Diagnostic check is crucial
The modern drycleaner relies heavily on one, sometimes two, drycleaning machines and processes up to eight loads per machine each day. If the machine develops a fault, this can lead to multiple claims and traditionally the cleaner would take responsibility.

Water damage or extensive contamination can quickly ruin an entire load and the total claim value can be £2,000 – £3,000 or even more.

Drycleaning machines are extremely complicated and the advent of sophisticated computer controls has made them even more so. However, the computer also has a powerful diagnostic function that enables it to warn the operator before disaster strikes.

It does this by interpreting unusual observations, such as a rapid rise in temperature, a fall in refrigerator pressure or a failure to satisfy the dryness controller. So when a warning appears in the control panel display, it is wise to pay attention to this and search for the true cause.

Walking round the machine and looking for visual clues is often sufficient. Droplets of water floating on the top of distilled perc or lying on the bottom of a tank of pure hydrocarbon need rectifying very quickly.

Padded jackets smell of perc

Fault: Several padded jackets were cleaned together in one load and the owners then complained that the jackets smelled of perc when they were returned. Loads cleaned since have not given any problems.

Cause: Modern drycleaning machines have “intelligent” dryness controllers and the European Standard for the safety of drycleaning machine design and construction requires that the cage door cannot be opened until the work is safely dry.

The machine’s dryness controller relies on a good flow of air over the refrigerated recovery head. If it detects that no more liquid solvent is being condensed from the drying air stream, it assumes the work must be dry. This works well provided that the operator has cleaned the lint filter regularly.

However, if the flow of air is much reduced by a lint-laden filter screen, then there is no condensation on the recovery head and the computer assumes, incorrectly, that the work is dry.

Responsibility: The drycleaner is to blame.

Rectification: Work which smells of solvent when unloaded from the cage should always be put back for an extra dry program. This can be started as soon as the lint filter has been checked and cleared.

Pinhole leaks caused greying

Fault: Operators had noticed a slightly sharp smell from the perc machine for some weeks. They raised the alarm when this pink cashmere-mix jacket took on a greyish tinge and also suffered matting, felting and localised distortion.

Water draining from the separator also had a blue tinge.

Cause: The symptoms correspond to a pinhole leak in the water-cooled coil of the still condenser.

This creates a thermal/chemical breakdown of the perc solvent in the still into hydrochloric acid and other chemicals, which attack the still wall and the still condenser.

The blue tinge to the separator water is copper chloride from the dissolving condenser, which now has tiny holes. The water from these leaks is too much for the separator to cope with and water droplets form in the distilled solvent tank. When this distilled solvent is used for a delicates’ program this will lead to greying and felting of wools and hair fibres.

Water is attracted to the textiles and this in turn attracts dissolved soiling, causing greying. Scales on the hair fibres rise, making them like barbed spears.

Felting shrinkage occurs with the normal mechanical action in the tumbling cage.

Responsibility: The risk of chemical breakdown reactions is reduced to a low level if the still is kept clean by regular pump out and routine scrape-out. It is important not to exceed the safe maximum setting for the still thermostat. In this case the operator is at fault for turning up the thermostat setting to speed distillation instead of cleaning out the still properly.

Rectification: Acid in the still can be cured with the correct additive. Some proprietary additives can be added to the button trap, others must go directly into the still itself.

However, these are only temporary cures. The still must be thoroughly cleaned out at the earliest opportunity and the thermostat re-set to the safe level at the same time as the still condenser is renewed.

Dirty fibres contaminate load

Fault: All the Items in a load were heavily contaminated with a wide range of coloured fibres and dirt particles of all types and sizes.

Cause: If filter fabric bursts at high pressure then dirt and lint on the filter will surge through the hole and contaminate the load. Alternatively, dirt and lint that builds up on the backplate of the drum (the rear of the stationary cylinder in which the cage rotates) can come away in a lump during the process.

Responsibility: The blame in either case lies with the cleaner. A good operator should watch the filter pressure and run the filter maintenance program before it rises above the safe limit given in the machine manual. The backplate on an old machine can be kept clean by washing down every month or two, using a high dip.

Rectification: Re-cleaning with a powerful anionic detergent may help. The detergent supplier can advise on the most suitable product. Items restored this way should then be cleaned again in a conventional cationic detergent to restore body, softness and antistatic properties. If any of the items can be washed, this will give a better chance of removing the dirt particles and lint. A colour detergent should be used for all loads except whites.

Avoiding unwanted smells

Fault: Over a period of several days, every item processed in the hydrocarbon machine acquired a dank odour, rather like that of a stale sewer. Eventually, the shop itself became so unpleasant that customers came in and then went out again, taking their work elsewhere.

Cause: Drycleaning is not guaranteed to kill all bacteria, although it usually does quite a good job.

Anaerobic bacteria (those which can survive without oxygen) can sometimes establish thriving colonies in the drycleaning machine tanks or pipework.They feed on the nutrients from the dirty clothes and the humidity in the textiles being processed. The smell is the excrement from the bacteria.

Responsibility: The cleaner is to blame for bacterial odours, because these usually result from poor operator maintenance or inadequate distillation to purify the solvent.

Rectification: The first step is to remove the bacteria from the machine. This means distilling all of the solvent, because distillation temperatures should be sufficient to kill the bugs in the solvent itself.

Whilst this is happening, the water separator(s) should be thoroughly cleaned out and disinfected, because a dirty separator provides the ideal breeding conditions for the young bugs.

Three loads of old stock can then be cleaned in the machine to gauge the improvement (by smelling the results). If this does not work, then the entire machine must be stripped down and every pipe and tank disinfected with sodium hypochlorite. This should only be necessary in exceptional circumstances.