the application of stepwise multivariate-linear regression models for determination of particleboard properties based on structural factors was studied. poplar (populus alba), beech (fagus orientaleis) and hornbeam wood (carpinus betulus) with dry density of 460, 630 and 790 kg/m3,respectively, were used as raw materials. three levels of boards target density (520, 620 and 720 kg m-3) and urea ...

This study reports the results of a study aimed at reducing the free formaldehyde content of Phenolformaldehyde resin by using Urea as means for forming a reversible adduct with formaldehyde. The highly volatile formaldehyde has an unpleasant odour and irritates the eyes and nasal passages. The free formaldehyde content (FFC) of the modified resol resin was determined by titration method. With ...

A new deformation technique of wood flow forming is promising for industrial uses of solid wood. Flow deformability, size stability, and good mechanical properties were obtained by using wood impregnated with low molecular weight phenol formaldehyde (PF) resin. In this study, to clarify the effect of the PF resin and moisture contents in wood on the flow deformability (extrudability) and the me...

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...

The objective of this project was to use sucrose as a partial substitute for melamine in the synthesis of sucrose–melamine-formaldehyde (SMF) resin. The SMF was synthesized in a base condition. The wet bonding strength, shelf life, and formaldehyde emission of the SMF resin were determined. Fourier transform infrared spectroscopy (FT-IR) and mass spectroscopy (MS) were employed to analyze the c...

Measurement of the strength of brittle materials, such as resin composites, is extremely difficult. Micro-indentation hardness testing is a convenient way of investigating the mechanical properties of a small volume of material. In this study, the mechanical properties of five commercially available flowable resin composites were investigated by the dynamic micro-indentation method. Additionall...

Uron resin, a kind of urea-formaldehyde (UF) resin containing much more uron structure, were prepared. Several modi ed UF resins were obtained from mixing uron resins with normal UF resins as well as synthesizing UF resin with uron resin as raw material. is work demonstrated that the introducing of the uron structure reduced free formaldehyde content of UF resin and formaldehyde emission levels...

This paper presents the results of a Forest Products Laboratory study regarding the effects of resin content, particle size, and molding pressure upon specific gravity, strength, and water absorption of hardboard products made of wood waste treated with powdered phenolic resin. Modulus of rupture in bending was found to vary approximately as the cube of specific gravity, whereas water absorptio...

in this study, the particleboard was made with rice husk and urea formaldehyde resin of 7, 8, 9 and 10 percent (based on dry weight of rice husk). to improve mechanism of bondability a definite amount of isocyanate resin is introduced to replace the same amount of urea formaldehyde resin. the effect of urea formaldehyde resin and diisocyanate content on bondability was evaluated by studying the...