Cleaning processes often offer considerable potential for improvement to make parts cleaning operations more reliable, economical and sustainable, according to Ecoclean. The first step is to perform a systematic process analysis that also takes a close look at the upstream and downstream production steps.
To guarantee the quality of the subsequent stages of the process, to avoid rejects and to guarantee the functionality of the final product, the constant cleanliness of the parts is an essential quality criterion. Ever stricter or even modified cleanliness specifications must be respected. In addition, the requirements of speed, cost
the efficiency and sustainability of the cleaning process are constantly increasing. However, the quality, speed and efficiency of the cleaning work do not only depend on the equipment, the treatment technology and the fluid used, but also on factors related to the cleaning process itself.
Systematic process analysis – overview So what if parts suddenly come out of the system stained, particle or thin film cleanliness specifications are no longer being met, cleaned parts arrive at the customer corroded, or cleaning is too slow/too expensive? In the case of these and other problems, a systematic process analysis such as that carried out by the Ecoclean Academy of Ecoclean GmbH can identify the root cause of the error. Cleaning experts not only focus on the actual cleaning process and equipment, but also assess the overall manufacturing environment. The smallest change to the part, part spectrum or material, type of contamination, or upstream or downstream process changes is enough to seriously alter cleaning results.
Stains and residues of thin layers on parts
According to cleaning experts, a poor cleaning result or one that does not meet the new, higher requirements is a “classic” reason for carrying out a process analysis. The first step is to identify the exact problem: are the thin film cleanliness specifications not being met or are there stains on the parts?
If staining is the problem, one of the questions to ask is whether the amount and composition of contaminants (processing medium and other substances) have changed or whether the constituents and concentration of the cleaning medium are still appropriate. . Other factors, such as the quality of the rinse water, the treatment of the bath, the technology and the sequence of the process, as well as the drying step, are also closely examined. These are other influencing variables which play a role if the cleanliness results of the thin layers are not satisfactory.
Inability to meet particulate cleanliness requirements
If the cleanliness analysis after the cleaning cycle shows too many or too large particles still adhering to the parts, this may also be due to the cleaning schedule and sequence of processes used. Possible causes are residual particles in the working chamber or on the workpiece carriers, an unsuitable filter system or a clogged filter. Sometimes it’s the wrong choice of cleaning containers, such as perforated galvanized sheet metal crates, that hampers the efficient and reliable detachment and removal of particles. This type of box blocks the ultrasonic waves and prevents them from developing their full effect on the wash load. Likewise, the spray pressure does not reach the inside of the perforated boxes. Another problem compared to round wire baskets is that the cleaning product does not drip as effectively from these boxes. This can result in the unwanted transfer of contaminants and/or cleaning chemicals. In any case, much longer and therefore more energy-intensive drying processes are required.
Another cause of failure of the cleanliness check is often burrs still clinging to the parts, which come off when handling the parts during the check for residual contamination and then end up on the particle filter. If these particles are examined under a microscope, it can be determined whether they are chips or burrs. If so, the upstream processes should be evaluated to know where the burrs are occurring and how to prevent them from forming. Particle cleanliness can also be affected by magnetism that is “purchased” with raw materials or occurs during the manufacturing process. Magnetism binds chips to parts and hinders or prevents their removal during the cleaning process.
Handling parts after cleaning
However, the cleaning process is not complete when the parts come out of the machine with the required level of cleanliness. To avoid recontamination or
corrosion, which can occur even with preserved or passivated parts, it is important to look at how the parts are handled after the cleaning step. The following questions need to be answered: Where, how and for how long are the parts stored? How are they transported to the next processing step? What type of packaging is needed for this? In addition, the high demands on cleanliness often make it necessary to carry out processes such as internal transport, assembly or packaging in a clean environment or clean room.
Cleaning Process Update
Besides cleanup issues, changed cleanup schedules can be an additional reason to perform a process scan. The goal is usually to shorten processing times or improve the cleaning result. As always, analysis begins with documenting the actual state, which includes checking process parameters, process sequence, and process times. Based on the results of the analysis, potential for improvement can be identified and appropriate measures can be defined. These may include upgrading the system, for example by upgrading or upgrading the ultrasound equipment.
It is essential that parts cleaning personnel are involved in process analysis and optimization measures. Staff awareness of cleanliness, as well as the capabilities of the cleaning technology and the impact of parameter settings on the cleaning outcome, is a key factor. In the event of a change of personnel, it is also important to pass on knowledge of how the cleaning system works and how, for example, bath treatment measures or regular maintenance work on the cleaning system is carried out. . Otherwise, problems that were eliminated in the past may reoccur. Investing in the training and further education of cleaning staff is therefore a cornerstone for achieving reliable cleanliness requirements in an economical and sustainable way. The Ecoclean Academy therefore also combines process analyzes with classical training.
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