Bio and recyclate - not either/or but both/and…

In the emerging circular economy, one critical question remains: how to service a world with materials that have the lowest possible environmental impact?

To that simple question there is no simple answer.

However, complex does not mean complicated – merely that a number of diverse material solutions do need to be considered, coordinated and integrated into a process.

Bio VS R

In the case of the plastics industry, the initial analysis has to focus on all the incoming materials or ingredients that comprise a recipe or application formulation.
Traditionally the process begins with the polymerisation of organic precursors in order to make the primary base resins that are used in plastics processing in order to make finished plastic products.
Such precursors are typically generated from non-renewable resources such as oil and other natural resources such as salt in the case of PVC.

Here we are modifying natural resources with the following impacts:

  • Extraction means non renewability and will lead at some point to exhaustion and depletion.
  • Extraction from oil itself generates a significant carbon footprint

The secondary part of the material lifecycle corresponds to the disposal of the end product. When end products are simply regarded as waste, the traditional options are to either landfill them or incinerate them (through energy recovery)

However, the first option leads to use up and sometimes pollute ground resources. The second option typically leads to the release of carbon into the atmosphere.
But when not regarded as waste, “re-use” and “repair” options for products exist. And then there is recycling: In essence, recycling means re-purposing the finished goods part of the waste stream back into the production of new goods.

The main challenges here concern re-introducing second-life material of sufficient quality back into the primary production stream. 

Firstly, there is a great diversity of materials, all with different degrees of  ability to actually be recycled. Metals are very versatile in this regard but plastics are more challenging.
Indeed, much of the work with post-use plastics feedstock involves the cleaning and the management of impurities and heterogeneity; for example, dealing with a wide mix of polymers, dealing with additives and colorants, labels and non-plastics elements that are in the waste stream.
This question of sorting is vital to the success of any closed loop or clear circularity scheme: an accurate sorting process, for example, is essential to PVC compounds for window frames, where the materials will go back into the same application.
The other mechanical recycling challenge is linked to the end product and its life cycle. Short life cycle products such as packaging or consumer products will generate materials that have not been affected by ageing and these materials will still be aligned in terms of legislation and regulations such as REACH.
Longer life cycle products are more challenging:  If we consider products which have been in service for decades, and with harsh weathering and exposure: this is the scenario we face in many PVC-based applications in building and construction.

Therefore, a variety of polymer recycling strategies are needed: These strategies will be mainly factored around issues such as feedstock homogeneity and availability as they impact the needs of the second-life product.

In all cases we can aim to maximize plastics recycling and the growth of second life materials. Some essential work will include:

Focusing on good quality feedstock polymers in order to create new materials, by developing specific compounding recipes.

Working on the combination between feedstock characteristics and the possibilities in compounding in order to achieve the best performance.
This latter approach illustrates what Benvic is currently doing for PVC: PVC materials are very versatile, and are able to easily be recycled up to 10 times. However, most PVC compounds are dedicated to particular product applications.
This means that if post-use PVC products are incorrectly dismantled and introduced to a specific supply chain, the feedstock quality will then decline.
This therefore obliges recyclers to create specific processes to sort and homogenise all incoming materials to create a quality and reliable secondary raw material.
And this is why Benvic has been developing its own in-house mechanical recycling capacity in order to fully align PVC recyclate into the mainstream of Benvic’s polymer compounding expertise.
It is clear that the complete replacement of virgin material with recyclate is not yet fully possible. Although chemical recycling provides a significant exception, mechanically recycled materials will always represent a downgrade in product properties. Some of these limitations can be anticipated in advance for certain characteristics, such as color or appearance for example.

Some new technologies of recycling are now under development to remove legacy additives, and this can also help can solve part of the paradigm – making more of the waste stream available.
One other strategy means working on upcycling for some second-life polymers, especially those used in packaging. Recent regulation changes, especially regarding the ban of single plastic use – will help generate significant new feedstocks of material to recycle but these volumes of recyclate will take time to find their applications and markets.
This is precisely the interface where compounding science operates: By developing the right compounding technologies, Benvic is able to improve the material characteristics to target new applications. Benvic has a number of these recyclate initiatives in its product development pipeline.
Recycling of post-use products has its limits - mainly in the overcoming of heterogeneous feedstocks in order to create significant material volume. 

Where this is the case, bio sourcing can present a useful alternative. The main attraction of bio sourcing lies in using new but renewable resources, principally from the biosphere and usually from photosynthesis - from a closed carbon loop in other words. The bio versus recycling options need to be assessed in terms of individual cases and overall environmental impact.
However, bio sourcing can be considered as an excellent alternative to recycling, particularly when the needs of the product make the use of recyclate very challenging; in food contact application, for example, or where color, aesthetics, or high stability is essential.

Benvic’s technology in new biobased resins such as PLA now provides an interesting way to challenge conventional techno-polymers:  Moreover, when using bio sourced conventional resins, such as PVC, help is given for critical applications such as pressure fittings, where reliability is required,
Time to develop new and reliable environmental solutions can always take time and so the immediate availability of bio sourced compounds can give an environmental improvement immediately.

The other dimension of the recycling/biosouring articulation is possible for a compounder as : 

  • Benvic’s technical teams are working on fillers for compounds and not just the base polymers. Additions of recycled fillers, for example, could be a significant way to maximize the environmental impact of a project and sometime with more options that a recycled resin.
  • Versatile PVC compounds also give way more possibilities to integrate new and varied types of fillers.
  • Resin that are reinforced with bio sourced fibres such as hemp or bamboo can be not only be interesting in terms of substitution, but also provide biosourced alternative for functions such as reinforcement. 
  • Other filling option can come from agriculture co-products: vegetal residues from local production for example, could be compounded in order to make greener products at a reasonable cost. The great variety of such fillers could work towards generating many different types of material and products.

In summary, recycling and bio sourcing are solutions that allow engineers to design products with much reduced environmental impacts.

This is a new science – without absolute solutions but a work in progress that is currently tackling multiple levels of materials technology - resins, additives, fillers, and recyclate.
Tailor-made approaches are able to generate optimum applications and products – all at affordable cost.
Benvic’s long standing compounding expertise is key to this plastics redesign. Our legacy foundations and our materials know-how put us in pole position to support existing and future customers in this way.

In fact, it is no exaggeration to say that all upcoming products and applications now require this kind of new environmental effectiveness. Benvic is more than happy to provide it.