The uniform, permanent and stable resistivity enabled by TUBALL is said to ensure enhanced safety at highly hazardous plants and reduces the cost of lining coatings.
Around 10% of all accidents involving storage tanks that occur in industrial facilities are caused by the electrostatic charge that is generated when two dissimilar materials are in relative motion to each other, TUBALL’s manufacturer OCSiAl reports. Product movement during filling develops a static charge between the liquid surface and the tank shell. The accumulated electrostatic charge can produce an incendiary spark that can lead to terrible accidents. Dissipation of this static charge is the role of anti-static fillers that are added to the body of the storage tank or to the lining coating, and the choice of additive is of critical importance.
Until recently, using a standard anti-static filler – such as conductive mica or carbon black – always involved a compromise that resulted in anti-static properties that were not stable over time and that were affected by weather conditions. Now, graphene nanotubes (also known as single wall carbon nanotubes) offer a new approach to conductive fillers for fibreglass plastics and their coatings.
TUBALL graphene nanotubes provide ESD protection by dissipating electrostatic charge inside and outside a storage tank. One of OCSiAl’s partners is now introducing nanotubes into anti-static fibreglass tanks for storing and transporting easily combustible materials. The previous conductive additive, carbon black, required a loading of 15% but this has now been replaced with just 0.5% of TUBALL MATRIX 204, a pre-dispersed concentrate of graphene nanotubes. Permanent and stable volume resistivity of less than 10^6 Ω·cm has been achieved, without ‘hot spots’ and independent of humidity. The product colour range has also been expanded.
Another of OCSiAl’s partners has launched a TUBALL-based lining coating system with an electrostatic dissipation function that is designed for storage tanks for highly flammable substances. This manufacturer has replaced 30% of conductive mica, in an epoxy system, with just 0.3% of TUBALL MATRIX 201 concentrate. The result is a stable level of volume resistivity of between 10^6 and 10^7 Ω·cm. The potential cost savings resulting from such significant reductions in the overall additive loading is also of great interest to coatings manufacturers, OCSiAl notes.
The application of graphene nanotube concentrates simplifies nanotube handling and makes it a standard and clean manufacturing process without the powder or dust usually associated with the utilisation of carbon black, OCSiAl reports.