• Journal of the Korean Wood Science and Technology
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• 제48권5호
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• pp.755-764
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• 2020

Due to pronounced mechanical performance and being environmental friendly, aqueous polymer isocyanate adhesive (API) has been widely applied in the production of formaldehyde-free wood products. In this study, flame retardant formaldehyde-free plywood was prepared by incorporation of flame retardants into the API adhesive. Partially phosphorylated poly (vinyl alcohol) (PPVA) which was prepared by reacting poly (vinyl alcohol) with phosphoric acid was used to replace PVA in API formula. In addition, Mg-Al layered double hydroxides (LDH) was chosen as additive flame retardant, replacing traditional filler CaCO₃ in API adhesive formula. And then, the flame retardant API adhesive with main agent (PPVA replacing PVA70wt.%, SBR emulsion 30wt.%), curing agent 10wt.% (accounts for of the main agent), and 20wt.% LDHs (accounts of the main agent) was used to prepare flame retardant plywood. The effect of application of PPVA and Mg-Al LDH on bonding strength of plywood was investigated. The flammability characteristics of the plywood were determined by cone calorimeter test (CCT). The results revealed that compared with the plywood prepared with API adhesive, the use of PPVA and LDH enhanced the flame retardancy of plywood without negatively affecting bonding strength. The CCT tests indicated that the heat release and smoke production flame retardant API plywood were lower than those of the ordinary API glued plywood. Promising developments for flame retardant API adhesive were expected in future applications of flame retardant formaldehyde-free plywood.

• Journal of the Korean Wood Science and Technology
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• 제49권6호
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• pp.667-678
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• 2021

The flame retardancy of plywood should be improved as much as possible while minimizing the impact on the bonding strength of plywood. Six commercial flame retardants and three laboratory synthesized phosphorous nitrogen flame retardants were selected. E₀, E₁ and E₂ grade commercial formaldehyde resins (UF) were applied in this study to evaluate the effect of different flame retardants on the curing time of resin, bonding strength, flame retardant performance, and formaldehyde emission of plywood. The results show that the effect of the addition of different flame retardants on the bonding strength of plywood gradually decreased with the increase of the formaldehyde molar ratio of the resin. The effect of flame retardants on the curing time of UF gradually decreased as the mole ratio of formaldehyde increasing, while the amount of formaldehyde emission varied according to the content of formaldehyde in the flame retardant. Compared with plywood without flame retardant, flame retardant of plywood added with phosphorous nitrogen flame retardant was improved.

• 대한안전경영과학회지
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• 제25권1호
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• pp.61-66
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• 2023

The purpose of this study is to compare and analyze the flame retardant performance of Japanese cypress(Chamaecyparis obtusa) plywood, commonly used in indoor decoration, furniture, and tableware, by treating it with three different fire retardants with different primary ingredients. The experiment was conducted in compliance with Article 31, Paragraph 2 of the Enforcement Decree of the Fire Facilities Installation and Management Act and Articles 4 and 7-2 of the Flame Retardant Performance Standards. After flame time, after glow time, char length, and char area were measured. As a result, first, after flame time was measured at 0 seconds regardless of whether the flame retardant treatment was applied. Second, after glow time was relatively long, measuring 22.7 seconds without treatment, which is likely due to the weak fire resistance and high concentration of carbon monoxide generated by the chemical characteristics of the Japanese cypress itself. Third, it was confirmed that the effects of the primary ingredient, phosphorus, in the flame retardant treatment varied depending on the technological development of the manufacturers of the same species of Japanese cypress plywood. In the future, it is expected that the results of this study will provide fundamental data to select flame retardant treatments that show high flame retardant performance according to the botanical characteristics of the wood.

• Journal of the Korean Wood Science and Technology
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• 제48권4호
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• pp.417-430
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• 2020

4종의 판상형 목재제품의 방염제 도포량과 침지시간에 따른 방염성능을 분석하기 위하여 소방청의 방염성능기준에 따라 목재제품의 탄화길이와 탄화면적을 측정하였다. 잣나무 합판, 낙엽송 합판, 편백 판재, 타공처리된 자작나무 합판에 자체 개발된 방염제를 각각 300, 500 g/㎡씩 도포하고 방염처리되지 않은 시험편과 비교하였다. 일반적으로 방염제의 도포량이 증가함에 따라 탄화길이와 탄화면적이 감소하여 방염성능이 증가하는 경향을 나타냈으나, 낙엽송 합판을 제외하고 탄화길이와 탄화면적의 감소량이 크지 않았다. 타공처리된 자작나무 합판의 침지시간에 따른 방염성능은 60분의 침지시간까지 양의 상관관계를 나타냈으나, 그 이후 점차 완만해지는 경향을 보였다. 방염제의 도포량과 침지시간에 따른 목재제품의 방염성능은 추후 방염성능 기준에 맞는 불연·준불연 목재의 생산을 위한 기초자료로 이용될 것으로 기대된다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.35-36
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• 2022

