Novel Applications and Environmental Aspects of Denim

Novel applications and environmental aspects of denim includes different topics. They consist of novel varieties of denim fabrics, non-apparel applications of denim, recovery and recycling of denim waste, effluent treatment in denim and jeans manufacture, and the environmental impacts of denim manufacture.

Novel denim varieties

Apart from the well-known standard denim, several novel varieties of denim fabrics exist, and they are finding extensive application in the fashion industry. Stretch denim, pseudo denim, generic denim and reverse denim are some interesting variants, and from the viewpoint of manufacturers and consumers, stretch denim has a huge potential. Cotton blends of lyocell, wool, silk, polyester, linen, hemp, etc. are also available on a commercial scale. The use of different fibres in combination with cotton has also improved the functionality of the denim material.

The coloration and washing techniques possible now on denim are innumerable, and the functional finishes are adding a different dimension to denim. As sustainability is becoming a major focus globally, use of biodegradable fibres in denim is ever increasing. Some sustainable varieties include denim made of polylactic acid, soybean and bamboo fibres. Other such variants include organic cotton denim and denim dyed with natural dyes without using metallic mordants.

Non-apparel applications

Known well for apparel use, denim is now finding novel applications in other sectors, including furniture, home interiors and automobiles. These alternative applications can increase the market share of denim considerably in industrial sectors where it was never thought to enter. Denim has become an interesting substrate to designers and technologists to create new products satisfying the changing consumer trends as well as the demands on creativity and unique products.

Denim has a significant market potential for being used in several fields. Denim and home textiles are two important and popular sectors of the textile industry, and it is possible to generate a synergistic effect and a different market by combining their aspects. If new denim fabrics are used for non-apparel applications, especially in-home interior textiles, furnishings, curtains, etc., it can create value addition to denim. But the utilisation of used denim garments to produce non-apparel denim articles is an environmentally friendly approach and will be more economical in achieving new market shares.

Recovery and recycling

Denim and jeans waste are creating a municipal dumping problem, and a proper recycling of this waste can result in novel products for other industrial sectors. In general practice, the denim waste is either dumped in municipal landfills or incinerated in solid waste incinerators. Waste denim can be recovered from the denim mill as well as from the jeans manufacturing units. Apart from this virgin material, the used jeans and garments can also be recovered systematically. Denim recycling possibilities are unlimited, and the adoption of an effective strategy will reduce the environmental impact and simultaneously contribute to the competitiveness of the industry, by addressing increasing issues of raw material access.

Denim is usually triturated and converted into nonwoven felts for the insulation in construction and automotive industries, but it is possible to shred the fabrics to get them back into a similar kind of fibre to virgin cotton. There is an increasing attention for this high end recycling of denim, and a number of fashionable products are already available in the market with a high content of recycled denim fibres. Nowadays the possibility of manufacturing denim from other waste materials is also becoming important.

Effluent treatments

Denim warp dyeing as well as the garment dyeing, washing and finishing processes result in huge effluent volumes, and their treatment is essential. The wastewater can be treated by several treatment methods based on biological or physicochemical processes, but it is not easy to decompose this type of wastewater to meet the discharge levels set by standards. However, a comprehensive treatment process that enables the reuse of this wastewater and process chemicals will be the preferable alternative in terms of environmental and economical considerations.

Rather than effluent treatment, effluent reduction at the source by implementing different ecological processes is receiving more attention nowadays. For pollution prevention, minimisation of the use of chemicals, dyes and water, as well as good housekeeping practices, should be considered. Combining different processing stages can also reduce the water and energy consumption, thereby increasing the productivity and decreasing production costs.

Environmental impacts

The overall environmental impact of denim manufacture is significant, especially in areas such as cotton growing, dyeing and washing, and many consumers are not aware of this aspect. In the case of denim, there are some inherent limitations, such as the ever-preferred use of indigo, its low affinity for cotton and poor fastness properties. As with other sectors, Life Cycle Assessment techniques are utilised to assess the impact of denim and to identify the possibilities for improving its environmental profile.

Improvements in each step of denim manufacture will offer significant reductions in the overall environmental impact as well as cost savings for the industry. Among all the processing steps, industrial as well as household laundries seem to offer the highest potential for improvement. Indeed, modern technologies have helped reducing the overall impact to some extent, but there is still a long way to go. Some of these possibilities include the use of organic cotton, reduction of dyes and chemicals, and producing less complex wastewater. Other environmentally friendly alternatives include electrochemical reduction, minimal application technologies and reduced water washing. It is very clear that the consumers will soon look for denim that has been manufactured with the highest environmental standards, maintaining sustainability throughout its life cycle.