Rememebr, if it has to appear and disappear quickly, you need ot key frame it for that, so the transition occurs over two frames (soild  -->inviisble, or the reverse, ) and the initial state of the object at start of animation!! 
this is curucial, Vue it willl assume you want to blend the visibility state between begining of animation, and start of the changes. If this occurs over many frames, it will slowlly appear/disappear.

So, it could be done thus:

Frame 1 = invisible (sets basic state, not seen at all)

Frame  50= invisible (sets LAST frame for this state)
frame 51 =  VIsible (sets first frame for this state)

frame 90 = Visible (last frame for this state)
frame 91 - invisible (first frame for this state)

:)

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