ROLL UP YOUR SLEEVES & GET READY FOR SPRING TRAINING! The Basics of Emulsion Manufacturing
Vince Vopat, Director of Sales, Bergkamp Objectives
Discuss: Equipment and materials of the emulsion manufacturing process Describe the manufacturing process Determining factors of successful asphalt emulsion process Emulsion defined
• Definition—an immiscible liquid dispersed within another Two steps
1. Asphalt is sheered into many small particles by a colloid mill
2. The soap chemistry (emulsifier) stabilizes the particles
+ + + + + + + +
The smaller and more single-sized the particles are, the better the emulsion “Lifting it on a table”
• Simple batch process – Colloid mill “lifts” – Emulsifier chemistry “holds”
Emulsifier All mills and emulsifiers are not equal • Highly modified, hard grades of asphalt require more energy Equipment
• Colloid Mill and motor – Motor is the source of the energy – Rotor-Stator translate that energy into the material – Different geometries with different motors
asphalt
asphalt
Bitumen Emulsions, SFERB Mill Rotor/Stator
Stator
Rotor
“Gap” is the clearance between the rotor and stator
Stator Rotor Equipment
• Tanks • Asphalt storage • Emulsion storage • Soap (optional) Equipment needed
• Asphalt Pump • Soap Pump • Pipes Batch process diagram
Asphalt
Emulsion
Soap Solution Colloid Mill Materials
• Asphalt • Water • Emulsifier • Acid/base (cationic/anionic) Preliminary steps
1. Manufacture soap 1. Fill tank with warm or hot water 2. Add acid/base (pH check) 3. Add emulsifier (pH check) 4. Check temperature of soap 2. Check asphalt temperature – Asphalt temperature requirement will be based on viscosity 3. Calculate emulsion temperature – Asphalt temperature (%factor) + Soap temperature (%factor) = Emulsion temperature
Asphalt
Soap Emulsion Solution Colloid Mill Batch processing steps
1. Start flow of soap 2. Turn on the mill 3. Start flow of asphalt 4. Control the asphalt content Controlling the process
• Asphalt/soap flow – Maintain steady flow – Maintain proportions – Control mill temperature – Keep temperature below 212°F Emulsion QA and handling
• Emulsion is stored according to type of product (specs) – Some emulsions stored at ambient, some 140°F, others – Stored in insulated, heated tank, with mild, occasional agitation – Emulsion must cool before shipped or used • Run tests for certification – Viscosity, distillations, etc. • Particle size analysis – Not for certification but very important information – Samples during the run from the mill and tank samples – Indicative of almost all emulsion properties General trends in manufacturing ease
Easier More Difficult
softer AC grades harder AC grades
unmodified modified
more emulsifier less emulsifier Product trends in manufacturing ease
Easier More Difficult
CSS CMS CRS-1 CRS-2P SS MS CRS-2 SBS polymer Microsurfacing RS High performance systems
• Heat exchangers • Multiple soap tanks • Flow meters • Actuated valves • PLC/Computer control Higher level process diagram Even higher performing
• Inline (Continuous) processing • No soap is manufactured separately • All materials metered and mixed inline Batch vs Inline
• Batch (manual) – Less capital investment – Less expensive, simpler components • Inline – On demand emulsion… constant state of readiness to produce – Automated…More accuracy and consistency, easy to tailor products – Less waste—more efficient with time and materials Laboratory/Pilot scale processing
• Formulation work – Very important and very different from full-scale production – Test performance of the emulsion – Predict any manufacturing problems – Recirculation mills shed little light on full-scale production Summary
• Asphalt Emulsion Manufacturing is a two step process of the colloid mill shearing and the emulsifier chemistry stabilizing • Many different configurations of colloid mills • Certain emulsion products are more difficult to manufacture due to asphalt properties and/or product formula • Laboratory manufacturing equipment should be chosen carefully when piloting full-scale production Questions