Know your solvent
Solvnt choice is critical for a successful drycleaning operation as the selection has long-term implications, particularly in a unit with just one machine.

Drycleaning machines are solvent-specific so the wrong choice affects the business for five or ten years. On a day-to-day basis, however, the choice is not too critical provided steps are taken to avoid the different pitfalls associated with each type.

Solvency power can now vary widely from cyclosiloxane which scores just 20 on the kauri-butanol (kb) solvency scale, through hydrocarbon with a kb value of 30 to perc which achieves 90!

Cyclosiloxane’s low solvency means it does relatively little damage to delicate trims or even to solvent-sensitive dyes, but conversely it will have little or no impact on stains so it is essential to treat these before the garments go into the machine.

Drying temperatures can be a problem with man-made fabrics and modern perc machines can now dry at temperatures down to 40C, which is much lower than the normal requirement for hydrocarbon or cyclosiloxane, both of which peak at 60 – 65C. This often makes perc safer for temperature-sensitive items, despite its strong solvency power.

Cleaning in perc can result in loss of fabric finish or of the yarn oils from silks and this can greatly change the feel and handle of a fine silk. However, the effect can be minimised by the use of the appropriate agent in the final bath.

Rainwear reproofing additives can give stiffness and useful stain repellence and a good retexturising agent can restore body and handle.

Most stains are water-based and where there is extensive food spillage it is often better to use a good wetcleaning process than to rely on stain pre-treatment/drycleaning.


The wrong detergent

Fault: The customer complained about a slight colour difference between this wedding dress and the original fabric sample supplied, after the dress had been wetcleaned to remove the extensive water-based food staining.

Cause: Viewing the dress and sample together under ultraviolet light reveals the problem. The cleaner was right to use wet treatment for the food spillage, but should have chosen a colour detergent. The optical brighteners (OBAs) in the general white-work detergent used have changed the colour.

Responsibility: The blame here lies with the cleaner. With just a little more knowledge and care, this claim could have been avoided.

Silk feels like limp raG

Fault: After being drycleaned in perc, this silk dress had lost its sheen, the print was faded and the customer said it felt like “a limp dish rag”.

Cause: Perc’s high solvency has stripped all the yarn oils from the silk so that it has lost its sheen and resilient handle. It looks and feels thin and faded, although it has probably lost little colour, if any.

Responsibility: This is an inevitable result of drycleaning this fabric in perc. The dress was labelled with P in a circle underlined, so the cleaner was right to assume it could be drycleaned in perc. The underline implies a need for reduced moisture and less mechanical action, so cleaning on a short, one bath cycle will minimise the changes. However, the effects are progressive, so the subsequent drycleanings will remove more yarn oils, and eventually the garment will look and feel dry, limp and faded.

Rectification: Cyclosiloxane or hydrocarbon cleaning would probably have been better for this garment, despite the label. To get a good result in perc, include a little suede oil in the bath and shorten the final spin. The oil will be left behind when the garment dries and will replace the original yarn oils that were lost in the solvent wash.

Stain becomes hard to treat
Fault: This jacket was cleaned in cyclosiloxane without pre-treating, but after cleaning, most of a food stain remained and post treatment did not improve the result.

Cause: Low power solvents such as hydrocarbon and cyclosiloxane are not designed to remove heavy food stains without pre-treatment. These solvents will not dissolve food stains and the residues then harden and set in the high temperature drying. The stains will then resist post-treatment, even with very good stain removal reagents.

Responsibility: The jacket’s owner is responsible for staining the garment, but the cleaner is responsible for failing to tackle the staining professionally. A much better result was possible here.

Rectification: An enzyme digester will some times break down the fatty proteins in food stains, even after they have been set. You will need a little patience, but this would certainly be worth trying if the normal sequence of protein remover then tannin remover does not work. Digesters should be available from your spotters’ supplier .