# The Influences of Selected Factors on Bending Moment Capacity of Case Furniture Joints
###### Abstract  
This study experimentally investigated the effects of selected factors on the bending moment capacity (BMC) of case furniture joints. The main aim was to explore mixed applications of wood-based materials and fasteners in manufacturing case furniture to reduce material costs. The study examined the effects of the face member material--particle board (PB), plywood (PL), and block board (BB)--edge member material (PB, PL, and BB), and joint shape (T-shape and L-shape) on BMC. Additionally, the study evaluated the effects of joint type (two eccentrics (TE), two dowels (TD), and one eccentric and one dowel (ED)), and material type (PB, PL, and BB) on BMC for L-shaped joints. The results showed that joint shape and face member material significantly affected the BMC of case furniture joint. The BMCs of T-shaped joints were significantly greater than those of L-shaped joints, regardless of the material of the face and edge members, except when the face member was made of PL. For L-shaped joints with PL face members, the BMCs were significantly higher compared to others. Joints constructed with TE exhibited significantly higher BMC compared to ED and TD for the same material type. For PB, TE joints exhibited an increase of approximately 3.0 Nm and 2.0 Nm compared to TD and ED, respectively. For PL, TE showed an increase of 9.1 Nm and 4.1 Nm compared to ED and TD, respectively. For BB, the increases were 7.0 Nm and 6.6 Nm compared to ED and TD. The BMC of joints made with PL and constructed with TE and ED was significantly greater than those of BB, followed by PB. However, for joints assembled with TD, there was no significant difference among the three materials. The ratios of BMC for joints constructed with ED compared to the half-sum of TE and TD were 0.73, 1.04, and 0.79 for PB, PL, and BB, respectively. These results suggest that the face member material predominantly influences the BMC of case furniture joints, indicating the potential to reduce costs by combining different materials and joint types. c 2024 14 1004 1004 10.10390/app14211  
influences joint strength. For instance, joints constructed with plywood have been found to be stronger than those made with block board, MDF, or particle board [10; 19; 20]. Regarding the effect of fastener type on joint strength, the fasteners commonly used in case furniture construction include Minifix (eccentric) [21; 22], biscuits [23; 24], screws [25; 26], auxetic dowels [27], nails [28], and staples [29]. Fastener type greatly affects joint strength, and an interaction effect exists between fastener type and material type on joint strength [30; 31; 32; 33; 34; 35]. With respect to load type, common methods for evaluating joint strength include bending load, diagonal compression, and tension tests [21; 30; 31; 36; 37]. Bending load capacity and strength parameters are often used as indicators of joint strength. For a given joint, diagonal tension results are generally higher than those for diagonal compression [21; 36; 37]. Research has also examined the influence of fastener quantity in case furniture joints, such as the number of dowels [38; 39; 40] and screws [41]. To optimize joint techniques, studies have further explored spacing and gluing type. Results indicate that joint strength increases with additional fasteners. Additional studies have investigated end distance [42; 43] and gluing type [23; 31; 44; 45; 46] for joints, showing that a smaller end distance reduces joint strength; commonly used glue includes PVAc. Although previous studies have examined the effects of wood-based material and fastener type on bending moment capacity (BMC), they typically used the same material for both face and edge members. The mixed use of different wood-based materials for face and edge members has not been investigated. Furthermore, the relationship between the BMC of eccentric fittings and wood dowels has yet to be examined.