2017 - An NDT study of new materials for greenhouses
The use of recycled paper in HDPE (High Density PolyEthylene) matrix composites has recently been introduced as an interesting alternative to traditional recycling process for paper. HDPE is also used as double wall greenhouse glazing because panels are easy to install, UV stabilized, and affordable. These type of products must also be strong enough and durable in order to react under tensile loads provided by wind and harsh weather conditions.
An interesting idea may be the insertion via injection moulding of chopped basalt and waste paper – i.e., two natural products – in pure HDPE samples. It completely follows the environmental sustainability concept centred on the triple ‘‘re”, i.e., recycle, reuse and reduce.
The research presented herein starts with a Differential Scanning Calorimetry (DSC) inspection of pure HDPE and HDPE mixed with 5% by weight of waste paper plus 5% by weight of chopped basalt as fillers in order to obtain an insight related to the temperature at which possible thermal events (endothermic or exothermic) occur. The dog-bone samples were also inspected under UV conditions (380 nm) before and after tensile tests. The latter approach was simulated firstly by Comsol Multiphysics computer program, and secondly recorded in real time via thermographic inspections.
Experimental setup of the tensile test which includes both the thermographic monitoring and the recording of the evolution of the temperatures via thermocouples. In particular, a Babuc M series produced by Laboratori di Strumentazione Industriale (LSI) SpA equipped with BST110 temperature probes was used.
The region of interest (ROI) is indicated by a red rectangle. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article).
Stefano Sfarra, Stefano Perilli, Dario Ambrosini, Domenica Paoletti, Iole Nardi, Tullio de Rubeis,