on 4 November 1872 to bring in machine reeling from France, and its 300 reels made it one of the largest mills in the world at a time when the biggest French and Italian plants had up to 150. Rearing stayed on family farms, and those farms later shrank: Japan had 15,497 large silkworm farms in 1979 and only 349 silkworm farms of any size in 2016. What finally let rearing move indoors was food. Breeders produced silkworms that can eat an artificial diet instead of fresh mulberry leaves, which a Chinese sericulture expert later described as separating the silkworm from the mulberry tree.

Silk-reeling machines inside the reeling plant of the Tomioka Silk Mill, Gunma, Japan, 2018. Photo: Suikotei / Wikimedia Commons (CC BY-SA 4.0)

Silkworm factories with robot arms

In Zhejiang, Mosang High-Tech took the idea to factory scale. In 2012 Jin Yao, now the company's chairman, learned that people were testing artificial feed. The company spent seven years breeding silkworms that would eat its "biscuits" of tofu dregs, corn flour, mulberry powder and vitamins, and it reached mass production in Shengzhou in 2019. In sterile rooms at constant temperature and humidity, robotic arms now place trays of silkworms at different stages, and cocoons pour off conveyor belts around the clock. The factory produces 40,000 tons of cocoons a year, which the company says equals the output of 400,000 farmers.

Silkworm cocoons in a basin at the Suzhou No. 1 Silk Factory, 2012. Photo: Caitriana Nicholson / Wikimedia Commons (CC BY-SA 2.0)

In Hunan, Zhongjian Xinke's factory in Liuyang automates the feeding and handling, the provincial government reported in November 2024. A large robotic arm fixes white plastic rearing frames in place and lays artificial feed on them, devices place the eggs, and conveyors carry the frames into rooms held at constant temperature and humidity. The line has five zones, one for each instar. Robots read QR codes on the floor, pull out frames, feed them like an assembly line and stack them back. Silkworms spin cocoons in 31 days, and 10 to 15 tons of cocoons come off the line each day.

ABB's Flexley Mover P603, an autonomous mobile robot for loads up to 1,500 kg. Photo: ABB

We found no ABB robot in a silkworm factory, though ABB makes robots for the same kinds of moves. Its Flexley Mover P603 is an autonomous mobile robot that carries racks, trolleys, containers and pallets of up to 1,500 kg and finds its way with Visual SLAM to within 5 mm, with no reflectors, which is close to what the QR-code robots in Liuyang do. ABB's Robotic Item Picker uses AI vision to find grasp points on items it has never seen and picks up to 1,400 an hour. Sorting is already being mechanized: in Guangxi, a pupa sorter does in under five minutes what took a skilled worker more than 30.

A suction gripper reaching into a bin of mixed items in ABB's Robotic Item Picker. Photo: ABB

Where silkworm farming is heading

Village rearing is changing too. China News Service reported on 22 September 2026 from Shiquan county in Shaanxi, where a shared rearing room for young silkworms streams temperature and humidity to an internet-of-things screen and more than 1,600 women work in the mulberry gardens and rearing rooms. In India, most farmers buy young silkworms from chawki rearing centres instead of hatching eggs themselves. Factories are finding new outputs as well: Bengaluru's Loopworm, which runs a 6,000-ton-a-year processing plant, turns leftover cocoon material into protein, because 43 of every 50 kg of cocoons used for silk are left over.

Silkworm cocoons, 2024. Photo: Fumikas Sagisavas / Wikimedia Commons (CC0)

ABB robots could possibly take on parts of this work. In a factory like Liuyang's, mobile robots such as the P603 could move rearing racks between rooms, and an arm with vision could grade cocoons. In semi-automated rooms, where people still feed and check silkworms, a GoFa cobot is designed to work alongside people with force and speed limits. Cells like these are usually planned in RobotStudio first. Our post on insect farming covers a related business.

Moving an ABB GoFa cobot arm by hand. Photo: ABB

The open problems are cost, disease and demand. In Anhui's Zhongfan village, a modern workshop would have cost at least 20 million yuan, so the village chose a semi-automated factory that now raises six batches a year instead of three. Disease is still a risk, and in Guangxi breeders now use probiotics against white muscardine disease. Demand can also collapse. In Coimbatore, India, sales of disease-free egg layings fell below 40,000 a month from June, about 200,000 piled up in cold storage, and the price of 100 layings rose from Rs 550 in 2021 to Rs 1,250, DT Next reported in October 2026.

Gathering mulberry leaves to feed silkworms in Japan, photographed for the Cheney Silk Company in 1918. Photo: Cheney Silk Company via Wikimedia Commons (public domain)

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