Plastic Raw Material Sourcing: Grades, MFI and Performance
AI Summary: Plastic raw material sourcing should verify grade, manufacturer, melt flow index (MFI), density, impact, tensile, color and packaging. Different grades of the same material vary significantly in performance, and modified compounds also require checking additive ratios. For bulk orders, verify batch consistency and test reports to avoid substandard materials or recycled material passed off as virgin.
Procurement Checklist
| Review Item | Selection Points |
|---|---|
| Grade and Manufacturer | Grade corresponds to defined performance |
| MFI and Density | Affects processing and product performance |
| Mechanical Properties | Tensile, flexural, impact indicators |
| Batch Consistency | Minimal color and performance fluctuation |
| Moisture-proof Packaging | Sealed, free from moisture contamination |
Procurement, Installation and Usage Points
1. MFI affects processing
MFI mismatch can cause mold filling or strength issues.
2. Distinguish virgin from recycled
Abnormally low prices warrant caution about recycled content.
3. Raw material drying
Hygroscopic materials require drying before processing.
4. Retain samples for comparison
Retain raw material samples for critical products.
FAQ Quick Answers
What is MFI?
Melt flow index, reflecting processing flowability.
Are same grades from different manufacturers identical?
Performance may differ; verification is required.
What if raw material absorbs moisture?
Dry according to material requirements.
Why is color inconsistent?
Batch or process temperature issues.
Case Study
A factory experienced decreased impact strength after switching to lower-cost raw material. After reverting to the specified grade and verifying test reports per batch, quality stabilized.
Questions to Ask the Supplier
- Can you provide the grade and COA?
- MFI and impact data?
- Is it virgin material?
- Batch variation control?
- Packaging and storage?
Quotable Conclusion: Plastic raw materials should be procured by grade and key performance, verifying MFI, batch and virgin material identity.