Finishing is a series of processing operations applied to a textile material that improves its appearance, performance, ‘hand’ (feel) and/or functional properties. Finishing processes are usually applied directly to fabrics after, or in combination with, dyeing. Technologies available for mechanical and chemical finishing of fabrics are extensive, with new finishing opportunities constantly being developed.
Wet processing techniques in this stage of the product life cycle consume a lot of energy and water. The heat setting in chemical and mechanical finishing has a significant effect on a garment’s carbon footprint. Large quantities of complex chemicals, many of which are potentially hazardous, are often used and must meet EU REACH and international ZDHC guidelines. Companies operating in this sector are facing significant challenges, many associated with the acquisition and disposal of these materials. Improving resource efficiency therefore brings environmental and financial benefits, and improves corporate reputation in increasingly competitive markets.
As factories can have very different set-ups, machinery, and processes, the best practices vary considerably and cannot be presented in full here. There are many opportunities to reduce environmental impacts as well as reduce costs and improve productivity. The following recommendations provide guidance which can be implemented in any size and type of finishing facility.
- Select quality chemicals: it is a false economy to save small amounts of money on chemicals procurement that can then lead to huge reprocessing and disposal costs.
- Accurately measure: weigh and measure all chemicals accurately, and monitor closely water consumption and wastewater treatment. Careful consideration of chemical management in the finishing processes is essential and should form part of a Quality Management System.
- Analyse process performance: improve quality and reduce unnecessary steps and excessive use of chemicals, add a controller unit to help monitor processes and operations.
- Seek expert advice: request process reviews from chemical suppliers and get technical support and information about the latest finishes and technologies. Recognised manufacturers can supply information on their new developments.
- Service machinery: Good preventative maintenance programmes check and calibrate key parts, such as electrical drives and pumps, and review machine safety, quality standards and productivity.
A. Hasanbeigi & L. Price’s review of emerging technologies for energy and water efficiency and pollution reduction in the textile industry describes 18 emerging technologies. The information presented for each technology was collected from various sources, including manufacturers. It is likely that no single technology will be the best or only solution but instead that a portfolio of technologies should be developed and deployed to address the increasing energy and water use and emissions of the textile industry.
Some of these technologies described in the technical review can offer bigger savings than others and should be carefully evaluated against costs and final product requirements. For instance, water and chemical-intensive wet fabric finishing can be eliminated with the use of ozone processing. Ozone treatment is a resource-friendly alternative to water and chemical fabric post-treatments. Primarily used in the denim industry, it is also used on knits and non-denim wovens in both yarn dyes and solids, to give a fabric an aged appearance. This innovation, however, requires specific equipment and investment.
To better understand the quantitative impact of finishing processes, view MADE-BY’s publicly available Wet Processing Benchmark. The Benchmark helps to understand the range of water and energy impacts of the most common wet processing techniques. It can also be used as a tool to help better understand their efficiency compared to industry averages.