WOOD RESEARCH Volume 69, Number 3, 2024
PATRIK MITRENGA, LINDA MAKOVICKÁ OSVALDOVÁ, MIROSLAVA VANDLÍČKOVÁ, and MILAN KONÁRIK

OPTIMIZING THE AMOUNT OF FLAME RETARDANT USED FOR SPRUCE WOOD

The study investigated the effect of the amount of selected retardant coatings produced and used in the Slovak Republic on the fire resistance of spruce wood samples. Experiments were conducted for two different types of flame retardants: intumescent flame retardant (IFR) and inorganic salt-based flame retardant (IS). Based on different amounts of coating applied to spruce wood samples, the important parameters as mass loss, mass loss rate and fire spread rate were determined. The experiment consisted of applying a flame source to the samples at an angle of 45° and monitoring the mass of the samples during the experiment. The findings show that when IFR is used, the protection effect of the wooden samples increases linearly with the amount of coating. However, for the samples on which an IS flame retardant was applied, a higher amount of coating had no effect on increasing the fire resistance of the wood. In this case, the average total mass loss was the same regardless of the amount of coating, yet a significant retardation effect was observed compared to the untreated samples. Samples treated with IFR showed a lower total mass loss and also a significantly lower maximum mass loss rate compared to the samples with applied IS flame retardant

WOOD RESEARCH Volume 69, Number 2, 2024
GÜL YILMAZ ATAY, NURŞAH BILGIÇ, and MARIATTI JAAFAR

THE USE OF BORIC ACID AND ANTIMONY OXIDE AS AUXILIARY MINERALS WITH HUNTITE HYDROMAGNESITE TO IMPROVE FLAME RETARDANT PROPERTIES OF WOODDUST COMPOSITES

Boric acid, antimony oxide minerals and huntite hydromagnesite minerals were used as auxiliary minerals in wood composites to change their flammability features. Composite samples were prepared by using different ratios of sawdust, huntite, hydromagnesite, antimony and boric acid combinations. The obtained samples were characterized by scanning electron microscopy (SEM) analysis to determine the structural and morphological properties of the composites. Thermal behavior of the composites was determined by differential thermal analysis-thermogravimetry (DTA-TG). Tensile and three-point bending tests were performed to understand the mechanical properties. Finally, the flame retardant performance of the samples was observed according to UL94 vertical flammability tests. It was concluded that wood composites containing inorganic minerals gained resistance against fire, a good synergistic effect was obtained in different additive types

WOOD RESEARCH Volume 69, Number 1, 2024
SEOK-UN JO, HAK-BYUNG CHAE, HEE-JUN PARK, and EUN-SUK JANG

THE OPTIMAL IMPREGNATION AMOUNTS OF FLAME-RETARDANT FOR KOREAN LARCH AND JAPANESE CEDAR BUILDING MATERIALS

In Korea, in accordance with regulations MOLIT notice 2023-24 regarding the flame retardant performance of building finishing materials and fire spread prevention structure, it is mandated that flame-retardant materials have a total heat emission less than 8 MJ/m2. Consequently, our study aimed to determine the quantity of flame-retardant treatment required to meet MOLIT notice 2023-24 for Korean larch and Japanese cedar, as commonly used exterior materials in construction. To this end, we investigated using a cone calorimeter to observe changes in the THR (total heat released) depending on the SCFI (solid content of flame-retardant impregnation). Our simple linear regression analysis indicated that the SCFI needed to satisfy the prescribed flame-retardant standard of 8 MJ/m2 was 93.9 kg/m3 for Korean larch and 144.6 kg/m3 for Japanese cedar. As a result, we established optimal impregnation levels of flame retardant for both species

WOOD RESEARCH Volume 67, Number 2, 2022
Caijuan Zhang, Hui Guo, XINJIE ZHOU, LILI YU, HUI LI, and Zhi-Bin Yang

Effects of differrent boron-based flame retardants on the combustibility of bamboo filaments

In this study, eight types of boron-based flame retardants were performed to evaluate the effects of different boron components on the combustibility of the bamboo filaments. Disodium octaborate tetrahydrate, boric acid/borax, and nano-ZnBO4 were used as the active flame retardant components. Besides, other inorganic flame retardants including nano-SiO2 and ammonium polyphosphate (APP) were also introduced in order to increase the flame retardant of these boron-based components. The combustibility of the bamboo filaments treated with different flame retardants were evaluated by cone calorimeter analysis. The results showed that the flame retardants including the heat release and smoke release resistance of the bamboo filaments with different boron-based components and nano-SiO2 or APP, could be significantly improved, especially, in the samples treated with the compound flame retardant composed of boric acid, borax and nano-SiO2, which was attributed to the synergistic effect of these flame retardant components.

WOOD RESEARCH Volume 67, Number 2, 2022
Kang Zhou, LI LUO, and Bin Na

Study on flame retardant leach resistant of modified poplar wood

After flame retardant and enhancing treatment, fast-grown poplar face the problem of leaching of pharmacy, which affected the effective permanence of the retard and further use is limited. In this paper, we study the fixed effect of low molecule phenol-formaldehyde (PF) resin on nitrogen and phosphorus (N-P) inorganic flame retardant composite under the condition of high relative humidity. The change of lateral sizes and quality of the specimens were emphasized in the experiment. Results reveal that the greater the concentration of flame retardant was, the greater weight gain percentage of the samples was, and the more serious leach was in the test, after the specimen was modified with the flame retardant. When weight gain percentage of the specimens is same, the greater the concentration of PF resin test solution was, better effect of the leach resistant will be obtained with the concentration of PF test solution increased. The PF resin with 25% concentration had the best effect to reduce the leach of N-P inorganic composite retards. From the comparative analysis above, it was advisable to indicate the PF resin with 25% concentration had the best effect to reduce the leach of N-P inorganic composite retards.

WOOD RESEARCH Volume 63, Number 2, 2018
Jiayu Cong, Guochao Yang, Lijuan Zhao, and Qiuhui Zhang

The synergistic smoke suppression effect of ferric oxide on flame retardant wood-polyurethane composites

Wood flour-polyurethane composites (WPC) with ammonium polyphosphate (APP) and ferric oxide (Fe2O3) were prepared to research the cooperative influence of smoke suppression and fire resistance. By the methods of cone calorimeter test (CCT), smoke density test (SDT), thermogravimetric analysis (TG), limiting oxygen index (LOI), field emission scanning electron microscope (FE-SEM) and Fourier transform infrared spectroscopy (FTIR). Remarkably, Fe2O3 has significant improvement on heat release rate (HRR), total heat release (THR), smoke factor (SF), and total smoke release (TSR) of the APP/WPC.SDT implied that Fe2O3 played a positive role during burning and there is a synergistic effect of smoke suppressing for Fe2O3 on APP/WPC. The LOI results showed that compared with samples without flame retardant, adding Fe2O3 improved the LOI value of WPC. TG indicated that Fe2O3 and APP played an effective role in the course of thermal degradation of WPC. And the SEM and FTIR showed that Fe2O3 and APP played a role in ameliorating the residual carbon structure.