|
Barrikade ®Fire resistant and thermal insulation material |
Product Datasheet |
1. What is Barrikade?
Barrikade ® is a low density, fire resistant, inorganic material consisting of vermiculite granules bonded together using an inorganic binder. Although in principle any inorganic binder could be used, the data presented in this document relates to sodium-silicate water glasses.
Barrikade is a non-combustible material, which possesses no known health and safety problems (see individual manufacturer's Materials Safety Data Sheet). It was developed to meet the high temperature fire resistance and thermal insulation requirements of various industries, including transportation, aerospace, offshore, and construction.
Barrikade was invented at TWI in 1997 and subsequently patented; this platform technology has now evolved to cover a number of products, namely:
| Barrikade ® Loose-fill | The first stage insulation product is an exfoliated vermiculite (typical particle size, 2-5mm) coated with Barrikade Binder. |
|
||||
| Barrikade ® Binder | A range of inorganic materials, glasses or ceramics (identified by TWI as suitable for the manufacture of Barrikade products). Silicate-based glasses ( eg water glass) being the most common. The Binder can also be used as an adhesive. | |||||
| Barrikade ® Core | The second stage insulation product - for example, a shaped product or panel. | |||||
| Barrikade ® Skin | A higher density product, usually fabricated as a skin to the Barrikade Core |
Typical Properties of Barrikade Core
| Forms Available | Rigid panels, moulded shapes, coatings |
| Composition | Exfoliated vermiculite granules bonded with a sodium silicate blend binder (Alternative inorganic binders can be used) |
| Structure | Open cellular structure |
| Thermal Conductivity | 0.10-0.35 W/m.K |
| Thermal Diffusivity | 8x10 -6 m 2 s -1 |
| Coefficient of Thermal Expansion | 13.5x10 -6 /°C |
| Density | 250-350 kgm -3 |
| Compression Strength | 0.70 MPa (for 250 kgm -3 ) |
| Flexural Strength | 0.25-0.60 MPa |
| Young's Modulus | 100 MPa |
| Organic Content | Nil |
| Asbestos Content | Nil |
| Machinability | Good (similar to wood) |
2. Benefits and features
|
|
3. Thermal properties
| Initial test data indicates that for a density of 250 kgm -3 Barrikade core possesses a thermal conductivity (K) value of 0.10-0.35W/m.K depending on mean temperature, as illustrated in the figure. Barrikade displays a uniform temperature distribution, with no hot spots. |
|
| The thermal performance of Barrikade Core has been assessed using a thermal gradient test. Barrikade Core is placed in the entrance of a furnace and the temperature held at 925°C, which is similar to the temperature used for the SOLAS (Safety Of Life At Sea) fire protocol. The back face is exposed to air and the temperature of this face recorded using several thermocouples. A typical thermal trace is given in the figure; it can be seen that the cold face temperature reaches a steady state of ~200°C over a thickness of 45mm. |
|
| Barrikade Core using water glass as the binder has been shown to be thermally stable up to 700°C (the glass transition temperature (T
g ) of the glass). Above this temperature the Barrikade material degrades and slumping occurs. This degradation is gradual and for certain single use applications, such as fire doors, Barrikade Core can withstand temperatures of over
900°C for several hours.
For higher temperature applications alternative binder systems can be used. For example, Barrikade Core using a phosphate binder has a temperature capability of up to 1200°C. |
|
4. Moisture resistance
All water-glass bonded Barrikade products absorb moisture over time. It is recommended that, where possible, sealed panel/moulding designs are employed to minimise water/moisture contact. (For more information refer to 'Using Barrikade ® - the practical approach', TWI Bulletin, July 2000).
Several chemical methods of improving moisture resistance have been evaluated, based on additions of insoluble metal salts to the binder and also the use of a carbon dioxide atmosphere during manufacture. These have been found to be highly effective. (For more information refer to 'Barrikade ® - tried and tested', TWI Bulletin, Sept 2002).
5. Acoustic insulation
Due to the microstructure of Barrikade it is anticipated that insulation of low-medium frequency may be achievable.6. Processing conditions
Typical stages for processing Barrikade as panels and mouldings include:
- Barrikade is a two-stage process. Stage 1 consists of coating vermiculite granules with Barrikade Binder, and curing. Stage 2 involves mixing the Barrikade Loose-fill with further Barrikade Binder, and curing in a mould. The most commonly used Barrikade Core material has a density of approximately 300kgm -3 , however Barrikade Core can be fabricated to various densities between 250 and 350kgm -3 by changing the ratio of binder to vermiculite in stages 1 and 2.
- The mix ratio for stage 1 is a 2:1 Barrikade Binder to vermiculite ratio by weight.
- Lay flat and cure in oven for 2 hours at 100°C.
- Mix the Barrikade Loose-fill with further Barrikade Binder in a 1:1 ratio by weight.
- Fill the mould cavity. The mould must be porous to allow moisture to escape during curing.
- Panels/sandwich can be produced using standard heated press. More complex shapes can be achieved using bespoke moulds.
- Cure for 4 hours at 100°C.
- Allow to cool. Remove mould.
- Dress/machine as required. Wear dust mask and goggles during this stage.
- Sandwich panels can be bonded in position as described in Section 7.
7. Panels and skins
Barrikade Core can be processed in thicknesses ranging between 5-200mm. The process is extremely robust and is limited only by the complexity of the mould design. Panels can be bonded together using Barrikade Binder (or other adhesive) to achieve thicker blocks/panels.
Barrikade ® Core laminated with various materials |
Barrikade Core will adhere to a range of materials, enabling sandwich panel construction or protection of existing surfaces. Typical skins/substrates include aluminium, steel, wood, polymer composites, glass and also a skin material comprising of vermiculite flour and Barrikade Binder. Barrikade Binder can be used as an adhesive, although alternatives can be used to improve bond strength. Care must be taken to address differences in thermal expansion coefficients.
8. Storage life
| Vermiculite: | Indefinite |
| Barrikade Binder: | 2 months from date of opening container |
| Barrikade Loose-fill: | 2 months, at 25°C, from coating date |
NOTE:
The above information is provided purely on an advisory basis and is not designed to create any representation of the capability of the Product. It is the User's responsibility to identify processing parameters and performance capabilities
specific to the end use requirements.
The data above is relevant to Barrikade materials produced using sodium-silicate water glass Barrikade Binder.
View a video clip on Barrikade - mpeg file 15599kB
To view a video clip you need an MPEG-1 Video Player. If you have difficulty with this, please talk to an experienced web user.
For further information about Barrikade, please contact Paul Jackson, Paul Burling or John Fernie at TWI Ltd, Granta Park, Great Abington, Cambridge CB21 6AL (previously CB1 6AL), UK
Tel: +44 (0)1223 899000, Fax: +44 (0)1223 892588, email:
barrikade@twi.co.uk
Copyright ©2004 TWI Ltd
