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Volcanic-rock continuous fibre: a growing demand

News International-French

21 Mar 2011

Isomatex proposes a novel approach for achieving engineering breakthroughs in the early stages of the mineral-fibre production process.

(Published on October - November 2007 – JEC Magazine #36)




As fibre-reinforcement markets expand due to diversification, fibre manufacturers are faced with the challenge of meeting a rapidly growing global demand. There is more to be done however, especially in production engineering at a time when the quality of reinforcement fibres (in terms of physical, thermal and electrical properties), timing, and accurate results have become critical.


New plant

Isomatex recently commissioned a new upscaled manufacturing plant for volcanic-rock continuous fibre. The new factory is currently under construction in the Crealys Scientific Park close to Namur in the heart of the Walloon region, and will be a sophisticated one. It will comply with all required IPPC (Integrated Pollution Prevention and Control) rules and the relevant European directives.


Full-scale production, which is expected to start before the end of this year, will need to be perfectly suited to the production of enhanced and blended basalt products in order to comply with the Best Available Techniques (BAT) concept. Significant R&D and engineering investments were made in order to focus on precisely controlled equipment to improve the stretched-fibre quality, and to increase the output capacity by controlling processing costs.


Fibre properties

In addition to the higher performance of volcanic fibres and their enhanced specific properties (strength, temperature range, IR-ray resistance and durability), which gives them the potential to replace S2-glass fibres cost-effectively, this new product has revealed a superior elasticity (high tensile modulus, or “Young’s Modulus”) and is a flawless substitute for aramid- and carbon-fibre products in many applications. Volcanic rock filaments are completely inert, with no environmental risks, and can easily be used with different types of technical plastics and resins. They satisfy the requirements of the high-performance segment of the global market for reinforced materials for composite products, and can be used in various branches of industry: aircraft/aerospace, automotive, civil, road & underground construction, engineering (pipeworks), corrosion-resistant equipment, marine, environmental safety and defence, naval construction, insulation, etc.


An innovation is a creative technology harnessed to high-tech process equipment with outstanding features, generating a product with properties that are superior to existing ones. One of the best ways for fibre manufacturers to ensure profitability in the current environment is to promote innovation through the use of advanced applications and techniques and, consequently, to improve the efficiency of their operations. Moreover, to enhance the main properties of lightweight advanced fibre-reinforced composite products in any field of application, the right choice of coated sizing agents in the fibre forming stage is decisive.


Therefore, a development contract was concluded with a highly specialised European research centre in order to evaluate the relationship between matrices and fibre reinforcement for industrial sectors like: automotive, where the vibration and noise in vehicles are major concerns; aircraft structures, where improved strength and stiffness are required and should be continuously improved; or concrete applications, where a modified sizing is required which, although it is slightly tacky, becomes well and quickly impregnated with resin.


Design and installation

It has taken four years of study and close collaboration with a number of research centres and engineering companies to bring the FILAVA® volcanic-rock filament from the prototype stage to production. A manufacturing plant with advanced computer-aided equipment is currently being installed. An integrated system complying with quality norms and European standards has been fully tested.


Over the past years, all the parties involved in the project worked hard to optimise the manufacturing process and deploy new technology to become as efficient and productive as possible, since many of the process parameters are coupled and hard to study or analyse separately. In a context of intense competition, scientific and technological advantages are the defining factors for a company’s steady development. Production needs to be enhanced not just with new technology and modern equipment, but also with the latest and newest ideas.



Specialised support is provided during commissioning. All works are supervised by highly qualified specialists and carried out in compliance with the beneficiaries’ designs, and in accordance with the design and process developed by the company.


Homogeneous batch composition and chemical analysis are becoming drastically important to the performance and manufacturing of blended-mineral continuous fibre products. A high-performance pneumatic system was designed to facilitate innovative improvements during the blending and conveying of raw materials in production processes. This pneumatic system runs cleaner than mechanical ones and is less susceptible to product contamination, thus facilitating materials recycling. It is totally enclosed in a dust-tight system, making it more environmentally acceptable than mechanical systems, which are dusty and dirty – but usually less expensive.


Furthermore, the alternative melting approaches, particularly electrical immersion or induction melting, offer the prospect of much higher energy efficiency associated to molten lava movement for temperature uniformity and reduced melt loss, despite the fact that the melting temperature for the basalt-based batch is significantly higher than the temperatures in conventional melting technologies for alkaline-earth aluminosilicate glasses.