This paper reports a comparison of adhesion behavior urea-formaldehyde (UF) with those melamine-urea-formaldehyde (MU) resins in bonding wood by analyzing the results published literatures. For this purpose, UF prepared blending low-viscosity resin (LVR) high-viscosity (HVR) at five different and two formaldehyde/urea (F/U) molar ratios (1.0 1.2) was compared MUF synthesized either simultaneous...

Adhesives products and demand for them in China are discussed in this paper with special emphasis on wood adhesives products in this decade. In 1994, the wood industries in China consumed more than 330,000 tons of adhesives. The estimated demand for wood adhesives will be more than 560,000 tons in the year 2000. The main wood adhesive used is urea-formaldehyde resin. Its consumption in 1994. wa...

By focusing on the disadvantages of weak water resistance and high formaldehyde emission urea–formaldehyde resin (UF), this research provides a new method to overcome these shortages UF by using tannin for partial substitution urea. Furthermore, plasma pretreatment wood was introduced strengthen bonding performance plywood. The investigation chemical structure tannin–urea–formaldehyde (TUF) wer...

in this research, the effect of nanoclay on physiochemical, thermal and structural properties of urea formaldehyde resin (uf) was investigated. the prepared gluf resin was mixed mechanically with the 0.5, 1 and 1.5% nanoclay for 5 min at room temperature. the physicochemical properties of the prepared resins were measured according to standard methods. also, the thermal and structural changes i...

Urea-formaldehyde is one of the commonly used resin types in particleboard industry. In this study, effect nanofibrillated cellulose (NFC) and titanium dioxide (TiO2) addition formulation urea formaldehyde on physical, mechanical, morphological properties samples was investigated. The NFC (0.5% 1%) TiO2 (0.5%, 1%, 2%) were added to 10% adhesive formulation. Two different pressure times, 4 8 min...

An experiment was conducted to investigate the effects of the resin solid content, catalyst content, and pH value obtained by the addition of two kinds of catalysts on the gel time of a urea–formaldehyde (UF) resin. Upon the addition of ammonium chloride, the pH value of the resin mixture decreased to 7 but not significantly further because of the limited free formaldehyde in the system. The pH...

this research was conducted to investigate the effect of acetylation and type of resin on fire resistance of one and three layered populus particleboard. populus particles were acetylated at three levels of acetyl content (wpg of 0, 8.39% and 17.27%). in manufacturing of one and three layered boards with acetylated particles in all thickness or surface of the boards two type of resin, urea form...