Comprehensive catalog of requirements
Accordingly, in 2012 Biotest contacted Prof. Andreas Gerdes at KIT’s Institute for Functional Interfaces. The investigation began with the scientists taking core samples at various points. This showed that water accumulates under the flooring as a result of damage caused by equipment, such as stainless steel tanks or troughs, that had fallen and broken the thin upper layer. The floor thus no longer met the requirements for surfaces laid out in the GMP standards (the German regulations are included in an appendix to the German Drug and Pharmaceutical Manufacturing Ordinance).
To avoid such problems in the new building, in 2013 Biotest invited Professor Gerdes, who was now also working for IONYS AG, to join the planning team. “We wanted to choose the new flooring on the basis of scientifically determined results,” Lapa says. Gerdes and his team developed an entirely new evaluation procedure for “Sustainable Flooring Systems for Clean Rooms.” Their goals was to reduce downtime, optimize maintenance and upkeep costs, and sustainably reduce life cycle costs.
The first step was to assemble a project-specific catalog of requirements. The Biotest employees responsible for production, maintenance, hygiene, and cleaning each outlined their requirements, including resistance to acid and other media, disinfectability, and wetting behavior. “At Biotest, production runs around the clock, seven days a week, and the facilities have to be disinfected five to six times every day,” explains Florian Thyroff, team manager for cleaning. “Once a month, the floor is disinfected with peracetic acid.” According to Antonio Condemi, who is responsible for Biotest’s properties and specializes in laboratory planning and clean rooms, high load-bearing capacity is also important, as the stainless steel containers used for column chromatography can weigh up to five tons, and various material handling vehicles are also used in the process. In addition, it must be possible to easily repair the flooring during ongoing operations. Given past experiences, this was a decisive point. The evaluation team was particularly impressed by the fact that norament® floors are easy to maintain even when heavily used – with nora® pads, for example, or simply by repairing minor damage themselves. Specifically, it is extremely important for Biotest that this work can be carried out during ongoing operations or in very short regular cleaning periods.
15 different products were tested
On the basis of these requirements, Gerdes and his employees developed a material profile and then tested floors from different manufacturers. The 15 products were subjected to extreme stresses; for example, they were placed in a bath of pure hydrochloric acid. This exposed clear weaknesses in some of the materials. In addition, the aging process was artificially simulated, in order to determine what the surface will look like in ten years.
From the initial determination of relevant parameters to the decision, the process lasted about six months. The scientists ranked the products after the final analysis, and nora® products were the front of the pack. Because of their sealed, highly leakproof surface, rubber flooring systems are extremely resistant to wear and can be used in areas which experience high pressure loads, such as those caused by fork lifts or the wheels of heavy equipment and machinery. Due to the elasticity of the homogeneous material, rubber floors are also able to withstand impacts, for example from falling tools, hose connectors, clamps, and other metal parts. In addition, they are easy and inexpensive to clean and can be fully disinfected. Another advantage: if the flooring is damaged, maintenance and repairs are very user-friendly. Many forms of contamination can be removed without leaving any residue. Surface scratches caused by heavy usage can also be removed using a pad. And when necessary, individual norament® rubber tiles can be replaced, which is usually not possible with mineral or resin-bonded systems.
17,000 square meters of rubber
Based on the analysis results, Biotest decided to install approximately 17,000 square meters of norament® grano in three different colors in the new production building, and to use the electrostatically dissipative variant in the clean rooms. The wall connections here were designed using cushioned-edge profiles. To create a cushioned-edge at a point where the flooring is to be penetrated, the rubber is heated and then shaped around the penetration. In this way, the flooring material turns from the horizontal to the vertical without any leaving gaps or joints. This is a substantial advantage. If liquids are spilled onto the floor, the transition to the vertical is not at ground level, but about two to three centimeters higher, which provides enormous advantages in terms of hygiene and maintenance.
Because installation is decisive for the later performance of a floor, the employees of the company responsible for the installation, Esper in Wiesbaden, were prepared for the project and received training from nora systems in Weinheim. This cooperation with a long-standing nora installation partner known for its consistently high quality ensured a flawless installation process. That the installation was comprehensively documented (room by room, in cooperation with QA) provides additional security for users. Thyroff is pleased. “Cleaning results are consistently good. Dirt can be removed easily and without leaving residue.” Lapa’s response is also positive. “The great advantage of rubber over other flooring materials is that it is possible to repair and replace damaged areas. This work can be carried out without any problems during regular routine shutdowns, which take about three weeks, and complex renovations are no longer necessary.”