Experimental verification of the joints strength features in the quality control of the mass-produced upholstery frames

Abstract

An upholstery frame is an element of upholstery furniture, which is heavily loaded with forces. Critical to the quality of the frame is the load capacity of the connections of its structure elements. Moreover an important issue is the repeatability of the suitable strength in the whole production batch. Tested wooden frame joints were made with glue and staples. The goal of our study was to compare the strength of the joints made by a man and by a robot in industrial mass production. The laboratory test was done on an universal testing machine which measure the stress–strain characteristics showing the yield behaviour of test samples. The results show that a “robotic technology” gives slightly higher strength values than the manual production. It was also observed that the force value distributions in compared two series of samples have different nature in the both technologies. Based on the observation of the technologies and based on the analysis of the research results, it was found that the reason for this is the greater constancy of technological parameters in robotic production (in the described case, the bigger variability of the strength of connections made by man was caused by the different exposure time of the adhesive to drying, while in “robotic” production gluing, was done in the same throughout the long production series).