  We examine the ejection of an initially strongly confined flexible polymer
from a spherical capsid through a nanoscale pore. We use molecular dynamics for
unprecedentedly high initial monomer densities. We show that the time for an
individual monomer to eject grows exponentially with the number of ejected
monomers. By measurements of the force at the pore we show this dependence to
be a consequence of the excess free energy of the polymer due to confinement
growing exponentially with the number of monomers initially inside the capsid.
This growth relates closely to the divergence of mixing energy in the
Flory-Huggins theory at large concentration. We show that the pressure inside
the capsid driving the ejection dominates the process that is characterized by
the ejection time growing linearly with the lengths of different polymers.
Waiting time profiles would indicate that the superlinear dependence obtained
for polymers amenable to computer simulations results from a finite-size effect
due to the final retraction of polymers' tails from capsids.
