How does dry cleaning work

A.� Dry cleaning was developed in response to delicate fabrics that can't be washed in a normal domestic machine. Also dry cleaning is used for shifting stains that water doesn't deal with very effectively, like oil-based paint.

�

When delicate fabrics are dry-cleaned they're immersed in a petroleum-based solvent, rather than water, which are very effective at removing oil and grease based stains. Traditionally kerosene or gasoline was used, however today perchloroethylene is the commonly used solvent.

�

Q.� Why do delicate fabrics not wash well

A.� Many delicate fabrics either shrink, loose colour or shape after being washed in water because of the reaction of their fibres with the molecules in water which form chemical bonds with individual molecules within each fibre. The net result is that the original look and feel of your favourite jacket or skirt is ruined. Dry cleaning overcomes these problems by leaving out water.

�

Q.� So it isn't 'dry' at all

A.� No, the fabric just doesn't get wet with water, that's the main difference.

�

Q.� What happens to the perchloroethylene that my clothes absorb

A.� Don't worry; it's not left in the fibres. The solvent is recovered using an extractor, so it doesn't get chance to cause pollution by evaporating into the atmosphere, it can then be reused. Afterwards the process reverts back to normal domestic cleaning as your clothes are given a press.

�

Q.� If perchloroethylene is capable of causing pollution, isn't it dangerous

A.� There has been quite a lot of controversy regarding the safety of dry cleaning, especially for workers within the industry who are exposed to perchloroethylene.

�

Perchloroethylene, or 'perc' has been linked to irritation of the eyes throat and noses, and more seriously with possibly adversely affecting the nervous system and organs.

�

To read about how traditional washing machines attempt to get clothes clean, click here.

�

If you want to ask The AnswerBank how something works, click here.

�

by Lisa Cardy