낙엽분말을 이용한 합판용 접착제의 증량에 관한 연구

김종만,박종열,이필우 ( Jong Man Kim,Jong Yeol Bark,Phil Woo Lee ) 한국산림과학회 1979 한국산림과학회지 Vol.42 No.1

It was planned and performed to study the possibility on the use of inexpensive and easily acquirable foliage powder, which processed by pulverizing after dried, instead of imported expensive wheat flour for the extending of plywood adhesives. Pine leaves of softwood trees, Poplar, Oak and Sycamore leaves of broad leaved species were selected and harvested to pulverize into the minute foliage powder. The harvested foliages from each selected species were pulverized into 40 mesh particles after dried at 100∼105℃ condition during 24 hours in drying oven. To compare the extending effect of plywood adhesives with these foliage powders 100 mesh wheat flour using at current plywood industry was also prepared. Foliage powder and wheat flour were extended into 10, 20, 30, 50 and 100% to the urea and phenol formaldehyde resin. After plywoods were processed by the above extending method shear strength of extended plywoods were analyzed and discussed. The results obtained at this study are as follows: 1) Among 10% extensions of urea formaldehyde resin plywood, dry shear strength of plywood extended by wheat flours was the highest and that of non-extended plywood the next. Plywood extended with foliage powder showed the lowest dry shear strength. The order of dry shear strength of plywoods extended by foliage powder was that of Oak foliage powder extension, the best, that of Sycamore, that of Pine, and that of Poplar. 2) Among 20% extensions of urea formaldehyde resin plywood, plywood extended by wheat flour showed the highest dry shear strength, and the next was plywood by Poplar foliage powder. All these two showed higher dry shear strength than non-extension plywoods. Except Poplar, dry shear strength of foliage powder extension plywoods was bad, but the order of dry shear strength of plywoods extended by foliage powder was Pine, Poplar and Oak. 3) In the case of 30% extensions of urea formaldehyde resin plywood, dry shear strength of wheat flour extension was the highest and non-extension the next. Dry shear strength of foliage powder extension plywoods was poor with a rapid falling-off in strength. 4) Among 50% and 100% extensions of urea formaldehyde resin plywood, only wheat flour showed excellent dry shear strength. In the case of foliage powder extension, low dry shear strength showed at the 50% extension of Pine and Poplar, and plywoods of 50% extension of Oak foliage powder delaminated without measured strength. All plywoods of 100% foliage powder extension delaminated, and then shear strength were not measured. 5) Among wet shear strength of 10% extensions of urea formaldehyde resin plywood, wheat flour extension was the highest as in the case of dry shear strength, and non-extension plywood the next. Except Poplar foliage extension, all foliage powder extension plywoods showed low shear strength. 6) Wet shear strength of plywoods of 20% extension lowered in order of non-extension plywood, plywood of wheat flour extension and plywood of foliage powder extension, but other plywoods of foliage powder extension except plywoods of Poplar and Oak foliage powder extension delaminated, 7) Wet shear strength of 30% or more extension of urea for madehyde resin plywood were weakly measured only at 30% and 50% extension of wheat flour, and wet shear strength of plywoods extended by foliage powder were not measured because of delaminating. 8) Dry shear strength of phenol formaldehyde plywoods extended by 10% wheat flour was the best, and shear strength of plywoods extended by foliage powder were low, but the order was Oak, Poplar, and Pine, Plywood of Sycamore foliage powder extension delaminated. 9) In the case of 20% extensions of phenol formaldehyde resin, dry shear strength of plywood extended by wheat flour was the best, but plywood of Pine foliage powder extension the next, and the next order was Oak and Poplar foliage powder. Plywood of Sycamore foliage powder extension delaminated. 10) Among dry shear strength of 3

