The straw bale construction technique is considered one of the most appropriate for the improvement of housing conditions in developing countries and for the reconstruction in post-emergency situations. In this environment, no electricity or other energy sources are available; for this reason, straw bales have to be produced by means of a human-powered press. This paper presents the designing process of a manual press, which is a key tool for the objectives introduced above. Following the definition of the machine architecture and the actuating mechanism (slider-crank), a design method based on energy considerations is introduced. Given the mechanical properties of straw, described by a simplified linear model, and the maximum work that a human operator can do, applying the designing method, it was possible to obtain the main functional parameters of the machine, such as the pressing piston stroke, and the length both of the connecting rod and of the crank. The method was experimentally validated and a prototype assembled and used for the production of infill bales in the construction of a warehouse in Haiti.
Authors: Franco, Walter; Iarussi, Federico; Quaglia, Giuseppe; Oct 2016
Link: http://www.sciencedirect.com/science/article/pii/S1537511016302744
See also: A new human-powered press for producing straw bales for load-bearing constructions (free PDF)
Autors: Dario Anastasio, Carlo Ferraresi, Walter Franco*, Francesco Gondino, Giuseppe Quaglia, Lorenzo Soprana