Let $\mathcal{F}$ be the family of all $k$-element subsets of $[n]$. What is the smallest $\ell$ such that we can partition $\mathcal{F}$ into $\ell$ families $F_1,\dots,F_\ell$ with the property that none of the $F_i$ contains two sets that intersect in at most two elements?
Of course, one can generalize this question to intersections of size at most $r$, but I couldn't even figure out this "simple" case. If no such lower bound is known, are there related problems I could look into?