The washroom is often seen as the “heart” of the laundry”. Its performance will affect the whole of the of the laundry operation.
When it is working at its optimum, using the correct processes and producing a good flow of work all will be well. The soiled work will emerge from the wash clean and stain-free with just the right amount of moisture remaining to make the finishing processes quick and efficient.
Equally problems in the washroom will, if severe enough, bring the whole production line to a halt. Even minor problems can have an effect. Production will keep going but at a much slower rate due to a restricted flow of work from the wash line.
The washroom’s workflow can be restricted in many ways. For example low steam or water pressure will mean that machinery takes longer to heat-up or to fill to the required dips.
A well-trained operator who is familiar with the normal time for any given process will often identify such faults quickly so they can be corrected and production will return to normal.
However, this assumes that the process selected meets all the requirements for good results first time on the classifications being handled. The level of re-wash will have a big effect on production. With the correct process, re-wash levels should be minimal and the laundry will consistently achieve a good standard of finished work.
Many washroom operators depend wholly on the machine’s programming to produce the correct result. They assume that selecting a particular program will produce the right chemicals in the correct amounts at the right time. If the work comes out grubby or stained – it’s not the operator’s fault.
However, often the process selected is one that was designed and developed several years ago and since then the range and type of customers have changed. The laundry may even have switched to a different detergent supplier. Such changes can affect the types and levels of soiling and the processes will need to be adapted accordingly.
For example, in recent years a large number of health spas, gymnasiums and keep fit businesses have opened. Most of these will use huge numbers of towels but the laundry’s normal towel process may not be able to remove the type of soiling found on gym/spa towels.
Out-of-date process
The reason for this is that the old towel process, which may have been used for years, was designed for hotel or hospital towels and these are generally very lightly soiled. They may have some shoe polish or body fluids on them but otherwise they are usually straightforward to process.
In contrast the spa or gym towel will often come into the laundry loaded with massage oils, creams and other emollients that are used to soften the skin or even produce synthetic tans. These oils, which are often fragrant, are fatty acids and if they are left on the towel for any length of time, they will not only destroy the towel’s dyes but will also gradually eat the cellulose in the cotton, thereby significantly reducing the fabric life.
However, the main problem is the oils and fats that remain on the gym or spa towel after washing. These residues can fuel spontaneous combustion so if they are not adequately removed the laundry could catch fire and possibly burn down.
This is reason that routine checks on processes and process controls are essential.
The type of fibre is the first consideration in designing any wash process. Loads of 100% cotton and linen, will withstand high temperatures and plenty of mechanical action but a load containing animal fibres will need lower temperatures and reduced mechanical action. It is therefore essential that the laundry knows its fibres and fabrics and the types of processes that will be safe.
The next concern is the type and level of soiling.
The type of soiling will dictate the temperature of the wash and the quantity of soiling will decide the number of wash stages needed.
As an illustration, a load of sheets from a five-star hotel will generally be lightly soiled with the occasional tea/coffee mark or other localised staining, so it is seldom necessary to have two separate wash stages as one wash should be more than adequate.
However, that wash may have to cover two conflicting requirements. High temperatures will set any protein staining but they are needed to remove body oils and fats. This problem can be readily resolved by using a single, stepped wash process.
For the first stage of the wash process, the machine is filled to the correct dip, then dosed with detergent and the temperature is raised to 38 – 39C for 3 – 4 minutes. Then without draining the washing machine or adding more water, steam or chemicals, increase the temperature to 71– 75C for 5 – 8 minutes.
This stepped process will produce water savings of 4 litres per kg. It will also produce savings in chemicals and in steam consumption as, rather than heating a fresh intake of cold water to the required temperature, it simply raises the temperature of the existing water from 39C to 71 – 75C. At the same time the stepped wash will also increase machine productivity as it cuts out the time needed to drain the machine, re-fill it and heat the cold water. The only time that two separate washes are required is when the amount of soiling necessitates extra chemicals.
Wash chemistry
The next design consideration is the wash chemistry. Most modern chemicals’ suppliers produce fully-built detergents that have been well formulated with just the right balance between the surfactants and the alkali and soil suspending agents. This often means that provided there is a generous lather throughout the main wash stages, there will be just the right amount of detergent, alkali and soil suspension to ensure good soil removal as long as the temperature is correct.
Oils and fats can only be effectively removed during the wash process by the use of elevated wash temperatures and good levels of alkalinity and mechanical action.
Maintaining a good lather throughout the main wash is important for all classifications.
If the lather is lost at any time, it will reduce soil removal and will probably result in soil redeposition and therefore in greying.
The solution is either to add sufficient detergent/ alkali until a lather is achieved – or to drain the machine and give the linen another wash stage.
There is no short-cut. Failure to maintain the lather throughout the main wash stage or stages will mean a dissatisfied customer, excessive amounts of re-wash and greyed stock.
When all the wash processes have been designed and prepared to meet the laundry’s needs, they must be checked to ensure they work as programmed before they are released for use. Many of the more recent PLC programming units demand actions to be entered or programmed in a specific sequence. If this order is not followed the program will simply “stop” and hold at the point of departure from the correct sequence.
The laundry should check and prepare its wash processes as a matter of routine. The programs should be prepared following the points detailed below.
Decide the type of fibre or fabric to be processed. This affects the temperature, mechanical action and the type of chemicals to be used.
Decide the type of soiling that will be on the linen. This dictates the temperatures and types of chemicals that will be needed.
Decide the level of soiling the process will be required to remove. This tells you how many wash stages will be needed and affects the machine’s degree of loading as well as the quantity of chemicals to be used.
Decide what chemicals are to be used and in what quantities.
Finally when the process has been prepared, check it to make sure it works.
Keeping regular checks on wash processes to make sure that they are meeting the laundry’s current needs will help to reduce re-wash levels and therefore costs and ensure a consistent standard of finished work.