합판의 내화처리와 열반건조에 관한 연구

김종만,이필우 한국목재공학회 1982 목재공학 Vol.10 No.1

Plywood used for construction as a decorative inner material is inflammable to bring large fire accidents and burn out human life and their properties. To diminish the fire disaster, fire retardant plywood has been required indeed. In the methods of manufacturing the fire retardant plywood the soaking method is occasionally used. However after soaking plywood into fire retardant chemical solutions, redrying of soaked plywood is the most important. In this study, 3.5mm thin and 5.0mm thick plywoods were selected for fire retardant treatment. Treating solutions were prepared for 20% dilute solutions of ammonium sulfate, monoammonium phosphate, diammonium phosphate, borax-boric acid and minalith, anti water solution. 1-, 3-, 6-, and 9 hour-soaking treatments were applied and after treatments hot plate drying was applied to those treated plywoods at 90℃, 120℃and 150℃ of press temperature. Drying rates, drying curves, water absorption rates of fire retardant chemicals, weight per volume and fire retardant degree of plywood were investigated. The results may be summarized as follows: 1. The plywoods treated with ammonium sulfate, rnonoammonium phosphate and diammonium phosphate and diammonium phosphate showed increase of chemical absorption rate with proportion to increase of treating tune, but not in case of the plywood treated with borax-boric acid and minalith. 2. In the treatment of definite time, the absorption rate per unit of volume of plywood showed higher in thin plywood (thickness of 3.5mm) than in thick plywood (thickness of 5.0mm). In both thin and thick plywoods, the highest absorption rate was observed in 9 hour-treatment of ammonium sulfate. The value was 1.353㎏/(30㎝)³ in thin plywood and 1.353㎏/(30㎝)³ in thick plywood. 3. The volume per weight of plywood after chemical treatment increased remarkably and. after hot plate drying, tire values were to a little extent higher than before chemical treatment. 4. The swelling rates of thickness in chemical-treated plywoods increased similarly with that of water-treated plywood in 1-and 3 hour-treatment of both thin and thick plywoods. But in 6- and 9 hour-treatment, the greater increased value showed in water-treated plywood than any other chemical, especially in thick plywood. 5. The shrinkage rates after hot plate drying showed the same tendency as the swelling rate, and the rate showed the increasing tendency with proportion to increase of treating time in thick plywood of both chemical and water treatments. 6. Among drying curves, the curves of water-treated plywood placed more highly than chemical-treated plywood without-relation to thickness in 6- and 9 hour-treatment except in 1- and 3 hour-treatment. 7. The drying rate related to thickness of treated plywood, was twice above in thin plywood com pared with thick plywood. 8. The drying rate remarkably increased with proportion to increase of the plate temperature and, the values were respectively 1.226%/min., 6.540%/min., 25.752%/min. in hot plate temperature of 90℃, l20℃, 150℃ in thin plywood and 0.550%/min., 2.490%/min, 8.187%/min. in hot plate temperature of 90℃, 120℃, 150℃ in thick plywood. 9. In the treatment at 120℃ of hot plate temperature, the drying rates of chemical-treated plywood showed the highest value in monoammonium phosphate of thin plywood and in diammonium phosphate of thick plywood. But the drying rate of water-treated plywood was highest in 6- and 9 hour-treatment. 10. The fire retardant degree of chemical-treated plywood was higher than that of the untreated plywood as shown in loss of weight, burning time, flame-exhausted time and carbonized area. 11. The Fire-retardant effect among fire retardant chemicals were the greatest in diammonium phosphate, the next were in monoammonium phosphate and ammonium sulfate, and the weakest were in borax-boric and minalith.

