Dosing regrind for a sustainable injection molding and extrusion process

In the plastics industry, savings go hand in hand with a stable and sustainable production process. Movacolor asked its engineers to develop a dosing machine that can dose rejects and sprouts directly as regrind along with the masterbatch or free flowing powder and correlate the volume of color directly to the volume of regrind. The engineers answered with the MCTwin.

Dosing system for simultaneously dosing masterbatch and regrind

The MCTwin consists out of two MCBalance units. The regrind unit functions as the master dosing unit and the color dosing system functions as slave. According to the amount of regrind, the masterbatch will be added accordingly. More regrind means less masterbatch and vice versa. In practice this means high savings on masterbatch and an effective use of rejects and sprouts.

Dosing regrind to a high capacity extrusion line

In an extrusion process, regrind can be in flake form, irregular form or pellet form. It can be factory scrap or post-consumer scrap. In all forms it is important that it is added into the process in such a way that it will not disturb the melting and/or gelation process in the screw. Therefore, the dosing volume must be constant and its amount should follow the volume of the main flow, also with high fluctuations in bulk density. For these cases Movacolor has developed the MCHigh Output which comes in both volumetric as well as gravimetric execution and goes as far up as 1000 kg/h. The MCHigh Output is a perfect unit to combine with the MCWeight (measuring main flow) and the MCBalance (dosing color, catalyst, or other additive).

FAQ's and interesting links

• More about dosing systems for injection molding.
• What you need to know about gravimetric dosing.