ICT
TECHNOLOGY OVERVIEW
Monitoring Surface Cleanliness and Bath Contamination CONTROLLED CLEANING QUALITY REDUCES COST RISKS
A
The consequence is often costly and resource-intensive process control: – In order to be on the safe side, cleaning agent concentrations are significantly higher than required for adequate cleaning in many cases. As a result, cleaning agent is carried over into the rinsing zones, where it’s removed by means of bath maintenance measures. – Due to the fact that the concentration levels of the cleaning agent’s ingredients and contamination in the baths are often unknown, baths are changed earlier than necessary, either partially or entirely, in order to be on the safe side. In addition to increased consumption of water, chemicals and energy, this results in considerable wastewater reconditioning and disposal costs, as well as reduced availability of the cleaning system. Overdosing of the cleaning agent and premature bath replacement can be avoided by continuously monitoring cleaning agent and contamination concentrations in the baths and by inspecting part cleanliness. Not infrequently, optimising runs reveal Process and Cost that specified residual Optimisation through contamination limit Continuous Bath values can also be Monitoring 1 reliably adhered In aqueous cleaning Image source: SITA to with lower processes, results are Messtechnik 1 concentrations influenced decisively Control unit for a system for fully automated monitoring of bath quality and cleaning agent of cleaning agent by temperature, concentration, as well as consumption-dependent, additional dosing of builders and tensides. ingredients and/or concentrations of reduced temperatures. builders and tensides in Measuring systems based on sensors which have been the cleaning agent and contamination in the baths. On the one specially developed for cleaning processes are available for hand, cleaning agent performance is decreased by carried-over determining the contamination load in the cleaning baths. particulate and oily contamination. On the other hand, builders They detect and document the extent to which the bath is and tensides are depleted to different extents during the cleaning contaminated with particulates and oils, and reliably indicate process, which also changes the quality of the cleaning results.
dmittedly, cleaning components represents a cost factor, but inadequate or no cleaning at all engenders a cost risk. For this reason, residual contamination limit values which have to be monitored and documented are being specified for more and more workpieces. Process optimisation by means of continuous monitoring of cleaning and rinsing baths is consequently becoming increasingly significant. Regardless of whether residual particulate contamination on components impairs their function or even causes complete failure, or if film-like residues diminish the quality of downstream processes such as coating, hardening, bonding or welding – the consequences are costly rework, complaints and, in the most unfavourable cases, expensive recalls which damage the company’s corporate image. In order to eliminate this cost risk, more and more companies are specifying component-specific residual contamination limit values, compliance with which has to be monitored and frequently documented. This is associated with stricter cleaning requirements, especially with regard to the quality of the cleaning and rinsing baths.
24 AUGUST 2011