수종 (數種) 내화약제로 처리된 합판의 기술적 성질에 관한 비교연구 : 처리합판의 휨강도에 미치는 침지시간의 영향 Effect of Soaking Time on the Static Bending Strength of Treated Plywood

김종만,정우양,이필우 한국목재공학회 1984 목재공학 Vol.12 No.2

This study was carried out to investigate. the influence of chemical type and its retention in the fire-retardant treated plywoods on the static bending strength, a property peculiar to plywood. Being soaked in 20% aqueous solution of (NH₄)₂SO₄, NH₄H₂PO₄, (NH₄)₂HPO₄, Borax-Boric acid and Minalith for 3 to 12 hours at three-hour intervals and redried at 120℃ in hot press, the treated plywoods were put to static bending test. The values of chemical treated plywoods in Stress at proportional limit, Modulus of elasticity, Modulus of rupture and Work per unit volume to proportional limit were widely higher than those of water treated plywoods(control) and Borax-Boric acid treatment showed the highest value in the four mechanical data. And the bending strength of fire-retardant treated plywoods increased with the extension of waking time or the increase of chemical retention in themselves. Borix-Boric acid was the desirable fire-retardant for thin plywood in view of mechanical strength and soaking defects in this study.

수종 내화약제로 처리된 합판의 기술적 성질에 관한 비교연구 (Ⅱ) : 열판건조시 열판온도가 처리합판의 휨강도에 미치는 영향 Effect of Platen Temperature in Press Drying on the Static Bending Strength of Treated Plywood

정우양,김종만,이필우 한국목재공학회 1984 목재공학 Vol.12 No.4

Soaking treated in 20% aqueous solutions of (NH₄)₂SO₄,(NH₄)H₂PO₄, (NH₄)₂HPO₄, Na₂B₄O_7-H₃BO₃(60:40) and Minalith, the mixed salts for 9 hrs, the wet 3.5mm meranti(Parashorea spp.) plywood, were press-dried at 90, 120 and 150℃ and put to static bending test to examine the influence of redrying temperature on the strength of fire-retardant treated plywoods in flexure. White water-soaking treatment (control) showed serious reduction in Stress at proportional limit, MOE, MOR, Work per unit volume at 150℃, all the fire-retardant treatments maintained bending strength even at 150℃ and showed rather increased values in case of some chemicals. In view of drying rate and maintenance of strength, the most pertinent platen temperature was 150℃ and Borax-Boric acid was the predominant fire-retardant In this study.

尿素樹脂 合板 耐火處理에 關한 硏究

李弼宇,金鍾萬 서울大學校 農科大學 1978 서울대농학연구지 Vol.3 No.1

This study was carried out to know the variations of the basic physical properties of urea resin plywood treated several fire-retardant chemicals including ammonium salts, which has been used for a long time. After plywoods were made from veneers which were soaked in fire-retradent solution various time conditions, they were investigated and analyzed specific gravities, equilibrium moisture contents, dry and wet shear strenght and absorbed chemical amounts of fire proofed plywoods treated with various conditions. The results may be summerized as follows: 1. The specific gravities of plywoods treated fire-retardant chemicals were lower than those of untreated plywoods and their ranges were 0.464 to 0.515, except ammonium chloride, and ammonium sulfate. 2. The amount of absorbed chemicals with ammonium sulfamate and diammonium phosphate were good and those of absorbed other chemicals were not definite difference. 3. There was no great changes according to the treating time of 15sec, 1 min. and 10 min. in the absorbed amount of chemicals. But one-hour treating time showed the greatest value. 4. The absorbed amounts of monoammonium phosphate decreased at the prolonged treating time. Those of zinc chloide, boric acid and borax increased rapidly at the treating time of one hour. 5. The equilibrium mositure contens of untreated plywood samples showed 5.04%at 24% R.H., 10.48% at 41% R.H., and 16.55% at R.H., while treated plywood samples 5.16-9.32% at 24% R.H., 10.15-18.31% AT 41% R.H. and 17.28-25.60% at 60% R.H. 6. Equilibrium mosture contents of treated plywoods showed higher values than untreated. Boric acid and ammonium chloride treated plywoods showed comparatively high equilibrium moisture contents. 7. Dry and wet shear strenght of treated plywoodsshowed decreasing at prolonged soaking times and the both strenght values were lower than those of untreated plywoods. 8. Dry and wet shear strength of zinc chloride and boric acid treated plywoods showed highest values at any times, while that of ammonium chloride treated showed lowest values.