Looking after polyester20 May 2021
Polyester is universally thought to be trouble-free but this is a false assumption, warns Roger Cawood
Polyester forms an important part of every retail cleaner’s workload and while it is a fairly straightforward textile in terms of drycleaning and waterbased processing, it does have very specific properties that we as professional cleaners should all be very much aware of. It has recently become evident that some cleaners are occasionally having problems which are directly related to how we handle it in cleaning, washing and finishing.
One of the most robust of all the textile fibres that we have to deal with, polyester is generally one of the easiest to clean. However, in my experience the majority of cleaners are unaware that it is what is known as an Oleophilic textile which quite simply means that it likes oil.
In the 1960s when the fibre became popular as a polyester/cotton workwear fabric, launderers and cleaners soon found that it was impossible to remove some oily soilings or deep-seated oil stains. The problem reached such proportions that the Spencer drycleaning machine manufacturer produced a dual solvent machine (the Aqua Solve) in an unsuccessful attempt to resolve the problem. So, when dealing with oil stains don’t give positive assurances to customers or be surprised if you have difficulties with oily stains and particularly with deep seated black oil. Use your kit paint remover to locally pre-spot oily stains working the stained area with a spatula, bear in mind that in recent years some cleaners have experienced dye fastness problems with polyester.
Once again pre-spot oily stains with your kit paint remover and depending on your stain removal reagent, you might need to flush out before processing. The difficulty of removing oil stains and oily soiling on polyester is greater when wetcleaning and if solvent processing is available, in most cases, it would be preferable to dryclean first.
Many cleaners today provide at least a limited laundry service and should therefore be aware of the risks to polyester from thermal shock which can result in permanent damage due to washing at temperatures exceeding 50C. If polyester is washed above 50C the temperature when rinsing must not be reduced at more than 50C per minute until it has once again been brought down to 50C. Rapid cooldown when washing above 50C sets creases into the fabric that cannot be removed. This is a problem well known to industrial launderers, industrial machines being programmed to ensure these parameters are not exceeded. Cleaners should be aware that polyester items may have been home washed at well above 50C and therefore already damaged when deposited for cleaning possibly resulting in a claim for compensation when the cleaner finds they cannot remove the creases.
My advice is to wash polyester at no more than 40C
Polyester fibres are thermoplastic which means they begin to soften and melt under the influence of heat. The maximum ironing temperature for polyester is 150C. Polyester fibres have a circular cross section and if ironed or pressed above this temperature there is an increasing risk with rising temperature that flat surfaces may be introduced on some fibres particularly along seams. This locally alters the light reflectance properties of the fabric and causes glazing and shine which can be very difficult or impossible to remove.
Roger Cawood FGCL.