Volume 20 Issue 3

This study explores the potential of porang flour (Amorphophallus muelleri) as a sustainable filler in urea formaldehyde (UF) and citric acid (CA) adhesives, highlighting its effect on enhancing plywood performance. The physical and mechanical properties of plywood bonded with varying compositions of porang flour (0%, 10%, 20%) were evaluated according to Japanese Agricultural Standard (JAS 233:2003) for plywood. Three-layer plywood panels were manufactured using sengon wood and both types of adhesives. The results showed that adding porang flour to UF and CA adhesives significantly increased the solids content and improved physical and mechanical properties. Plywood bonded with UF exhibited superior density, water absorption, thickness swelling, and shear strength properties. Conversely, plywood bonded with CA adhesive showed better results in moisture content, modulus of elasticity (MOE), and modulus of rupture (MOR). Overall, adding 10% porang flour was optimal for improving plywood’s physical and mechanical properties. These findings suggest that porang flour is an eco-friendly additive that can enhance the performance of natural adhesives in plywood manufacturing, providing a greener alternative to conventional adhesives.

Bleached kraft papers obtained from unbeaten (UB) and beaten (B) pulps were separately treated with zinc borate (ZB) and boric acid (BA) to improve their flame retardancy. The immersion method was chosen for application, and natural soy protein was added as a binder. The combined effect of soy protein (SP) and used boron compounds was observed. To investigate the thermal and fire resistance properties of the bleached kraft papers (BKP), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), limited oxygen index levels (LOI), and UL-94 burning test were performed.  The brightness and color parameters (L*, a*, b*, ∆L*, ∆a*, ∆b*, ∆E*) were also measured to determine the optical properties. The results showed that the combined effect of ZB and BA used with SP increased the flame resistance of kraft papers. The bleached kraft paper treated with BA had better flame retardancy in terms of LOI and UL-94 burning tests than paper treated with ZB. These results were also consistent with the TGA and DSC findings. Furthermore, the optical properties varied slightly depending on the chemical usage rates. Zinc borate and SP had a more positive effect on the brightness values of the bleached kraft papers compared to BA and SP.

Consumers rely on sensory perception to judge the appearance of furniture, often guided by intuitive associations with shape. This process allows furniture designers to better understand and respond to consumer preferences and expectations. This work used a questionnaire design and analysis survey by using the material, color, style, shape, and surface decoration of furniture as the main evaluation indexes. Additionally, consumers’ furniture appearance indicators were analyzed by combining quantitative and qualitative research methods. Satisfaction analysis (attitude index) of color, shape, material, style, and surface decoration of furniture for different consumers’ age, education level, and gender. Finally, consumers’ psychological and perceptual preferences were analyzed based on the correlation between indicators to form product imagery. This study can guide the appearance design of furniture and avoid design blindness, thus reducing the design risk.

The problem with plastic packaging is globally recognized, as plastic packages often end up in landfills without degrading. Using packages made from natural materials is the best choice to address and sustainably solve this issue. In this work, a single-use container (tray) was prepared from arecanut leaf sheath through a hot-compression molding process. The electrical energy required for the compression molding process was obtained from mainly electricity and 3 kW solar cells, reducing the cost by more than 50%, depending on the mold size and operating temperature. The pressing of arecanut leaf sheaths through a two-roll mill for 20 cycles at a high temperature (80 °C) before the compression molding process can increase the mechanical properties of the tray container. The tensile strength of the leaf sheath tray was higher than for polystyrene (PS) and polypropylene (PP) commercial trays. Reducing bacterial contamination of the plates can be achieved by using ultraviolet (UV) light. Almost all bacteria were reduced from 410 CFU/g to ˂10 CFU/g after UV exposure (40 μW/cm²) for 10 min. This suggests the possibility of using arecanut leaf sheath plates as food contact material, especially in single-use container applications.