Can anyone help me with this problem? I have a large glass bottle washer in the factory in which I work. The bottles are transported around the machine (upside down) in round metal carriers. As the bottles travel thorugh the machine they are subjected to a variety of treatments to enusre they are clean. After the treatments are complete the bottles enter a spray rinse section which uses a blend of hard and softwater to achive a hardness of around 120ppm. Once the bottles are finished in the rinse section the bottle carriers are turned 180 degrees and we rely upon gravity for the bottles to fall out.
If we drift away from this hard/soft water mix of 120ppm the bottles start to hang up inside of the carriers (its almost magic). There is nothing to hold the bottle up. Effectivly we have a standard british glass pint bottle hanging vertically in a metal cylinder. Only one part of the bottle is in contact with the metal tube (remember the metal tube is heavily covered in limescale). If we go to softwater (0-5ppm) the bottles do not fall out and if we go hard (240ppm max) the bottles do not fall out.
Can anyone explain what is happening here?
A caustic cleaning chemical is used further upstream from the rinse section and a surfactant is added to one of the wash tanks to prevent foaming. The tanks are also heated but the rinse water is at ambient temperature.
From what I have read and with limited brainpower I understand the following to be true.
The softwater has a low water tension and therefore high adhesive properties and the hard water has high water tension and low adhesive properties.
Help?
