Saint-Gobain Boron Nitride Powder Solutions
Functional fillers and additives to enable high performance solutions
Saint-Gobain Boron Nitride Powder Solutions merge the key properties of hexagonal boron nitride (hBN) and over 60 years of manufacturing expertise to offer a complete portfolio of hBN powders. With a variety of particle shapes and sizes available, Saint-Gobain Boron Nitride Powder Solutions enable our customers to maximize the benefits of boron nitride in a wide array of markets and applications.
Commonly referred to as "white graphite," hBN crystals naturally form into platelets with a roughly hexagonal shape. While widely known as a high performance dielectric cooling filler, hBN powders add value to many different industries. Learn more about our product offering below!
Powder Solutions Products
What is the benefit of using different particle shapes, such as platelets or sphericals?
Platelets tend to align in the direction of resin flow, and due to its inherent anisotropy, offer a very good in-plane thermal conductivity. Platelets also allow for the addition of BN to systems that require a very thin layer or bond line that would be too big to allow agglomerates to be added.
Agglomerate grades - where small BN platelets are randomly oriented in all directions, like a snowball - overcome this limitation making BN an isotropic filler suitable for in-plane as well as through-plane thermal conductivity improvements. Spherical Agglomerates (SA grades) are lower density, but have the benefit of high flowability, packing, and tight particle size distribution. High Density Agglomerates (HD grades) are the strongest agglomerates and will resist breakdown during mixing.
What particle size or distribution do I need for my application?
You should be sure that the largest particle size does not exceed the intended thickness or cross section of the final product. It isn’t uncommon for formulators to mix more than one size distribution to achieve better packing of the BN particles and optimal percolation in the resin matrix.
Why is mixing/dispersion shear important to my grade selection?
Platelet grades are single-crystal BN particles, that are small but robust, and do not break down under high shear forces. Platelet grades are suitable for high shear operations like twin screw compounding and extrusion.
Spherical and agglomerated grades, on the other hand, are comprised of multiple small boron nitride platelets, held together by interlocking planes without addition of any binder system. This makes these grades particularly susceptible to breaking apart when subjected to high shear. These grades are suitable for low-medium shear mixing operations.
How much powder do I need to put in my polymer to increase its thermal conductivity?
The best results occur when there is percolation of the filler particles through the thickness of the composite. This creates a continuous thermal pathway along the filler particles, which will boost the thermal conductivity much more than a system without good particle-to-particle contact. The percolation threshold should be considered when determining the amount of filler to add to the system.
What factors should I consider for improvement in thermal conductivity of a polymeric system?
Boron nitride grade selection for thermal conductivity improvement typically depends on 3 key factors:
- Particle size tolerance of your resin system (or bond line thickness)
- Desired plane of thermal conductivity improvement (in-plane or through-plane)
- Mixing/dispersion process employed (high shear or low/medium shear)
Why use BN instead of graphite or other solid lubricants?
BN is white, non-toxic, stable, and inert. It is oxidation resistant up to about 900°C (unlike graphite, which oxidizes below 500°C). BN keeps its lubricity above 500°C, which is the limiting temperature for graphite as a solid lubricant in air. BN also retains it lubricity in inert or vacuum conditions.
In addition, boron nitride has a low dielectric constant, making it an ideal material for insulation, protection and low dielectric loss.
How do different grades impact the properties of a cosmetic formulation?
The key difference is in particle size and crystal morphology. All grades are high purity and pass global regulations for heavy metals. With grades ranging from 2 to 30 microns in average diameter, the appearance will change as well, going from a matte white appearance to a more translucent or shiny appearance as platelet diameter increases.
Single platelets of high purity hexagonal BN appear transparent when viewed through the platelet face. This can be seen visually on large platelets, which appear to sparkle when light reflects off the platelet face. Most fine mesh BN powders form agglomerates that, if not dispersed, appear white and opaque.
How much powder is typically used in a cosmetic formulation?
The amount of BN filler in a formulation is completely up to formulator, the application, and desired results. BN is typically added to cosmetic formulations from 3 – 10%.
What is the standard packaging and lot size for BN powders?
Standard packaging for boron nitride powders is 25 kg in cardboard boxes or drums. Depending on the grade, our manufacturing lot sizes could be between 250 lbs to 1200 lbs.
*Value for in-plane thermal conductivity