Gravimetric Dosing Units

Gravimetric dosing units from Digicolor allow reliable processing of masterbatch, additives or regrind. These dosing units work in a loss-in-weight process and are extremely precise. Equipped with an industrial-grade, speed-controlled motor, these units cover a wide dosing performance spectrum. In addition, each dosing unit is equipped with a colour touch panel, which makes it very easy to enter and optimise the few dosing parameters. Gravimetric Digicolor metering units are ideally suited for metering colour batch, additives and recyclate in the application areas of injection moulding, extrusion and blow moulding.

Gravimetric dosing units for recyclate dosing

In addition to masterbatch metering, Digicolor metering systems are used for the addition of regrind or recyclate in in-house recycling applications. With Digicolor dosing systems, the so-called post-industrial recyclate can be fed back into the manufacturing process.

This recyclate is regrind that is obtained directly after plastics processing from sprues or rejects by grinding in plastic granulators. Grinding provides the processor with granular recycling material of such high quality that it can be used in the production of plastic products either in full or in defined percentages.

For this purpose, Digicolor integrates such dosing units into complete recycling systems consisting of granulator, granulate conveying technology and dosing technology. In this way, inline recycling applications are realised. These inline recycling solutions are adapted to the production process and the product specifications of the processor. With the appropriate processing and dosing, considerable material cost savings per year can be achieved.

Sizes of the gravimetric dosing units:

• Digicolor DCG-18: throughputs up to 16 kg/h, for one component.
  • Equipped with 7 litre stainless steel dosing hopper as standard
  • Hardened stainless steel dosing screws
  • Special dosing screws for regrind dosing
• Digicolor DCG-38: Throughputs up to 70 kg/h, for one component
  • Equipped with 15-litre stainless steel metering hopper as standard
  • Hardened stainless steel dosing screws
  • Special dosing screws for regrind dosing

For the installation of a dosing unit on the infeed zone of the injection moulding or extrusion machine, there are standardised mounting flanges to facilitate unit assembly. Furthermore, the product range offers a selection of stainless steel metering hoppers in different sizes from 5 litres to 15 litres volume. On the one hand, these are used to optimise metering units according to the application-specific throughput rates in kg/h. Different dosing hopper variants also offer the possibility to take into account space conditions on the processing machines.

Advantages of gravimetric dosing units:

• Simple operation of the device by
  • Input of the shot weight
  • Indication of the batch proportion in %
  • Saving of dosing recipes
• Easy product or batch change
• Processing of regrind or recycled material
• Low empty weight of the metering unit
• Installation directly above the feed zone of the machine
• Different, application-specific dosing screws
• Special equipment for dosing the recycling granulate
• Documentation and traceability of the dosing quantities possible

The modular system of highly wear-resistant, ionitrided metering screws in combination with a powerful geared motor, enables optimum adaptation of the metering process to different materials and throughputs.