Choosing Black Masterbatch for Blown Film
Blown film is unforgiving of poor dispersion — undispersed carbon black shows up as gels and pinholes. Start with a masterbatch dispersed by high-intensity two-stage extrusion.
Match the carrier to your resin (LDPE/LLDPE for most film) and choose CB content so your target opacity is reached at a 1–4% addition rate. For cost-sensitive bags, an rPE or Y-Series grade keeps performance while lowering cost and footprint.
For thin film and high clarity-of-color requirements, a high-color-black grade gives a cleaner, deeper black at lower let-down. Always trial on your line and confirm opacity, gels and mechanicals before scaling.