Required to work even with incorrect dosage
In large washing plants, dosing of detergent usually takes place automatically, while in smaller plants dosing is done manually. Therefore, it has been an important aspect of the development work that the killing and deactivating effect on bacteria and viruses should be independent of the human factor – even if the detergent were incorrectly dosed, the combination of the program's temperature and time will guarantee a hygienically clean wash.
In order to be able to study deactivation and killing of viruses and bacteria present in a product or in a production plant, practical experiments have often been used in the past with contaminated washcloths that passed through the washing machine, which were then analyzed after washing. The advantage of working with mathematical modeling is that you take advantage of the great knowledge and established methodology that is already used to study at what temperatures different microorganisms die or are inactivated. Using mathematical models in this way is a classic methodology from the food and process industry area. RISE has, among other things, done similar assignments where deactivation of microorganisms in recycled paper fibers from paper napkins were studied.
– Some viruses are always relevant for the customer to work with, such as winter vomiting. What RISE offers is an understanding of which viruses and bacteria we really need to deactivate and relate to, what is required to kill or deactivate, the amount of microorganisms in the process, as well as the consequences of different amounts and types of microorganisms, says Erik Nygren, who worked in the project together with colleague Lars Hamberg, researcher in process technology, safety and hygiene at RISE. For example, a vomiting disease is not such a serious infection for most people, but the perceived feeling is very stressful.
Combination of competences
By combining two different core competencies, RISE has contributed with an understanding of the evaluation of various infectious diseases, process technical understanding and engineering thinking. This is to be able to map processes together with the customer and mathematically model them in order to get a figure on how much viruses and bacteria are deactivated and killed in the washing process.
– The challenge lies in understanding the customer's actual needs to be able to meet these. Another important part is the educational aspect, as it is part of RISE's overall goal to strengthen the competitiveness of Swedish industry, says Erik Nygren. We must not only deliver a product, but also an understanding - for example of how to identify and prevent the spread of disease-causing or product-destroying microorganisms. In this project, we model on laundry and drying products, but it can just as easily be about recycling food packaging.
Erik Nygren believes that demand for this type of service will increase, especially from customers who need to work with microbiological risk assessments based on the Swedish Work Environment Authority's regulations. RISE is well equipped to take on similar assignments as for Electrolux Professional in several sectors, both through strong interdisciplinary expertise, where customers do not have to turn to several players to solve the task, and through a well-proven methodology combined with a large database of current microorganisms.
– We have worked together with RISE in various contexts for many years, so it was an obvious contact to make when we realized the seriousness of the new situation that the pandemic entailed, says Silvana Johansson. It is important for us to be able to offer a washing process based on research and facts, as that is our guarantee that our customers get a safe product. We have benefited greatly from the collaboration and received a very good delivery in the form of project management, shared knowledge, reports and webinars.