In order to supplement the flame-retardant performance of oil stain, which can prevent wooden buildings from contamination, (NH4)2HPO4, a phosphorus flame-retardant, was added to oil stain and applied for each type of plywood, and an experiment was conducted. The addition rate was set to 0-60%, but white powder appeared on the surface of plywood from 40% and thus it was impossible to experiment, so the maximum addition rate was selected as 30%. As a result of the experiment, acacia plywood had the best performance. As the rate of addition of the flame retardant increased, the remaining time and carbonization length of all plywood decreased, but the carbonization length of the MDF plywood was not met with the standards.

• Korean Chemical Engineering Research
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• 제52권2호
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• pp.256-260
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• 2014

건축물 내부의 장식을 위해 사용되는 MDF합판은 화염의 착화를 지연시키기 위해 방염처리하도록 규정하고 있어 일반적으로 방염도료나 방염액 또는 방염필름 등을 적용하여 착화를 지연시키는데 이 때 적용하는 시료에 따라 방염성능과 연소 시 발생되는 가스의 유독성의 차이가 발생할 수 있어 본 연구에서는 MDF에 적용된 방염시료들의 방염성능 및 연소특성에 대해 비교분석하였으며 그 결과 방염성능에 부합하는 제품이 확인되었으나 방염처리방법에 따라 방염성능의 차이가 존재함을 확인할 수 있었으며 연소과정에서 발생되어지는 여러 종류의 유독가스의 영향도 함께 고려해야 할 요소임을 확인할 수 있었다.

• Journal of the Korean Wood Science and Technology
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• 제14권4호
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• pp.21-28
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• 1986

Plywood used for construction as a decorative inner material is inflammable and can fire accident, causing destruction of human life and property. In this study, 3.5mm Kapur plywoods were soaked in the 23% monoammonium phosphate solutions by cold soaking method 3, 6, 9hrs and hot-cold bath method for 3/3hrs, and redrying was carried out by press-drying at the platen temperature of 110, 130, 160, 180$^{\circ}C$, and then fire test was carried out to investigate burning point, flame exhausted length, frame spread length, back side carbonized area and weight loss. The results are as follows; 1. In cold soaking method for 3, 6, 9hrs. retentions of monoammonium phosphate were 0.377, 0.448, 0.498kg/(30cm)$^3$ respectively, and in hot-cold bath method for 3/3hrs, the retention was 1.331kg(30cm)$^3$ that exceeded the minimum retention 1.124kg/(30cm)$^3$. 2. Correlation coefficients among the variable were shown in table 2. From the table, it could be recognized that there were close negative correlations between the treatment and burning point, flame spread length, back side carbonized area, flame exhausted time and weight loss, and there was negative correlation between treating time and back side carbonized area, but there was positive correlation between platen temperature and burning point. 3. From table 3, it can be observed that there were highly significant differences for burning point, flame spread length, flame exhausted time, back side carhonized area, weight loss between treatments. And in 2-way interactions, there were also highly significant for burning point, flame spread length, flame exhausted time, weight loss between time x treatment. 4. It was observed that burning point, flame exhausted time, flame spread length, back side carbonized area, and weight loss in fire-retardant treated plywood were the best effects in fire-retardant treated plywood, water treated plywood and nontreated plywood. In conclusion, I can estimate that absorbed chemical contents by hot-cold bath method for 3/3hrs, have a lot of effects on fire-retardant factors such as burning point, flame spread length, flame exhausted time, backside carbonized area and weight loss, but platen temperatures have a little effects on the fire factors.

