In more and more industrial companies it’s necessary to create a particle free environment, since the products are more and more sensible and can be damaged badly by particles accordingly. Even if the production environment is in a cleanroom, it is no guarantee that the integrated machine will have the same air purity class as its surroundings.
The starting position
One of our customers faced exactly that challenge: a machine manufacturer, who produces measuring devices for contactless and non-destructive characterisations of surfaces and layers for double-sided sample inspection. After a detailed analysis of the production process it has been ascertained that in closing the machine the clean air in the cleanroom environment could not get inside the machine. Moreover, this generated particles even during operation. Therefore it is possible that there’s a higher particle concentration inside the machine than outside the machine in the cleanroom environment.
Every “impurity” of machines can have dire consequences. An undesirable particle on any of the samples can distort the test result or increase the scrap rate.
To find an appropriate solution, measurements inside the machine had to be performed. With the measurements it was proven that the real concentration inside the machine was just an ISO class 8 and therefore the concerns about „impurity“ confirmed.
Test phase 1
To integrate a fan filter module (fan filter unit) which can guarantee the clean air supply inside the machine was the first approach. To test the idea, standard fan filter modules, which haven’t been individually altered yet, were connected to the machine.
Even though the modules hadn’t been fitted exactly, this short term solution led to a reduction of particles and therefore to a better air purity class of ISO 6.
Test phase 2
After the first successful starter tests the problem of exact adjustment of the fan filter module onto the machine arose. Initially the filter modules were integrated onto the machine’s surface, where the modules were permanently installed and the machine was supplied with a vertical airflow.
Moreover, the fan filter module had to be equipped with ion staffs to meet the criteria needed for electrostatics. Another “cleanliness problem” arose thereafter, since these staffs also had to be cleaned. To minimize this cleaning effort the ion staffs were processed into some sort of drawer. An easy and fast cleaning is now possible at any time.
The first approach was unsuitable for the machine manufacturer and his surface measuring devices, since they serve double-sided test inspections and therefore need to be surrounded by airflow from both sides. Therefore only a horizontal air flow as a solution was possible.
In cooperation with our customer a solution was found. The fan filter module has been connected to the rear of the machine, which has been closed with a metal sheet.
This solution’s decisive advantage is that the customer can integrate the module with 2 seals himself. With the lateral inclusion a vertical airflow can be produced, where both sides are surrounded by clean air.
With the joint solution’s realisation an optimal air purity for sensible samples was achieved, even inside the machine. Therefore a particle and error free measuring process was made possible for the machine manufacturer. The construction of a costly cleanroom can be substituted by this easy, fast and cost-efficient variation inside the machine, as this example shows.
Since customer requirements and technical machining data changes, it is necessary for a successful solution’s realization to adapt the concept continually. If you want to know, to what extent a solution like that would be feasible for your machines, just get in touch with us.
We advice you any time.