Used for centuries for their insulating properties, oyster shells are now being reused to create a unique eco-friendly fabric in the western oyster industry of Taiwan.
Entrepreneur Eddie Wang remembers the shells of the bivalve mollusk that littered the streets of his hometown in western Yunlin County and which residents used to insulate their homes.
“They burned the shells and applied the residue to the walls. The houses then became warm in the winter and cool in the summer,” the 42-year-old Taiwanese told AFP at his factory in Tainan, in the southwest of the island.
“So I was curious as to why oyster shells had such a miraculous effect.”
His company Creative Tech Textile, founded in 2010, produced an “eco-friendly fabric” – polyester made from recycled plastic bottles – but Mr Wang found it “ordinary”.
He collaborated with a research institute to experiment with making fabric from oyster shell residue, a childhood memory he had in mind. The research culminated in 2017 with the discovery of a process for making a material similar to wool.
Today, its Taiwanese factory uses some 100 tons per year of these protective envelopes to produce about 900 tons of ” seawool » (in French, “sea wool”), a patented and trademarked fabric.
The fabric and the clothing made from it generates some 220 million New Taiwan dollars (6.2 million euros) a year, most of which is bought by sustainable and outdoor clothing brands in Europe and the United States.
Manufacturing this wool in Taiwan would not be possible without the self-governing island’s unique oyster farming, Wang said.
“A magic wool”
“You don’t find this industrial chain anywhere else in the world,” assures the entrepreneur.
“We have people to harvest the oysters, we have specialists to clean the oyster shells and we have people to dry and calcine [traiter] the shells,” he observes.
The island of Taiwan has a strong appetite for the mollusk, harvesting some 200,000 tonnes each year and enjoying it locally, including crispy oyster omelettes and noodle dishes.
Its popularity also means that around 160,000 tonnes of the bivalve’s shells are thrown away annually, according to the Ministry of Agriculture.
They pile up in the streets of oyster-farming towns, mainly in Yunlin, Changhua and Chiayi counties in western Taiwan, and give off a fishy smell to the surrounding area, providing breeding grounds for mosquitoes.
In Mr. Wang’s factory, the shells are reduced to tiny beads, then mixed with yarn made from recycled plastic bottles.
“It creates a magical wool,” he explains. “Oyster shell is a material with low thermal conductivity — it neither absorbs nor dissipates heat.”
Half an hour from the store where the entrepreneur displays his sports jackets and tracksuits, the state-owned Taiwan Sugar Corporation (TSC) also has a factory that grinds shells into powder, which is used to make household products such as incense sticks.
The ground limestone husks help reduce the smoke and toxicity associated with burning incense, said Chen Wei-jen, deputy head of TSC’s biotechnology division.
“We hope that oyster shells can have industrial applications, and that interested companies can use them as raw materials to make their products more eco-friendly” and add value to them, Chen Wei-jen said.
“Turned into gold”
In order to be consumed and then have their shells used by the industry, the bivalves from the oyster county of Chiayi are first collected at dawn in traps installed along the coast.
There they are sorted before being sent to factories like the one owned by entrepreneur Dai Sen-tai. Machines clean them. They are then sent to small family businesses that shuck them and then send the empty shells further south.
Mr Dai is the third generation of oyster farmers in his family and says he is happy that Taiwan is bringing this marine waste back to life.
“When I was a kid, nobody wanted oyster shells. They were thrown away and abandoned everywhere,” he told AFP.
“It’s a good thing that this waste is now being turned into gold.”