Diseño y Construcción de un Equipo de Ensayo de Control de la Estabilidad Dimensional por Fatiga Mediante Martilleo Constante para Espuma de Poliuretano (Esponja Blanda) Utilizada en Tapicería y Colchones.

Abstract

A fatigue dimensional stability control testing machine by constant hammering for polyurethane foam (soft foam) used in tapestry and mattresses was designed and built in order to help the necessary sponge quality control for this application. The machine is according to the ASTM D 3574 - 05 Test I3. However, the thickness loss and structural breaking down will be evaluated by visual checking. The other parameters to design the machine were gotten by sponge compression testing carried out in the material resistance lab of ESPOCH. That is why, provisional elements were used simulating those the machine would have. The machine is designed not only to test sponge 5 cm tick according to the regulation but also to test sponge 10 cm tick. The eccentric – biela system was chosen as a main device among the proposed design choices. It transmits the back – and – forth movement and the necessary running to the indentor to compress the sponge. An electrical engine of 0,25 hp and 1730 rpm, non – speed – crown reducer with relation 1:50 and two open band system, was chosen to transmit the torque and angular speed required by the eccentric. The other machine elements were designed with recommended safety factors. A rele – time was used allowing to turn off the machine automatically after the determined period by the test.