HANSER Hanser Publishers, Munich • Hanser Gardner Publications ...
HANSER Hanser Publishers, Munich • Hanser Gardner Publications ...
HANSER Hanser Publishers, Munich • Hanser Gardner Publications ...
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for values of the ratio n (R0 + R1) I (R0 - JR1) > 37<br />
For smaller values of this ratio, Ga1111111118 has to be multiplied by the factor Pp given in<br />
Figure 5.1. The height H and width W are obtained in this case from Equation 5.6 and<br />
Equation 5.7.<br />
5.1.1.2 Shear Rate in Die Channels<br />
The shear rate for the channels treated above can be computed from [3]<br />
The shear rate for an equilateral triangle is given by [4]<br />
where d is the half length of a side of the triangle.<br />
The relation for a quadratic cross-section is [4]<br />
where a is the length of a side of the square.<br />
(5.9)<br />
(5.10)<br />
(5.11)<br />
(5.12)<br />
(5.13)<br />
In the case of channels with varying cross-sections along the die length, for example,<br />
convergent or divergent channels, the channel is divided into a number of sufficiently<br />
small increments and the average dimensions of each increment are used in the equations<br />
given above [3].<br />
5.1.1.3 General Relation for Pressure Drop in Any Given Channel Geometry<br />
(5.8)<br />
By means of the substitute radius defined by SCHENKEL [5] the pressure drop in crosssections<br />
other than the ones treated in the preceding sections can be calculated. The<br />
substitute radius is expressed by [5]