Recently there has been increased interest in using the Sonolator homogenizer for wax emulsions. The Sonolator has been used successfully for years in the chemical industry for creating wax emulsions. One theory behind the increased interest may be due to higher costs for petroleum based products. Operations utilizing wax emulsions are looking for stable emulsions which utilize as little of the more expensive oils as possible. Likewise, operations utilizing wax emulsions are exploring making their own emulsions in-house rather than purchasing emulsions from outside vendors.
Stability of the emulsion can be improved through two ways. First, increasing the amount of energy used in the mixing process may help reduce particle sizes and thereby create a more stable emulsion. Secondly, emulsifying agents are often utilized to improve stability.
FIGURE A – LOWER PRESSURE
Testing here at Sonic has revealed combining the two techniques of intimate mixing and an emulsifier yield excellent stability and particle size control. Varying operating pressure in the Sonolator homogenizer results in higher pressures yielding smaller particle sizes. When an emulsifier is added these results are improved. Moving the particle size distribution graph to the left and making the distribution tighter around the mean. Figure A, shows results of a relatively low pressure and amount of emulsifier. For comparison, Figure B shows a graph of higher pressure and increased emulsifier.
FIGURE B – HIGHER PRESSURE
Using a combination of operating pressure changes and various amounts of emulsifier producers have been able to control the particle size within their wax emulsions. Additionally, operations requiring wax emulsions are able to save costs creating the emulsions in-house instead of purchasing pre-emulsified stocks.
These results are consistent across both premix, batch or single-feed and multiple-feed methods. Whether putting all ingredients in one tank and running through a Sonolator homogenizer or piping directly from multiple source ingredients into a multiple-feed Sonolator homogenizer more vigorous mixing and emulsifiers create excellent wax emulsions.