I recently saw several websites about appliances which had pictures of a service guy holding a dryer lint screen under running water in the sink to allegedly demonstrate how fabric softener sheets can make the filter impenetrable. After only a minute of reflection on dryer technology and physics, I feel obligated to repudiate their claims....
Most dryer lint screens have a very fine mesh. If you hold a dryer screen under running tap water, most of the water will shed off the surface without going thru. This is NOT due to fabric softener permeation, but a natural fact of physics. Tap water falling from a spigot does not have the power to work thru the mesh very well on its own, plus other factors such as water hardness affect the surface tension of water anyway. The key word here is "Surface Tension"...(ok, two words). The running water demonstration proves nothing other than a full stream of water won't go thru a filter screen well. D-U-H-H-H!
This can not even remotely be associated with the way a dryer processes air thu the screen. For one thing, the water which must exit a clothes dryer is heated to vapor form, almost like air. This is very different than a solid stream of tap water, and passes thru the screens relatively friction-free. Another reason why this theory does not "hold water" is that the dryer has a blower which is sucking air thru that screen at 650 C.F.M. Nothing short of molasses is going to stay behind the screen, so again the theory of water not being able to pass thru these screens is ludicrous.
Does this make sense to other technicians also, or should we just let this go unnoticed?