Meaning
Concentrated additive carriers deliver heavy inorganic fillers into base polymers during single-screw or twin-screw extrusion. A high-density masterbatch incorporates up to eighty percent mineral loading into a carrier resin to simplify dosing during compounding. Moulding facilities use these concentrates to increase component mass or improve acoustic dampening without handling dusty raw powders.
Dosing Mechanism
Matching carrier melt flow index with base resin characteristics ensures rapid dispersion throughout the primary melt stream during processing. High concentration of dense fillers like barium sulfate or tungsten powder alters the bulk density of pellet blends inside feed hoppers. Gravimetric loss-in-weight feeders adjust screw speeds automatically to compensate for changes in bulk density.
Mixing elements on extrusion screws disrupt pellet agglomerates to achieve uniform filler distribution before the melt reaches the die.
Pellet Inclusion
Incomplete melting of carrier resin in a high-density masterbatch causes un-melted gel particles and un-dispersed filler clusters in thin-wall mouldings. Structural inclusions create surface blemishes and reduce tensile strength in structural components.
Feeder Economics
Masterbatch dosing eliminates specialized powder handling infrastructure but incurs higher material costs per kilogram than direct raw mineral feeding. High filler loadings increase carrier degradation risks during repeated thermal processing cycles. Compounding operations balance capital equipment investment against concentrate premium costs when selecting blending methods.
