Further advancement in paraffin wax industry lead manufacturers to develop Solvent De-Oiling method. In this process slack wax is heated and mixed with MEK and Toluene and chilled until the Solvent recovers oil; this part called Crystallization.
At this point characteristic of paraffin wax such as melting point, penetration and oil content will be controlled by the amount of solvent mixed with slack wax. Crystalized wax is filtered multiple times to separate solvent. Then Crystalized wax will go through solvent recovery plant.
At this point the solvent free paraffin wax will send through Decoloring & Deodorizing units in order to separate the remaining impurities and odor removal. Finished product is fully refined paraffin wax.
As Solvent Refining process is costly and requires specific and advanced machinery and techniques, manufacturers of paraffin wax whom do not have the capital or expertise use alternative process; Sweating Process.