The value of cleanliness in medical equipment manufacturing

Products used in dentistry and medicine must meet exacting cleanliness standards, and instruments classified as critical have to be sterile when they are used. To supply sterilized items to customers, medical instruments company Gebr. Brasseler GmbH invested in a new cleaning and packaging facility with a cleanroom. Around 12,000 different parts undergo in-process and final cleaning in an array of Dürr Ecoclean solvent-based cleaning systems and aqueous-type, ultrasonic, ultra-fine cleaning systems made by UCM AG.
 

Cleanliness compliance

Although its products are marketed in around 100 countries, Brasseler conducts all development and manufacturing at its Lemgo, Germany, site, relying on more than 1,000 employees.

“In order to further improve our customer service, we invested in a new packaging concept and a cleanroom of around 250m2 last year. This will enable us to produce up to 10 million instruments in sterile packaging for dental and medical uses each year. Our part cleaning operations had to be fully revamped as well in this context,” says Helge Neitzel, head of Abrasive Instrument Manufacturing at Brasseler.

High demands were placed on the new in-process and pre-packaging cleaning equipment. Apart from cleanliness, the specification called for high throughput and availability rates as well as flawless technical documentation. Given the diversity of parts and materials – the company produces about 12,000 items made of carbide metal alloys, stainless-grade and other steels, ceramics, and titanium – it was necessary to provide several solvent-based cleaning systems to perform cleaning between the individual process steps.

“This allows us to segregate the material flows and hence, to prevent cross-contaminations,” explains Marcus Becker, Cleaning Technology group leader at Brasseler. Final product cleaning and the cleaning cycle ahead of product packaging in the cleanroom are performed with ultrasonic, ultra-fine cleaning equipment using aqueous media. The company also thought it was important to source both system types from the same manufacturer.

In researching eligible equipment manufacturers, Brasseler project managers attended the parts2clean trade fair. They then performed cleaning tests with six manufacturers. In the end, the company opted for Dürr Ecoclean GmbH’s solvent-based EcoCBase P2 and Compact 70P cleaning systems. Both models use modified alcohol, which removes both polar and non-polar contaminants from the product. Cleaning and drying operations are performed under vacuum, so no additional explosion protection is necessary. For multi-chamber systems used in ultra-fine cleaning, Brasseler chose the solution proposed by the Swiss UCM AG, a Dürr Ecoclean group company.

“What mattered to us was the overall package – the advice received, the cleaning test results, equipment design and technology, the service network, and the price/performance ratio. Their offering matched our expectations exactly,” Neitzel explains.
 

Fast, efficient cleaning

Following machining, grinding, coating, and other processes, approximately 950,000 parts go through solvent-based cleaning in two shifts every day. The control units can store eight cleaning programs each, selectable via a bar code, depending on the cleaning step.

For reliable removal of machining oil, grease or abrasive residue, chips, particles and chemicals from the galvanizing process, and other contaminants, the systems possess two flooding tanks – one for pre-cleaning and the main cleaning/degreasing tank. Additional steam degreasing features and ultrasound units ensure cleanliness for the next downstream operation.

“All this is performed in short treatment cycles. This is due, on the one hand, to the high vacuum power. On the other hand, the work chamber is filled very quickly thanks to the powerful pumps and large-diameter piping. Indeed, this is a point on which the Ecoclean systems distinguished themselves from the competition,” Becker adds.

Also contributing to high cleaning quality is the reconditioning of the solvent through continuous distillation plus full-flow and bypass filtration. Some filters are equipped with magnetic inserts, which improve retention of metal chips.
 

Direct transfer to cleanroom

A four-sided overflow feature, developed by UCM, is used on all tanks. The cleaning or rinsing fluid is introduced from below, moves upward, and then flows out over the rim of the tank on all sides. Foreign matter and particles are discharged from the tank without delay. This ensures the product receives an intense cleaning treatment while also preventing re-contamination when the parts are lifted out of the bath.

“We found this feature on no other manufacturer’s product. A further detail we liked about UCM’s system is the medicinal trays. Due to their special design, they prevent disease agents from accumulating and settling in the trays,” Becker explains.

The quality of the cleaning and rinsing baths is continuously monitored by sensors, even the ultra-fine cleaning processes.

The first cleaning stage uses three tanks to ensure that materials gathered in cleaning are properly segregated. These are followed by a rinse process, another cleaning step, and three rinsing steps, of which the last two are carried out with de-mineralized water. To prevent any re-contamination of the parts in the hot-air drying process, the dryers are equipped with HEPA filters.

The pre-packaging cleaning system is virtually identical. Here, the first cleaning step is performed in a tray, irrespective of product material. In addition to the HEPA filters, laminar flow boxes are fitted above the last rinsing stage and the dryers. The cleaning system and its conveyor unit are fully enclosed to ensure cleanliness.

For their intermediate and final cleaning processes, Brasseler works with 16 cleaning programs. Programs are selected via a bar code on the product routing documents, which is read by a scanner.

“We can combine up to 12 orders in one batch. The control software checks automatically if all parts are to be cleaned by the same program. If this is not the case, an alarm signal is issued and the process cannot be started,” Becker says.
 

Equipment validation

Except for one solvent-based system, all new cleaning equipment was qualified in compliance with EU and U.S. Food and Drug Administration (FDA) rules and the cleaning processes were validated accordingly.

“Dürr Ecoclean and UCM cooperated with us in carrying out the necessary DQ, IQ, and OQ qualification steps and in preparing the requisite documentation. They also helped us develop the diverse cleaning processes. Actually, the new equipment provides us with cleaning capabilities that exceed our current needs. We consider this an investment in the future, just like the new packaging solution and the cleanroom. It all helps us to further expand our market position,” Neitzel concludes.

UCM AG
www.ucm-ag.com

Dürr Ecoclean
www.durr-ecoclean.com

Gebr. Brasseler GmbH & Co. KG
www.brasseler.de