• Journal of the Korean Wood Science and Technology
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• 제15권3호
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• pp.56-67
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• 1987

Plywoods used for construction as a decorative interior material are inflammable and can make fire accidents, causing destruction of human life and property. Therefore, it is indeed required to make fire-retardant treated plywood. In this study, 3.7mm yellow meranti plywoods were soaked in 18% boric acid solutions and tap water by hot-cold bath for 1/2, 2/2, 4/2, 6/2 hours and redrying of treated plywoods was carried out by press drying at the platen temperature of 110, 130, 160, $180^{\circ}C$ and then it was conducted to investigate solution absorption, drying rates, dynamic young's modulus. specific gravity and fire-retardant factors such as burning point, flame spread length. flame exhausted time, back side carbonized area and weight loss by treating time, treating solutions and platen temperature. The results are as follows; 1. When plywood was impregnated with the hot bath temperature of $70^{\circ}C$ for 1. 2, 4, 6 hours and the cold bath temperature of $15^{\circ}C$ for 2 hours respectively, retentions of boric acid were 1.565, l.597, 1.643, 1.709kg/$(30cm)^3$ and all of them exceeded the minimum retention [1.125kg/$(30cm)^3$] even in the shortest treatment. 2. In hot-cold bath method for 1/2 hours, the drying rates of treated plywood remarkably increased with the extension of platen temperature of 110, 130, 160, $180^{\circ}C$ and the values of boric acid treated plywood were 5.900, 10.196, 45.42, 54.958m.c%/min and the values of water treated plywood were 6.014, 12.373, 46.520, 55.730m.c%/min and drying rates of water treated plywood were faster than those of boric acid treated plywood. 3. The values of boric acid treated plywoods in dynamic young's modulus were widely higher than those of water treated plywoods. And it can be observed that there were highly significant differences for treating time between dynamic young's modulus, and the values of boric acid plywoods increased with the extension of treating time but on the contrary water treated plywoods were decreased values with prolonged time 4. It was observed that there were highly significant differences for platen temperature between dynamic young's modulus. When the values of water treated plywoods in dyna nic young's modulus were abruptly decreased according to the rise of platen temperature. boric acid treated plywoods showed rather increased values at $160^{\circ}C$ of platen temperature. And in 2- way interactions, there were also highly significant for dynamic young's modulus between treating time x treating solutions and platen temperature x treating solutions. 5. Correlation coefficients of fire-retardant factors were shown in table 5. It could be recognized that there were close correlations between the treating solutions and burning point, flame spread length, back side carbonized area, flame exhausted time and weight loss, but there was no correlation between fire-retardant factors and treating time and platen temperature. 6. From table 6, it can be observed that there were highly significant differences for burning point, flame spread length, flame exhausted time, back side carbonized area, weight loss between treating solutions. And in 2-way interactions, there were highly significant for burning point, flame spread length, weight loss between treating time $\times$ treating solutions.

• Journal of the Korean Wood Science and Technology
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• 제43권2호
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• pp.258-264
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• 2015

To evaluate the influence of 3A zeolite on the flame retardant properties of poplar plywood. Ammonium polyphosphate (APP) and 3A zeolite were used as flame retardants to prepare plywood samples. The combustion properties, such as heat release rate (HRR), total heat release (THR), mean CO and $CO_2$ yield, smoke production rate (SPR), and total smoke production (TSP), were characterized by a cone calorimeter. A synergistic effect was observed between 3A zeolite and APP on reducing the HRR and mean CO yield. The probable flame retardation mechanism was proposed.

• Journal of the Korean Wood Science and Technology
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• 제49권1호
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• pp.44-56
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• 2021

소방청의 방염성능기준에 제시된 45°멕켈 버어너법을 이용하여 물유리 농도와 첨가제 종류에 따른 합판의 탄화길이 및 면적 등의 방염성능을 측정하였다. 합판에 농도 20-50%의 물유리를 처리한 결과, 방염성능은 물유리의 농도와 비례하는 경향을 나타냈다. 그러나 30%를 넘는 고농도의 물유리로 처리된 합판의 표면에서 백화현상과 끈적임이 발생하여 농도 30%를 최적 조건으로 결정하였다. 농도 30%의 물유리에 서로 다른 비율의 첨가제를 추가하여 실험을 수행한 결과, 수산화칼륨 15% 조건과 수산화알루미늄 1-10%의 조건에서 방염성능 기준을 만족하였다. 반면에 황산마그네슘은 방염성능에 크게 영향을 미치지 않았다. 물유리와 첨가제에 따른 방염성능의 결과는 방염제를 활용한 불연재에 대한 기초자료로 활용될 것으로 기대된다.