material solutions

Cause and answer

1 October 2005



In the second of his new series on laundry problems, Richard Neale explains how the correct identification of faults can lead to an answer to the problem


The range of problems for the launderer and rental operator continues to diverge. With continued pressure on prices and margins, it is important to be able to identify causes and solutions quickly. This month’s article looks at some of the most common problems – and some of the more unusual ones.

Garment rental operators have always faced the problem of customers who demand contrasting career wear with scant regard for colour transfer problems and a distinct lack of willingness to pay extra for colourfast fabric. The cost per metre of fabric for a contrasting red trim on a white garment could be double the cost for a standard red, but the difference in the garment price is very small. It must be paid if the entire batch is not to turn pale pink during the first few washes.

The rental operator who is well armed with a sound technical understanding of the problems described this month will always fare better; in the competitive marketplace, it does not take much to differentiate the best from the mediocre.



Synthetic starch blends can contaminate feeders

There are serial problems involving sticky white residues on sheet feeders. These frequently traced back to recent deliveries of sheets and pillowcases. The white residue accumulates wherever the wet sheet is dragged over the feeder component and becomes a problem within about four or five hours.
If a sample of the build-up is dissolved in warm water it will be found that a large amount (but not all) of the residue is soluble and free lint appears floating on the surface. The problem lies in the manufacturer’s finish applied to the new sheeting before it was converted into sheets and pillowcases.
There have been vociferous complaints over the last ten years about the difficulty in getting a good finish on a new pillowcase until it has been through ten or more washes.
Some suppliers appear to answering these complaints by using a finish which is a blend of synthetic PVA and natural starch. If the wash process is very good and removes all of the finish (which comes away much more easily), there is no problem. If the process is poor and very little finish is released, there is equally little problem.
If the wash process loosens the finish but does not remove it, then it will rub off along with surface lint and create the problem described.
The solution is to give new sheeting a pre-wash designed to remove the finish and set the cost of this against the improvement in ironed finish now immediately achievable.



Edge abrasion will downgrade circulating stock

A rental general manager has to be a master of many technical disciplines but the most pitfalls are found in linen purchase. A towel or a sheet or napkin with a natural selvedge (as opposed to a hemmed edge) should give excellent service provided the edge has been formed to resist normal use and abuse from both processing equipment and the hands of the user.
There are a variety of selvedges available but the strongest usually involve the weft thread being cut off and then tucked back into the first two centimetres or so of the woven edge. This produces a strong and serviceable edge which will resist the occasional gorilla-like handling it receives in use.
However, the ‘knuckle’ of the weft yarn which is looped back to form the edge is vulnerable to abrasion in laundry processing or in use.
If failures start to occur it is vital to track down the cause and to prove this quickly, otherwise a large quantity of circulating stock may be downgraded and it could be many months before stock injections can be reduced back to economic levels.
Areas to check include laundry chutes in large hotels, ironing lines with rough edges or damaged areas and continuous washing lines.



Protein stains will need professional washing

Despite the claims of the detergent supplier, a garment which is heavily soiled with abattoir staining or fish slime needs a good two or three wash process with adequate chemistry, temperature and stage times for efficient removal.
Meat and fish gunge is composed mainly of proteins and needs a sluice, a low temperature pre-wash (below 38C for at least four minutes) and a high temperature main-wash which runs for at least eight minutes and may need double this.
The wash product will probably be based on sodium metasilicate rather than one of the cheaper modern alternatives.
The difference is seen in the photograph. A sample of the soiling was cut from the complaint garment before it was given a proper wash of the type described. When the unwashed sample is put back into the garment it is possible to see the improvement achieved, in this case with a re-wash which involved a main-wash stage of eight minutes with no bleaching stage. The laundry concerned did not have a difficult problem, it simply took cost cutting one step too far!



Mechanical damage versus chemical damage

Serial failures and rejects caused by holes in bedlinen are infuriating and expensive. The misuse of sodium hypochlorite bleach in continuous batch washers has generated problems across the rental sector, because it is so difficult to prevent a trace of bleach getting back into the hot wash zone where it causes damage out of all proportion to the amount recycled.
Holes from this cause are accompanied by an overall weakening of the sheet which can be recognised by testing the strength of a few yarns adjacent to the holes themselves.
The fault can also be caused by mechanical tears around trolley wheels, linen chute snags, folder jam-ups and so on.
These are the first suspects if the yarn strength is good but the tears are still occurring. So the first step to take if holes start to appear is to check the overall strength of the circulating stock.
If there are plenty of holes and the yarns around these feel weak, urgent action is needed. The degree of chemical damage from the wash process can be measured using a 25-wash test piece. The rotting of the cellulose in the cotton is assessed by laboratory determination of the cuprammonium fluidity of the washed test fabric.
If the increase in fluidity exceeds 3.0 units then the entire circulating stock is at risk and will require premature replacement. The quicker the wash process can be corrected the lower the replacement cost will be.



Contract curtains are best designed for washing
CURTAIN CALL: A simple rub test with water and then with drycleaning solvent should avoid prints like that shown here from fading

The majority of contract curtaining is still unlabelled with the exception of public sector (particularly healthcare) fabric. Most gives less shrinkage if drycleaned rather than washed (but the curtains will still shrink visibly and the customer needs to be made aware of this beforehand). However, washing is generally better at removing food and drink spillages and it produces a brighter, fresher result after the removal of atmospheric soiling which builds up at the window.
Most prints also dryclean better than they wash but there are now some important exceptions. The floral blue patterned curtain shown is a good example.
A simple rub test with water and then with drycleaning solvent is all it takes to demonstrate that the print will fade considerably in perchloroethylene but will survive far better in water. The item is a clear candidate for a careful wash cycle.
This means that the customer must be made aware of the degree of fading that will still occur and must allow for the wash shrinkage in the initial design. Wash shrinkage can be compensated for either by changing the row of hanging attachment points on the three row ‘ruflette’ header or by allowing adequate fabric in the hem so that the hemline can be adjusted after washing. The first method is much better and far less expensive/time-consuming.



Hole (Butlins) Hole (Butlins)
butchers coat butchers coat
Feeder debris Feeder debris
curtains print curtains print
frayed edge frayed edge


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