Effect of raw material ingredient ratio to the quality of Melamine Urea Formaldehyde adhesive for moisture resistance and eco-friendly plywood manufacturing

Abstract

The use of Melamine Urea Formaldehyde (MUF) adhesive in the woodbased panel industry is the approach to create wood products that are durable to humid use condition and safe in minimizing formaldehyde toxic emission at cost into competition. This study evaluated the effects of raw material mol ratio for sythesyzing MUF adhesive at the scales of 2 kg; 100 kg and 1.000 kg/batch. The molar quantitative ratios (Formaldehyde/Ure + Melamine) are 1.5; 1.75; 2.0. Experimental results showed technical parameters of MUF glue after synthesis (24 hours) achieved the following quality parameters: transparent color, dry content: 48 - 53%; Viscosity: 15 -17 mpas; pH = 7.0 - 8.0; Pot life: 20 days (30 - 35 o C). The free formaldehyde content of plywood using synthesized MUF adhesive meets European E1 standard for the ratio of F / U + M = 1.5 and 1.75. The adhesion strength of the plywood gained by 1.5 - 1.8 MPA, Class 2 according to EN 314 - 1&2 standard for use in humid environments. The plywood has high mechanical strength value of bending strength (MOR) by 78 - 88 Mpa and modulus of elassticity (MOE) by 7,900 - 9,000 Mpa.