Aspects regarding FEM simulation of stress in hammer mill working tool

Considering the need for development and improvement of biomass processing equipment, researchers bring contribution by making suggestions to design also through simulation and modelling of different stresses that occur on equipment’s working tools. In this paper the stress in hammer mill working tools was analysed using FEM simulation with the help of SolidWorks 2016 Premium, projecting the geometric model and FEM simulation for a MC 22 hammer mill. The hammer mill has a four bolts rotor on which are the hammer disposed. The hammer mills rotor frequency is about 2940 rot/min. An important result in FEM simulation was the fact that the maximum reaction in the hammer joint was 11635 N. After FEM simulation experimental research were done using shredded miscanthus and energetic willow, the mill being equipped alternately with 4 types of hammers, with corners processed differently

Morphological and Mechanical Properties of Book Cellulose-Based Paper (XX^th Century) Treated with Hydroxyapatite Nanoparticles

Paper aging and protection processes play an essential function in the preservation of library collections and archives. In this study, some physical-mechanical properties of paper samples from XXth century books (private collections), such as pH acidity, tensile strength, and modulus of elasticity, as well as optical properties, such as absolute change in yellowness, were examined before and after treating them with hydroxyapatite nanoparticles (HAp). Accelerated light aging was also evaluated and discussed. The treatment with HAp nanoparticles increased the paper’s pH to slightly alkaline values (approximately pH 8). Washing and treating the paper improved its mechanical properties compared to untreated paper; the tear length increased by 35% and the modulus of elasticity increased by 56%. That the treated and aged samples are more elastic than the original samples demonstrates that HAp nanoparticles consolidated the cellulose fibers. Additionally, particle morphology, size, composition and size distribution were assessed via image analysis using scanning electron microscopy (SEM-EDX), atomic force microscopy (AFM), and the ImageJ processing program