Ground-breaking research into recycling options for multi-layer packaging

Strength test of housing planksThe partners of the innovative ‘Virtuous Circle’ project recently announced the results of ground-breaking research into new recycling options for multilayer food packaging. The findings shed new light on the potential of this type of packaging to be ‘upcycled’ for use in products of value in a circular economy.

Multi-material multilayer films are an innovative type of packaging used to preserve food and to protect it from contamination or from oxygen that would lead to faster degradation of food. Multi-layer packaging, while highly effective, has been criticised for being challenging to recycle due to the challenges of separating the different layers and sorting them by type. In addition, the general preconception is that even if these materials can be technically recycled, the resulting raw material is of such poor quality that it effectively amounts to ‘downcycling.

One of the core aims of the ‘Virtuous Circle’ project, launched in South Africa in October 2016, has been to challenge these assumptions. Project partners DuPont and Rural Waste Poverty Alleviation Solutions (RWPA) have worked together on testing innovative methods of creating new products of genuine value from multilayer film packaging after it has served its original purpose.

 ‘While multi-layers play an essential role in preserving food, waste from this type of packaging has been growing steadily, so a solution had to be found,’ says Dr Andrew Venter, CEO of Wildlands.

The main focus of the Virtuous Circle project is the distribution of nutritious Futurelife Smart food in Amcor manufactured multilayer film pouches to school children in South Africa. Additionally, there is the subsequent recycling of these pouches into school desks. Each Wildlands Green Desk not only ensures that 40kgs of waste is diverted from landfill, but also contribute to address a current shortage of an estimated three million schools desks in South Africa.

The desks have been made possible because of an innovative process developed by project partners Wildlands and RWPA Solutions. This results in desks that are stiffer and stronger using recyclate multilayer waste compared with virgin low-density polyethylene resin. A unique characteristic of RWPA’s methodology is that no water is required to clean the multilayer film before it is recycled.

The desks containing recycled waste from the multilayer pouches are now being delivered to schools involved in the project.  In this way, the school children, who have already enjoyed the nutritious food kept fresh by the pouches, are getting to see first-hand the benefits of a circular economy approach.

Research undertaken in parallel as part of the project has also demonstrated that there are other potential uses for higher volumes of multilayer comingled film waste – ones that can add value in larger market segments in an economically efficient way.

Until now, it has been necessary to add recycled high-density polyethylene (HDPE) to recycled multilayer waste to achieve stiffness and strength in end-products. Research carried out by DuPont and RWPA Solutions, indicates a new way to recycle multilayers and contribute to high quality products without the use of HDPE has been successfully tested.

By mixing compatibilisers and coupling agents with the raw material converted from the comingled multilayer film waste, and combining it with sawdust, it is possible to manufacture building planks for the construction of low cost housing that comfortably conform to strength standards under South African building codes.

Karlheinz Hausmann from DuPont Performance Materials says: ‘The key element is the use of compatibilisers and coupling agents. It is now possible to develop an end product using multilayer waste that is 16% stronger than before and meets a genuine need in an important market. Rather than being recovered for energy or simply sent to landfill, the compatibilisers transform the waste into a valuable and cost effective raw material.’

Commenting on the significance of the findings for housing markets in developing countries Iqbal Hirji, Founder of RWPA Solutions explains: ‘Houses built with materials containing recycled comingled film waste bring significant improvement in both comfort and safety for many developing countries’ inhabitants. These houses can last more than 10 years if properly maintained. It can help respond to housing shortages in many areas. Not only can they be rented like normal houses, making it economically sustainable, however, at the end of life the planks can be reground and remoulded into new planks again.This adds to the environmental sustainability of the model and provides a true Circular Economy solution.’