FACTORY TALK: ADVANCE DENIM
Advance Denim’s general manager, Amy Wang, takes stock of the competitive advantages of the company’s latest factory, challenging the “common” misconception that Vietnamese-made denim is in any way “more basic”.
A new route forward
Advance Sico, the Vietnamese counterpart to China’s oldest denim mill, Advance Denim, commenced operations in 2020. As overseer of both sites, Ms Wang, who first joined the manufacturer’s headquarters in Foshan’s Shunde district, in Guangdong, upon completion of her textile engineering studies in 1993, deconstructed Advance’s full denim production process before work even started on Advance Sico, with the clear aim to “make it the most innovative and sustainable denim factory in Vietnam”. Located in the resort town of Nha Trang along the country’s south-central coast, the mill is outfitted with similar “cutting-edge” technologies as those installed at Advance Denim in China, with the added benefit of a site-specific, eco-tech water purification system and its own team of in-house Japanese rope-dyeing technicians.
Nha Trang’s situation also facilitates the more efficient shipping of Advance Sico’s fabrics, Ms Wang explains, as well as speeds up the supplier’s ability to fulfil orders placed by customers now manufacturing nearby or in neighbouring countries, such as Cambodia, due to relatively cheaper production costs and advantageous free trade agreements with Japan, the European Union and other partners. The beauty of the town’s natural environment only underscores the need to act responsibly, to mitigate working in a way that might inconvenience future generations, she adds.
Shared aspirations
In this vein, Advance has been working towards company-wide strategic goals around increasing the proportion of sustainable fibres used throughout its product lines for the past six years. Its target was for 90% of fibres to be derived from “green” sources by 2023. Capacity at Advance Sico is just under 1.4 million metres of denim a month, with room to grow with demand (its sister mill in China can make up to 36.6 million metres annually, nearly three times more). The facility has already installed 160 rapier looms by Picanol, in addition to two rope-dyeing ranges and two new pre-shrinkage finishing machines to support the sanforisation process. Thanks to their close ties, Advance Sico “inherits” the same “innovative spirit and ability” and access to the latest technologies which has served to benefit researchers at its Chinese head offices over the years.
Although neither manufacturing site has reached the threshold of 90% “green” fibres comprising its fabrics, the business is “very close” to doing so and expects to realise this ambition by midway through the year, Ms Wang tells Inside Denim. She shares that, across the board, Advance pays more attention to environmental impact criteria such as carbon emissions, water and energy savings and chemical usage when assessing a fibre’s sustainability. Lenzing’s biodegradable Tencel lyocell, made from wood cellulose, and lower-impact viscose EcoVero are considered two “good” options. Approximately 1,000 tonnes of Tencel were used by Advance’s Shunde denim-making facility in 2018.
Expanding impact
Another such preferred fibre singled out by Ms Wang is Good Earth Cotton, a traceable and “carbon positive” regenerative cotton crop grown in Australia and, more recently, on in-conversion farms in India. Advance Sico announced its partnership with Good Earth Cotton last October and the first fabrics to come from the collaboration will be released during the first half of this year, she confirms. Over time, the Vietnamese mill will gradually increase use of this fibre in its denim fabrics “as conditions permit”. Advance Denim, meanwhile, was the first Chinese denim mill to be certified by GOTS (Global Organic Textile Standard), it says, and 40% of the cotton it used in 2019 was sustainably sourced, according to its website. Advance Sico also works to GOTS’ specifications.
Examples of other eco-friendlier fibres now often requested by “significant” brands, bound by their own sustainability targets, include recycled cotton, hemp, recycled polyester and biodegradable polyesters and nylons, Ms Wang states. Yet, finding partners that share Advance’s enthusiasm for developing greener fibres, and are willing to invest in the appropriate processes, is an ongoing challenge. The company still managed to recently launch a new collection with a higher-than-before proportion of recycled fibre content thanks in large part to what Ms Wang says is an innovatively spun yarn whose “unique construction” limits fibres’ loss of strength and can thus deliver improved durability. Enhanced fabric softness and a greater “vintage” slub texture also result, she says, describing the hand-feel as comparable to that of a traditional denim.
Tools and trade
A sustainability goal that Advance Sico did tick off ahead of the new year, though, is 100% use of speciality chemicals supplier Archroma’s aniline-free, pre-reduced Denisol Pure Indigo 30 for “cleaner and safer” dyeing with “minimal” sodium hydrosulfite. Advance Denim originally adopted this process at Shunde not long after the liquid indigo initially hit the market in 2018. Researchers at the company further optimised the dye application process with the introduction of BioBlue Indigo technology in 2021, which enables the removal of hydrosulfite from production. BioBlue results in effluent with 70% lower chemical oxygen demand (COD) and 55% lower biological oxygen demand (BOD) than would typically be observed following use of the compound as a reducing agent, as validated by a third party. Similarly, the company’s in-house Bigbox is an inert gas system that dyes warp yarns and replaces the eight to 13 boxes conventionally used to dye denim with a single “very big” box. This results in water savings of up to 98% versus rope dyeing.
For the Nha Trang site, the team designed a reverse osmosis water purification system capable of processing up to 3,000 cubic metres of wastewater every day. The “state-of-the-art” circular water technology developed for Advance Sico biologically cleans the wastewater it generates by mixing it with air and bacteria after an initial screening treatment. Next, remaining organic matter is taken out of the water via ozonation, followed by an ultrafiltration process and reverse osmosis purification, which can “remove up to 90% of all COD”, prior to refiltration. Having passed through this system, water was found to be close to 50% cleaner than the national baseline standard for COD, helped by the mill’s relatively low hydrosulfite use, Ms Wang tells us. Clean water then circulates back to the denim finishing area, and the indigo filtered out is also recycled. Advance’s ultimate goal is to recycle 100% of wastewater generated in its plants, to truly close this loop.
Generally, today’s market is perhaps too focused on the eco-friendliness of different fibres, Ms Wang believes. The broader impact of the production process in full is still largely overlooked. “[Some brands and consumers] don’t quite understand or realise its importance,” she explains. With more education, transparency and traceability from farm to shelf, Ms Wang hopes customers will come to appreciate the multiple steps taken to produce sustainable denim, whether in Vietnam, China or elsewhere – and be willing to pay for it.