5- WASHING CHEMICALS
Chapter 5 summary
Substances defined as detergents are those that have the property of
removing dirt from an object without damaging it.
Detergents are combinations of chemical compounds which, associated
with the factors of time, temperature and mechanical action, allow a
surface to be freed of its dirt.
These are the constituents of detergents, and provide special wetting,
foaming and detergent properties.
They reduce the surface tension, causing water to behave in a particular
fashion in the presence of solids and fats.
Diagram of a surfactant molecule:
Types of surfactants:
Depending on their Ionic behaviour in aqueous
solution, they are classified into 4 groups:
Anionic S. (-
Noionic S. (nil)
Anphoteric S. (depending on
Examples of use:
How do surfactants work?
The soiled fabric comes into contact with the water
The bath with detergent wets the fabrics and the dirt
The surfactants separate the dirt from the substrate
The dirt is stabilised. The hydrophilic part in contact with the bath.
The lipophilic part in contact with the dirt.
They are added to detergents to protect or improve the detersive efficiency.
They add detergent properties that improve the detergent process.
They remove the hardness from the water
They provide the bath with alkalinity
They prevent the dirt from re-depositing
They improve the emulsion and
dispersion of the dirt
In laundering we use the term "whiteners" to refer to the chemicals that
remove the colouring dirt and keep the fabrics white. In the composition of a
detergent, we can find the following:
This enhance the
whitener so that it acts
at low temperature
DO NOT attack the
These reflect the light
and give the sensation of
Minority substances in the composition of a detergent. Their properties differ from
one detergent to another:
: These are natural proteins that enhance detergents and allow them to work
at a low temperature. Each type of enzyme degrades one type of substance.
These keep the dirt removed from the fabrics in
suspension in the bath.
These are used to protect the substrates on which the
These are needed to ensure that the detergent solution
possesses an optimum level of foam.
This is added to make the product pleasant to use and to leave a residual
Without a mission in the detergent process, they are necessary to ensure that
detergents have a presence that aids their use and that allows their properties to
Auxiliary presentation agent in liquid detergents. Influences fluidity,
viscosity, density, etc.
A colourless and crystalline powder. It acts as an absorbent and helps to
disperse all the compounds of a detergent powder evenly.
is a chemical element that captures electrons, ending up with
a positive charge.
is a chemical element that cedes electrons, ending up with a
less positive charge than it had.