JML flat mops, or anything that's virtually a direct copies of those, have a single piece plastic head that slots into a microfibre mat, and the plastic head is liable to crack and break. It's 'bendable" in the sense that its edges can be folded up to work on skirtings etc, but those bends are not strong.

And guess what, mine cracked and broke. Honestly it's a cheap mop/sweep, but they don't seem to sell replacement heads anywhere anyway. So of course I made one.

I think it's superior to the standard head, because the edges are not folded but hinged. I invented a kind of secure slotted hinge for this, so that the head can be printed in multiple parts rather than in-place (a necessity, since this is quite wide, and would not fit on my Ender-3 build plate if printed in one piece) and still remain secure and firm in use.

https://www.jmldirect.com/microfibre-mop-flexible-super-absorbent-microfibre-floor-mop-and-mitt-wet-or-dry