Non-PFAS polymer processing aids: Slip velocity measurements and time-to-clear studies in blown film extrusion
Bibliographic record
Abstract
Polymer processing aids (PPAs) reduce and/or eliminate sharkskin melt fracture (MF) instabilities in polyethylene extrusion. This is achieved by increasing the critical flow rate at which MF occurs thus resulting in increased extrusion rate, productivity, as well as reduced energy cost. Fluoropolymers, classified as per- and poly-fluoroalkyl substances (PFAS), have been successfully used as PPAs for several decades but have come under increasing regulatory and consumer scrutiny. Non-PFAS PPAs have been developed and their performance in film extrusion is evaluated in this work. Slip velocity measurements have been carried out using capillary and parallel plate rheometry for the newly developed non-PFAS PPAs as well as a traditional PFAS PPA. A transient flow model has been developed to describe PPA layer thickness build-up and model predictions have been used to correlate experimental observations from time-to-clear (TTC) studies in pilot scale blown film extrusion.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".