"‘Machine Replacement Impossible’ Car Seats Completed by Skilled Craftsmen’s Fingertips"

Report on Duol Ulsan Plant, an Automotive Interior Materials Company
Car Seats, the Most Physically Interactive Part, Over 90% of Work Done by Humans
Daily Production of 1,300-1,400 Units, Monthly Average of 25,000 to 28,000 Units

A view of the seat sewing line at Duol's Ulsan plant, an automotive interior materials company. The task of joining fabric divided into 100 pieces is carried out 100% by skilled workers manually. Photo by Kim Heeyoon

[Ulsan=Asia Economy Reporter Kim Heeyoon] “A product is made up of 100 pieces, but due to the characteristics of leather and fabric, many processes cannot be replaced by machines, so most are made by hand.”

In the automotive industry, which integrates the latest technology, seat manufacturing remains a field where skilled craftsmanship is crucial. On the 14th, the manufacturing line at Duol’s Ulsan plant, a mid-sized company specializing in automotive interior materials, was busy with leather inspection and cutting work. Unlike fabric or synthetic leather of uniform size, natural leather varies in size, so the staff in charge were checking the cutting sizes one by one. Factory manager Lee Yongjin explained, “We focus on quality control to the extent that even tiny scratches or mosquito bite marks on the leather are treated as defects,” adding, “Through more than 10 inspections, we reduce the defect rate to 1%.”

Founded in 1971 as an interior materials company, Duol started supplying seat fabric for Hyundai Motor’s Pony and expanded its business areas to seat covers, airbag cushions, and more, growing into an automotive interior materials manufacturer. Operating production plants in Ganghwa, Asan, Banwol, and Ulsan, despite the impact of COVID-19, the Ulsan plant is busy producing seat covers for Hyundai Motor’s popular models such as the GV80, Palisade, Ioniq 5, and Santa Fe. The factory manager introduced, “We ship 1,300 to 1,400 units daily, producing an average of 25,000 to 28,000 units monthly.”

A machine that cuts fabric according to the pattern. When the workload is heavy, it cuts dozens of sheets at once. All processes are carried out under the supervision of the responsible staff. Photo by Kim Heeyoon

Seat Sewing Requires Delicate Skills, Completed by Skilled Hands

The fabric and leather used in car seats are manufactured differently from ordinary fabrics. To withstand wear from physical contact with drivers or passengers and vibrations during the vehicle’s lifecycle from production to disposal, while providing comfort, padding sponge is laminated inside the fabric. The sewing process assembling the thickened fabric pieces seemed difficult to handle without skilled workers. The sewing line supervisor said, “60% of the entire factory workforce and 100% of the sewing line are female employees with 10 to 20 years of experience,” emphasizing, “Especially inspection and sewing require delicate skills, making automation equipment or smart factory adoption difficult, so this remains a ‘human domain.’”

The adjacent work line was busy with punching and quilting. Thousands of holes are punched into the leather fabric in specific shapes such as diamond or wave patterns. Since stitch spacing and stitch count vary by vehicle model, different needles and sewing machines with varying heights are used to maintain a 1mm spacing. Particularly, the Side Airbag (SAB) process uses special sewing machines and computer programs to recognize the airbag area and adjust sewing methods accordingly. A factory official added that skilled personnel certified by the company handle this process due to its importance in quality.

Exterior view of Dool Ulsan Factory. Photo by Dool

Proactive Development of Eco-Friendly Fabrics, Leading Interior Material Upgrading

As the trend of “vegan interior” has taken hold in line with the eco-friendly image of electric vehicles, Duol leveraged its strengths in fabric to develop eco-friendly materials. They have secured manufacturing technologies for fabrics made from corn-extracted yarn (PLA), bamboo, sugarcane, and hold related patents. Especially, PLA fabric emits almost no harmful substances during combustion or decomposition and offers cost reduction benefits, allowing flexible response to trade regulations. Currently, Duol’s eco-friendly fabric is exclusively supplied to the Ioniq 5, and orders for the Ioniq 6 have also been confirmed. A company representative explained, “Our future goal is to expand supply to follow-up vehicles of our largest client and new customer models.”

Duol recently completed establishing a subsidiary in Mexico and has begun actively expanding into the North American market. Following a 9.6% year-on-year increase in North American sales in Q3 last year, sales in China rose 37.8% year-on-year to 24.3 billion KRW, showing steady growth in overseas sales. The factory manager stated, “As the proportion of electric vehicles increases, we are focusing on upgrading eco-friendly interior materials to match the body structure changes without engines, while aiming to achieve the highest sales ever at the Ulsan plant through main model deliveries since the company’s founding,” adding, “At the company level, we will strive to expand market share through orders by operating 21 local subsidiaries in China, Europe, South America, and other regions.”

This content was produced with the assistance of AI translation services.