How can the latest design and technology help to create wear without waste? And what can we all do to reduce the impact of throwaway fashion?

Little black dress

  • Photo of dyes run out of an Indian dye house.

    Dyes run out of an Indian dye house.

    Dye me a river

    Textiles dyeing currently accounts for a whopping 17-20 percent of worldwide industrial water pollution. Large tubs of dyed water end up in our rivers and streams. And because it’s expensive to clean and reuse coloured water developing countries without strict pollution controls tend to just dump it.

    The new dyeing technology that’s poured into this little black dress doesn’t use water at all. If the process is seductive to polyester producers it will reduce water pollution. It could make a massive impact since these synthetic fabrics make up almost half of all textiles we buy.

    Photo of DyeCat founder Richard Blackburn.

    DyeCat founder Richard Blackburn.

    Colour Conundrum

    How does the new technology work?

    ‘The trick lies in colouring the polyester as it is made,’ explains Richard Blackburn, an expert in colouration technology at the University of Leeds.

    ‘My team realised that because polyester is a man-made plastic we could build in colour as the plastic is made, rather than to produce the raw material, make the fibre and then have to dye it. This cuts out the polluting dyeing step altogether. We’ve created the company DyeCat to market our idea.’

    Microscope image of filaments coloured conventionally and with DyeCat's method.

    The DyeCat filament (left) is coloured equally throughout, whereas conventional dyeing (right) is patchy.

    In the mix

    To produce plastics you grow a chain of molecules in a ‘polymerisation’ reaction. To help the molecules link together and speed up the reaction, you add chemicals called catalysts.

    Richards’s company DyeCat invented a range of catalysts each with a colour-giving molecule called a chromophore attached. The coloured catalyst bonds to the ends of the plastic chain that becomes part of the material.

    ‘The colours are superior to those of standard dyeing. We can create darker shades and they’re all completely colour fast– you can’t wash them out!’ Richard enthuses.

    Filaments ready to be made into yarn.

    Filaments ready to be made into yarn.

    A chilling spin

    Once the raw coloured plastic is made the next step is to make it into fine filaments.

    ‘This process is called ‘melt spinning’, explains Richard. ‘It involves dripping the melted plastic in thin strands over a spinning wheel which is cooled by water or liquid nitrogen. We then ‘drawn’ or twist filaments into smooth neat yarns, ready to be woven into textiles.’

    Image of corn.

    PLA fibres are made from extracted corn starch and sugar.

    A brighter future

    Richard can also use DyeCat’s colour technology to dye new sustainable alternatives to oil-based polyesters. Promising materials, such as the corn-sugar-based polylactic acid (PLA) in this little black dress damage easily in harsh dyeing conditions. This new technique doesn’t damage.

    Richard has high hopes for the technology.

    ‘We want to encourage as many textile manufactures as possible to start to use our new technology. Our innovation will help PLA replace traditional polyesters to increase sustainability on two fronts – in a cleaner colouring process and biodegradable materials.’