High-tech handicraft - 1500 sqm cleanroom for 190 seamstresses

Published: 18-Apr-2023

Artivion (Jotec) is expanding its production facilities in Hechingen. The US company develops and produces vascular implants for the aorta worldwide. At the German site patient-specific solutions are manufactured for heart vascular dilation, partially by hand

Those who think that sewing is somewhat of an antiquated handicraft, have not seen the new Artivion production facility in Hechingen. The corporate expansion put into operation in 2022 shines with modernity on each of the most 6000 square meters. The centrepiece of the facility is a 1500 sqm cleanroom facility where stent prostheses are produced for the minimally invasive vascular surgery in a mixture of high-tech and traditional craftsmanship. The implants consist of textile tubes on which stiffening wires are sewn namely by hand, because no machine has been able to do this yet. The stent prostheses are later minimally invasively inserted in the aortas of the patients who suffer from aneurysms. Precisely implanted, they prevent a life-threatening rupture of the arteries. At the specialised site in Hechingen up to 190 seamstresses (mostly women) can now manufacture these implants in shifts and according to a prosthetic plan tailored to individual patients.

Production under cleanroom conditions

Florian Tyrs, one of the two managing directors in Hechingen, was already involved in the development of this special implants. You could feel his excitement when he talks about the products:

“We have been manufacturing these patient-specific solutions for over 10 years now, which are sewn by hand. No machine is able to do this yet. Of course, this is associated with significant staff costs, but this allows us to supply a highly functional product which can be used in vascular surgery without adjustments or complications. This is truly unique on the market. I am always pleased to know that our innovative technologies help to save lives.”

In order to fully exclude the contamination of the product and the associated risks for the patients, the implants are produced and packaged under cleanroom conditions. The new cleanroom is the most important element of the production and literally an affair of the heart for the young managing director in both sense of the term:

“We had reached the limits of our capacity in our old production facility and we wanted to strengthen our site with the new construction and to further expand our expertise in the field of medical technology. In doing so we really thought big and planned for the future. The cleanroom production on more than 1500 sqm is the centrepiece of the facility. Here we have put great value on functional processes and the latest technology and are very satisfied about how the production conditions have been improved. This way we can supply an even better quality and have significantly fewer waste.”

Self-supporting construction with walkable ceiling

The company Schilling Engineering, also based in Baden-Württemberg and specialised in delivery of cleanrooms precisely according to the requirements of the processes and circumstances, was commissioned with the planning and installation of the entire cleanroom system. For the medium-sized company the Artivion order was the largest order in its history.

Ute Schilling, the Managing Director of the family-owned company recalls:

“The order from Artivion was something very special. The layout was optimised and specified according to Artivion's product and process flow. Therefore, the cleanroom is aligned with the requirements and interdependencies of the 22 rooms with local conditions. The production areas had to be fully preserved and at the same time no changes were to be made to the building structure of the hall. The technical implementation was examined by engineers, the air conditioning was designed and plans were made for the installation location of the equipment with maintenance accessibility. Here a walkable technical level was created above the locks without requiring metal construction and the entire production area was approved.”

The cleanroom facility is constructed to be fully self-supporting and consists of 22 rooms divided into 12 work areas, 2 offices, personnel and material locks and with a utility and cleaning room each. The entire area is designed for cleanroom class ISO 8. 126 Filter-Fan-Units clean the air in an air-circulation process in order to keep harmful particles away from sensitive processes.

Effective infiltration

The effective infiltration of the large number of employees was particularly challenging during planning. More than 250 persons are employed in shifts for various works within the cleanroom. The personnel must be at their workstation within a time frame of only 20 minutes without waiting times. Three personnel locks were planned in the final solution, which lead into a shared intermediate corridor, which is located between the personnel locks and the work area. 16 roller shutters and 12 sliding doors allow for a comfortable and secure access via contact-less waiving switch in the individual areas.

In addition to the functional processes Artivion also ensured a good work atmosphere within the cleanrooms. According to Florian Tyrs:

“The production of our stent grafts and the associated minimally invasive delivery systems require individual work steps which must be coordinated with each other. For this reason we have planned for various rooms in the cleanroom facility where the individual teams work. The work atmosphere also requires smaller units. This was very important for us. The cleanrooms are bright and they run mostly very quietly and with less noticeable draft. So far, we have had very positive feedback from our employees. Compared with our old cleanroom the working conditions have improved significantly.”

Air-conditioning and dehumidification

However, the actual purpose of a cleanroom facility is of course the safety of the end products. This entire air is exchanged in the cleanrooms 20 times an hour and the harmful particles are transported out of the room with a laminar flow. This ensures compliance with cleanroom classification at all times and provides the certified procedure required for the manufacture of medical technology products. 

In addition to the cleanliness, the air-conditioning must also be ensured with the temperature and humidity control. Most of the cleanrooms, where up to 95 sewing stations can be accommodated, are operated with a temperature of 21 degree Celsius and a relative humidity of 55%. In addition, a special work area “Coating” requires a specially high level of dehumidification because the used coating solution reacts to humidity. This cleanroom area is operated with a rel. humidity of maximum 35% with a separate ventilation unit.

In another work area the produced implants are loaded in a minimally invasive disposable delivery system. To ensure the function, these mechanical parts must be oiled and packaged double-sterile in the cleanroom. For this requirement special extractor hoods and material locks tailored to the size of the instruments were supplied by Schilling Engineering.

Ute Schilling describes the requirements her team had to deal with during the planning:

“The overall planning of the cleanroom facility was very complicated. At times, ten of our engineers worked on the project at the same time in order to implement the requirements in detail construction and to comply with the tight schedule of 10 months between the ordering and qualification”

Timely delivery in five stages

The implants are pulled into minimally invasive disposable delivery systems and prepared for use in surgery

The implants are pulled into minimally invasive disposable delivery systems and prepared for use in surgery

The delivery and installation were planned by the cleanroom company in five stages, so that during the installation of one stage Schilling Engineering was able to prefabricate components as finished kits for the next stage. Four air-conditioning units were installed on the walkable upper ceiling of the lock area for the extensive air-conditioning. There is also a main air-conditioning system outside the building. In addition, there is a fine control for the individual rooms via 9 decentralised ceiling units. The cleanroom facility was qualified in accordance with GMP specifications and equipped with a remote control as well as a monitoring by the company Briem. The cleanroom for the production of the products was subsequently audited and approved by DEKRA.

The young managing director is visibly proud when looking at the complex facility, where one tooth meshes with the other:

“We are very proud of the fact that we were able to implement the project with the qualification within the required time frame under complicated conditions of the pandemic situation e.g. with supply bottlenecks and personnel shortages. I would like to thank Artivion for the good cooperation. We were able to overcome challenges together through the support and quick communication channels.”

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