Methods for Removing Colour from Polyester and Cotton Blended Textile Waste

Sammanfattning: The textile industry is developing at a fast pace, and is constantly changing. It is constantly evolving new methods for recycling and further research is important for future needs. The ability to recycle a textile blended material is a step towards a more sustainable industry. There are however different difficulties around the various processes that have to be removed for recycling. The purpose of the study is to find methods for removing dyes from polyester and cotton blended textile waste for recycling. To investigate the subject, a literature study combined with interviews with experts was performed. The results of the study shows that it is possible to remove dye from cotton and polyester individually. To remove dye from cotton chlorine and hydrogen peroxide are used. Another method is to use a reducing agent hydrosulphite and after use together with lye. There are several ways to remove colour from polyester, although it will almost always have a residue of colour left. One can either melt the pigment into the fibre by using heat. Another method is to use chemicals which increase the amorphous areas in the fibres and the colour will be penetrated. Finally, when investigating a method for removing dye from a polyester and cotton textile blend. The study has highlighted the need of developing new methods without destroying the quality of the fibres. By this study it has been concluded removing dye from fibres are difficult but can be achieved with certain chemicals and processes. It is concluded in the study, removing dye from polyester and cotton individually can be succeed. However, removing colour from a blended fabric is rather difficult. The study has focus on discussing the difficulties when decolouring a blended textile.