MORPHOLOGY OF EPSILON-CAPROLACTAM CRYSTALS DEPENDENT ON THE CRYSTALLIZATION CONDITIONS

The morphology of caprolactam crystals is an important property becaus e it can affect their filterability. This study shows that the morphol ogy of caprolactam crystals depends on the water content of the mother liquor and on the applied growth kinetics. Needle-like crystals were formed during single crystal experiments under two sets of conditions: (1) at high growth rates in a water rich mother liquor and (2) at low growth rates in the absence of water. Experiments were also performed in a lab-scale batch crystallizer and in a pilot-scale continuous cry stallizer but did not yield exclusively needle-like crystals.