The last 35 years has seen massive changes in our working lives, with the PC, laptop, internet, Cloud, mobiles, AI and robotics, each producing paradigm shifts in how we work, play and interact with each other. The next 10 years are expected to offer answers to the current challenges (which could be beyond our immediate comprehension), but the laundry and textile rental sector should be exploring the adoption of new thinking and techniques (especially robotics and artificial intelligence). We have to be the leaders because we are more dependent than others on energy, water and labour. Affordable energy will be much scarcer (with massive reductions in carbon emissions worldwide), with good quality water expected to follow suit. The most immediate problem in the developed world is the cost and quality of labour, which is why robotics (coupled with energy and water economy) is setting the agenda for machine and process development. This month we look at where we are now and what skills our leaders of the future – our laundry managers and laundry engineers – are going to need.
Present situation
Even those managers in our sector with the rosiest coloured spectacles would freely admit that most of our rental laundries could be more efficient. Very few are consistently achieving over 200 pieces per operator hour (ppoh), consuming less than 4 litre/ kg and with an energy requirement of below 1.0kWh/kg dry textiles sold. Yet we know that this level of efficiency is achievable, even though only a few demonstrate it. The reason is that the day-to-day stresses of running a successful laundry always seem to dictate today’s priorities, with no chance to step back and take a longer-term view.
Leading suppliers are now addressing this, with plans to make machines that communicate with the laundry manager and the laundry engineer, so that it becomes much easier to optimise in real time the operating costs of each individual piece of kit. Only then can the final piece of the jigsaw be designed – the link between all of the individual machines to produce a fully integrated laundry operating at minimum cost, achieving maximum productivity and delivering consistent quality. We don’t want washer extractor controllers which can just offer any dip required, we want machines which can automatically optimise every dip, depending on the alkalinity of the local water for example. Let’s see what is needed (much of which is already on the CAD screens of every leading machine manufacturer).
Collection and delivery
The electric vans of the future will probably carry just two types of container – a wheeled and lidded plastic trolley and a lightweight canvas washable laundry bag capable of being handled by just one person when full. It is unlikely that single use plastic will be permitted (because the uncontrolled build-up of microplastics in the world’s oceans and in every human body will have to be addressed). This means that every rental container could need to be suitable for use in hotel corridors and restaurant kitchens, for example. The vans and loading platforms will be designed for safe operation by just one person to accommodate future labour costs. The containers could be suitable for automatic discharge at the entrance to the sorting area in the rental laundry. The soiled textiles could be unloaded automatically onto a carefully designed series of sorting belts, whilst the containers will go through decontamination (probably a batch of washing for the bags and an automatic trolley washer).
Sorting
One common current way of separating out clumps of soiled textiles is to transfer them from the initial conveyor onto a second belt moving at a faster speed. This can be repeated a second and even a third time to separate even the largest clump. Once the items are moving separately, they can be scanned for metal and anything containing metal can be diverted to a special line to be made safe by the one operative in charge of the sorting area.
Every item can then be passed under a visual scanner and diverted according to its appropriate classification. The scanner would probably use a simple form of artificial intelligence (AI), working in the same way as the human brain, using visual recognition. Alternatively, if the items are labelled with radio frequency identification (RFID) tags they could be recognised by the signals from these. A series of air jets would then blow each item off the conveyor, at appropriate points, into the collection container for the classification. Much of this is already available and being taken up.
For critical applications, where a double check on the sorted batches is needed, this can be automatically added using a second camera after each sort to verify that the item is going into the correct load, diverting any errors back around and into the system again. Detectors for metal objects and other potential hazards can easily be built into systems of this type.
None of the components of the system described is particularly expensive and the easy option of double checks on each sorted article means that systems with very low error counts should be economically quite feasible.
Washing
The move towards CBTWs capable of handling every batch of washing can be expected to continue. Up to the present, the trend has been to higher batch weights to give greater hourly throughputs from every washing line, but now greater attention is needed to produce machines with the labour-saving automation of a CBTW, but which can handle economically the much smaller batches required by smaller commercial laundries and on-premises laundries. Considerable progress has already been made with smaller CBTWs, but much better small designs are needed for the full potential of low-capacity machines to be realised.
Current CBTW designs often represent beautiful engineering, but they are imperfect when it comes to automatically optimising water flows and chemical dosing, for example. The recent development of pulse flow technology represents a significant step forward but is not always understood by some designers. The key is the recognition that each compartment of the washer is a chemical reactor, and the efficiency of the reaction can be improved using the counterflow rate of water through the stage. If this is varied in the optimum manner, then the washing and rinsing proceeds more quickly, enabling either reduced water demand, better quality, reduced chemistry or greater throughput (with shorter stage times). The target varies with the customer, making this another area for an appropriately programmed AI-driven controller.
Dewatering
Perhaps the most rewarding area for further work with AI control is at the membrane press on the CBTW line. The efficiency of the dewatering has a dramatic effect on the operating cost and the productivity of the tumble dryers, for example. Because these consume large amounts of expensive heat energy in a thermally inefficient process, any improvement at the press can have a dramatic effect on the overall cost, especially for fully dried towelling. The same is true of the effect on the ironer.
The press needs a rapid ramp up to pressure, without causing any burst tears, followed by enough time at pressure to remove moisture by the cheapest method – squeezing it out. In rough terms, pressing consumes only one fifteenth of the energy of the tumble dryer, per litre of water removed. Yet it takes considerable time and skill to set up and maintain a membrane press with the right settings to deliver no burst tears and enough time at pressure. The engineering team has to tune the ‘wait times’ in the programme sequences down to the minimum and identify every means possible to minimise the ramp time and maximise the time at pressure. It should now be possible to deliver this optimisation using an intelligent electronic controller, where again AI should come into its own.
