On the safe side with JENSEN
The currently rampant coronavirus Covid19 is a new type of coronavirus that was previously unknown in humans. Signs of infection are fever, cough and shortness of breath. In severe cases the virus can lead to pneumonia, kidney failure or death. The virus spreads by droplet infection from person to person, e.g. by sneezing, direct contact or general spread via the air. The infection itself occurs via the respiratory tract. In principle, viruses are not able to copy their own RNA (ribonucleic acid), which means that the viruses need human cells to reproduce. What makes the new virus particularly dangerous is the long incubation period: Infected people only show symptoms after about two weeks. During this time the virus can spread unhindered.
Coronavirus-infected by linen?
The risk of being infected during the transport of bed linen and co. as well as during the washing process itself is being considered as low. A prerequisite for this, however, is the compliance with current hygiene standards. A mixing of linen without pathogens with material containing pathogens can never be excluded. In principle, a risk of infection is possible, in this case one speaks of linen suspected of being infected. This must be treated with disinfectant to interrupt the chain of infection.
JENSEN meets highest hygiene demands
Tunnel washers from JENSEN meet highest hygiene requirements and are designed for disinfecting washing procedures according to RKI guidelines, e.g. 10 minutes at 90° C (194°F). The Robert Koch Institute (RKI) is the government’s central scientific institution in the field of biomedicine and one of the most important bodies for the safeguarding of public health in Germany.
Total process control thanks to FlexWash
The FlexWash technology in the renowned JENSEN tunnel washers offers the total process control of each batch. Washing is done in standing baths in the pre-wash and main wash areas with the bath exchange process and rinsing is in counterflow. JENSEN was the first manufacturer in the world to develop this process and bring it to market.
Every batch stays in its own bath until the start of the rinse zone and has its own individually programmed quantity of detergent, process water temperature, bath level, etc. FlexWash provides the benefits of washing and rinsing with the standing bath technology. The full batch integrity of linen and liquor results in fewer empty pockets.
The design of the steam nozzles, a very efficient and fast heating of the laundry (not only the liquor), where steam is blown upwards into the drums resulting in an even heat distribution in the batch. A uniform thermal disinfection of the linen is the perfect result.
Completely closed recovery system keeps everything inside
In the SL version of a JENSEN tunnel washer, there is no need for recovery tanks and only one or two central pipelines are necessary. Thus, dirt and bacteria build-up in tanks are avoided. All pipelines are also made from stainless steel, effectively preventing corrosion and contamination. The amount of maintenance required is much less since there is no need to carry out the regular and often difficult task of cleaning tanks. This means that laundry processing is made much faster. Thanks to the completely closed recovery system without tanks, heat losses are also avoided much more effectively. In open tanks, as in conventional machines, heat escapes upwards, even if the machine is covered. Even if such tanks are fitted with lids and are insulated, more heat escapes via the larger surface area. In addition, tanks make access and cleaning more difficult.
With the SL, the heat is left in the compartments and thus in the linen, the pipes with a small surface area radiate very little heat: The energy remains in the system!
That leads to the next major hygiene factor – the right temperature over a defined period of time.
Temperature is key for hygiene
Temperature plays a crucial part of the wash process. If appropriate temperatures are not reached, it could result in dirty or stained linen, or worse: improperly disinfected linen. With a current emphasis on safety and reduced contamination, it is no understatement to stress the importance of guaranteeing the correct temperatures throughout your wash cycle. An efficient insulation of the main washing zone for very low temperature losses is another tool to meet high hygiene demands. As a standard, a thermostop is programmed in the control system, i.e. after the (planned) switch-off of the machine, the drum continues to swivel until all items in the main wash zone are thermally disinfected and only then does it stop.
Temperature on the wash process
Increasing temperature boosts the energy and movement of molecules in the wash process. This helps your wash process in several ways: Speeds up chemical reactions, easier grease, oil and fat removal, causes some soils to dissolve better and is necessary for disinfection. Exposure to high temperatures is necessary to disinfect linen. By increasing temperature or increasing the exposure times to a high temperature, one can achieve higher levels of disinfection. An automatic monitoring of temperature and time in the main wash zone by means of an electronic thermometer measures the real liquor temperature on the last main washing compartment and transmits it by remote transmission to the control of the tunnel washer. In this way it can be checked whether a pre-defined temperature at the beginning of the main wash has also been maintained for a defined period of e.g. 10 minutes until the end of the main wash.
Actual temperature vs setting temperature
The difference in temperature between the PLC setting and the actual temperature of the linen is common, and without testing equipment it is very difficult to test the temperature of linen inside a drum.
Hot water will naturally cool down until it reaches the surrounding temperature. This happens in a cup of hot water as well as in your main wash section of your tunnel washer. Different kinds of insulation around the inner drum will also have different insulating results. In colder months, the surrounding temperature is colder and can have a greater effect on the temperature decrease. It is also important to remember, as hot water gets in contact with pipes, machine, and linen, it cools down too. The PLC is reporting the temperature of the sensor on the tunnel drum, it is not giving a reading of the actual temperature of the linen inside the tunnel—and this is the only thing that matters for disinfection.
