Understanding Melt Flow Index

Melt flow index (MFI) is one of the most quoted numbers when selecting an EVA copolymer, yet it is often misunderstood. Expressed in grams per 10 minutes, MFI is an inverse measure of viscosity: a higher number means the polymer flows more easily under heat and pressure.

How MFI Maps to Process

• Low MFI (2-10): thick melt, best for blown film and extrusion coating where strength matters.
• Medium MFI (20-55): easy pumping and coating, common for hot melt and laminating adhesive.
• Ultra-high MFI (100+): very fluid, ideal for masterbatch carrier and high-speed dosing.

Where Evatane 28-25 Fits

At MFI 25, Evatane 28-25 sits in the medium range. It flows well through slot-die coaters and hot melt lines without demanding extreme temperatures, while still holding enough body to form cohesive bonds. That balance is why a single medium-flow grade can serve several converting steps.

Practical Takeaway

Choose MFI from the process, not the price list: match the flow to your equipment, then tune VA content for the flexibility, polarity or solubility your formulation needs.