Carrier Resin Ratio

Dosing Proportion

Masterbatch preparation relies on maintaining a precise mass balance between the active concentrate and the polymer that encapsulates it. The carrier resin ratio is established during the initial dry blending stage before twin-screw extrusion. Moulding plants must match the carrier polymer with the base resin to prevent delamination or loss of mechanical performance.

An incompatible carrier degrades melt strength and introduces surface blemishes on the moulded part.

Melt Consistency

Flow behaviour in the injection barrel depends on the thermal characteristics of the compound’s constituent materials. The carrier resin ratio governs the viscosity of the melted masterbatch as it joins the primary resin stream. A closely matched viscosity ensures uniform colour and additive distribution without creating stagnant zones in the screw.

Differences in melt flow index between the carrier and the main polymer can cause severe screw slippage or surging.

Dispersion Efficiency

Downstream performance of functional additives like UV stabilizers or flame retardants hinges on their uniform distribution. Adjusting the carrier resin ratio allows compounders to tailor the release rate and wet-out time of these additives during the plasticizing phase. A high ratio of carrier polymer provides a thermal shield during early barrel zones, preserving heat-sensitive additives.

This protection prevents premature degradation and maintains the target properties of the finished product.