Finding the right recipe for laundering chefs’ wear

Chefs' jackets have long been associated with rancid odours, greying, un-removed stains, black marks and unexplained damage. The list is a long one and embroidery that changes colour in washing has now joined to the list.
However, the days when customers would accept garments that were still stained on return and with aluminium and rust marking are at an end. While the service provider must be firm about the customer's responsibility for garment abuse, making it clear that it must be paid for, rancid odours, greying, yellowing and yellow stains should be problems of the past.
Fortunately much has changed in the last two years and the market leaders are now able to produce coats that stay white and unstained and that give a commercially acceptable life.
This has been achieved with work in all areas, from fabric design to improved wash chemistry to a better understanding of and dealing with user abuse.
The detergent suppliers have had to find ways of removing the yellow/brown staining caused by the oxidised proteins picked up from hot ovens. This staining is very resistant to conventional washing. It can defy removal without heavy bleaching and often even this is not enough.
Worse than this staining is greasy fatty marking, which might not discolour a garment significantly but develops during laundering, leaving the unfortunate launderer to explain why the garment looks worse now than when it was sent in.
Abuse in the kitchen from aluminium marking and iron marking is prevalent, with staining from utensils, pans, ovens and oxidised blood (haemoglobin is a major iron contributor, which must be addressed).
Abuse in the form of knife cuts can be particularly difficult to deal with, until the launderer recognises the symptoms of knife cuts and the difference between these and a snarl up in the garment folder.
Finally, some chefs still demand embroidered garments and the problems with different embroidery threads are currently being
re-examined.
While the launderer's role continues to be a challenging one, this month's article suggests effective ways to address some of the main problems.

Embroidered logo designs
Most garment renters and many purchasers of chefs' wear know that they should specify embroidery thread that is resistant to sodium hypochlorite bleaching in every wash, as this is commonly used to remove and control stains. This specification usually results in the use of a high quality polyester thread.
Viscose rayon is the main alternative to polyester but it is much more difficult to dye so as to be resistant to bleach in every wash, so it is generally considered unsuitable for this application.
To distinguish viscose rayon thread from polyester in quality control, bring a short length of thread near to the flame from a gas lighter.
The viscose rayon will burn immediately with an after smell of burning paper.
The polyester will melt, give off black smoke as it burns and leave a sickly sweet after smell. This test should be done over an ashtray, taking great care not to burn hand or nose as molten polyester is very hot.
High quality cotton embroidery threads that have been coloured using vat dyes are also available. Confusingly, these will burn in the same way as viscose.
It is essential to rinse the garment correctly and this applies to the embroidery threads as well (although it might be much more difficult to rinse clear if the threads are dense, as in higher quality embroidered designs).
If there are traces of hypochlorite left in the embroidery, these will concentrate in drying and can change the colour at the high temperatures in the tunnel finisher (a process that typically takes 22 minutes at 155C).
Often the change is only a slight fade but occasionally there may be a change in hue, with burgundy changing to gold, for example.

Basic principles of stain removal
Vegetable dye stains from tea, coffee, red wine, beetroot, blackcurrant and most food colourings will not wash out. They need to be de-coloured with bleach, either with peroxide in the main wash or with hypochlorite in the rinse.
These are the only stains that should require bleach; the rest ought to be washed out. This means that protein stains must be softened in a cool pre-wash running below 40C for at least four minutes and many proteins need five to six minutes for this.
They will then come out in a vigorous main wash with plenty of detergency at high temperature - typically 85C to remove the most stubborn ones.
The high temperature opens up the yarns and fibres and releases the soiling more readily.
However, a well-designed main wash is of no use unless the
pre-wash is correct. If protein stains are subjected to a pre-wash above 40C (even 42C can be too high), they will set onto the fabric and become impossible to remove by washing, no matter how good the main wash.
This is a major problem when designing heat recovery systems, which feed warm water into the pre-wash of a tunnel washer. The only solution is to employ very high levels of alkalinity to chemically burn the proteins off the fabric, but this always risks damaging the fabric (hydrolysis of the polyester) and the excess alkali then has to be rinsed off or otherwise neutralised.
In theory, oils and greases ought to come off by emulsifying with extra detergent but this can become expensive. A much better solution is to add a small amount of emulsifier to the pre-wash. Even 2 - 3ml/kg of textiles can make a big difference. The emulsifier appears to cling to the fabric and is carried forward from pre-wash to main wash.
For food oils, an emulsifier with a mid-range HLB value (hydrophilic-lipophilic balance) usually works best.
This is essential for polyester and polycotton garments, because the oils and greases and fats are held to the polyester by a strong oleophilic attraction and the launderer must break this bond to obtain an acceptable result.

Aluminium marking
Aluminium from pans and cookware and iron from other utensils transfers readily to chefs' wear to create ugly black marking. It cannot be removed by washing and is classed as abuse.
It can be removed by special chemical treatments, but these can reduce the life of the washing machine (in the case of iron mark removal) and will reduce the life of the fabric. They are well worth employing as occasional recovery processes, but should not be used regularly.
Aluminium will dissolve in a strong alkali, such as sodium hydroxide or sodium metasilicate. It needs high concentration - typically 2 - 4% in the wash liquor or even higher in extreme cases - and high temperature.
The temperature should be raised to above 60C for about 10 minutes, but remember that although the hotter and longer the greater the effect, fabric damage will increase.
Cotton fibres will be mercerised and become very soft by surface degradation and polyester will be hydrolysed and can eventually crumble to dust. The most likely effect after a few recovery treatments is a reduction in tear strength, so that the garments have a tendency to split between the shoulder blades.

Knife cuts
Every rip or tear in a garment is not necessarily the result of an accident in the laundry, despite this being the most common first conclusion from the customer. Knife cuts are surprisingly common as the point of initiation of a tear and any rip should be examined carefully to find out where it started.
Many knife cuts actually cross the weave of the fabric, whilst rips and tears follow the line of the warp or the weft.
If the cut travels across several warp or weft threads on a "diagonal" or a curve, then it is very unlikely to be a conventional tear.
If the knife has a soft serrated edge it can give a curvy cut, which can be recognised readily if the launderer knows what to look for.

EMBROIDERY DESIGNS: Embroidered designs must be executed in a thread that resists bleaching if fading and colour change are to be avoided