Don't get ripped off with excessive Snorkel Prices:
Roediger Agencies cc
REG No: 93/29837/23
VAT No: 4200155465
Polymer Science Building
De Beer Street, STELLENBOSCH 7600
PO Box 3202
Tel: +27 21 887 0010
Fax: +27 21 886 4731
Cell: 083 250 9281
7 April 2011
PO Box 941
Dear Mr Pretorius
A snorkel (LLDPE) was sent to the analytical laboratory of Roediger Agencies cc for accelerated weathering.
Results were obtained via the following test method.
A QUV fluorescent UV/condensation tester can be used to accelerate weathering. Different types of
ultraviolet light bulbs can be used in the tester to emphasize different wavelengths. UVB radiation is
responsible for most polymer damage.
The bulbs used were of the type UVB–313, which gives the highest irradiation at a wavelength of 313 nm.
Results obtained with these lamps correlate well with results of outdoor exposure for gloss retention on
coatings and for the material integrity of plastics. With the exception of the automotive industry, the UVB-313
is the most widely used light source for the ASTM G-53 devices. However, the short wavelength output
below the solar cut-off can cause anomalous results.
Two types of weathering cycles are used; 1) Wet cycle is an 8 h exposure to a UV cycle at 45 °C, followed
by a 4 h condensation cycle at 50 °C, only the actual UV exposures hours are taken into consideration to
determine the outdoor exposure equivalent. 2) Dry cycle a continuous exposure to a UV cycle at 45 °C. The
reported number of hours of exposure is equivalent to the total time of UV exposure recorded.
In our experience with tests carried out to evaluate the weathering of plasticised poly(vinyl chloride), an
exposure time of 3000 hours correlates to a ten-year period. It must be borne in mind that the degradation
that takes place is not linear over the time of exposure, it is exponential.
The snorkel has been exposed to a wet cycle for 600 hours which equates to ±1 year outdoor.
After 600 hours in the wet cycle, no loss in gloss and no cracking are visible when looking at the photographs
Dr. AHA Roediger.