Originally Posted by heferly
Wow, that blows...glad i checked the link, cause i was gonna flame you for being too rough on your fermentor
sorry for the loss...looks like they just glued the bottom on instead of welding it
I doubt they do either. That would cause melted plastic or glue bead or possibly voids.
I'm fairly certain the bucket is a single injected plastic piece. The design of the newer bottom probably allows flexing of the plastic, which creates a small crack as you use it (pick it up and down and the bottom "bounces" slightly)
The ribs around the bottom edge would distribute that force across more surface area, which would help prevent this eventual damage.
Removing the ribs could be a way to save plastic. Every bit of material saved is money in the pocket. However, in order to keep the flexing from damaging the bottoms, they would have to increase the bead area that transitions the bottom to the side, which saves less plastic.
They may have removed the ribs to help keep the ribs from sticking in the mold, although that material is not really known to be problematic, and the ribs are pretty hefty, so I don't see a problem unless they somehow get damaged on the mold, which would require occasional repair. Not a big deal as this would be a relatively simple fix I think, and not one that would happen often if the mold and ejection system were designed properly.
More than likely, they did it to save plastic and make a "cleaner" looking product and simply did not foresee the consequences of the bottom flexing over time.
Another small possibility would be "Flow Lines" or "Knit Lines" where two areas of melted plastic meet. The cooler plastic from where two areas of melted plastic come together during the shooting process, and don't quite form a complete bond across the surface. This leaves a tiny line which can sometimes be a weakness, depending. In this case, I believe they shoot from the center of the bottom and the plastic spreads across the bottom and then up the sides, with really no chance of causing a Flow Line that I can see.