| Carrier Compatibility | Polyethylene-based carrier or a carrier proven compatible with the selected PE resin | Supplier technical data sheet; trial in the actual LDPE, LLDPE, or HDPE grade | 15% | PE carrier confirmed | PE carrier confirmed | Universal carrier | PE carrier confirmed | Prefer a carrier that matches the base resin to reduce phase separation and surface defects. |
| Pigment Loading | Consistent pigment concentration with a clear recommended let-down ratio | Certificate of analysis and gravimetric verification where required | 10% | 45% | 50% | 40% | 50% | Higher loading does not automatically mean better performance; evaluate color strength at the same dosage. |
| Color Strength | At least 95% of the approved reference at the agreed let-down ratio | Instrumental comparison against an approved color standard | 15% | 98% | 96% | 93% | 99% | Samples below the agreed strength should be rejected or technically requalified. |
| Color Difference | ΔE00 ≤ 1.0 for a critical color; ΔE00 ≤ 1.5 for a general industrial color | 分光测色仪 using CIE L*a*b* and CIEDE2000 calculation | 15% | 0.62 | 0.88 | 1.34 | 0.54 | Use the same film thickness, substrate, lighting condition, and measurement geometry for every sample. |
| Dispersion Quality | No visible agglomerates; uniform color with no streaks, specks, or die build-up | Microscopic film inspection and production-line trial | 15% | No visible specks | Minor specks | Occasional streaks | No visible specks | Dispersion should be checked at the intended processing speed and screw configuration. |
| Moisture Content | Preferably ≤ 0.15% before processing, unless the formulation specifies otherwise | Karl Fischer titration or validated moisture analyzer | 8% | 0.08% | 0.11% | 0.18% | 0.07% | Excess moisture may cause bubbles, silver streaks, and unstable extrusion. |
| Melt Flow Behavior | Stable flow at the selected processing temperature and compatible with the PE resin | ASTM D1238 or ISO 1133; compare with the base resin and processing conditions | 8% | 18 g/10 min | 22 g/10 min | 7 g/10 min | 20 g/10 min | Large flow differences can affect dosing, mixing, extrusion pressure, and final thickness. |
| Heat Stability | No visible shade shift or degradation during the complete residence time | Step-heating trial at the actual processing temperature; compare ΔE00 before and after heating | 7% | ΔE00 0.48 | ΔE00 0.73 | ΔE00 1.42 | ΔE00 0.39 | Confirm suitability for the highest temperature and longest residence time used in production. |
| Migration and Bleeding Risk | No visible bleeding, blooming, or transfer under the intended application conditions | Heat-aging, rubbing, and contact testing appropriate to the end use | 5% | No visible transfer | No visible transfer | Slight transfer after aging | No visible transfer | Food-contact, toy, medical, and packaging applications require separate regulatory verification. |
| Let-Down Efficiency | Achieve the required shade at the lowest practical dosage without sacrificing uniformity | Compare color strength and dispersion at identical addition levels | 7% | 2.0% | 1.8% | 2.5% | 1.6% | A lower dosage may reduce cost, but only when color consistency and physical properties remain acceptable. |
| Production Consistency | Stable results across at least three production or laboratory batches | Batch-to-batch ΔE00, moisture, pellet appearance, and dosage verification | 5% | ΔE00 range 0.31 | ΔE00 range 0.82 | ΔE00 range 1.18 | ΔE00 range 0.27 | Do not approve a sample based on a single test batch when color tolerance is critical. |
| Documentation and Technical Support | Complete TDS, SDS, COA, recommended dosage, processing guidance, and traceability | Document review and technical response-time assessment | 5% | Complete | COA format limited | Processing data limited | Complete | Strong documentation reduces qualification time and supports quality control after approval. |
| Weighted Screening Result | 100% | 92/100 | 86/100 | 74/100 | 95/100 | Advance the highest-scoring sample only after confirming production-scale performance, regulatory suitability, and total cost. |