Coathanger manifolds

The coathanger manifold design can be tuned for a processing window of different flow rate plastics. This mani-... 

For HDPF (rheological data are given in Table 2.3) design a coathanger manifold to feed a film die having a width 2W = 1.0 m and height of 0.0508 cm. Assume constant curvature of the manifold. 

FIGURE 7.57 Planar expanded view of coathanger manifolds for HDPE and nylon 6 for feeding the elUptically shaped annular die in Design Problem VI. 

A.4 Pressure Drop Across a Coathanger Die. Determine the pressure drop across the coathanger manifold and land for the sheet die discussed in Example 7.1. The extrusion rate is 200 kg/h. Note The pressure drop in the whole of the manifold system is calculated by calculating the pressure drop at the center of the die that is, y = L 0) and x = 0 in Fig. 7.32.)... 

Coathanger die n. A sheet-, or film-extrusion die whose melt-distribution manifold has the obtuse-isoceles outline of a coathanger. This popular die design is said to yield uniform distribution of material across the full width of the extruded web, thus producing sheet of laterally more uniform thickness. Side-fed blow-molding dies and spiral-type dies for blown film may also be spoken as a coathanger dies. 

The design of the manifold is now considered. The most widely used design is that of the coathanger type, which is shown in Figure 7.30 along with some other designs. As stated earlier the purpose of the manifold is to distribute the... 

Residence Time of a Fluid Particle Along a Flow Path. Show that the residence time in a coathanger die of a particle along any flow path is (note that the residence time consists of the residence time in the manifold plus that in the land region)... 

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