textile rental focus

Material solutions

1 January 2006



In his new series dealing with laundry problems, Richard Neale looks at mildew staining, flame retardent textiles, water hardness and colour loss


Mildew growth attacked hotel’s flood-damaged bedlinen

Fault: The hotel that sent this pillow slip – along with several hundred others as well as sheeting – was recently flooded. The linen room was in the basement and all the stock was left standing in the flood water for several days before being removed and dried before being sent to the laundry.

Whilst folded there did not seem to be a major problem – until the pillow slips were ‘opened up’ to show the exceptionally heavy mildew growth; growth that was so severe that other bacteria was also beginning to ‘grow’ on the mildew (pink spots and rings around some of the mildew staining).

Cause: Leaving the sheets and pillow slips in contaminated flood water for several days provided the ideal growth conditions for mildew and the microbiological contamination in the flood water gave the right conditions for this excessive damage to this representative sample pillow slip.

The problem has been made worse by leaving the bed linen in a folded condition to dry. The outside surface of the wet stock dried quickly – so there was no obvious fungus growth – whilst the fungus was ‘cooking and growing’ inside the folded stock.

Solution: Prevention is always better than cure. The first step would have been to open out and unfold all of the flooded stock to dry so that the contaminated water was not held inside the folded article to permit the mildew to form.

However, the problem now is to remove the mildew staining. This can be completed fairly easily – and with little damage to the textiles – but extreme care is required.

Wash processes, using a washing machine to treat the mildew can work, but they require exceptionally high levels of chlorine bleach and the risks of excessive damage to the textiles is significant.

The safest way is to prepare a ‘soak tank’. This is ideally a large polythene or plastic laundry trolley, depending upon the amount of stock to be treated, that has a drain and plug fitted.

Ensure there is no brass or iron fittings on the trolley or soak tank as the chlorine will attack them and possibly cause severe discolouration of materials being treated. Prepare a stock solution containing not more than 2 grains per gallon (7ml/litre) of available chlorine in cold water (18-20C).

Mix the solution well before then adding the mildewed textiles for an ‘over-night’ soak.

In the morning, remove the soaked textiles (taking all normal health and safety precautions and wearing appropriate PPE) and process using the normal process for that classification.

The remaining soak solution can be ‘topped-up’ and used for another batch – but it is important to test the strength of the solution (titrate with N/10 Sodium Arsenite solution and Potassium starch iodide paper) before re-using.

Responsibility: For causing the mildew, the hotel staff for not drying the bed linen correctly. For removing the mildew staining with minimal damage, the professional launderer.



Home wash in bleach caused boiler suit to remove its flame retardency

Fault: Flame retardant boiler suits were purchased for the engineering staff at a large factory where a high volume of welding is undertaken. The boiler suits were allegedly all sent to a commercial laundry for processing – but after only a few weeks, one of the staff complained that his boilersuit ‘caught fire’ and he was burnt as a result, whilst trying to put out the burning garment. The launderer was being blamed.
Cause: Most flame retardant textiles are treated during manufacture with proprietary treatments like Proban or Pyrovatex - which are both highly sensitive and lose their effectiveness if not processed correctly. High wash temperatures or high alkalinities and bleaches often affect these types of finishes and it is essential that the manufacturer’s instructions are rigidly followed if the wearer is to have the protection required.
In this case, the customer submitted several boilersuits for flame retardency validation. One of the samples submitted readily burnt whereas the others were perfectly satisfactory and complied with the standard of protection required. Closer examination under ultra violet light confirmed that the garments that still met the original fabric specifications had been routinely and regularly drycleaned by the laundry service provider – but the garment that failed had been washed.
Further investigation revealed that the wearer was unhappy about sending his garments to the launderer as he felt that his boilersuit was smelling ‘sweaty’ and not being cleaned effectively – so he decided to take the garment home for washing where it was processed at high temperature with ‘a little bleach’.
Responsibility: Clearly, in this instance, the wearer was to blame for not following the care label instructions when washing the boilersuit at home.
However, the launderer could have been sensitive to the fact that boilersuits are often heavily soiled with sweat and perspiration which is not always effectively removed during drycleaning. A well designed wash process periodically given to the garments after drycleaning would have improved customer satisfaction and avoided the problem that occurred – which could have resulted in a fatality.



