Fibre Analysis Flashcards
What are the 4 factors that affect the transfer of fibres?
size of the contact area
contact pressure
how long contact for
nature of donor and recipient fabrics
What are the 4 factors that affect the rate of loss of fibres?
the activity level of recipient garment
contact of the recipient with other surfaces
the strength of the initial transfer
nature of recipient fabric
Name 2 natural fibres and examples of them.
vegatable fibres = cellulose, lignin
Animal fibres = proteins
Name 2 manufactured fibres and examples of them.
Synthetic fibres = polymers
regenerated fibres = treated cellulose
What is a hazard with mineral fibres?
if you breathe them in they can cause a tumour
What is the most prevalent plant fibre?
cotton
What are seed fibres (natural fibre)?
hairs attached to seeds of plants (cotton)
What are bast fibres (natural fibre)?
form in bundles in stalk/stem (flax, hemp)
What are leaf fibres (natural fibre)?
leaves + leaf stalks (sisal, abaca)
What are fruit fibres (natural fibre)?
from husks/fruit (coir)
What is wool made from?
keratin
What is silk made from?
fibroin
How are man-made fibres made?
force polymeric material through holes of spinner
What were the first two man-made fibres?
Rayon
Nylon
1911
What are regenerated fibres (man-made fibre)?
made from regenerated cellulose
nylon, acetate, triacetate
What are synthetic fibres (man-made fibre)?
synthetic chemicals called polymers
nylons, polyesters, acrylics
Stereomicroscope
produced 3D image
offer large working distance
can be lighted from below or vertically from above
should be used first to examine fibres
Name 8 features noted when looking at fibres under a microscope?
crimp length colour relative diameter lustre apparent cross-section damage adhering debris
What are the 7 methods of collection of fibres?
tweezers tape lift 1:1 lift scraping vacuuming combing cuttings/pullings
Name 7 ways of analysing fibres?
polarised light microscopy fluorescence electron microscopy microspectrophotometry FTIR FTIR-ATR GCMS fibre dye analysis
Polarised light microscopy
easy, quick and non-destructive way to determine the polymer class of synthetic fibres
isotropic material
-the molecule has no specific or regular orientation of agreement
anisotropic
- molecules have a regular and specific orientation
-drawing process in synthetic fibres production makes them anisotropic
-will display certain optical characteristics which can be exploited to identify their genetic class.
studies interaction of plane polarised light with the anisotropic substances
refractive indices, the birefringence of synthetic fibres can be determined
Fluorescence microscopy
there are substances in fibre that fluoresce when illuminated with a certain range of excitation energy
- optical brightness
- dyes
- pigments
- contaminants
Microspectrophotometry
can be applied to a single fibre
non-destructive
can discriminate between fibres of the same colour
allows analysis of light absorption by the fibre in the visible and UV region of the electromagnetic spectrum
absorbance of fibre plotted against wavelength
Scanning Electron Microscope
can magnify x100,000
coupled with EDM used as imaging and microanalytical tool in characterisation of fibres
surface morphology can be examined with great depth of field
