Formulation of a Model Resin System for Benchmarking Processing-Property Relationships in High-Performance Photo 3D Printing Applications.

A well-defined resin system is needed to serve as a benchmark for 3D printing of high-performance composites. This work describes the design and characterization of such a system that takes into account processability and performance considerations. The Grunberg–Nissan model for resin viscosity and the Fox equation for polymer Tg were used to determine proper monomer ratios. The target viscosity of the resin was below 500 cP, and the target final Tg of the cured polymer was 150 °C based on tan-δ peak from dynamic mechanical analysis. A tri-component model resin system, termed DA-2 resin, was determined and fully characterized. The printed polymer exhibited good thermal properties and high mechanical strength after post-cure, but has a comparatively low fracture toughness. The model resin will be used in additive manufacturing of fiber reinforced composite materials as well as for understanding the fundamental processing–property relationships in light-based 3D printing

Preventing Indoor Bioaerosol Contamination in Food Processing Environments and HVAC Systems: Assessment of Particle Deposition for Hygienic Design Purposes

International audienceThis chapter deals with airborne particle contamination in foodprocessing indoor environments and particularly within heating, ventilation, andair-conditioning (HVAC) systems in food factory buildings. The major types ofbioaerosols encountered in the food manufacturing sector as well as the bioaerosolsampling methods are firstly introduced. Secondly, some features of air handlingsystems such as zoning, cleanrooms, localized air handling systems, and HVACsystems are presented. Besides, the study of particle deposition to duct surfacesfrom turbulent airflow is reviewed and discussed. Substantially, an original workcombining industrial diagnosis and experiments at factory scale with experiments atlaboratory scale is then proposed through the case study of the CleanAirNet project.The CleanAirNet project (Hygienic Design of Ventilation Duct Networks in FoodFactories) aimed at producing new knowledge, models, and techniques to helpcontrol the safety of the food products through a better control of aerosol particletransport and deposition in the ventilation networks of the food industry. Thedifferent work packages of the project are presented relatively to the state-of-the-art particle deposition on duct surfaces. The methodological findings and relevantapplications (e.g., a newly patented particle trapping device for air handlingsystems) for food industries are exposed. The CleanAirNet project was supportedby the French National Research Agency (ANR) from 2008 to 2012; the project consortium was conducted by seven institutes and universities, as well as threeindustries from the food sector