  We study the translocation process of a polymer in the absence of external
fields for various pore diameters $b$ and membrane thickness $L$. The polymer
performs Rouse and reptation dynamics. The mean translocation time $<\tau_t>$
that the polymer needs to escape from a cell, and the mean dwell time
$<\tau_d>$ that the polymer spends in the pore during the translocation
process, obey scaling relations in terms of the polymer length $N$, $L$ and
$b/R_g$, where $R_g$ is the radius of gyration for the polymer. We explain
these relations using simple arguments based on polymer dynamics and the
equilibrium properties of polymers.
