Shampoo cleaning is generally a hand process, which uses a foaming detergent solution to effect the cleaning. Despite its simplicity, shampoo cleaning requires considerable skill if it is to be successful. Shampoos may be purchased in aerosol cans, which provide a shampoo foam, and they are also available as a concentrated detergent, which is diluted with water. In this case, the detergent solution is applied to the upholstery by means of a clean cloth or sponge. It is essential that only upholstery shampoos be used. Detergents formulated for other purposes (e.g. dishwashing) often produce sticky residues, which may lead to acceleration of soiling. Of equal importance is the technique for applying the shampoo to the fabric. Excess water must be avoided, otherwise the interior of the furniture will become wet. This causes excess drying times, mildew and odours and may lift soil from the interior of the furniture to stain the surface of the fabric. Finally, scrubbing can produce a hairy surface.
Hot Water Extraction
Hot water extraction is commonly referred to as 'steam cleaning' and is a machine process. The hot water extraction machine applies a hot detergent solution to the fabric and then extracts it before it penetrates the filling. This process does not apply steam to the fabric, as the common expression would apply. Hot water extraction is possibly most familiar as a carpet cleaning process. In fact, many carpet cleaners have expanded their services to include upholstery cleaning. Hot water extraction machines are also available for hire by consumers. This relatively simple process has several potential dangers for the inexperienced user. Of chief concern is the risk of over wetting. For this reason alone, consumers may be well advised to have this process performed by an experienced tradesman.
On-site dry-cleaning is a method of cleaning which is relatively new to Australia and New Zealand. Essentially, the process is similar to hot water extraction and uses very similar machinery.
The on-site dry-cleaning machine sprays a solvent onto the fabric and then extracts it by means of a vacuum extractor.
The solvent is at room temperature and is not heated. When it is sprayed onto the fabric, it flushes off any loose soil particles and dissolves oily soils.
The dirty solvent is directed into a waste container and may be reclaimed for cleaning and further use.
The solvent is generally based on 1.1.1 trichloroethane and may contain special additives designed to enhance the cleaning performance. Any such solvent additives are generally proprietary secrets. Typically the solvents are non-flammable but are toxic. The machine exhausts vapour to the outside of the building by means of a flexible hose.
Unless this is done, the solvents' vapours could present a health hazard. For this reason, it is essential that the machine operator be properly trained and that they ensure that the solvent residues in the fabric are minimised.
On-site dry-cleaning must be done in a well ventilated room, and ventilation must be maintained until the furniture is dry from solvents. Because many stains are water soluble and not solvent-soluble, it is often necessary to pre-spot fabrics with special water-based cleaning agents. This is similar to the general procedure used by dry-cleaners when dealing with clothing.