Interplay between Chain Relaxation Time and Melt Crystallization Time in Microinjection Molding of Polyoxymethylene
Bibliographic record
Abstract
Microinjection-molding subjects the polymer melt to high cooling and shear rates, which significantly affects the crystallization behavior during solidification. In this work, fast scanning chip calorimetry, conventional differential scanning calorimetry, melt rheology experiments, and polarized light optical microscopy permitted drawing conclusions about the crystallization of polyoxymethylene under such processing conditions. Computer simulations and Cox–Merz experiments predict orientation of molecular segments and shear-induced formation of crystal nuclei in all regions of the component, that is, in both the skin and core. However, as the result of the interplay between the cooling rate/crystallization temperature and the chain relaxation time, the survival of nuclei is restricted to skin-near layers. In contrast to the fast cooling skin, in the slowly cooling core region, the initially oriented structure recovers to the random coil state due to the much shorter relaxation time compared to the crystallization time. The study suggests that structure formation of crystallizable polymers during melt processing, including microinjection molding, largely depends on the (temperature-dependent) ratio between the chain relaxation and chain crystallization time.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| 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) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".