Energy efficient machine tools

The growing global energy demand from industry results in significant ecological and economical costs. Aiming to decrease the impact of machining operations, an increasing number of research activities and publications regarding energy efficient machine tools and machining processes can be found in the literature. This keynote paper provides an overview of current machine- and process-related measures to improve the energy efficiency of metal cutting machine tools. Based on an analysis of the energy requirements of machine tool components, design measures to reduce the energy demand of main and support units are introduced. Next, methods for an energy efficient operation of machine tools are reviewed. Furthermore, latest developments and already available energy efficiency options in the machine tool industry are discussed. The paper concludes with recommendations and future research questions for more energy efficient machine tools

Natural Fiber Based Composites

Entitled “Natural Fiber-Based Composites”, this Special Issue has the objective to give an inventory of the latest research in the area of composites reinforced with natural fibers. Fibers of renewable origin have many advantages. They are abundant and cheap, they have a reduced impact on the environment, and they are also independent from fossil resources. Their ability to mechanically reinforce thermoplastic matrices is well known, as their natural heat insulation ability. In the last twenty years, the use of cellulosic and lignocellulosic agricultural by-products for composite applications has been of great interest, especially for reinforcing matrices. The matrices can themselves be of renewable origin (e.g., proteins, starch, polylactic acid, polyhydroxyalkanoates, polyamides, etc.), thus contributing to the development of 100% bio-based composites with a controlled end of life. This Special Issue’s objective is to give an inventory of the latest research in this area of composites reinforced with natural fibers, focusing in particular on the preparation and molding processes of such materials (e.g., extrusion, injection-molding, hot pressing, etc.) and their characterization. It contains one review and nineteen research reports authored by researchers from four continents and sixteen countries, namely, Brazil, China, France, Italy, Japan, Malaysia, Mexico, Pakistan, Poland, Qatar, Serbia, Slovenia, Spain, Sweden, Tunisia, and Vietnam. It provides an update on current research in the field of natural fiber based composite materials. All these contributions will be a source of inspiration for the development of new composites, especially for producers of natural fibers, polymer matrices of renewable origin and composite materials. Generally speaking, these new materials are environmentally friendly and will undoubtedly find numerous applications in the years to come in many sectors. Dr. Philippe Evon Guest Edito

"Natural Fiber Based Composites", edited by Philippe Evon (Printed Edition of the Special Issue Published in Coatings)

This book is a printed edition of the Special Issue "Natural Fiber Based Composites" that was published in Coatings and edited by Dr. Philippe Evon. Dr. EVON is Research Engineer at the Laboratoire de Chimie Agro-industrielle (LCA). He has the habilitation to supervise researches (HDR). He specializes in the valorization of wastes from biomass to produce extracts and to design agromaterials. He is mainly developing studies for using biomass as raw material for: - Producing bioactive extracts through fractionation processes using “green” solvents and the twin-screw extrusion technology as continuous extraction technique. - The manufacture of agromaterials by combining single- or twin-screw extrusion technologies with molding processes (e.g. injection-molding or thermopressing). He is the Manager of the LCA’s Industrial Technological Hall “AGROMAT” dedicated to agromaterial’s (https://www6.toulouse.inra.fr/lca/AGROMAT), which is located in Tarbes (South-West of France)

Production and characterisation of pine wood powders from a multi-blade shaft mill

Wood is an important raw material for the manufacture of consumer products and in achieving societal goals for greater sustainability. Wood powders are feedstock for many biorefining and conversion techniques, including chemical, enzymatic and thermochemical processes and for composite manufacture, 3D printing and wood pellet production. Size reduction, therefore, is a key operation in wood utilisation and powder characteristics, such as shape, particle size distribution and micromorphology play a role in powder quality and end-use application. While in a green state, the native chemical composition and structure of wood are preserved. Powders are commonly produced from wood chips using impact mills, which require pre-sized, pre-screened and pre-dried chips. These steps necessitate repeated handling, intermediate storage and contribute to dry matter losses, operation-based emissions and the degradation of the wood chemistry.This thesis investigated a new size reduction technology, known as the multi-blade shaft mill (MBSM). The MBSM performance was studied through the milling of Scots pine (Pinus sylvestris L.) wood using a designed series of experiments and through modelling with multi-linear regression (MLR) analyses. Light microscopy combined with histochemical techniques were used to investigate particle micromorphology and distribution of native extractives in powders. The aim was to evaluate the technical performance of the MBSM with relation to operational parameters, to characterise the produced powders and to evaluate the technology through comparison with impact milling.The results showed that the MBSM could effectively mill both green and dry wood. Produced powders showed distinct differences compared to those obtained using a hammer mill (HM). The specific milling energy of the MBSM was lowest for green wood and within the range of other established size reduction technologies. However, much narrower particle size distributions were observed in MBSM powders and they had significantly greater amounts of finer particles. Particles with high aspect ratio and sphericity were a characteristic of MBSM powders and this Production and characterisation of pine wood powders from a multi-blade shaft mill was true for wood milled above and below its fibre saturation point. MBSM powders from green wood showed evidence of higher specific surface area, larger pore volume and greater micropore diameter than those from HM powder. Preliminary microscopic examination suggested that cell walls in MBSM powders showed evidence of retaining their original native wood structure. Consequently, their extractive content appeared intact. This was in contrast to HM powder and it may reflect the differences between the two size reduction mechanisms. According to the produced MLR models, the results suggest that MBSM milling is more akin to a sawing process and opposite to that of impact-based mills

Volume 2 – Conference: Wednesday, March 9

10. Internationales Fluidtechnisches Kolloquium:Group 1 | 2: Novel System Structures Group 3 | 5: Pumps Group 4: Thermal Behaviour Group 6: Industrial Hydraulic

Proceedings of Young Researchers' Forum II: Construction Materials

This is the second Young Researchers Forum for early-career scientists and engineers working in the field of construction materials to be held at Department of Civil, Environmental and Geomatic Engineering, University College London, London. The first meeting was organised by the Construction Materials Group, The Society of Chemical Industry in May 2012