Avaliação das propriedades mecânicas e planejamento estatístico experimental em blenda PVC/NBR para aplicação em juntas de vedação para ligações flangeadas.

Abstract

Materials such as gaskets need to have good characteristics of sealability to promote a correct sealing in the union of flanges in industrial piping, ensuring good lifetime, good temperature range of application and especially security. In this context, this work aims to objective to evaluate the mechanical characteristics of PVC/NBR blends for application as gaskets. For this purpose, proposals and development of four formulations, varying the contents of mineral filler (CaCO3 ) like 10 and 40 pcr, and NBR, such as 10 and 30 pcr in the material compositions. The results obtained revealed that both the presence of filler and nitrile rubber promoted changes in the Density of the compositions, as well as this influenced their performance in the Compression and Recovery tests, and the formulations with higher NBR content had higher compressibility. To be evaluated the Tensile Strength of the formulations, it was verified that both the increase in filler and NBR content promoted reduction of this property. It was also observed, by the Relaxation test Creep, that the formulations failed to perform a good resistance to tightening over time at a temperature of 70°C. Finally, it was verified Sealability test that there was a lot of variation in leak results, far beyond what is acceptable for joints, revealing in parallel the other analyzes to be unfeasibility of these blends for the studied application.