Powder feeder boosts plastic pipe production
15 Jan 2000
Many process engineers will specify plastic pipework for particular processes, but few might appreciate just how much process engineering goes into its manufacture. When Wavin, a leading UK supplier of plastic piping, wanted a new feeding, weighing and metering system to handle the polymer powders and pigments used in its manufacturing process, it called in the process weighing and metering specialist Rospen Industries.
The contract required Rospen to deliver a system capable of dosing PVC powders with small pigments and special additives to an extruder surge hopper on the production plant. The system was designed to be retrofitted on to the existing plant and is refilled using dedicated vacuum hopper loaders.
The PVC powder is added to a weighed mixing vessel before the pigment and additives are dispensed. The ingredients in the 10kg batch are mixed to an accuracy of 2g ( 0.02 per cent). Capable of handling up to four different ingredients, the system completes the mix-dispense cycle every 30-40 seconds, maintaining an overall rate of more than 800kg/h.
As some of the additives can be non-free-flowing powders, each feeder is a fully agitated true metering screw feeder capable of handling difficult materials as well as granules and prills.
Each unit in the system can be quick-released and removed for clean-down and a faster change of ingredients.
