- Whether to Weather: Longer Term Exposure to Come?
April 3, 2017
Whether to Weather: Longer Term Exposure to Come?
The 303 Vinyl Profile Performance Standard Maintenance Task Group (chair: Jeff Franson [Quanex]) is circulating a second ballot for an update of AAMA 303-12, Voluntary Specification for Rigid Polyvinyl Chloride (PVC) Exterior Profiles. Even as this step unfolds, future considerations are already on the table for discussion.
- Revisit the laminates section of AAMA 303, once the new laminates document is complete.
- An update to AAMA 109, which describes vinyl profile certification, will be required once 303 is re-issued.
- Research into extending outdoor weathering tests for certification from the current two years to three years or more. This is proving to be a somewhat contentious proposition.
At issue is whether such an extended weathering period would provide any meaningful information or certainty of product performance. It had been asserted that that current exposure data shows the biggest changes occur over a two-year period. In view of this, several task group members advocated leaving the weathering test at 2 years for certification purposes. Others voiced concern that, while there are no apparent color hold failures evident in the field, the test data is 15 years old and new compounds and new technology are available; thus, a research study to weather profiles for three or more years would be advisable. However, If weathering is extended to three or more years, color hold guidelines may have to be adjusted, as the two-year guidelines may not apply.
After much discussion, it was decided to form a study group that will report to VMC Technical Steering to assemble data from volunteer companies for the purposes of researching 5-year weathering.
Regarding capped profiles, it was decided to remove the heat build-up requirement for core material in capped profiles, which will change the text in Section 8 and Table 2.
In the co-extrusion section, it was noted that the document needs to better define the material that should be exposed to weathering, e.g., areas of the profile that are exposed when the window is open, or areas to which hardware is attached. Also, the question of delamination of cap and core in extreme cold was raised. If this is judged a valid concern, the possible adaptation of freeze/thaw testing referenced in the AAMA 614 series could be used for round robin testing to investigate whether there is an issue.