The influence of selected factors on the strength of angle joints of frame elements

The influence of selected factors on the strength of angle joints of frame elements. The research determined the impact of 5 types of adhesives (PVAc, EVA, PO, PO met., PUR) and the time elapsed since the moment of gluing (4, 8, 12, 24 and 72h) on the strength of the mitre joints of frame elements made of MDF. The elements of the frames were additionally connected with metal staples. As a reference option, joining elements without an adhesive, using only staples, was employed. The strength of the connections was determined as the maximum module when testing connections in two configurations: compression and tensile strength. For each variant, 10 repetitions were performed. It was demonstrated that regardless of the test system or the time elapsed since gluing, the highest values of the modules were recorded in the case of the EVA adhesive. In turn, the use of PO and PUR adhesives requires a long bonding time, while PO met. and PVAc adhesives are characterized by low suitability for gluing mitre joints made of MDF sheets (values of modules comparable to the values of modules having only stapled connections).