Handles - Knotted Reinforced
This has string handles uses soft cord that is passed
through four holes cut into the bag. Knots in the cords'
ends keep it from pulling through the holes when the
bag is filled and lifted.
In this design, knots concentrate forces around the
bag's holes when the filled bag is lifted. Some bags
use cardboard reinforcing plates (see Movie 1), which
are further reinforced when the material in the bag's
top gets folded over the card. The plates and added
material better distribute the forces coming from the
knots. Even with reinforcement, this bag often fails
at the handle when the knot pulls through the holes.