Hardness in water to blame for premature greying of towels

Fault: This is a classic illustration of poor towelling processing and procedures. The centre towel is a new unwashed towel and the other two grey towels have only been washed (according to the owners) less than 25 times.
Already the whiteness reflectance level on the washed towels has dropped from 92% to less than 80% and both towels have frayed hem edges.
The towel owner, a health gymnasium, is blaming the laundry who in turn is blaming the manufacturer.
Cause: Although a well operated laundry will have their water softened, very few of their customers do. Consequently most towels are well and truly ‘loaded’ with hardness salts when received at the laundry.
The Hollingsworth equation can predict just how much additional hardness will be carried into the wash process on soiled towelling. A simple water hardness test on the pre-wash water (without any detergent in it) will confirm the ‘scale’ of the problem to be overcome.
A further problem is that hardness salts are preferentially attracted to greasy soiling and will form a hard crust over any greasy soiling making it even more difficult for the detergent to emulsify the grease.
This problem, compounded by reduced detergent usage levels and lower wash temperatures (cost savings?) are the recipe for disaster – especially with a gymnasium where the towelling will be more heavily soiled with embrocating and massage oils.
But this is not the only problem. The fraying to the towel hems are a direct result of excess tumble drying and over-heating, which can also contribute to increased greying levels as the increasing hot-air temperature re-circulates dust from the atmosphere which lodges into the towel fibres and is firmly held there by the electrostatic forces created during tumbling.
Solution: Due to the amount of hardness salts on the incoming soiled towels, the first part of the wash process should always be a cold, high dip, clear water rinse for 3-4 minutes. This will rinse off the majority of the incoming hardness salts as well as remove any loose debris and water soluble soiling on the towels.
This should be followed by a single wash ‘stepped’ process stage, with the correct amount of detergent added to achieve not less than 800ppm alkalinity – starting off at not more than 40C for 4-5 mins and then, without draining, increase the temperature to not less than 71C for 6-8 mins. At the end of this stage the towels can be rinsed as normal.
Bleaching should, where possible, be avoided. Accept that there may be up to a 5% re-wash level (with this process 1-2% is realistically achievable) and only bleach the re-wash. Even then the rewash should be checked for marks and stains that are not affected by a normal wash process and require specialist treatment, for example iron mould or rust.
When bleaching, especially with hypochlorite – remember, maximum temperature of 60ºC and 3-6grains/lb or 95-190ml/kg of available chlorine – and rinse well.
Do not over tumble dry - it is the most expensive means of removing moisture from washed textiles. Ensure moisture retention following water extraction is as low as possible (45-48%MR) and ensure that tumblers are well tuned. Most well operated and maintained modern tumblers can dry a full load of towels within 20 mins; if it takes longer, tumbler efficiency should be checked and action taken to stop any leaks and cool air ingress.
Responsibility: The launderer.



Colour loss is enough to make a chef see red

Fault: A restaurant purchased new black and white check 100% cotton trousers for their chefs. Within five laundry cycles the black and white material degenerated into a light brown and white check. The material had already been laboratory tested prior to purchase and given a ‘clean bill of health’ for colourfastness, fabric strength and dimensional stability.
Cause: Unless stipulated, the colourfastness test on most ‘washable’ materials will normally be using a ‘standard detergent’ to ISO105 part C06 at 60C standards. This does not include the effect of bleaches or washing at higher temperatures, which are often needed when washing heavily soiled greasy chefs’ clothing.
What has occurred in this instance, which is evidenced by a strong ‘fatty’ residual smell on the washed trousers, is the laundry have complied with the care label and washed at 60C, failed to remove all the residual soiling and heavily bleached the fabric in order to help remove the soiling – but in so doing have removed some of the base colours used in the black dye recipe on these trousers.
Solution: The fabric manufacturer failed to have the fabric tested, based on the end-use application. It may well be that this material is excellent for suiting or other ‘light user’ areas, but the dye and process recommendations on the care label are totally inadequate for the actual end-use application. These chef’s trousers can never be returned to their original condition.
The only way that these chef’s trousers can be processed to avoid the colour loss is at a lower temperature which will result in the laundry becoming non-compliant with the requirements for processing workwear used in the Food Industry.
Responsibility: The garment manufacturer. The material is not ‘fit for use’ as chef’s clothing.



chef trousers chef trousers
boiler suit boiler suit
pillow mildew pillow mildew
grey towels grey towels


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