Hydrophobic silicas comprise a unique group of materials that feature many types of advantageous properties and attributes. Their features make them suitable for a wide range of applications, including sealants, greases, adhesives, processing aids, and personal care products, among many others.
This material functions as a kind of anti-caking substance to eliminate, reduce, or mitigate the risk of hardening or “caking” within powders. It achieves this through moisture control (e.g. repellency) that helps to keep the particles consistently defined and separate, facilitating the free-flow of the powder.
Benefits of Using Hydrophobic Silica
If you’re considering hydrophobic silica, this material features numerous benefits that make it crucial for an array of compounds. These key advantages include:
- Adsorbent — Can adsorb liquids, solids, and gasses to create powder from liquids and pastes
- Anti-Blocking — Keeps film sheets separate and prevents sticking
- Anti-Sagging — Keeps wet coatings or paints from running or drooping
- Anti-Setoff — Prevents the potential inadvertent transfer of ink between printed pages known as setoff
- Anti-Setting — Helps increase the amount of time it takes for paint and pigments to dry on metallic and other surfaces when used with certain chemicals
- Free Flow of Powders — Functions as an anti-caking agent that keeps powders from hardening or caking
- Foam Control — Decreases foam levels or minimizes foam buildup
- Hydrophobicity Control — Serves as a natural water repellent that causes water to form droplets
- Mechanical and Optical Properties Improvements — Improves the transparency, clarity, and durability, among other material qualities
- Reinforcement — Provides reinforcement for some materials’ elastomeric properties
- Pigment Stabilization and Dispersion — Facilitates the reliable application of certain types of complex pigments
- Print Definition — Reduces the risk of smudging, runoff, and other issues that could otherwise compromise print clarity and definition
- Processability Improvements — Enables increased processing along with application precision
- Rheology Control — Maintains the consistency of products throughout containers or batches
- Thickening — Increases the thickness of sealants, pigments, adhesives, and other types of liquid products to help improve application control and prevent running
- Thixotropy — Thins compounds that are normally thicker, specifically through stirring, shaking, or disturbing these compounds using other methods
- Suspension and Stability Behavior — Helps stabilize complex liquids while evenly suspending ingredient mixtures in batches
Hydrophobic Silica Free Flow Applications
Hydrophobic silica allows for the free flow and storage of a variety of powdered products, which are often prone to caking and hardening. The consensus for why this material has this effect is that hydrophobic silica forms a mono-particle silica layer around the particles within the powder. Subsequently, this layer helps reduce any “inner friction” that could otherwise develop, creating a kind of ball-bearing effect. In turn, applications benefit from increased consistency of product throughout batches, minimizing the risk of potential issues during processing.
Many different industries use hydrophobic silica across a range of products and applications. Some of the different products that utilize hydrophobic silica include:
- Coatings and paint
- Animal nutrition and feed
- Printing inks
- Powdered defoamers and antifoams
- PVC-based plastics
- Pharmaceuticals and cosmetics
- Tablet powder blends
- Plastic powders
- Fire extinguisher powder
- Polyester resins and gel coats
Industry Example: Tire Recycling
Hundreds of millions of tires are disposed of every year. If they are not recycled or reused, this can have a significant negative effect on the environment.
The use of hydrophobic silica can help lessen the environmental impact of tire disposal by allowing for a more efficient recycling process. Specifically, hydrophobic silica helps during the grinding of the recycled tires into progressively smaller-sized granules. It assists with the free flow and particle screening of the granules, and imparts water repellency to help with moisture control.
Hydrophobic Silica Products from Applied Material Solutions
When selecting a hydrophobic silica, turn to Applied Material Solutions. We offer a wide variety of options, including fumed and precipitated products.