Solution dye for polyester

Information

Impacts:

Sustainability Energy Carbon Water

Sector:

Manufacture of textiles, clothes and leather

Cost savings:

Up to 11 % of the total carbon footprint of a 100 % polyester ladies top is due to the yarn dyeing stage

Investment cost:

There is no specific investment cost.

Payback time:

No investment is required so this represents an instant benefit

Resource savings: Energy:

Significant energy and water savings as well as reduced carbon emissions and wastewater production (see Table 7 on p30 of the WRAP Valuing Our Clothes report included in the source list below for further information on savings)

Experts estimate that up to 11 % of the 'cradle-to-factory gate' carbon footprint of a 100 % polyester ladies top, for example, is due to the yarn dyeing stage. Coloured polyester fibres may be more expensive than standard uncoloured ones since they include the cost of dye pigments added before the extrusion process. However, by eliminating this wet dyeing process, money is saved on water and chemicals, and energy savings are also achieved.

Solution dye (otherwise known as dope dye or spin dye) is a one-step process in which dyes – in the form of colour chips – are added to the liquid chemical solution before it is extruded into long fibres. The colour is locked into the solution and the fibre has superior colour consistency compared to other dyeing methods. It is a known commercial technology that can be found across the synthetic textiles supply chain and eliminates the need for a wet dyeing process at the yarn stage.

Solution-dyed fibres are some of the most colourfast in the industry. As the colour goes all the way through the fibre, it is nearly impossible to fade or bleach the colour from the fabric. The textiles industry is showing renewed interest in solution dyeing of synthetic fibres because of its environmental impacts and resource savings. Significant energy and wastewater savings are achieved (in some cases no wastewater is produced) as well as a reduction in carbon emissions.

It is possible to use a wide range of colours, but high colour volumes have traditionally been difficult due to the required fibre extrusion minimums. Solutions include working from stock colours in yarn dyed applications, and collaborating across businesses to form alliances on core key basic colours to drive the industry forward.

Benefits

Colour is distributed through and locked into the fibre resulting in superior colourfastness to chemicals, washing, water and light
A wide range of colours is available
Colour reproducibility and uniformity
Water and chemical savings are achieved
Energy savings
Reduced C02 emissions