Over load or under load?* published in Clean India Journal, June 2012, has been a matter of discussion for laundry managers. Kiran Raj Singh, Laundry Manager, Shangri-la’s-Eros Hotel, New Delhi revives the old discussion saying that machines carry the tag: ‘Maximum Allowed Load’. Now, would this mean to run at lesser load so that machine will perform better and live longer or vice versa?
Paul Creek, Managing Director, Creek Solutions Pty Ltd: Filling to capacity allows optimum effectiveness of the machine – as well as saving on early wear and tear on bearings etc. Many modern machines do have capacity to part load and then human judgement comes into play with what is half load – is it 60% or 40% then there may be over use of chemicals or utility use leading to early degradation of linen ad high per kilo costs or higher rewash resulting in heavier do seers of chemical to make right and tying up the machine for an additional wash.
Not loading machine to capacity will also slow down the daily production. A series of different size machines will resolve this.
Klaus Menker, Laundry Management Consultants: The washing machine (and tumble dryer) capacity is first of all a sales & marketing question. In a second step it is a question of the material. When you have a drum volume of 1,000 litre, we are talking today about a 100kg washing machine. 20 years back the same washing machine was specified as 83kg washing machine.
Some suppliers today do not take a ratio of 10:1, they take a ratio of 9:1 for instance and immediately you have a 111kg washing machine (instead of 100kg). In other words, from supplier A you can buy a 111kg washing machine and from supplier B, a 100kg. Finally the load volume is the same but you think that you bought more capacity for the same costs which is finally not true.
If you are washing pure polyester, you should take a ratio of 14:1. This leads to a 71kg washing machine.
So when we are talking about the correct load we should talk about the drum volume and the ratio of loading. Finally you get the best wash results with a ratio between 12:1-10:1 at cotton. Anything else will reduce the mechanical action of the wash process.
Kiran Raj Singh: If the same machine is sold as 111kg or 100kg, will the machine be strong enough to take load of 111kg dry linen? Will it not be overloaded?
Klaus Menker: I think it is not a question of load factor; it is simply a question of quality.
The quality of equipment is always different. You will find high quality washing machines where you pay US$100,000 for a drum volume of 1,000 litre and other supplier offers the same for US$50,000. Somewhere must be the reason for this different.
The programming of the washing machine as well the specification have a stronger influence on wear and tear than the load factor.
But in hotel laundries, the owner has to pay for the equipment and in most cases the operating company the maintenance costs. This is the reason why you find low cost equipment in hotel laundries.
From my experience most people think a 100kg washing machine can wash 100kg per hour. But this is not true. It depends on the programming as well on water pressure or heating capabilities. In addition you have to take loading and unloading into account.
So finally the programming of the washing machine as well the specification have a stronger influence on wear and tear than the load factor.
Roly Ecobisag, Sales and Service Manager, R&L Provider Technical Support Services: Mechanical action is one factor to have a good washing result and to have a good mechanical action, your machine must have a good design on drum paddling plus the proper rpm base drum diameter. Loading ratio is also computed depending on the type of load to achieve proper mechanical action base on washer capacity. Further more, you also have to consider the other elements of washing which is the time, chemical, and temperature in washing. Proper combination of these four elements, will result in a good washing.
Paul Creek: Loading the machines is important, and a good operator will know the differences between the times they load. Towels can be often loaded at a greater ratio than bed linen (by observation and the first grip space from the underside of the drum). Once the linen has been wetted down, the linen should sit at 10 to two on the clock and the mechanical action while in process should show a definite throwing motion.
Vijay Rodda, Laundry / Detergent / Ozone wash / Textiles Consultant: Now-a-days, the loading factor [ratio of kg:litre (of basket)] is at 1:10. Hence, sheets have an issue of entanglement, if loaded full. Recommended 80-85%. Towels can be loaded near 100%. Process parameters can be tested with these loadings, & the best process arrived at.
Sidney Chelsky, President, Careful Consulting Services: If you load the towels to 100%, my experience shows that it takes longer to dry and sometimes the towels in the middle of the dryer are still damp. It needs room to drop and get the heat and air flow to the towels. I would not load towels more than 80%. By doing so, your drying time is shorter and therefore your fuel savings are more.
Klaus Menker: We are not talking about tumble dryers where the load ratio is 1:20-1:25. We are talking about washing machines where the load ratio is somewhere at 1:10.
You cannot overload a washing machine with towels simply reasoned by the space, towels need for their volume.
Cotton can take up to three times more water, compared to the dry weight. So there is no reason to discuss about a 10% different load in dry weight.
The load factor is only important for the mechanical action of the wash process. Everybody should know Sinner’s Circle which is the base of each cleaning process. If you change the mechanical action, you change the whole process.