ReLast: recycled stretch denim for maximum comfort

Our Re Family features three innovative fabrics aimed at advancing sustainability in the denim industry: ReGen, ReLast, and ReSolve. Of particular note is ReLast, the world’s first recycled stretch denim, which not only offers enhanced elasticity but also sets a new standard for eco-conscious fashion.

What’s going on in the synthetic fiber market?

According to the Materials Market Report of Textile Exchange, polyester is the most common fiber worldwide. In 2022, its production volumes grew to 63 million tonnes compared to 61 million tonnes in 2021, making up a market share of about 54% of global fiber production.

Polyamide (nylon) represented around 5% of the global fiber market, with 6.2 million tonnes manufactured in 2022. Other synthetic fibers such as polypropylene, acrylics, and elastane had a combined production volume of 6 million tonnes and a market share of around 5% of the global fiber production in 2022.

What is elastane?

Elastane is a lightweight synthetic fiber that provides clothing with elastic properties. It is commonly used in various types of apparel that require a form-fitting and flexible design, ranging from swimwear to jeans.

Elastane is derived from petroleum and is made from a polymer known as polyurethane, which is a nonrenewable resource. While obtaining the raw materials for elastane is generally not harmful to the environment, as they are typically produced in a laboratory setting, the manufacturing process requires significant amounts of energy and involves various chemicals.

One of the major environmental concerns associated with elastane is its non-biodegradability. Although stretch fabrics usually contain a low percentage of elastane—typically between 1% and 5%—they can persist in the environment for centuries due to their inability to break down naturally. Additionally, textiles made with elastane are often challenging to recycle, which means they frequently end up in landfills at the end of their lifespan, leading to an accumulation over time.

Furthermore, petroleum-based fibers contribute to pollution not only when discarded but also through wear and tear and washing. According to 2020 data from the United Nations Environment Programme (UNEP), approximately 9% of the microplastics released into oceans annually come from microfibers shed by synthetic textiles. UNEP also reports that around 60% of all clothing contains synthetic materials.

Stretch denim revolution

Elastane was invented in the late 1950s, but it wasn’t introduced to the denim industry until two decades later. Fashion designer Peter Golding launched his first pair of stretch jeans in London in 1978.

The introduction of stretch denim fabrics revolutionized the industry. The benefits of stretch denim extend beyond just comfort; they also provide increased freedom of movement and a softer hand feel compared to the stiffness often felt when wearing traditional 100% cotton jeans.

This new type of fabric allowed brands to create more feminine and form-fitting designs, enhancing the body’s shape and winning the hearts of millions of women worldwide. Additionally, stretch denim retains its shape over time, quickly recovering to its original form after use or washing. Today, stretch denim accounts for approximately 80% of the global denim market.

Candiani was one of the first denim producers to fully embrace the potential of stretch denim. Our mill gained international acclaim in the 1980s for blending the new elastic properties with authentic denim aesthetics, creating the fabrics that became the foundation of the burgeoning premium denim industry in Los Angeles. Adriano Goldschmied, the father of premium denim, stated that these new premium denim brands transformed jeans from a mere commodity into symbols of luxury and style.

How ReLast works

Given the environmental challenges associated with elastane, we have been actively seeking solutions to minimize the negative impact of stretch denim. ReLast is the second component of our broader Re Family, which began in 2018 with ReGen. ReGen is made from recycled materials sourced from post-industrial cotton waste and TENCEL™ x REFIBRA™, a blend of leftover materials such as cotton and wood. In recognition of its innovation, ReGen received the ITMA Sustainable Innovation Award in 2019.

The ReLast collection features stretch denim fabrics that include an exclusive GRS-certified pre-consumer recycled elastomer derived from leftovers of the elastane manufacturing process. GRS stands for Global Recycled Standard, which ensures that products contain at least 20% recycled content. It also verifies traceability, as well as social and environmental management practices, and imposes chemical restrictions throughout the entire supply chain. This material provides advanced stretch performance and a snug fit that retains its shape over time while contributing to waste reduction.

ReLast fabrics come in varying levels of elasticity, depending on the percentage of elastic yarns used, ranging from comfort stretch to super stretch. Additionally, they are treated with our patented Kitotex® technology, which replaces PVA—a substance that can release microplastics into the environment when not disposed of properly—with chitosan.

Chitosan is obtained from chitin, which is available from numerous renewable sources. We specifically use fungal chitosan from Aspergillus niger. Chitosan has several benefits:

• It is biodegradable and non-toxic, showcasing binding and film-forming qualities
• It helps remove pollutants and heavy metals from wastewater
• It breaks down organic matter, thus reducing the amount of sludge needing extraction from sewage systems
• It acts as a coagulant, aiding in the flocculation of suspended particles, which makes their removal easier
• It possesses bacteriostatic properties, inhibiting the growth and reproduction of bacteria by disrupting their cell membranes

Our Kitotex® technology functions at a temperature that is 40% lower than traditional agents, helping to reduce CO2 emissions and mitigate climate change impacts. Furthermore, it enhances color saturation, improving the overall aesthetics of the denim.

ReLast was succeeded by ReSolve in 2020, a collection of stretch denim fabrics that features a custom-made elastane. This elastane has no negative impact on the environment, as it can break down over time without releasing any harmful substances.

Pre-consumer waste

The expansion of the fashion industry has led to an increasing amount of post-industrial and pre-consumer waste. This type of waste consists of materials and items that never reach the final consumer and is typically either incinerated or sent to landfills.

A research project conducted by OCAD University in Ontario, Canada, reports that, on average, 35% of all materials within the supply chain end up as post-industrial or pre-consumer waste. Furthermore, 47% of all fibers entering the fashion value chain are wasted at various stages of production, from fiber and yarn to fabric and garments.

Sources of post-industrial and pre-consumer waste include (but are not limited to):

• The fibers that are inevitably lost during the textile manufacturing process
• Over-orders by manufacturers, who, according to EU data, tend to order 3-10% more materials than they actually need
• Inconsistencies in fabrics, which can occur at different stages of the production process
• Textile scraps generated from the cutting process, which can account for 8-15% of the total fabric, according to EU data
• Semi-processed or finished garments with damages such as holes or stains

Recycling pre-consumer waste

Recycling post-industrial and pre-consumer waste is a well-established practice in the textile industry. One reason is that recycling items made from a single material is easier than recycling blends. Additionally, manufacturers have long recognized the importance of reusing valuable materials to improve efficiency and reduce costs. Finally, since post-industrial and pre-consumer waste is typically in good condition and has not been subjected to wear and tear, it is strong enough for manufacturers to produce products that are entirely made from recycled materials.

The main environmental benefits of recycling post-industrial and pre-consumer waste include diverting discarded materials from landfills and incinerators, conserving natural raw materials, and reducing the amount of water and energy required in the manufacturing process compared to sourcing new resources. Furthermore, establishing recycling programs can also create new job opportunities.