Producing hybrid pultruded structural products based on preforms

Abstract

Abstract Hybrid pultrusion is a process that can be used to fabricate different products, enclosing distinct techniques and materials. Its development comes from the need to obtain properties' reinforcement of the structural profiles obtained by pultrusion, allowing its application into specific situations, such as thermal or acoustic insulation or to increase the product's moment of inertia, without having a proportional weight increase. In this work was developed based on a novel idea of manufacturing pultruded pipes around preforms of good thermal and/or acoustic insulator materials, such as cork and polyurethane foam. However, the same terminology was already used to describe fabrication techniques in which pultruded structural profiles were combined with concrete structures in order to increase the mechanical and/or flexural resistance, diminishing the total weight. Nevertheless, no industrial equipment is currently available on the market regarding the production of hybrid pultruded products based on preforms. Thus, novel equipment has been designed to provide a good connection with a conventional existing pultrusion machine, allowing the production of pultruded pipes that involve cork and polyurethane foam preforms in a continuous way. The equipment has been developed and tested, enable obtaining hybrid pultruded products that can be applied in several situations where flexural strength, acoustic or thermal insulation must be improved relatively to conventional pultruded products, broadening the market for this type of structural products. The manufacturing equipment is prepared to work without permanent workers, needing to be refilled every 60 min and showed to be competitive, being able to add value to the conventional profiles already on the market. Preliminary tests were carried out showing clearly the improvement of the mechanical strength, thermal insulation and acoustic insulation capacities.