PVOH is a thermoplastic polymer that is usually recovered as a white or yellow powder by hydrolysis of polyvinyl acetate. It is used in large quantities as a sizing agent in the paper industry, for coating yarn in the textile industry, and for adhesive manufacture. Presently only small quantities are processed into films. These films can, for example, be used as water-soluble packaging for gel-like products such as soaps and cleaning agents. This application is, however, limited to concentrated products having a very low water content, otherwise the films would dissolve.
The aim of this project is to develop water-soluble films that are suitable for packaging products having high water contents such as aqueous solutions. On contact with water at defined temperatures, the films must completely dissolve in a reasonable time. Furthermore, the films must be biodegradable and possess the thermoplastic and sealing properties necessary for being processed into bags. The mechanical properties of the films must also be suitable for the intended applications.
Potential uses include packaging for individual portions of cleaning agents, so allowing easier and more efficient dosing of the products, and also for individual portions of windscreen cleaner for cars. However, water-soluble packaging has a host of other prospective applications. The two project partners, the Fraunhofer IVV and SOKUFOL-Folien GmbH, are working together to develop these films and are pursuing various strategies including the use of co-extrusion methods, wet chemical coatings, and nanoscale surface functionalization.