Pure Loop spotlights recycling of glass-fibre-reinforced composites

Pure Loop is showcasing its integrated shredder-extruder ISEC evo for injection moulders at Fakuma, first launched almost 10 years ago.

What’s new is the focus on the machine’s ability to keep composite materials, particularly those reinforced with glass fibre, in the loop.

Glass-fibre reinforced polymer composites are made by incorporating glass fibres into a polymer matrix, resulting in a high-strength, lightweight, and durable material. They exhibit excellent resistance to corrosion, heat, and chemical exposure, making them suitable for demanding applications. These composites are widely used in aerospace, automotive, construction, and marine industries due to their strength-to-weight ratio and versatility. They are also commonly used in reinforcing concrete structures, wind turbine blades, and piping systems for enhanced performance and longevity.

Pure Loop’s machine, which is equipped with a melt filter, can cope with challenging materials of different sizes and shapes. The use of high-quality carbide knives, a protected rotor, special treatment of the screw flights and other measures increase the wear resistance of the system. As a result, glass fibres can also be optimally processed, the Erema subsidiary claims.

The machine can process up to 100% glass fibre material, Manfred Dobersberger, managing director of Pure Loop told Sustainable Plastics.

The origin story of that development started with a light-hearted suggestion from a client, who asked Dobersberger if he could run the machine on 100% glass fibre. The suggestion turned into a serious goal for PureLoop when Dobersberger considered what would have to be adapted: running the extruder at a higher temperature to melt the glass, using stronger knives… and the rest is history.

“Now we can recycle glass fibre scraps and make a new compound out of it in one step. This is something that no one else in the world has ever done – we are quite proud of it,” Dobersberger said.

Focus on speciality materials

PureLoop has switched its focus to composites recycling following trends it has detected in the market towards thermoplastic materials, 3D-printing, and automotive applications.

“We see that there is a movement away from thermoset materials to thermoplastic materials. Wind turbine manufacturing, for example, uses glass-fibre reinforced thermoplastics that need to be recycled after 10 or 20 years,” Dobersberger said.

“There’s also a massive interest in 3D-printing of larger products. The focus is no longer on printing small objects like, say, glasses from a monofilm but rather we’re hearing from people in the industry that you can have a 3D-printer the size of a football field where you can print an entire boat, for example. We also have customers that use it for printing technical products like automotive components. For smaller scales, it is cheaper to print 10,000 pieces than using injection moulding. A lot of these 3D-prinitng developments use glass-fibre reinforcements, so we are advancing our processes into this direction.”

Demand from automotive industry

Since the European Commission updated its Directive on end-of-life vehicles, setting a 25% recycled plastic mandate for vehicles placed on the market from July 2023, automotive brands and members of the plastic industry value chain have accelerated their efforts to transition to a circular economy for automotive parts.

Recycled composites reinforced with glass-fibre can make important contributions to this requirement whilst also replacing costly metal parts. Moreover, the glass-fibre reinforced virgin composites often used in car parts eventually also need to be recycled. Over six million vehicles in Europe reach the end of their life every year. Inadequate management of end-of-life vehicles not only leads to economic losses, but also contributes to environmental pollution.

“As we face all these new challenges, we are developing new processes and already have important results to share,” Derenberger said.

Minimising degradation

Tests at PureLoop’s research and development centre in Ansfelden, Austria, have shown the ISEC evo performs at the highest level.

During the production of glass fibre-reinforced fabric, scrap is produced from the non-crimp fabric or also residual spools. The 100% glass fibres were fed into the recycling process without pre-shredding and compounded with polypropylene or other polymers.

"In the tests, the recycled pellets produced showed higher mechanical properties than the virgin material from well-known manufacturers," Dobersberger noted.

The ISEC evo has been designed to re-inject material rather than rejecting it. Disposing of scrap parts and sprues from the injection moulding process is often time consuming and expensive. Feeding them back to the production process therefore offers economic benefits for injection moulders.

In contrast to grinding processes, only minimal changes in the Melt Flow Index (MFI) occur during repelletising and there is no dust, which promotes the formation of soot particles. The regranulate has the same shape and melt performance as virgin material, which makes it easier to feed back into the injection moulding machine.

"When you're working with glass, wear and tear is a typical issue. Over the years, we've learnt to design our machines in a way that reduces this wear. As a result, the components inside the machine have a longer lifespan. This is crucial for customers because it helps them understand the operational costs, how often they’ll need to make modifications, and when upgrades might be necessary,” Dobersberger explained.

“Another aspect that often surprises people is how minimal our modifications to the process are. For example, when working with glass fibre—particularly in injection moulding—we see that the fibre length is typically changed by only about 6% to 10%. In traditional injection moulding, the fibres break down much more. Our process, on the other hand, is gentler, helping to preserve both the mechanical and physical properties of the materials, including the polymer itself.”

“In nylon or polyester applications, for instance, where polymer degradation is a concern, we see that our process modifies the material by just around 6% to 8%, which is much less than the industry standard. This means we can maintain better material properties while minimising degradation.”

Sales up

Pure Loop has not been affected by the sales slump that many plastics machinery manufacturers, and recyclers in particular, have been facing the in the past couple of years. Its success is thanks to a mix of prior preparation, market analysis, and high-quality product offering, Dobersberger said.

“I’d say we’re one of the fortunate ones, because we started preparing for this situation about three or four years ago. That gave us a bit of extra momentum. We haven’t faced any issues related to declining sales; in fact, our sales are moving in the opposite direction, which is surprising given the current challenges.”

“I believe this success comes from us identifying early on the slowing trends in industries like the blown film, piping, and extrusion sectors. These are highly competitive markets, with significant pressure from Asian countries. However, the quality and reliability of our machines have allowed us to stay ahead.”

“In certain markets, the level of quality we offer isn’t just a nice-to-have, it’s a must-have. People are willing to pay a premium for our products because they know they need that reliability to maintain consistent operations.”

More growth expected for 2025

Dobersberger expects Pure Loop to continue to grow next year, even if the recycling industry faces another challenging year. The goal is to increase sales by 7% to 10%, ‘maybe even 12%’, he said, which would be ‘solid progress’ given the overall situation for recyclers in Europe.

“What I’m seeing right now, especially when I talk to some of the larger players in the market, is that their productivity, which was around 50-70% a few months ago, is now back up to around 80-90%. So, there’s definitely some light at the end of the tunnel,” Dobersberger said.

“However, rather than jumping straight into new investments, these companies are first focusing on regaining stability. Once that’s achieved, they’ll likely start investing in new products or projects. I expect next year to be challenging, especially for standard applications, due to the high prices of polymers, which have a big impact on the industry. As for other sectors like automotive and technical applications, the outlook depends on several factors, but I’m confident that our company will continue to grow next year,” he concluded.

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