Mr. E. Kim from EcoTech USA(267-516-6222) explains basic design features of dry cleaning machines. In this episode, he explains the difference between a soft-mount and a hard-mount.
[Hard-Mount Machine}
- Traditional setup where the drum housing is directly bolted to the frame
- The extraction speed usually tops out below 550 rpm with a lot of vibration
- Heavier-than-water solvent like perc can be extracted efficiently at lower rpm
- Even though more solvent is left in clothes after extraction, it doesn’t slow down the production because perc evaporate very quickly, 30 times faster than hydrocarbon (vapor pressure: 14 mmHg @ 20°C).
[Soft-Mount Machine]
- It is a more modern setup where the drum housing is suspended by suspensions.
- The extraction speed usually tops out over 800 rpm with the vibration damped by the suspensions.
- Lighter-than-water solvent like hydrocarbon needs a higher rpm to be removed from clothes. Otherwise, too much solvent is left in clothes that in turn needs to be removed by drying.
- Hydrocarbon solvent does not evaporate easily (vapor pressure: 0.48 mm Hg at 20 °C), so it must be removed as much as possible during extraction to shorten the drying cycle.
