These innovative fibre additives and functional composite fillers are derived from an unusual source: fruit waste
These innovative fibre additives and functional composite fillers are derived from an unusual source: fruit waste. Here’s how circular economy processes are enabling more sustainable biocomposite materials.
Founded in 2017, BioPowder is a producer and supplier of high-grade fruit stone powders and bio-based abrasives derived from fruit processing streams. The company pitches itself as a key part in a sustainable supply chain that converts excess organic material from the fruit industry into fully biodegradable ingredients for reuse in other sectors.
Not all plant-based ingredients are automatically sustainable, with renewables often coming from sources that involve industrial farming, and the use of agrochemicals and monocultures. While certain staple food crops such as corn and have been used as raw materials for non-food biomass products in the past, in the context of a growing world population and misallocation of food there needs to be a better solution, says BioPowder co-founder Kathrin Schilling.
“The ultimate goal is to produce end-products that allow manufacturers to generate the minimum environmental impact and maximum added-value in terms of technical properties and sustainable material design,” she says. “Within a bio-based composite, all of its constituents – the resin, fillers and reinforcing particles – can be bio-based. Composites with a higher bio-based content generally have a lower carbon footprint, specifically as less emissions are generated throughout the entire product lifecycle.”
PERFORMANCE PARTICLES
Backed by decades of experience in the biomass processing industry, BioPowder’s small team takes excess fruit waste and converts it into fully biodegradable ingredients that can be used to form novel biocomposite materials with a wide range of industrial applications.
“We produce sustainable fillers, reinforcing powders and functional additives that composite manufacturers can use in their compounding processes to produce biocomposite materials,” Schilling explains. “To do this, we make so-called ‘performance particles’ from recycled olive stones.”
For centuries, olives have been an essential staple food in the Mediterranean region. Today, olive stones have become a sought-after filler material with added value for ceramics, coatings, composites, polymers, asphalt and bitumen. Besides adding a significant bio-based percentage to existing materials, they have strong binding and texturising capabilities, and have been proven to boost material resistance, tensile strength and lifespan.
“Olive stones are very hard and have very low density – only around a third of the density of conventional fillers,” Schilling says. “When they are incorporated into a bio-based composite, they can add significant strength and stability, while also offering lightweighting benefits which are fundamentally important for parts and components within the automotive, aerospace or shipbuilding industries, where every gram of weight counts.”
Olive stones can also provide other functional and aesthetic benefits, too. “We can create very unique textures and surface effects such as anti-slip properties,” Schilling continues. “Not only is the resulting material fully degradable, but it is fully compostable in different environments and doesn’t require industrial recycling processes. Also, we shouldn’t forget that olive stones contain certain bioactive compounds that can deliver antioxidant and even antimicrobial properties to materials.”
Schilling explains the processes involved in converting olive stones into useable biocomposite materials, which begins with the process of creating olive oil.
“When olives are pressed during the olive oil process, a solid residue or paste consisting of pulp shell and crushed olive stones remains,” she explains. “We separate the stones from the paste, as the stones are a hard lignocellulosic material which is truly multifunctional. In the past, it has been used as an alternative biofuel. Then, the stones undergo a process that we call micronisation, which involves drying the raw material and then carrying out several stages of milling, sieving and classification to produce particles in very defined micrometre ranges.”
The biocomposite market is very strict when it comes to particle size, she adds, because this determines the powder’s texture, flow behaviour, density and aesthetics. “When the powder is incorporated into composites, the micron range can have a huge impact on parameters like dispersibility, viscosity, elasticity and surface properties,” Schilling adds.
At the end of BioPowder’s complex treatment process, pure, clean olive pit granules remain, which can be transformed into high-grade powders for use as fillers and additives in a wide variety of composite materials.
BIO-BASED IS BETTER
BioPowder’s whole approach is built on the circular economy concept, which represents a shift from the traditional ‘take, make, waste’ industrial model to a system that operates on the principles of reducing, reusing and recycling.
“Bio-based composites have a lower environmental impact than conventional composites because they are derived from plant-based raw materials, and they can also deliver better technical features,” Schilling says. “Our powders have been incorporated into a wide range of materials and applications as functional fillers, such as within the polyethylene, polypropylene, PVC, polystyrene and PU industries. These materials are often used within injection or extrusion-based manufacturing techniques for high-tech parts within the automotive, shipbuilding and aerospace sectors, and for biodegradable consumer items and construction parts. The main incentive for these applications is lightweighting paired with high hardness properties, and of course the fact that our powders consist of 100% bio-based content.”
Another key application space is rubber composites, Schilling adds: “Our powders can be added to rubber or thermal plastic elastomer materials to reinforce them with added strength, resistance, or certain surface texture properties. We also have applications within the coatings market, ranging from protective coatings to floorings, to food coatings and bio-based leather alternatives.”
Going forward, BioPowder will continue to emphasise the importance of ensuring that resources are used and reused as efficiently as possible. Schilling concludes: “To be truly sustainable and forward-thinking, there should be a more holistic approach to composite production. There are hundreds of thousands of opportunities to make new types of composites, and the good news is that more and more of these are being derived from bio-based sources.”
For more information visit: www.bio-powder.com
