ObjectivesTo gain insight into the experiences and concerns of front-line National Health Service (NHS) workers while caring for patients with COVID-19.DesignQualitative analysis of data collected through an anonymous website (www.covidconfidential) provided a repository of uncensored COVID-19 experiences of front-line NHS workers, accessed via a link advertised on the Twitter feed of two high profile medical tweeters and their retweets.SettingCommunity of NHS workers who accessed this social media.Participants54 healthcare workers, including doctors, nurses and physiotherapists, accessed the website and left a ‘story’.ResultsStories ranged from 1 word to 10 min in length. Thematic analysis identified common themes, with a central aspect being the experience and psychological consequence of trauma. Specific themes were: (1) the shock of the virus, (2) staff sacrifice and dedication, (3) collateral damage ranging from personal health concerns to the long-term impact on, and care of, discharged patients and (4) a hierarchy of power and inequality within the healthcare system.ConclusionsCOVID-19 confidential gave an outlet for unprompted and uncensored stories of healthcare workers in the context of COVID-19. In addition to personal experiences of trauma, there were perceptions that many operational difficulties stemmed from inequalities of power between management and front-line workers. Learning from these experiences will reduce staff distress and improve patient care in the face of further waves of the pandemic.

Polymeric materials hold several advantages over metal components in heat exchangers such as cost savings, lighter weight and corrosion resistance. However, it is challenging to engineer plastics with good heat transfer characteristics, processability and required strength. Neat polymer resins have inferior mechanical and thermal properties relative to metals, requiring careful consideration of the entire heat exchanger system from materials to system design, to achieve sufficient performance. This review summarizes the physical parameters governing polymer and composite thermal conductivity, as well as the latest research on augmenting thermal conductivity. Highly filled composites containing carbon or metal have achieved thermal conductivity an order of magnitude higher than that of neat polymers. The effects of critical additive characteristics, such as interfacial compatibility, filler shape factor, loading level and processing technique, are reviewed. In addition to lower material costs, high volume processing technologies such as injection molding and extrusion are responsible for the cost savings of

Purpose This study aims to evaluate the performance of injection molding inserts produced via rapid and conventional manufacturing techniques considering the mechanical and thermal performance of the tools as well as the resulting molded part quality. Design/methodology/approach Three insert materials and manufacturing techniques were evaluated, jetted photopolymer (PolyJet) 3D printing using digital ABS, direct metal laser sintering (DMLS) using bronze and machining using stainless steel. Molding trials were performed, and the insert surface temperature, longevity and part properties were evaluated. Complementary information was acquired using computer simulation. Findings Similar behavior and part quality were observed in machined and DMLS inserts. The latter were used for 500 cycles without any signs of failure. PolyJet inserts had increased cycle time and slower rate of cooling which increased shrinkage and crystallinity in the molded parts. PolyJet inserts could be produced quickly at a lower cost than machined or DMLS inserts. Research limitations/implications Cooling within the insert was not studied; inserts were cooled indirectly by the mold plates behind them. Subsequent studies will incorporate cooling lines directly into the inserts. Originality/value Little research has been done to understand the thermal behavior of inserts manufactured via rapid tooling techniques. This study provides a direct comparison between rapid tooling techniques, which is supported by simulation results and analysis of the actual molding properties.

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The effectiveness of seven methods for controlling switchover from the filling to packing stage were investigated, including: (1) screw position, (2) injection time, (3) machine pressure, (4) nozzle pressure, (5) runner pressure near the sprue, (6) cavity pressure near the gate, and (7) cavity temperature at the end of flow. The activation threshold for each of the seven switchover methods was iteratively determined so as to produce similar part weights relative to a standard process. A design of experiments was implemented for each of the seven switchover methods that perturbs the process settings by an amount equal to six standard deviations of the standard process so as to replicate the expected long‐term process variation. The results suggest that conventional switchover methods (e.g., screw position) had lower short‐term variation, but other methods were more robust with respect to rejecting long‐term process variation. The merits of different dimensional measurements for quality control are also discussed relative to the society of the plastics industry (SPI) standard tolerances. POLYM. ENG. SCI., 50:2031–2043, 2010. © 2010 Society of Plastics Engineers