Aerial view

Compounding

Basis stabilisation
Aerial view
Product feeding in a differential dosing scale
Vacuum weighing system with conveying scale
Feeding hopper

The task

  • Base polymer with variations in melt viscosity
  • ATEX gas zone outside the system
  • Due to volatile combustible components the ATEX zone is inside the system / handling in a nitrogen atmosphere
  • Unstable material / risk of oxidation
  • Best possible homogenisation concept
  • Maximum availability required (24h a day, 7 days a week)
  • Long conveying distances (approx. 400 m) with large throughputs
  • Continuous feeding of the extruder

The Solution

Bulk goods handling in the compounding process
  • Due to the fact that the supplied base polymer is an unstable product and is prone to oxidation, as well as for explosion prevention, the system has been designed for operation under nitrogen. The conveying medium nitrogen is circulated for efficiency and cost reasons. As a result, losses are reduced to a minimum.
  • A distance of 400 meters is to be bridged from the acceptance point of the raw polymer to the scale, which is used to weigh the polymer. This is accomplished by means of pressure conveying with nitrogen.
  • To increase the consistency of the product quality, the crude polymer is repeatedly conveyed in homogenising silos and mixed.
  • The material is sucked onto a conveying scale from the homogenising silos. In order to achieve a further intersection of the material, it can be fed from the different silos to the scale. From the conveying scale, the blended product is then emptied into a screw mixing silo and has thus passed through a multi-stage homogenisation process.
  • AZODOS® differential dosing scales now take over the continuous feed of the extruder, both with the polymer and with the necessary additives for base stabilisation of the polymer.
  • The differential dosing scales of the additives are fed from big bag and sack emptying stations.
  • The granules which are present after the compounding and granulating process are conveyed by means of pressure conveying into the finished product silos, which in turn are constructed as homogenising silos. From these silos, a buffer silo is filled, which is upstream of the filling station. This buffer silo is equipped with load cells. This ensures a continuous level control of the material to be filled.
  • The complete system, including the extrusion process to the granulation process, is controlled, monitored and completely documented by the AZO process control and visualisation system as well as the PLC. The orders are received, processed and documented back to the ERP system via an interface to the ERP system.
  • The entire system can be viewed using remote maintenance and is managed by AZO through a 24-hour maintenance contract.

Name of contact

AZO UK Ltd. | Chris Matthews | Sales Manager – UK & Ireland

Chris Matthews
Sales Manager