{"id":4120,"date":"2026-05-27T02:01:07","date_gmt":"2026-05-27T02:01:07","guid":{"rendered":"https:\/\/kitech-recycling.com\/?p=4120"},"modified":"2026-05-27T02:01:07","modified_gmt":"2026-05-27T02:01:07","slug":"recycled-pellet-quality-grades","status":"publish","type":"post","link":"https:\/\/kitech-recycling.com\/pt\/blog\/recycled-pellet-quality-grades\/","title":{"rendered":"Graus de qualidade de pellets de pl\u00e1stico reciclado: padr\u00f5es rA-rD explicados"},"content":{"rendered":"

When purchasing agents ask a recycled pellet supplier to price out \u201cprime quality\u201d grades, the answers they receive are never the same. \u201cWe have prime-grade rHDPE, sir,\u201d one recycled pellet vendor says. \u201cWe can quote on commercial-grade recycled pellets,\u201d another responds. \u201cStandard quality\u2026 with no specification to back it up,\u201d says a third. Since virtually all virgin plastic resin grades conform to ISO standards, complete with published specification data sheets, they can be compared to each other more easily than this tangled world of informal recycled pellet labels. Buyers, of course, lose money due to this ambiguity, but production stops and product recalls may be more costly for those products going to cons\u03bcmers in the auto industry and food industry.<\/span><\/p>\n

This primer will empower you to select recycled pellets effectively.<\/p>\n

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“Recycled Pellets” Is Not a Quality Statement \u2014 Here Is Why That Matters<\/h2>\n

Try searching the ASTM catalog for a generic, universal performance grade specification for recycled plastic pellet and you will fail.ASTM offers ASTM D5491-08(2022) a classification standard for recycled post-cons\u03bcmer polyethylene film,and ASTM D5577-19to identify contaminants in recyclate materials. The European Committee for Standardization (CEN) published EN 18065:2025 in August 2025 which, classifies data Quality Levels (DQL 1-4) for recycled plastics- this classifies the transparency of the recyclate rather than its performance. It tell you what data surrounds the recyclate but nothing of how it will perform on your injection molding press.<\/p>\n

The absence of a standard system meant that industry created its own le\u00d7icon. In fact, a 2024 report published in Nature Communications detailed the sale of commercial, PCR HDPE plastics known as “Natural” and “Jazz” — evidence that has now received peer review as confirmation that this grade nomenclature is informal, commercial, and unregulated. A report from the California Integrated Waste Management Board found that many of the producers\u2019 materials were coming in at grade level 1 of their five-tier scale- and did not have quality control equipment on line to produce otherwise.<\/p>\n

The practical result: 2 bags of \u2018recycled HDPE pellets\u2019 from two different sources might have an MFR value difference of 5-10, moisture a magnitude higher and the content of contamination might have two very different consequences when used in production. If you are buying recycled resin, you should be describing something – not describing a prayer, you know, a wish and a prayer. Learn more in our guide on what a plastic pellet is and how it is made<\/a>.<\/p>\n

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The 4-Tier Grade Framework: Prime, Commercial, Utility, and Regrind<\/h2>\n

Although not officially defined in any international standard, in practice the commercial qualities of recycled plastic pellets are defined on a four-level system. This has been synthesized from the CIWMB\/CSU Chico five-grade quality system , the DataIntelo market grades, and peer-reviewed MFI data from studies on commercial PCR pellets .10 The below outlines the expectations you should place upon any supplier of recycled plastic pellets.<\/p>\n

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Buyer case-Rotterdam, Netherlands A procurement manager, looking to purchase rHDPE for their detergent bottles, is sent two prices, \u201cprime grade rHDPE\u201d, for \u201c\u20ac1850\/MT\u201d and \u201crecycled HDPE pellets\u201d for \u201c\u20ac1420\/MT\u201d. Without a common language regarding the materials she will be able to go no further comparing offers. The less expensive could have an MFR value 0,95g\/10\u2019 – which cannot be used in the process.<\/p>\n

The more expensive material has already been validated on 190C\/2.16kg per ASTM D1238-23a relative to commercial grade MFI specifications. Using the table below she\u2019ll be ready to provide the adequate specifications to finalize the order.<\/p>\n<\/div>\n

\n\n\n\n\n\n\n\n\n
Grade Tier<\/th>\nMFI Consistency<\/th>\nMoisture<\/th>\nContamination<\/th>\nTypical Applications<\/th>\n<\/tr>\n<\/thead>\n
Prime<\/strong><\/td>\n\u00b15\u201310% of target<\/td>\n<750 ppm<\/td>\n<0.05%<\/td>\nFilm, food-adjacent packaging, automotive, precision injection<\/td>\n<\/tr>\n
Commercial<\/strong><\/td>\n\u00b115% of target<\/td>\n<1,500 ppm<\/td>\n0.05\u20130.95%<\/td>\nGeneral injection molding, blow molding, pipe extrusion<\/td>\n<\/tr>\n
Utility<\/strong><\/td>\n\u00b130% of target<\/td>\n<5,000 ppm<\/td>\n0.5\u20132%<\/td>\nConstruction pipes, agricultural uses, drainage, industrial parts<\/td>\n<\/tr>\n
Regrind<\/strong><\/td>\nUncontrolled<\/td>\nVariable<\/td>\n>2% possible<\/td>\nBlend carrier with virgin resin; plastic l\u03bcmber; low-spec moldings<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