Tumble drying
Despite startling advances in thermal efficiency of tumble drying, this is still the Cinderella stage of the laundry, consuming large quantities of heat energy whilst often producing variable degrees of dryness and many shades of grey; and failing to maximise productivity and energy efficiency. The concept of automatic terminators was a great step forward, but it has been constrained by the need to set these up correctly, keep them clean and keep them tuned. Self-cleaning lint screens should have removed one repetitive labour task, but these need to be further developed and the principles properly applied also to the infra-red dryness detectors on the automatic terminators. An AI driven controller is now the natural answer to both of these.
The next step is even more important; we need real time optimisation of both energy consumption and productivity. Many laundries have now optimised the sequence of classifications into the CBTW to eliminate tumbler holds, which bring washing to a halt while the press waits for a tumbler to become free. In plants where there is genuinely insufficient tumbler capacity to operate without tumbler holds, it is still possible to eliminate holds by the intelligent diversion of the very occasional batch to off-line drying in a separate freestanding dryer.
Ironing
The laundry ironer is often one of the poorest achievers when its performance is rated against its design capability. This is because top-flight productivity and quality depends on correct dewatering of wet textiles coming forward, edge to edge feeding, and optimum settings for roll to bed fit, cladding porosity, vacuum suction, roll to roll stretch, roll to bed alignment and so on.
Some experienced ironer supervisors and laundry engineers have demonstrated ability to set the ironer line up correctly and maintain optimum set-up, but this is the exception rather than the rule. The next step should be continuous monitoring and optimisation using an AI driven controller. We know enough about ironing to give the controller the information needed; the last step is to automate this intelligently.
Conclusion
So, the laundry manager of the future (and the future is less than ten years away) must be able to recognise and institute the good laundering principles mentioned in this article. They must set the direction of travel to optimum performance in terms of productivity and quality.
They will then need to strong back-up from a dedicated, very knowledgeable and highly skilled Laundry Engineer, able to incorporate practical requirements into advanced electronic controls. These require a rethink of our present laundry training syllabuses and materials to back these up, but that is for a future topic in LCN’s ‘Material Solutions’.
Latest advice on provision of mops for healthcare
History
LCNi received a verbal query, during a recent conference, on the provision of mops for cleaners in a modern healthcare facility (a substantial private hospital). The general manager needed to know how disinfection could be achieved and how the provisions of the UK Department of Health advice note (HTM 01-04) are applied to mop decontamination.
Present arrangement
There are two popular types of mophead: the standard Kentucky construction made from 100% cotton threads in a metal or similar head which can be screwed onto the handle; and the removable microfibre mophead which is secured to the crosshead of the mop by Velcro, for example. Cleansing of the Kentucky mophead was widely based on implied thermal disinfection (using a wash stage maintained at 71C for 3 min.)
Disinfection
Disinfection advice in the UK was updated in the early 2000s by a government advice note referenced HTM 01-04, which unfortunately made no specific mention of mops.
Meanwhile, European countries were moving on to a new European Norme (EN14065: Laundry processed textiles biocontamination control system) which did not specify any particular disinfection method but required feedback controls sufficient to give justified assurance of disinfection to the level agreed with the customer. The UK National Health Service (NHS) adopted EN14065 as a requirement of all contracts for decontamination of healthcare linen around 2010. This standard does not mention mops specifically but the standard can be readily applied successfully to mops, provided the customer includes the decontamination of mopheads in its agreed specifications for disinfection.
Disinfection of mopheads requires a separate specification because soiled general healthcare textiles might have 106 or 107 viable micro-organisms per sq cm, whereas mopheads might display nearer to 1011 or 1012 – that is over 100,000 times more organisms to be destroyed. A laundering process to decontaminate general healthcare textiles might need to achieve a log10 reduction of say 5, whereas mopheads might require a log10 reduction to nearer 10. To get this degree of power needs careful thought and a properly designed mophead process.
The simplest form of chemical decontamination is probably the use of a medium temperature (below 60C) bath containing 150 parts per million sodium hypochlorite (‘chlorine bleach’) for at least 3 minutes. This can safely be used on Kentucky style cotton mopheads, with only a slight reduction in cotton life but it cannot be used for microfibre mopheads. Chemical disinfectants are available which are suitable for microfibres, althoughbugs can become resistant (by mutation) to a particular chemical, but the checks will swiftly reveal this and allow a switch to an alternative. Only hypochlorite and ozone disinfection appear to be immune to mutations.
Of course, some bugs (such as Bacillus cereus and Clostridium difficile) are resistant to both thermal and chemical decontamination and for these, dilution becomes essential. This might call for additional rinse stages in a washer extractor or an increase in the flow to the rinse on a tunnel washer.
The way ahead
The typical Kentucky mop is used with a standard mop bucket and hot water charged with an appropriate detergent. The mop is rinsed in the bucket, squeezed to remove most of the water and then used to wipe the dirty floor. It is then rinsed again in the mop bucket and squeezed again for re-use. This means that the mop is being used with progressively dirtier water, so that even a clean floor area is going to become immediately contaminated.
The microfibre mop is seen as the future, because the standard method will involve a fresh and disinfected lightweight mop head being fixed to the crossbar and then dipped in the uncontaminated contents of the mop bucket and squeezed out. It is then used to clean one specific area of just a few square metres. It is not dipped into the mop bucket again but stripped off the crossbar and put into the dirty mophead receptacle for decontamination. A fresh decontaminated mophead is then selected to clean the next dedicated area, and so on.
Conclusion
We hope we have addressed this reader’s query, and if you have a laundering or cleaning problem, please do not hesitate to email the editor at Kathy.Bowry@laundryandcleaningnews.com
