Basic materials
such as synthetic and and natural resins, and fibers have not
changed much over the last 20-30 years. Most fabrics still
utilize nylon, polypropylene, polyester, cotton and wool fibers and
the bulk of polymer films is still based on polypropylene, polyester
and polyethylene. Value added properties such as chemical
resistance, anti-stain (or low surface energy), release,
hydrophilicity, vapor and gas barrier, electrical
conductivity, and abrasion resistance may be added to fabrics, films
and papers, by altering the material surface without affecting its
overall physical and mechanical properties.
TREATED AND COATED FABRICS
Sigma has developed
two different technologies and production equipment for treating and
coating fabrics.
-
Atmospheric plasma
treatment which is used to treat and graft the fabric surface (see
also Atmospheric Plasma treatment section), and the
-
DryFabTM
nanolayer polymer coating process, (see also Radiation Cured
Polymers and Turn Key Equipment)
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Plasma Treatment
–Activation and cleaning:
This improves fabric dye uptake, adhesion and printing
quality
–Plasma grafting:
Used to create hydrophilic and hydrophobic surfaces
–Surface microroughness:
Change “Feel” properties and produce an anti-pilling effect on
Wool
–Shrinking and Heat Setting:
Desirable Effect for
Select Fabrics
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DryFabTM -
Functionalized Fabrics
Current commercial fabric treatment/coating technologies,
utilize solvent/water based processes.
DryFabTM
is an environmentally friendly 100%
solids “Dry Coating” process:
-
•No solvents
which require Recovery
-
•No hazardous
waste for disposal
-
•No primers,
surfactants and adhesion promoters
nnThe
process takes place in a vacuum environment -
ideal
for containment of monomers during the deposition process
nMonomers
are deposited as a vapor that conformally coats
the fibers –
do
not change porosity or breathability
–
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n
UNIQUE DUAL
FUNCTIONALITY
Conventional
wet processes that are used to functionalize fabrics,
impart the same properties on both sides of the material.
For example an anti-stain coating is water and oil
repelling. An apparel in contact with the body with an
anti-stain coating will feel very uncomfortable due to its
inability to absorb moisture.
The
DryFabTM process can produce different functionalities on each side
of a single fabric layer. For example an absorbing
cotton fabric can be made anti-stain only on the outside
surface, allowing the cotton against the body to absorb
moisture.
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DryFabTM
FUNCTIONALIZES FABRICS WITHOUT AFFECTING THEIR BREATHABILITY
For most applications, functionality
must be added to fabrics without affecting porosity and breathability. The vapor based vacuum coating process has
the ability to conformally coat individual fabric fibers (even
micro-fibers) without beaching contact points and blocking the
fabric
•
DryFabTM Coated Fabric
Uncoated Fabric
•
Nanolayer
Coated Fibers Do Not Block
Fabric Pores
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