Any kind of waste container (small or large) that is used with a cyclone device must contain dead air to achieve the best possible separation of fine dust. There must be no air leakage into the waste container through 1) the lid-to-rim joint and 2) the cyclone-to-lid joint. Any air leakage through either of these joints will degrade the separation of fine dust. Flexible, elastic, compressible, conformable, leakproof gaskets must be used. It is not apparent that the metal garbage can in the video has an adequate seal at its rim. If the garbage can becomes deformed, then its rim seal likely also becomes deformed and leaky, even if the rim seal was once demonstrated to be leakproof. The two seals into the waste can should be periodically tested to prove air-tightness. Otherwise, the cyclone device might be deceptively operating very poorly with fine dust.
That's a fair point. I didn't explain in the video, but I used a thick self stick weatherstripping around the lip of the can and lid. This in fact provides an excellent air seal as evidenced by the crushing of the can. If leaks were occurring the can wouldn't have been crushed so thoroughly. If you look at the lip on the crushed can you can see the weatherstripping. It hasn't been applied to the new can in this video yet. Anyway, long story short, self stick weatherstripping does a great job of air sealing the metal can.