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One big caveat: a more sustainable tier is not necessarily more expensive every time, during each market cycle. At the peak of the 2020 crude oil crash, select recycled HDPE grades actually spent time briefly trading at a slight premi\u03bcm to virgin material due to virgin pricing declining more rapidly than recycled contracts re-aligned. Most of the time, prime certified pellet products will trade at a 5 to 15 percent discount to uncategorized pellets; however buyers need to run sensitivities both ways.<\/p>\n

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The 8 Quality Parameters That Define Each Grade Level<\/h2>\n

Always ask for test data to support each grade claim for each of the eight parameters. When assessment is made of a new recycled resin supplier ask for the test reports to verify their compliance to these parameters.<\/p>\n

\n\n\n\n\n\n\n\n\n\n\n\n\n
#<\/th>\nParameter<\/th>\nTest Standard<\/th>\nPrime Grade Threshold<\/th>\nDeviation Indicates<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nMelt Flow Index (MFI\/MFR)<\/strong><\/td>\nASTM D1238-23a \/ ISO 1133<\/td>\n\u00b15\u201310% of grade spec<\/td>\nChain scission, cross-linking, PP contamination in HDPE<\/td>\n<\/tr>\n
2<\/td>\nDensity<\/strong><\/td>\nASTM D792 \/ D1505-25 \/ ISO 1183-1<\/td>\nrHDPE: 0.941\u20130.965 g\/cm\u00b3<\/td>\nFiller or additive contamination (>0.970 g\/cm\u00b3 is non-preferred for HDPE recycling)<\/td>\n<\/tr>\n
3<\/td>\nMoisture Content<\/strong><\/td>\nASTM D4019<\/td>\n<750 ppm (film grade); <200 ppm (hygroscopic rPET\/PA)<\/td>\nSplay marks, voids, hydrolytic degradation in melt<\/td>\n<\/tr>\n
4<\/td>\nContamination \/ Gels<\/strong><\/td>\nASTM D5577-19 \/ D6265-23<\/td>\n<15 gels per sq.in. (Prime); <0.05% unmelted particles<\/td>\nMixed polymer streams, insufficient sorting or washing<\/td>\n<\/tr>\n
5<\/td>\nColor (L* value)<\/strong><\/td>\nColorimetry (CIE L*a*b*)<\/td>\nL* > 60 for natural\/clear applications<\/td>\nMixed-color feedstock, oxidative degradation, carbon black contamination<\/td>\n<\/tr>\n
6<\/td>\nParticle Size & Uniformity<\/strong><\/td>\nASTM D7486-22<\/td>\n3\u20135 mm; size coefficient of variation \u2264 10%<\/td>\nInconsistent die cut, hopper bridging, uneven plasticization in barrel<\/td>\n<\/tr>\n
7<\/td>\nOdor \/ Total VOC (TVOC)<\/strong><\/td>\nVDA 270 \/ ISO 16000-6 (GC-MS)<\/td>\nTVOC < 50 \u03bcg\/g (food-adjacent); VDA 270 \u2264 3 (automotive)<\/td>\nRetained VOCs from food, detergent, or chemical packaging<\/td>\n<\/tr>\n
8<\/td>\nThermal Stability (DSC \/ FTIR)<\/strong><\/td>\nDSC \/ ASTM E1131 \/ FTIR-ATR<\/td>\nSingle melt peak; no secondary polymer peaks<\/td>\nMixed polymer contamination \u2014 e.g., PP secondary peak in HDPE signals “Jazz grade” quality ceiling<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

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It\u2019s true that melt flow index (parameter 1) is always talked about, but actually parameters 7 and 8 are the ones where premi\u03bcm claims most often falter. Depending on collection source (mixed detergent\/dairy streams) and processing rigours, post-consumer r-HDPE can contain total VOCs of 150-400 g\/g even pre-odorization – the \u2018food-related\u2019 tolerance limit for this being 50g\/g – meaning an 8-10 \u2018factor\u2019 increase. Identifying pp contamination of HDPE by heat (DSC additional peaks) is likely to be quicker than waiting through a full battery of mechanical properties.<\/p>\n

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Post-Consumer (PCR) vs Post-Industrial (PIR): What the Grade Ceiling Looks Like<\/h2>\n

Feedstock origin \u2014 whether the plastic was consumer-used or diverted from manufacturing \u2014 directly sets the grade ceiling attainable from any pelletizing system.<\/p>\n

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Post-Consumer Resin (PCR)<\/h3>\n