Switching requires cleaning and flushing lines, tanks, and the colloid mill to avoid cross contamination that can destabilize the next batch. pH control systems must be reconfigured because cationic systems often use acidified soap solutions, while anionic may use different pH ranges and additives. Dosing pumps for emulsifier and modifiers need new set points and often different materials compatibility. QC targets also change for particle charge and breaking behavior. Many plants dedicate soap tanks or even separate lines to reduce downtime and prevent accidental mixing.