How are emulsions manufactured?
Asphalt emulsions are manufactured in specialized plants. The first step is making the soap. In most cases this is done in a separate tank where the surfactant is activated by chemically reacting it in water. The ionic charge on the surfactant molecule can be positive or negative. Generally an acid is added to the surfactant to activate the cationics (positive charge) and a base to activate the anionics (negative charge). Depending upon the chemistry of the aggregate, the emulsion charge can aid the attraction and adhesion of the asphalt to the aggregate. There is also one class of emulsifiers that is nonionic and needs no activation; one end of the molecule is already soluble in water.
Next the soap water solution and hot asphalt are separately metered into the mill at predetermined rates and temperatures. Mechanical energy is the fourth essential element in the emulsion manufacture. Normally, a colloid mill provides the energy to shear the asphalt into the microscopic particles.
The mill consists of a heavy duty shaft connected to a large electric motor on one end and a circular cutting blade, called rotor, on the other end. The rotor spins at high speed in very close proximity to a stationary structure called the stator.
Dosch-King Emulsions’ founded in 1970 manufactures cationic and anionic water based emulsions for the paving and pavement preservation industry. North Florida Emulsions’ founded in 2003 is a combination construction company (DK) and an emulsion manufacturing facility (DKE) all in one.