PoDV (Polymer Diverter Valve)

Description

For difficult products sensitive to temperature fluctuations, this function is indispensable during start-up, because underwater pelletizing requires an optimum volumetric flow through every die hole right from the start. Most upstream equipment, such as the extruder, responds slowly during ramp-up. The valve also allows the operator to visually check the compounding process and is often used for online material or colour changes.

The valve consists of a heated body with an integrated hydraulically actuated pin that switches the melt flow from the start-up position to the production position within one second. The valve inlet channel is often adapted directly to the outlet of the extruder, screen changer or melt pump, eliminating the need for an adapter.

A cone on the die plate downstream of the valve outlet shortens the flow channel and reduces the dead volume of melt upstream of the plate. As a result, no excessive amount of melt flows through the plate after extrusion stops, and the system can be restarted with a largely clean die plate, reducing the risk of polymer wrap-around and agglomerate formation during start-up.

A mobile support stand makes it easier to remove or move the valve aside when the extruder screw is pulled.

Optional equipment

• Cone on the die plate to reduce dead volume
• Mobile support stand