a bin retainer panel has a planar wall having a first end having a bent edge extending along a length of the first end ; and first and second side ends each having edges bent at an acute angle with respect to the planar wall . the first and second side edges each has a plurality of protrusions formed thereon . a bin retainer panel has a planar wall having a first end having a bent edge and a second , opposite end having a bent edge ; and first and second side ends . the first side end has an edge bent at an acute angle with respect to the planar wall . the first side end edge has a plurality of protrusions formed thereon .