The world's first commercial polyester material to offer pH control is to be launched by Teijin Fibers Ltd. The company has developed a new polyester fabric that remains gentle to human skin by stably maintaining its mildly acidic pH level, similar to healthy skin. The fabric is expected to meet growing consumer demands for clothing with value-added properties such as gentleness to skin, odor prevention, and antibacterial and stain resistance.
The fabric's mild acidity was achieved by modifying polyester polymer, rather than adhering agents to fibers, to enable it to maintain its pH level stably after repeated wash and wear, while also maintaining polyester's superior characteristics such as water-absorption and quick-drying properties. Presently, fabrics that possess such properties use agents that are adhered to their fibers through post-processing treatment, which can lead to low functionality, limited durability and a loss of original texture over time. Fabrics offering pH control have been limited to water-absorbing (hydrophilic) fibers, such as cotton and rayon, neither of which sufficiently promotes the rapid drying of large amounts of perspiration, a basic requirement of high-performance sportswear.
How the New Fabric Maintains its pH: The skin of a healthy person generally is mildly acidic, but can become more alkaline due to sweating (summer) or drying (winter). The continuance of either condition for very long can result in odors and stains due to destructive bacteria which in turn can lead to increased susceptibility to the damaging effects of the sun's ultraviolet rays. Teijin Fibers modified polyester polymer, which is intrinsically hydrophobic (neutral), to create localized hydrophilic properties and mild acidity on the fiber's surface. As a result, the new fabric maintains its mildly acidic pH level even when the wearer is perspiring
How the New Fabric Promotes Cleanliness:
Antibacterial - The growth of bacteria such as Staphylococcus aureus and Corynebacterium, which cause odors and dry, rough skin, can be selectively controlled by the fabric's mildly acidic state. This promotes the growth of beneficial bacteria such as Staphylococcus epidermidis, which helps to protect and maintain healthy skin
Deodorization - Alkaline components from sweat, such as ammonia, are quickly absorbed and neutralized by the fabric's mild acidity, which helps to prevent clothing from developing odors.
Sebum stain resistance - The fabric's hydrophilic surface enables washing to remove stains caused by sebum, an oily secretion on the skin, which minimizes the spread of bacteria and helps to maintain the clothing's cleanliness.
UV protection - The fabric's mild acidity helps to protect skin from ultraviolet rays by promoting the presence of beneficial bacteria.
The new fabric will be ready to sell in time for spring and summer 2012 sportswear. It also will be marketed for general apparel and other applications.
About 39 mln tons of polyethylene terephtalate (PET) fibers are produced for the textiles industry annually. PET fibers are used in a variety of products, but in their pristine state the fibers are not easy to work with. Conventionally, PET fiber for textile is treated with large volumes of water containing specific chemicals to increase affinity of the fiber for water, so that it can be more easily colored. The purchase and disposal of these chemical solutions for treatment is costly, and in addition, the process consumes a lot of energy because the fibers have to be dried again afterwards. A more environmentally friendly process to treat textile fibers that are used in garments, carpets, curtains, and other applications has recently been reported by researchers from the University of Torino (Italy). Treating polymeric fibers with a low-temperature partially ionized gas increases the ability of the fibers to attract water, which is necessary to make them easier to process. According to the researchers, the proposed treatment with plasma, instead of the aqueous solutions, roughens the surface of the fibers and generates polar groups and radicals onto the surface. The experiments confirm that the plasma treatment has a comparable effect to the chemical treatment: the affinity for water is increased, which makes the processing of the fibers easier. After treatment, a water droplet on the fiber surface is spread out more, because it is easier for the surface and water molecules to interact. Atmospheric-pressure glow-discharge plasma is a green and alternative method to render PET fibers hydrophilic without using wet treatments. Moreover, the possibility of working in continuous (by using a roll-to-roll system), is a very important feature for the industrialization of this process.