The lag of the phreatic line depends on factors such as: permeability of soils, drawdown rate, drawdown ratio
and slope gradient during rapid drawdown, the stabilizing effect of the water on the upstream face is lost, but the pore-water pressures within the embankment may remain high.
As multilayer reflector of the fiber is drawn from the rolled multilayer film in the preform, the thickness of the individual layers in the preform can be determined by multiplying the desired layer thickness in the fiber by the drawdown ratio
used during the drawing process.
This means each polymer has a different drawdown ratio
Han  and Huang and White  obtained experimental results on die swell of non-circular fibers, but they studied only free swelling with no drawdown, of which the state is far from real industrial spinning process with a large drawdown ratio
The preferred drawdown ratio
for a die is between 1.
The melt strength and drawdown ratio
(DDR) for the samples at 230 C are shown in Fig.
increased roughly and linearly for both polymers.
The two most critical dimensions, however are land length and drawdown ratio
Crystalline orientation and birefringence were found to correlated with spinline stress better than drawdown ratio
The amount of shielding in a given area is inversely proportional to the drawdown ratio
of the sheet.
Process variables in the blown film process include: 1) temperature of the melt leaving the die; 2) die gap; 3) die land length; 4) blowup ratio (BUR), defined as the ratio of final film-tube diameter to die diameter; 5) drawdown ratio
, defined as the ratio of film velocity at the nip roll to average melt velocity in the die; and 6) frost-line height and cooling conditions.
At loading levels of 6% to 10%, the masterbatch dramatically increases the extensional force that can be applied to PLA during processing at drawdown ratios
as high as 35:1 (see graph).