Phototendering is the process by which organic
fibres and
textiles
Textile is an Hyponymy and hypernymy, umbrella term that includes various Fiber, fiber-based materials, including fibers, yarns, Staple (textiles)#Filament fiber, filaments, Thread (yarn), threads, and different types of #Fabric, fabric. ...
lose strength and flexibility due to exposure to sunlight. The
ultraviolet
Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of ...
component of the sun's spectrum affects fibres, causing chain
degradation and, hence, loss of strength. Colour fade is a common problem in phototendering.
UV degradation
The rate of deterioration is also affected by
pigments
A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly solubility, insoluble and reactivity (chemistry), chemically unreactive in water or another medium; in contrast, dyes are colored sub ...
and
dyes
Juan de Guillebon, better known by his stage name DyE, is a French musician. He is known for the music video of the single "Fantasy (DyE song), Fantasy" from his first album ''Taki 183 (album), Taki 183''. This video became popular, attracting ...
present in the textiles. Pigments can also be affected, generally fading after UVA and UVB radiation exposure.
Great care is needed to preserve museum artefacts from the harmful effects of UV light, which can also be present in
fluorescent lamps, such as ancient textiles. Paintings such as
watercolours need protection from sunlight to preserve the original colours.
Many synthetic
polymers
A polymer () is a substance or material that consists of very large molecules, or macromolecules, that are constituted by many repeating subunits derived from one or more species of monomers. Due to their broad spectrum of properties, b ...
are also degraded by
UV light, and
polypropylene
Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. It is produced via chain-growth polymerization from the monomer Propene, propylene.
Polypropylene belongs to the group of polyolefin ...
is especially susceptible. As a result, UV stabilisers are added to many
thermoplastics
A thermoplastic, or thermosoftening plastic, is any plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling.
Most thermoplastics have a high molecular weight. The polymer chains as ...
. Ultraviolet absorbers such as
carbon black
Carbon black (with subtypes acetylene black, channel black, furnace black, lamp black and thermal black) is a material produced by the incomplete combustion of coal tar, vegetable matter, or petroleum products, including fuel oil, fluid cataly ...
are also effective in protecting products against
UV degradation.
See also
*
Polymer degradation
*
UV Stabilizers in plastics
References
{{Reflist
External links
Patent for Protection of Fibres from Phototendering
Mechanical failure