Ironing is a tedious chore, but wearing crumpled clothing is unprofessional. That’s why “wrinkle-resistant” garments have become so popular. But the current methods for making these textiles often release formaldehyde — a chemical that in large amounts is hazardous to human health — into the air and water. Now a team reports in ACS Sustainable Chemistry & Engineering a method for making wrinkle-resistant cotton fabrics that is more environmentally friendly and cost effective.
Manufacturers typically use a chemical process called cross-linking to create textiles that are less likely to wrinkle. But these methods often involve agents that contain a significant amount of the hazardous chemical formaldehyde. This substance can leak from the clothing during the manufacturing, wearing or washing of clothes, and this has raised environmental and health concerns. Other processes have been developed, but they either still include formaldehyde, or they are exorbitantly expensive. Yiqi Yang and colleagues wanted to develop a cross-linking method that could create wrinkle-resistant cotton clothing that overcomes these challenges.
Wrinkle-resistant properties without requiring formaldehyde are obtained by cross-linking citric acid with xylitol. Citric acid is a mediocre anti-wrinkling agent, and it tends to yellow fabrics. But when cross-linked with xylitol, the discoloration is mitigated and the anti-wrinkling effect is improved. This citric acid/xylitol combination is made entirely of renewable raw materials, making it environmentally friendly. The researchers demonstrated a scale-up method that is more cost-effective than other “green” options and is cost-competitive with formaldehyde-based approaches currently used by textile manufacturers.
Clothing and textiles have come a long way since the cotton, rayon and wool of the past. Clothing from work and business attire to casual and athletic gear have taken on physical properties that prevent stains, protect from water, and kill odor and bacteria. Even textiles like bedding and furniture textiles can be treated to increase the safety for consumers in commercial settings like hotels and hospitals. These garments, while still cotton, polyester, and wool, have been treated, often with nano-treatments, to enhance their usefulness and durability without degrading the feel of the fabric.
Many manufacturer and retailers will not advertise that their products use nanotechnology to enhance some physical property, but the treatments do exist and they have been around for decades. Companies like Nano-Tex use nanofabrication techniques to make fabrics that are wrinkle and stain resistant.
A number of companies in the textile industry supply manufacturing technology to treat textiles in various stages of the manufacturing process. DuPont has divisions that are examining incorporating Teflon in textiles to increase durability. Plasmatreat uses a number of different nanoparticle suspensions that can be incorporated into the manufacturing process to enhance colorfastness or add antimicrobial properties. Plasmatreat uses an openair® plasma deposition process where they coat yarns with nanoparticles just after the spinning stage. The treatment is fast and effective, treating yarns with nanoparticles like titanium dioxide at a rate of one kilometer per minute.