What is a monofilament?
Single filament that can function as a yarn, it can be knitted woven or braided
What is a yarn?
Intertwined system by simultaneous tension and torsion of carded fibers
What is the geometric prequisit of a fibre?
length 100x diameter
Name 4 natural fibres
Cotton, cellulose, wool, asbestos
What is the titer?
The linear density of the yarn, expressed in g/km (1tex) or g/9km (1 Dernier)
How is the titer calculated for mulitple fibres?
What is a fabric?
A planar structure consiting of yarns and fibres.
What is the tenacity?
In which ways can a bundel of fibres be alligned?
What is the crimp of a fibre?
“waviness” of a fibre
The parts where it diverges from the main line.
Name three fibre production methods with one example each.
Melt spinning (TP)
Dry spinning (cellulose)
Wet spinning (Aramid)
Name the components and the method.
Melt spinning
What are the stages of melt spinning?
Melting and transport
Extrusion
melt cooling
drawing and texturing
post extrusion
What is the difference between the POY and the FDY system for producing fibres?
The fdy process includes drawing units, for high orientation and therefore mechanical stability
How is the drawing ratio calculated?
How does the Drawing ratio effect the strength?
The increase in drawing ratio increases the strength.
How does the Drawing ratio effect the crystallinity?
The fibres order due to elongation in one direction, which leads to post cristalization.
Name the post processing processes.
Texturing
interlacing
Twisting
heat stabilization
dye
Explain the post processing method of texturing and name the variants.
Enhancing the arangement in 2d. Produces higher Volumes.
air jet method
edge crimping method
false twisting
gear crimpling
Explain the process of interlacing.
Arranging fibres to pass over and under eachother, whcih can be used for combining them
increase in titer
Explain the process of twisting.
Method of joining two fibres.
titer depends on turns per meter.
What is achieved by Heat stabilization?
The reduction of shrinkage with temperature.
What are the stages of a BCF machine?
Chamin
application of process oil
pre heating
drawing
fixing
texturisation
stabilization
interalcing with air
winding
Which materials are used for unwoven fibres?
PP, PET
How is paper produced?
By breaking the polymeric chains in cellulose with acid and then reconecting the material by beating.
Is paper an anisotropic or isotropic material?
Anisotropic
the toughness depends on that
Describe the behaviour of the strength iwth increased synthetic or binder content.
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