Suitable for disposable diapers, masks, feminine hygiene products, and other sanitary applications, Toray has created a spunbond nonwoven fabric that is persistently hydrophilic and is gentle on the skin.
Spunbond nonwovens for sanitary applications are normally made of polypropylene (PP), which is softer than polyester (PET). Since PP is hydrophobic, PP spunbond nonwovens must be coated with hydrophilic agents for the application of diapers, masks, and feminine hygiene products. However, the coated hydrophilic agents are easily runoff from the fabrics on contact with water. Consequently, the fabrics lose hydrophilicity.
Toray Industries, Inc., Tokyo/Japan, has been working on this problem through research into hydrophilizing polymer itself rather than surface treatment of the fabrics. The company has been focusing on PET and developed special domain structures by copolymerizing PET with a well-defined molar mass hydrophilic component. The domain structures enable to significantly improve the hydrophilicity of the PET and result in a new spunbond nonwoven fabric that is persistently hydrophilic.
This fabric is as soft as PP nonwovens, which have very good flexibility. Persistent hydrophilicity of the fabric promotes liquid permeation without liquid remaining or spreading out on the surface. In addition, the fabric shows no cytotoxicity, which is an indicator of the skin irritation. The PET can be polymerized using bio-based or recycled materials.