Podcast: What goes into reliable flooring for EV battery manufacturing plants?

Vikki Young is the global research and development group leader for Sherwin-Williams high performance floor coatings. Vikki received her bachelor's degree in chemical engineering from the University of Minnesota before working at Tennant Company for more than 20 years. Vikki recently spoke with Thomas Wilk, editor in chief of Plant Services, to answer a really interesting question: what goes into reliable flooring in EV battery production facilities, and how are these floors maintained to ensure asset reliability and worker safety?

Below is the transcript from the podcast:

PS: Before we get into specific questions on floors and coatings, could you tell us a little bit about your job and what your daily projects look like?

VY: Sure, as you already mentioned, I am the group leader for research and development of industrial type floor coatings with Sherwin-Williams. On a day-to-day basis I manage a group of chemists that are looking at new opportunities for floor coating formulations.

PS: I love the fact we're going to talk about EV battery production facilities today because (1) they’re a high growth area and (2) they’re specialty buildings. What can you tell us about the ways that these facilities are different from other large manufacturing environments, like pulp and paper or petroleum?

VY: Many of the electrical vehicle battery plants today are newly built facilities, so we have owners that are concerned about protecting their floors during construction, but also during the production process when they are up and running. Another consideration is that these facilities use a variety of really harsh chemicals during the production process. For example, there's n-methylpyrrolidone (NMP), and it's used to create these battery type mixtures with carbon black and graphite. These mixtures can potentially spill onto the floor during production, and they can create a potential slip hazard for workers. 

In addition to that, these types of facilities have clean and dry rooms within the facility, and there needs to be considerations for moisture control and electrostatic discharge control as well because there are sensitive electronic parts being produced in those areas.

PS: In our previous communication you had separated out the difference between flooring and coatings, and those are two different parts of the same product here. Your team pays special attention to both of those areas of the floor?

VY: Yes, in these electronic vehicle facilities, the main floor surface is concrete, it's just above ground. It needs to be protected, so floor coating systems are really important. They're tailored to meet the requirements for these EV battery facilities. The system builds, for example, are designed using conventional coatings, but they have unique requirements in each of the sections of the production layout. 

As I mentioned before, clean and dry rooms require electrostatic control coatings, and also special coatings that can block and absorb moisture vapor that might be coming from the concrete. Moisture and static discharge control is really important, so we don't damage these sensitive electronic components. 

There's also these areas where harsh chemicals are being used, and they require specialized systems that have proven performance to be resistant to chemical spills. At Sherwin-Williams we like to partner with these owners, the general contractors and the installers at these facilities to review the site conditions and really understand that production layout. What types of materials are being used during the manufacturing process is really important, and I can provide more examples on how we can tailor a system especially for these facilities.

PS: That's a great opportunity to talk about custom applications, whether there are standard high performance flooring choices across plants or whether your team customizes the flooring system to each EV factory. Could you give us a couple of examples of the way that your team has gone onto a site and taken a look, and assessed the environmental conditions or the geographic location and decided about on a specific flooring option?

VY: Sure. So as I mentioned before, in these facilities, they're using solvents like NMP in their cathode slurries. There also is NMP in the cathode binder resins -- it helps to break them down in during the battery process, so it's really a concern that these chemicals don't get into the concrete or into the environment below the concrete.

Also, workers have to be protected. During the production process when they're using these materials, they’re could potentially be spills, so we have to make sure that we have the right floor coating that is resistant and won't soften and blister if the chemicals are on the flooring surface.

Sherwin will partner with the owner to perform different types of chemical resistance testing. We can do this either in the laboratory setting or we can do this on-site with the actual slurry mixtures and binder formulas that are being used in these EV battery facilities. We have found that many of the owners prefer on-site testing because they do want to protect the sensitive formulas that they're using, and it also gives us a real world type setting to run that testing.

Another concern is all the carbon black and graphite that's being used to make these components, because they do have electrical conductivity, but part of the process is that these materials are being moved around, powder can easily get on the floor, and both graphite and carbon black can be really slippery. In those situations we have to make sure that we partner with them to develop a regular cleaning program.

There's also automated guided vehicles (AGVs) in these facilities that can track these powders around the facility and cause a black kind of almost a pathway where they start to slip around, because the powders are creating a slip hazard for these vehicles as well. So it's really important to contain the carbon black and graphite, otherwise these automated vehicles can't transport the materials from one production location to another because they're slipping and spinning and become inactivated.

PS: You know Vikki, I hadn't even considered AGVs as part of this equation, but of course they are, aren't they? That's a really interesting point.

VY: Yes, and we can go in and run testing on the floor for what we call coefficient of friction. So what is the likelihood that the surface, whether it's contaminated or not, would create a slip hazard. We'll bring in robot type testers that can run across the floor with different types of what we call shoes -- leather- or rubber-soled shoes -- to test slip resistance or the probability of slip on a wet or dry floor. There's also other types of testers that are being used to test the traction of the floor itself without anything on the surface.

Electrostatic discharge is also a concern that I mentioned before. We want to make sure that we have a coating on the floor that will help reduce the chance of a person building body voltage on themselves while they're working. So, these coatings will actually ground the conductivity or discharge it across the floor so it doesn't harm the components within that clean and dry environment.