We’re pretty confident most of us have it, and it’s most likely right outside your door. We’re talking about your wooden patio furniture! Your tables, chairs, chaises, adirondacks, benches and umbrellas. What the heck is this lignin? Well put on your Chem 101 hats. Lignin is a complex polymer of aromatic alcohols derived from wood, and constitutes 30% of non-fossil organic carbon and a quarter to a third of the dry mass of wood. Sooo, it’s a big make up of your wooden furniture right outside your door.
Being in the protecting business, we’re taking a closer look at the effects our beloved sun’s UV rays have on wood (lignin in the wood to be technical here). The lignin in our wooden furniture absorbs UV and causes discoloration and structural weakness. Studies have shown that discoloration and structural weakness is noticeable after only 250 hours of UV exposure, or roughly 31 sunny days! Yes, that can even happen here in the Great NorthWet Northwest.
Real world example: Fig 1.
Ever seen this happen to your favorite table? Lignin is photo-degraded by light (especially UV light) quicker than the other cell wall polymers. This decreases its water resistance, and can result in the buildup of yellowish to brown color. The effects of the degradation by light in the visible wavelengths usually follows, which causes lignin to become greyish or bleached in appearance over time.
Stained Wood – Light Damage:
Figure 2. The 10 year test results of the National Park Service’s Wood Stain Durability Test are shown above. The upper half of the test board was exposed in a window to north light. The bottom was covered during the test period. Comparison of the corresponding exposed and unexposed areas reveals the extreme susceptibility of certain commonly used wood stains to damage by light. **
“The aniline dyes (what gives the wood stain it’s color) proved to be extremely light sensitive with noticeable fading even on a year to year basis.” – National Park Service
The weathered look has its place, just not where you want to sit down and relax, or to serve your favorite BBQ dish on. When painted wood is exposed to UV for years, you’ll find cracking and flaking over time. Fig 4
So how can our covers help?
- All of Classic’s woven covers possess UV protection factors greater than 50, which is rated ‘excellent’ Fig 5.
- All of our woven patio furniture covers block at least 99.93% of all UV radiation due to their special backing.
- Choose a model with a UV protective-coating for longer lasting protection.
- Save money and convenience
- Check out how to properly store your patio furniture whether it be between seasons, showers, or weekends.
Protection like this has never been easier!
Basic Wood Anatomy and Behavior. Erica N. Skadsen 4/2007
“INFLUENCE OF LIGNIN CONTENT ON PHOTODEGRADATION IN WOOD/HDPE COMPOSITES UNDER UV WEATHERING” Chaochanchaikul et al. (2012).
“Photodegradation” BioResources7(1), 38-55. http://www.ncsu.edu/bioresources/BioRes_07/BioRes_07_1_0038_Chaochanchaikul_JS_Infl_Lignin_Photodegr_HDPE_UV_Weath_2000.pdf
**Photo Credit: Mike Wiltshire, National Park Service.