Extrusion 2-2016

43 / 68

43
Extrusion 2/2016 Film Extrusion, Coating
New Technology for Breathable
Products
“DoubleCoat ” combines extrusion
coating with hot melt lamination and
thus facilitates coating thickness minimi-
sation. For example, a minimum coating
layer thickness of 7µm can be achieved
using TPE on a PP nonwoven. This cor-
responds with roughly a mere quarter of
the current average for such coatings
and results in enormous material savings.
Excellent product quality is guaranteed
and even with thin coating layers adhe-
sion to the substrate is perfect and no
pinholes occur.
Another exciting feature of the process is
enhanced product breathability. The
coating thickness has a significant effect
on the water vapour transmission rate
(WVTR), as a thinner layer results in a re-
duction in water vapour flow resistance.
Consequently, standard product breatha-
bility can be increased several times over.
able, flexible and serve as an effective
barrier against viruses and bacteria. The
process could also be used for protective
clothing such as disposal overalls, or in
view of its soft touch, stretchability and
high breathability, for hygiene products.
Moreover traditional construction indus-
try products such as roofing underlay can
benefit to an equal extent from this new
method.
Interested customers will soon be able to
see the outstanding performance of
SML’s FlexPack extrusion coating line
with the “DoubleCoat” process for
themselves, as a production scale pilot
plant will be available for trials from April
2016.
SML has developed and ins-
talled a new laminating
line that is capable of
downgauging the coating
layer to a previously unob-
tainable extent using the
so-called “DoubleCoat”
process. “DoubleCoat”, for
which a patent is pending,
has been integrated into
the proven FlexPack extru-
sion coating line thereby
enlarging considerably the
attainable range of breath-
able products.
SML Maschinengesellschaft mbH
Bundesstr. 1a; 4860 Lenzing, Austria
A further advantage offered by the new
process is a reduction in the melt tempe-
rature to a minimum. This has a very po-
sitive effect on the mechanical characte-
ristics of the coating because the material
is subject to less stress during extrusion.
The advantages of the “DoubleCoat”
process at a glance:
• Reduced coating layer thickness
• Material savings and hence lower costs
• Strong adhesion
• Improved breathability
• High water column
• Enhanced mechanical properties
The “DoubleCoat” process provides
fresh possibilities for enhanced product
properties and lower production costs
with regard to a variety of applications.
These include medical products such as
surgical drapes, which are highly breath-
gmbh
Extruders & Extrusion facilities
eMail:
Plastic-Maschinen-Handelsges. mbH
Broichhausener Str. 4 · D-53773 Hennef
Tel. +49-2244-83041 · Fax +49-2244-83045
25
Visit our homepage
with many used machines for the
plastic extrusion business:
in stock · functionally tested · operational
Gleichlaufender Doppelschneckenextruder RZE 85-33D