Test your temperature
It is crucially important to guarantee two things: first, that the linen reaches the required temperature, and second, that it maintains that temperature for the required time. This should be the most basic quality standard for all laundries, especially during this time, and the only way to really guarantee this is to test.
How to test?
There are many RFID temperature testing devices in the market. The device can be washed together with the linen, and thus more accurately records the temperature of the linen. It records a temperature reading every 10 seconds. Running the test a few times in your tunnel can help you determine the temperature behavior of your tunnel and any difference between the linen and PLC temperatures. For maximum quality control, this test can be conducted seasonally. Tests are a vital part of JENSEN’s product development, and these have also to be done for UVClean to ensure a proper impact and value for customers.
Clean, cleaner, UVClean
The new UVClean system (pat. pend.) in JENSEN tunnel washers prevents bacterial growth in double drum sections automatically and without any chemical supply – it is the most natural, most ecological and most efficient way of eliminating germs and bacteria. And what’s more: contrary to chemical methods, bacteria cannot become resistant to UV radiation. Once again, the JENSEN engineering team has come up with a simple, yet innovative way to add value to our customer’s laundries.
Bacterial contamination in a tunnel washer
Usually, all the linen is disinfected in the main washing zone of the tunnel washer. Nevertheless, there is a risk in all types of tunnel washers that the linen gets re-contaminated by microorganisms in the rinsing zone, namely because of bacterial biofilms within the tunnel washer that find a perfect breeding ground in a warm and humid environment in areas that are not consistently flushed by the wash liquor. The disinfection of internal surfaces in a tunnel washer is thus key to avoid germ growth and biofilms, and it’s a topic that many laundries are very well aware of. Below the bath level, the internal surfaces of the outer drum are constantly flushed with liquor. Thanks to the fluid mechanics, microorganisms cannot accumulate here, and disinfectants can act directly on the surfaces and prevent germ colonization. Above the bath level, the internal surfaces are not washed and are constantly kept moist by temperature, splash water such as liquor with detergents, auxiliary washing products, starch, as well as condensate. The conditions are warm and humid, similar to a steam bath. This climate favors the growth of microorganisms that accumulate on the surfaces and can form a biofilm. The cleaning of these surfaces on the inside of the machine is difficult and costly. Our target was to eliminate microorganisms on internal surfaces before any biofilm formation occurs.
Inspired by nature, perfected by JENSEN engineers
The solution was obvious and natural: Ultraviolet C radiation is a natural approach to current methods to treat localized biofilms. This method is also used in the pharmaceutical industry when multidrug-resistant microorganisms need to be cured, e.g. when antibiotics fail. It kills microorganisms such as germs, bacteria, viruses or other pathogens or prevent their growth. Compared to other disinfection procedures, it has the advantage that chemicals can be omitted and that these operations have no issues with emissions and disposal. UV-C radiation is now used for an ever increasing bandwidth of applications. For example, it is used for disinfection in purification plants, laboratories, air conditioning systems and even in swimming pools and aquariums as well as on various stages of the industrial processing of food and drinks. In medical practices and hospitals, the UV-C radiation is used to sterilize instruments, work surfaces and ambient air. In 2019, JENSEN is introducing UV-C technology for tunnel washer systems. In the tunnel washer, two UV-C lamps mounted in a housing on the outer drum irradiate the inner surfaces between the inner and outer drums. The reflection effect reaches the inner surfaces and kills microorganisms. It’s a simple, almost maintenance-free system that can be operated at very low costs, with two 10W bulbs that need to be replaced approximately after one year. After 16 months with 24/7 operation, the UV lamps still produce 75% of the radiation emission. The exchange of the lamps is quite easy. Cleaning of the lamps is easy as well, and UV-Clean is also available as a retrofit option for existing JENSEN tunnel washers. Contact samples from the surfaces can easily be taken through two control flanges, meaning that the efficiency of the UVClean system can be measured at any given time. Also, the radiation performance of the lamps can be checked through inspection windows.
Test results
Extensive tests, carried out by the JENSEN development team at a customer’s laundry show the effectiveness of eliminating bacteria with UVClean. For this, the JENSEN development team used defined germinated DesValiG test specimens of the wfk Institute for Applied Research (wfk-iaf.de/en/). Via test flanges, the test specimens were inserted into the shell of an outer drum at different distances from the radiation source. The irradiation took place for a defined duration. The test specimens were then sent to the wfk Institute for evaluation.
«We evaluated the reduction of the defined sample germs as well as the total germ count, and were amazed by the results» says Martin Sukop, Sales Manager JENSEN Germany, «That’s why we highly recommend UVClean as an ecological and viable way to eliminate germs, bacteria and biofilms in the tunnel washer. It’s a simple, almost maintenance free system that prevents laundries from a lot of problems.»
JENSEN tunnel washers meet highest hygiene requirements and are designed for disinfecting washing procedures – join us to be on the safe side with our various processes to ensure a perfect linen result for our health.
