In practical applications, polyurethane (PU) foam must be rigid to meet the demands of various industries and provide comfort and protection in everyday life. PU foam components are extensively used in structural foam, thermal insulation, decorative panels, packaging, imitation wood, and floral foam, as well as in models and prototypes. Conventional technology for producing PU foam parts often leads to defects such as deformation, short shots, entrapped air, warpage, flash, micro-bubbles, weld lines, and voids. Therefore, the development of rigid PU foam parts has become a crucial research focus in the industry. This study proposes an innovative manufacturing process for producing rigid PU foam parts using silicone rubber molds (SRMs). The deformation of the silicone rubber mold can be predicted based on its wall thickness, following a trend equation with a correlation coefficient of 0.9951. The volume of the PU foam part can also be predicted by the weight of the PU foaming agent, as indicated by a trend equation with a correlation coefficient of 0.9824. The optimal weight ratio of the foaming agent to water, yielding the highest surface hardness, was found to be 5:1. The surface hardness of the PU foam part can also be predicted based on the weight of the water used, according to a proposed prediction equation with a correlation coefficient of 0.7517. The average surface hardness of the fabricated PU foam part has a Shore O hardness value of approximately 75. Foam parts made with 1.5 g of water added to 15 g of a foaming agent have the fewest internal pores, resulting in the densest interior. PU foam parts exhibit excellent mechanical properties when 3 g of water is added to the PU foaming agent, as evidenced by their surface hardness and compressive strength. Using rigid PU foam parts as a backing material in the proposed method can reduce rapid tool production costs by about 62%. Finally, an innovative manufacturing process for creating large SRMs using rigid PU foam parts as backing material is demonstrated.
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http://dx.doi.org/10.3390/polym16152210 | DOI Listing |
Chemosphere
December 2024
Arcadis G&M of North Carolina, Inc., 175 Regency Woods Place, Suite 400, Cary, NC, 27518, USA. Electronic address:
When fire suppression systems that held aqueous film forming foams (AFFF) are transitioned to per- and polyfluoroalkyl substance (PFAS)-free firefighting formulations, PFAS can dissolve from the wetted surfaces of the systems and release into the new firefighting formulations. The overall objective of this work was to characterize PFAS residual mass on the wetted surfaces of aircraft rescue and firefighting (ARFF) vehicle on-board fire suppression system components from the water, mixed fire water, and foam concentrate systems with various geometries, materials of construction, and locations within the fire suppression system. The ARFF vehicle components were dismantled from the system after a triple water rinse procedure which removed 19,600 mg total measured PFAS post-TOP assay from the foam concentrate system and 23 mg total measured PFAS post-TOP assay from the water system.
View Article and Find Full Text PDFMaterials (Basel)
November 2024
Department of Chemistry, Rzeszow University of Technology, 35-959 Rzeszow, Poland.
Nanocomposite flexible polyurethane foams (nFPUfs) were obtained by modifying the polyurethane formulation by adding a halloysite nano-filler in the amount of one to five parts by weight per hundred parts of used polyol (php). Flexible polyurethane (PU) foams with an open-cell structure and with a beneficial SAG factor were obtained. Premixes with nano-filler had a lower reactivity than the reference PU system.
View Article and Find Full Text PDFToxics
November 2024
School of Public Health, Ningxia Medical University, Yinchuan 750004, China.
Background: The primary flame retardants in vehicles, organophosphates (OPEs) and polybrominated diphenyl ethers (PBDEs), volatilize and accumulate in the enclosed vehicle environment, posing potential health risks. Amidst the rising number of vehicles, the scrutiny of persistent organic pollutants like OPEs and PBDEs in vehicles is increasing. This study investigates occupational and nonoccupational population exposure to specific OPEs (TnBP, TBOEP, TEHP, TCEP, TCiPP, TDCiPP, TPhP, EHDPP) and PBDEs (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, BDE-183, BDE-209) in vehicle dust.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
December 2024
National Aquatic Resource Research & Development Agency (NARA), Crow Island, Colombo 15, Sri Lanka.
Microplastics are pervasive pollutants in marine ecosystems worldwide and are increasingly recognized as a significant environmental threat. Sri Lanka, an island nation, is not exempt from this issue. While microplastic pollution has been extensively studied in the southern and western parts of Sri Lanka, limited data is available for the northern coastal regions.
View Article and Find Full Text PDFPolymers (Basel)
August 2024
Department of Mechanical Engineering, Ming Chi University of Technology, No. 84, Gungjuan Road, New Taipei City 24301, Taiwan.
In practical applications, polyurethane (PU) foam must be rigid to meet the demands of various industries and provide comfort and protection in everyday life. PU foam components are extensively used in structural foam, thermal insulation, decorative panels, packaging, imitation wood, and floral foam, as well as in models and prototypes. Conventional technology for producing PU foam parts often leads to defects such as deformation, short shots, entrapped air, warpage, flash, micro-bubbles, weld lines, and voids.
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