Series editors' preface - Wood Tools

eaves of buildings are a source from which
infestation may arise. Other moths that may
cause damage to textiles include the brown
clothes moth (Hofmannophila pseudospretella)
the tapestry moth (Trichophaga tapetzella) and
the white shouldered house moth (Endrosis
sarcitrella). As with other insects the best
chance of prevention and treatment is
provided by correct identification of the
insect(s) causing the problem.
Mould can also damage textiles. The dark
stains, a by product of enzymes produced by
the organisms to breakdown the fibres, may
degrade the fibres.
Chemicals used for remedial and preventive
treatments of textiles against insect attack are
discussed in Chapters 6 and 7 but it is worth
mentioning here that some of these chemicals
may themselves cause damage to textiles as
well as being hazardous to those carrying out
the treatment or subsequently handling treated
material. Methyl bromide may attack proteins
such as keratin that contain sulphur bridges,
accelerating their deterioration. It may also
damage rubber and imparts an unpleasant
smell to leather. Ethylene oxide is a suspected
carcinogen. It can soften glues and reacts with
cellulose causing permanent alterations. It also
reacts with protein causing premature ageing.
Naphthalene is alkaline. It may affect dyes,
soften varnishes and promote the corrosion of
some metals. Paradichlorobenzene can
damage dyes, feathers and leather. Sulphuryl
fluoride (SO 2F 2), registered in the USA as
Vikane, though thought to be one of the least
reactive fumigants, may react with metals and
if mixed with water vapour may form
sulphuric acid (H 2SO 4). Further information on
these interactions may be obtained from Peltz
and Rossal (1983). Because of these specific
reactions and concern for the health, safety
and welfare of personnel and the environment,
chemical insecticides are much less
commonly employed than they once were. For
textiles, treatment by freezing or by prolonged
exposure to inert gases is now generally
preferred to active chemical methods the use
of which is now generally confined to sanitizing
the built environments where textiles may
be stored or displayed. Further information on
disinfestation and disinfection may be
obtained from Tímár-Balázsy and Eastop
(1998).
Deterioration of other materials and structures 353
Structure of textiles
The very structure of a textile may assist in its
degradation. For example, the pile on velvet
or plush may be less resistant to mechanical
abrasion than the ground weave, resulting in
pile loss, particularly if the ground weave has
weakened, reducing its ability to hold pile
yarn in place. Thread floats from satin weave
and warp faced braids are more vulnerable to
wear than the heavier and more protected
weft threads. In combination weaves, for
example silk warp and wool weft, one fibre
may degrade more quickly than the other
rendering the cloth weaker in one direction.
Other examples include failure of adhesive
in bonded textiles. An example of an adhesive
bonded textile is an open weave cloth which
has been adhered to a second layer of cloth
to give the decorative top layer the extra body
required to make it sufficiently robust to be
used as an upholstery covering. After wet
cleaning, canvas work panels, particularly
those which have been tent stitched, may
become distorted and stamped designs may
loose some definition. In moist conditions
glazed fabrics are prone to mould attack
because some dressings and glazes, such as
starch and gelatine, are hygroscopic and therefore
retain moisture and contain nutrients
which may support fungal life.
Dyes and finishes
Following the absorption of light energy by a
dye molecule various photo-physical processes
may occur which result in the absorbed
energy being converted harmlessly to heat
(McLaren, 1983). Alternatively, in the presence
of oxygen and moisture chemical reactions can
occur which result in a shift in the wavelength
at which they absorb light, a phenomenon
known as fading. A slight shift will result in
some loss of colour, a large shift will result in
total loss of perceived colour. Many dyes of
moderate resistance to light are faded primarily
by the visible light they absorb (McLaren,
1956). The mechanisms of fading, which are
both highly specific and highly complex, have
been reviewed by Bentley et al. (1974),
Egerton and Morgan (1970), Griffiths (1972),
Leaver (1980) and Meier (1977). Some dyes are
pH-sensitive and their colour may change as
the textile becomes acidic on ageing, or is
neutralized or made alkaline by wet cleaning.