Technical Spoke: Material Flow Index (MFI)
Material FlowIndexTesting
Controlled melt-flow testing for thermoplastic materials to evaluate flow behaviour, material consistency and processing characteristics under defined test conditions.
MATERIAL TEST
MELT FLOW INDEX
MFR / MVR
POLYMER EVALUATION
Why MFI Matters
How does the polymer flow during processing?
Material Flow Index testing evaluates the flow behaviour of a thermoplastic material under defined temperature and load conditions.
The resulting melt-flow measurement can provide useful information for material comparison, incoming material verification, process evaluation and quality control.
MFI results are meaningful only when the material, conditioning, temperature, applied load, specimen preparation and applicable test method are controlled and documented consistently.
Test Overview
Material Flow Index
Test Type
Melt Flow Index / Melt Flow Rate Testing
Testing Location
Mascot Plastic Industries Laboratory
Primary Result
Melt Flow Measurement under Defined Conditions
Application
Thermoplastic material evaluation and process-related material comparison
Terminology
MFI, MFR and MVR
Different melt-flow measurements describe polymer flow behaviour in related but distinct ways. The applicable terminology should follow the selected test method and reporting requirement.
Material Flow Index is commonly used to describe a melt-flow test performed under defined temperature and load conditions.
Material Flow Index is commonly used to describe a melt-flow test performed under defined temperature and load conditions.
Melt Mass-Flow Rate expresses the mass of polymer flowing through the specified test arrangement over a defined period.
Melt Mass-Flow Rate expresses the mass of polymer flowing through the specified test arrangement over a defined period.
Melt Volume-Flow Rate expresses polymer flow in volumetric terms under defined test conditions.
Melt Volume-Flow Rate expresses polymer flow in volumetric terms under defined test conditions.
Test Flow
How MFI testing works
A controlled sequence from material identification and preparation through melt-flow measurement and documented results.
01
Material
The polymer material, grade and specimen identification are recorded before testing.
02
Preparation
The test material is prepared and conditioned according to the applicable procedure.
03
Temperature
The specified test temperature is established and controlled.
04
Loading
The defined material charge and test load are applied according to the selected method.
05
Flow
Molten polymer flows through the test arrangement under the defined conditions.
06
Result
The melt-flow result and relevant observations are recorded for evaluation.
Test Results
What MFI testing tells you
Melt-flow testing provides a practical indicator of polymer flow behaviour that can support material and manufacturing decisions.
Melt Flow Behaviour
Provides an indication of how readily a thermoplastic material flows under the defined test temperature and load.
Material Consistency
Results can be compared against defined requirements or historical values to identify potential variation in incoming or production material.
Process Relevance
Melt-flow characteristics can provide useful input when evaluating material suitability for a particular processing application.
Material Evaluation Sequence
From polymer sample to result
The fundamental sequence used to evaluate melt-flow behaviour under controlled conditions.
01
Material
Polymer sample
02
Condition
Defined preparation
03
Temperature
Controlled condition
04
Flow
Material extrusion
05
Result
Measured flow value
Key Applications
Where MFI testing is used
Melt-flow testing can support material qualification, incoming inspection, process development and quality evaluation across thermoplastic applications.
Key Application
Injection Moulding Materials
Evaluates melt-flow behaviour of thermoplastic materials used in injection moulding applications.
Injection moulding grades
Engineering plastics
Commodity thermoplastics
Production materials
Material comparison
Key Application
Incoming Material Inspection
Provides a measurable flow characteristic that can be compared with defined material requirements or supplier documentation.
Incoming raw material
Supplier verification
Batch comparison
Material traceability
Quality inspection
Key Application
Material Selection & Development
Supports engineering teams when comparing thermoplastic materials for a proposed application or processing requirement.
Material screening
Grade comparison
New product development
Process evaluation
Material substitution
Key Application
Production & Quality Control
Melt-flow results can be used as one part of a broader quality-control approach for monitoring material consistency.
Production quality
Batch-to-batch comparison
Process investigation
Quality verification
Material consistency
Engineering Value
Why MFI testing matters
Melt-flow results can provide useful evidence for material, process and quality decisions when interpreted together with the relevant product and processing requirements.
Material Verification
Helps compare a received polymer against defined requirements, supplier information or established internal values.
Material Selection
Provides a useful flow-related characteristic when evaluating alternative thermoplastic grades for a manufacturing application.
Process Evaluation
Can support investigation of material-related changes that may influence processing behaviour.
Quality Investigation
MFI results can contribute to root-cause investigation when production behaviour or material performance changes unexpectedly.
Material Scope
Thermoplastic material evaluation
MFI testing may be applicable to a range of thermoplastic materials when the selected material and test method are compatible with the laboratory procedure.
Polyolefins
Applicable thermoplastic grades where melt-flow characterization is required.
Engineering Plastics
Selected engineering thermoplastic materials subject to the applicable test procedure.
Production Grades
Materials used in production that require flow-property comparison or verification.
Development Materials
Candidate materials being evaluated during product and process development.
Laboratory Documentation
Typical test record
The actual test record should follow the applicable procedure, material specification and customer requirement.
✓
Material identification
✓
Material grade
✓
Specimen identification
✓
Test date
✓
Test conditions
✓
Temperature condition
✓
Applied load condition
✓
Melt-flow result
For OEM & Engineering Teams
Turn material data into engineering confidence.
Documented melt-flow results can support material qualification, incoming inspection, process evaluation, production consistency and engineering investigation.
✓
Material qualification
✓
Quality verification
✓
Material comparison
✓
Process evaluation
✓
Engineering investigation
Technical Note
Melt-flow testing is highly dependent on the material, specimen preparation, temperature, applied load, conditioning and applicable test method. MFI, MFR and MVR terminology should therefore be reported according to the selected procedure and customer or product requirement. Results should be interpreted within the context of the material grade and its intended processing application.
Laboratory Capability
Need MFI testing for your material?
Share your polymer grade, material specification, required test condition and intended application so the appropriate melt-flow testing requirement can be discussed with the Mascot Plastic Industries team.
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