SoliBulk ZR-Grade

SoliBulk ZR-Grade

SoliBulk™ ZR-Grade

At the core of our SoliWool™ product line lies SoliBulk™, an extensive range of high-temperature bulk fibers offered in both Refractory Ceramic Fiber and Low Bio Persistence variations. These fibers serve as excellent raw materials for secondary processing, including the production of VF shapes, as well as infilling air gaps. All products offered in the SoliWool™ product range share the Ultra Low Shot technology which has been developed to achieve the highest possible thermal insulation value, provides a extremely high fiber index, and specifically for the SoliBulk to differentiate from other suppliers with a higher yield in secondary processing. We offer our SoliBulk as standard product, and as engineered bulk. As engineered bulk we tailor our SoliBulk products with additional processing like deshotting and milling.

SoliBulk ZR-grade oliBulk ZR-grade is our highest positioned refractory ceramic fiber (RCF-Zr) bulk fiber with a classification temperature of 1430°C. The combination of a high level of Zirconia, which is resulting in minimizing shrinkage, and the use of our Generation III spinning technology makes SoliBulk ZR a better solution for applications operating continuously till 1430°C.

SoliBulk ZR-Grade

Datasheets, Media & Downloads


SoliBulk STD Datasheet EN


SoliBlanket/SoliBulk/SoliSlab/Solibloc X-grade MSDS EN


SoliBulk™ ZR-grade is our highest classified refractory ceramic fiber (RCF-Zr) bulk fiber in the SoliBulk product range. With a classification temperature of 1430°C it is engineered to perform in a wide range of applications up till 1300°C continuously.

SoliBulk™ ZR-grade shares the Ultra Low Shot technology with the other products in the SoliBulk range. Our Ultra Low Shot fiber technology is enabling a higher fiber index and lower shot contents. In result, you will benefit from a higher yield in the further processing of the fiber, or enhance properties of your final product. In wet processes, the impact of shot content in bulk fiber on yield is often underestimated. In Vacuum Forming production, shot particles tend to sink in the liquid mixture, reducing the volume per kilogram of bulk fiber used.

With the Ultra Low Shot technology we typically improve the yield by 15-30 % over Generation I and Generation II products. By us utilizing the latest fiber technology, you will experience stronger and higher quality Vacuum Formed shapes, while optimizing the use of raw materials.

We offer our SoliBulk™ as standard product, and as engineered bulk. As engineered bulk, we tailor our SoliBulk with additional processing like deshotting and milling. For specific requirements on our SoliBulk Engineered bulk products or if you need additional information, please contact the team at Vulcor Insulation.

SoliBulk™ ZR-grade can be used for a large variety of applications using secondary processing, like: vacuum formed shapes, reinforcement of insulating castables, and raw material for mastics and coatings. Long fibers are used for yarn and rope manufacturing, get blown or injected fiber for double wall chimneys, or used as infill for airgaps and cavities. Please note that each of these final applications require fiber specifically tailored for the final application. This might be as easy as selecting a lubricated for unlubricated bulk fiber, but in some cases also require a particular fiber length.

All grades of SoliBulk are available in different types designed for various applications:

Lubricated bulk – used for yarn/ textile, joint filler;
Unlubricated bulk – used for mastics and vacuum forming.
We offer all bulk fibers in different styles in line with the application requirements:

Chopped – high density VF shapes and mastics
Short         – standard VF manufacturing and mastics
Medium    – infill for double walled chimneys
Long          – void/joint fillers, dry injected fibers and textiles

SoliBulk™ ZR-grade is part of the SoliBulk product range. SoliBulk productrange is one of the most extensive product ranges targeting a wide range of atmospheres and temperatures, providing tailored solutions to meet specific requirements. This versatility enables us to deliver high-performance insulation products that excel, giving you the ability to make the best quality products and optimizing customer satisfaction.


  • Low shot technology
  • Higher yield in secondary processing
  • Excellent insulation performance
  • High handling strength
  • Excellent thermal stability
  • Resistant to thermal shock
  • Proven technical solution

Typical applications

  • Raw material for Vacuum Forming process;
  • Raw material for insulating castables, mastics and coatings;
  • Filling and stuffing of voids and gaps in furnace lining;
  • Injected/blown fiber in double wall chimneys;
  • Long fibers for yarn production (textiles);
  • General technical insulation of furnaces and technical installations.


Loose insulation wool from high temperature Refractory Ceramic Fiber (RCF).

Temperature range

SoliBulk ZR-grade has a classification temperature of 1430°C and advised for maximum continuous use at 1300°C.

The maximum continuous use temperature provided on the website is a guideline and only applicable in a clean oxidizing atmosphere.

Product range

SoliBulk is part of an extensive product range supplied by Vulcor Insulation. Vulcor Insulation is supplying insulation solutions from cryogenic to high temperature applications. All products offered by Vulcor are manufactured in house or sourced from exclusive trusted 3rd party partners.

Technical support

SoliBulk is offered in various types and styles. It is crucial to match the fiber to the application. For that reason, please always consult with our experts.

Vulcor Insulation provides specifiers and customers with guidance on all aspects of the materials selection for their application, the installation and compliance with relevant regulations and performance standards.

For additional information about product performance, or to identify the recommended product for your application, please contact the team at Vulcor Insulation.



SoliBulk is packaged on our new state-of-the-art production line, targeted to minimize deviation of the fiber length throughout the packaging. With our new packaging equipment we are able to supply our bulk fiber products in tight and compressed shrinkwrap bags. This allows minimizing time required for unpacking and ensures consistency of the fiber length. We do this by a using a multi axle compression which ensure a consistent fiber length throughout the bag.

Each pallet has 30 bags with a dimension of 600x400x400 mm. The weight per bag is varying based on the  desired fiber length in  final application. Short and chopped fiber can be packed with a higher density in the bag and for that reason has more material per bag. Long fiber,  which is mainly used for infill, is not heavily compacted to ensure a stable fiber length and consistency within the bag.


Type kg/bag bag p/pallet kg/pallet
Chopped 20 30 600
Short (VF) 18 30 540
Medium 15 30 450
Long 12 30 360


Properties measured Standard Unit SoliBulk ZR-grade
Grade RCF
Colour white
Classification temperature °C 1430
Continuous use temperature °C 1300
Beaker value (fiber length), ml
Chopped 60-100
Short (VF) 140-200
Medium 250-400
Long 450-600
Mean Fiber Diameter micron 2-3.5
Short contents Jetsieve > 45 micron < 42%
Chemical composition, % EN 12677
Al2O3 34-37
SiO2 48-51
ZrO2 14-17
Fe2O3 < 0,2
Other < 0,25