1. What is Melt Flow Index?

Definition: Melt Flow Index (MI) is a measure of the flow properties of a polymer when it is melted under specific conditions.

Purpose: It helps determine the viscosity and processability of thermoplastic materials.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( MI \) — Melt Flow Index (g/10min)
• \( M_p \) — Weight of polymer (grams)

Explanation: The weight of polymer extruded in 10 minutes is divided by 10 to standardize the measurement.

3. Importance of Melt Flow Index

Details: MI is crucial for quality control, material selection, and predicting polymer behavior during processing.

4. Using the Calculator

Tips: Enter the weight of polymer in grams collected during the standard 10-minute test. Value must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What does a high Melt Flow Index indicate?
A: A high MI indicates lower viscosity and better flow characteristics under the test conditions.

Q2: What are standard test conditions?
A: ASTM D1238 and ISO 1133 specify standard temperatures and loads for different polymers.

Q3: How does temperature affect MI?
A: Higher temperatures generally increase flow rate and thus the MI value.

Q4: What's a typical MI range for common plastics?
A: It varies widely - from 0.1 g/10min for some engineering plastics to over 100 g/10min for certain polyethylenes.

Q5: Can MI predict mechanical properties?
A: Indirectly - higher MI polymers generally have lower molecular weight and thus different mechanical properties.