First-rate resistance to microbes and hydrolysis
Synthetic materials in long-term contact with soils and similar substances or
heavy contamination under conditions favourable to microbes can be
destroyed by enzymes from the organisms, which attack the chemical
bonds. Under particularly unfavourable conditions, the first signs of
damage can become apparent after two to six months.
Moreover, in tropical climates many plastics in contact with warm water or
water vapour undergo irreversible degradation of the molecular chains
(hydrolysis) at about 60°C or above. Materials with little
stabilization can suffer a loss of more than 95% of their tensile
strength after just three weeks of exposure to hydrolytic conditions
at 80°C.
For many hoses, NORRES uses a special, high quality ether-polyurethane
instead of the ester-polyurethane frequently used for commercial
applications. Our ether-polyurethane hoses have the following
characteristics:
- Resistant to microbes
(The chemical structure of ether-polyurethanes gives
the materials permanent resistance to
microbial attack. We believe this is clearly a better solution than
ester-polyurethanes that are often stabilized with for
health not completely harmless additives for this purpose.
With these ester-polyurethanes there is a risk that the additive will
leach out, causing the level to fall below that required for
protection as the additive migrates to
the surface of the hose and comes in contact with the user and the
material transported.)
-
Resistant to hydrolysis.
(This is critical for wet applications at higher
temperatures and for use in tropical climates.)
-
Better chemical stability than comparable ester-polyurethanes.
-
Better flexibility at low temperatures than comparable ester-polyurethanes.
These characteristics are particularly important in public utility
vehicles. NORRES manufactures a comprehensive range of products that
are specially designed for the diverse operating conditions
prevailing in this sector. The following pages contain useful
information about hose qualities for use on street cleaning machines
of all sizes, including crush-proof hedge suction hoses for public
utility machines and gardening or landscaping applications.
All information provided by NORRES in the drawings on these pages is
merely intended as a guide to help you identify and recommend the
most suitable hose qualities in quotations to customers.
Engineering modifications subject to change. |
NORCONNECT 231 / NORCONNECT 232
