Spray Foam Beyond HCFC-141b
Bibliographic record
Abstract
Sprayed rigid foam is a significant segment of the polyurethane industry, and as in other rigid foam segments, spray foam formulators need to find ways to meet current product requirements when the use of HCFC-141b is phased out in January 2003. Due to some of the unique characteristics of the spray foam industry, though, the choice of a replacement blowing agent is perhaps more complex than in any other rigid foam sector. The alternatives receiving the most consideration today are HFC-245fa, hydrocarbons, and water. All of these potential blowing agents have significant hurdles to overcome before they could serve as satisfactory replacements for HCFC-141b in the spray foam market. As of May 1999, a firm commitment to commercialize HFC-245fa has not been made. The use of hydrocarbons in spray would require significant improvements in safe handling procedures and modifications to spray equipment due to flammability issues. And with water-blown systems, dimensional stability and adhesion are two technical hurdles that must be overcome. It is conceded as well that insulation performance (as measured by initial k-factor) will not be as good for a water-blown foam as with HCFC-141b. It was because of the lack of an obvious HCFC-141b replacement for the spray foam industry that Huntsman Polyurethanes decided to investigate possible solutions. Any alternative would need to meet the processing and handling requirements that are currently met with HCFC-141b systems. The objective of this work is to develop zero-ODP (ozone depletion potential) technology that meets the performance characteristics that are currently achieved with HCFC-141b spray foam roofing systems. The focus of this paper is on the development of water-blown technology for roofing systems. Foams were processed via high-pressure spray equipment in a controlled environment. The study looked at the effect of polyol, catalyst, blowing agent, and processing variables on foam quality.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 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) | 0.002 | 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".