Shoe Recycling: A Sustainable Future for End-of-Life Footwear

Shoe Recycling

Introduction

Fashion’s constant evolution and high demand for new shoes result in over 20 billion produced annually, contributing to environmental issues. The global footwear industry, expected to exceed $95 billion by 2025, accounts for 1.4% of manufacturing-related greenhouse gas emissions. Non-biodegradable materials make shoe decomposition challenging, taking up to 1,000 years, and landfill disposal releases toxic chemicals.

The need for sustainable shoe recycling to address End-Of-Life (EOL) shoe waste has become more apparent than ever.

Sustainability Options

To promote sustainability with discarded shoes, individuals can donate gently used pairs to charities or sell them online. For shoes beyond wear, collection points like shoe banks recycle or repurpose materials. Although EOL shoe recycling options in Australia are limited, ongoing efforts are focused on developing more efficient methods to address environmental concerns and foster sustainability. One such initiative is “TreadLightly” – a national recycling program in Australia that repurposes unwanted sport and active lifestyle footwear, fostering collaboration among various stakeholders in the sporting community to minimize environmental impact. Find out more.

Challenges

While the concept of recycling EOL shoes is appealing, it presents significant challenges. The complex construction of shoes, with multiple materials bonded together, makes the recycling process difficult. Shoes often contain dozens of materials, including metals, which hinder effective shredding and recycling. As a result, shoe recycling is not a common practice in Australia, and only a small percentage of shoes are recycled.

The Role of Shredding Technology in EOL Shoe Recycling

The use of shredding technology offers numerous benefits for shoe recycling. It allows for the efficient disassembly of EOL shoes, breaking them down into individual parts. This makes it easier to recycle each component, resulting in less waste and higher recycling rates. Shredding also simplifies the extraction of valuable materials, such as rubber, which can be repurposed to produce new products.

Shredding process:

Similar to other recycling systems like tyre and C&D, the shredding process can be outlined as follows;

  1. Sorting: Categorising shoes before batch processing enhances material yield and purity. High-foam-content shoes are recycled separately from leather-based ones.
  2. Pre-Shredding: Shoes are pre-shredded to expose embedded metal parts, ideally creating 20-30 mm chips.
  3. Metal Removal: Specialist equipment, including magnetic separators, removes metal components. Manual removal is an option but may be cost-prohibitive.
  4. Granulation: Further fragmentation into 3–6 mm crumb optimises yield and purity through a granulator after metal removal.
  5. Material Separation: Air separation technologies utilise particle size and weight differences for efficient separation of fines and rubber.

The Benefits of Shredding Technology

Shredding technology offers several benefits for EOL shoe recycling:

  1. Efficient Material Separation: Enables precise separation of shoe materials, boosting resource recovery and minimising waste.
  2. Increased Recycling Rates: Break down shoes into smaller pieces, streamlining the recycling process, elevating recycling rates, and promoting sustainable waste management.
  3. Resource Conservation: Shredding reduces the demand for new materials in shoe production, supporting a circular economy and natural resource conservation.
  4. Environmental Gains: Diverts EOL shoes from landfills and incineration, curbing carbon emissions and pollution associated with disposal.
  5. Economic Opportunities: The technology opens doors for new industries and job creation, contributing to economic growth in EOL shoe recycling.

Diversification

Existing recycling facilities that use shredding technology, such as tyre recycling centres, have the potential to diversify their feedstock by including EOL shoes or deconstructed shoe soles in their rubber output, potentially combining the crumb for the manufacture of recycled products, such as rubber matting.

Recycled material applications

Advanced recycling processes are revolutionising the disposal of End-of-Life (EOL) shoes, extracting leather, rubber, foam, and textiles for various sustainable applications. Leather is repurposed into sheets or insulation, reclaimed rubber for eco-friendly surfacing, recycled foams find use in flooring and soundproofing, and mixed textiles contribute to construction and insulation. Despite the perception of down-cycling, these applications offer environmental and economic benefits over traditional landfill disposal.

Manufacturers, recognising the urgency to divert shoe waste from landfills, are in the race to design sneakers that can be recycled back into sneakers easily in a sustainable, cost and energy-efficient way. This strategic shift will propel the industry towards a circular economy.

Conclusion

In conclusion, the pressing issue of over 20 billion shoes being produced annually demands attention to end-of-life (EOL) waste. Shredding technology is a key solution, enabling efficient recycling and resource conservation. Diversifying existing facilities to include EOL shoes offers economic potential. At the same time, the applications of recycled materials present sustainable alternatives, emphasising the importance of embracing innovative recycling for a greener footwear industry.

Sources

Jennifer Okafor, BSc Sept,2023.

Michael James Lee, Shahin Rahimifard.

Lucianne Tonti. Jan, 2023.

Buy Recycled

Tread Lightly