低甲醛释放高密度纤维板的制备及性能
|
摘要
以桉木纤维为原料,异氰酸酯为胶黏剂制备低甲醛释放的高密度纤维板,并且探讨该纤维板应用于地板基材的可行性。通过差示扫描量热法测定了异氰酸酯的热反应特性,在确定最佳固化温度的基础上,采用施胶量为5.6%、石蜡添加量为1.0%、热压温度为200℃、热压时间为10 min的工艺制备不同密度的纤维板,并结合力学试验机、24 h吸水厚度膨胀率、吸水率和扫描电子显微镜测试结果分析密度变化对板材的力学、耐水和微观结构等性能的影响。结果表明:随着密度的提高,板材内部变得更致密,孔隙率更低,应力集中点减少,纤维之间能够更有效地传递应力,提高了纤维板的力学性能;同时,致密的内部结构阻止了水分渗透,进而提高了板材的耐水性能。最后,为了验证该产品的可行性,在纤维板工业生产线上生产密度为0.84 g/cm3的产品,并与小试样品性能进行对比,结果表明,工业生产线所制产品性能符合LY/T 1611—2011行业标准。此外,生产线上纤维的铺装比实验室手工铺装更均匀,固化效果更好,因此其性能优于实验室样品。
Known as toxin substance,formaldehyde can be released to the environment from flooring made from fiberboards.Formaldehyde emission could lead to human health problems,so it is necessary to produce fiberboards with low formaldehyde emission. In this study,the low formaldehyde emission high-density fiberboard was prepared by eucalyptus fiber and isocyanate adhesive,and the feasibility of the fiberboard applying in flooring substrate was discussed.The thermal reaction characteristics of the isocyanates was determined by the differential scanning calorimetry( DSC) from 25 ℃ to 300 ℃. On the basis of the optimum curing temperature,fiberboards with four different densities were prepared by the hot-pressing technology with 10 min at 200 ℃, and the contents of isocyanates and paraffin were 5.6% and 1.0%,respectively. The effects of the density variation on the mechanical properties,water resistance and microstructures of the fiberboards were analyzed by the mechanical testing machine,methods of 24 h thickness swelling and water absorption,and the scanning electron microscope,respectively. The results revealed that the mechanical properties and water resistance enhanced with the increase of the density. As the density increased,the internal part of the panel became more and more compact and the porosity became lower,reducing the stress concentration.These results can contribute to transfer the stress more effectively and improve the mechanical properties of the fiberboards.Meanwhile,the compact internal structures can resist the water penetration,thus improving the water resistance.In order to verify the feasibility of the products,the fiberboard with a density of 0.84 g/cm3 was produced in the fiberboard production line,and then the properties of this product were compared with the samples with the similar density prepared in the laboratory. The results showed that the performances of the industrial products meet the requirements of the industrial standard of LY/T 1611-2011. Furthermore,the fiber pavement on the industry line exhibited better uniformity than that in the laboratory,leading to better comprehensive properties than those of the laboratory products and made it with huge potential to use the fiberboards in the flooring substrate field.
Known as toxin substance,formaldehyde can be released to the environment from flooring made from fiberboards.Formaldehyde emission could lead to human health problems,so it is necessary to produce fiberboards with low formaldehyde emission. In this study,the low formaldehyde emission high-density fiberboard was prepared by eucalyptus fiber and isocyanate adhesive,and the feasibility of the fiberboard applying in flooring substrate was discussed.The thermal reaction characteristics of the isocyanates was determined by the differential scanning calorimetry( DSC) from 25 ℃ to 300 ℃. On the basis of the optimum curing temperature,fiberboards with four different densities were prepared by the hot-pressing technology with 10 min at 200 ℃, and the contents of isocyanates and paraffin were 5.6% and 1.0%,respectively. The effects of the density variation on the mechanical properties,water resistance and microstructures of the fiberboards were analyzed by the mechanical testing machine,methods of 24 h thickness swelling and water absorption,and the scanning electron microscope,respectively. The results revealed that the mechanical properties and water resistance enhanced with the increase of the density. As the density increased,the internal part of the panel became more and more compact and the porosity became lower,reducing the stress concentration.These results can contribute to transfer the stress more effectively and improve the mechanical properties of the fiberboards.Meanwhile,the compact internal structures can resist the water penetration,thus improving the water resistance.In order to verify the feasibility of the products,the fiberboard with a density of 0.84 g/cm3 was produced in the fiberboard production line,and then the properties of this product were compared with the samples with the similar density prepared in the laboratory. The results showed that the performances of the industrial products meet the requirements of the industrial standard of LY/T 1611-2011. Furthermore,the fiber pavement on the industry line exhibited better uniformity than that in the laboratory,leading to better comprehensive properties than those of the laboratory products and made it with huge potential to use the fiberboards in the flooring substrate field.
引文
[1]SONG W,ZHU M H,LIN W,et al.Determining optimum material mixture ratio and hot-pressing parameters for new hybrid fiberreinforced composites:modeling and optimization by response surface methodology[J].BioResources,2018,13(2):4202-4223.DOI:10.15376/biores.13.2.4202-4223.
[2]SONG W,ZHU M H,ZHANG S B.Comparison of the properties of fiberboard composites with bamboo green,wood,or their combination as the fibrous raw material[J].BioResources,2018,13(2):3315-3334.DOI:10.15376/biores.13.2.3315-3334.
[3]任一萍,唐启恒,郭文静,等.催化剂JSB1对UF树脂制备纤维板力学性能的影响[J].粘接,2017,38(10):43-47.REN Y P,TANG Q H,GUO W J,et al.Effect of catalyst-JSB1on mechanical properties of fiber board prepared with UF resin[J].Adhesion,2017,38(10):43-47.
[4]陈秀兰,王俊伟,朱光华,等.改性脲醛树脂中三聚氰胺添加量对中纤板防潮性能的影响[J].木材工业,2015,29(4):40-42.DOI:10.19455/j.mcgy.2015.04.009.CHEN X L,WANG J W,ZHU G H,et al.Effect of melamine usage in melamine modified urea-formaldehyde resin on moisture resistance of medium density fibreboard[J].China Wood Industry,2015,29(4):40-42.
[5]崔举庆,全清豪,韩书广,等.MUF胶黏剂的稀释对降低纤维板施胶量的影响[J].林业科技开发,2015,29(2):63-65.DOI:10.13360/j.issn.1000-8101.2015.02.015.CUI J Q,QUAN Q H,HAN S G,et al.Influence of dilution of melamine-urea-formaldehyde resin on lowering adhesive consumption in fiberboard manufacturing[J].China Forestry Science and Technology,2015,29(2):63-65.
[6]SONG W,CAO Y,WANG D D,et al.An investigation on formaldehyde emission characteristics of wood building materials in Chinese standard tests:product emission levels,measurement uncertainties,and data correlations between various tests[J].PloSONE,2015,10(12):e0144374.DOI:10.1371/journal.pone.0144374.eCollection 2015.
[7]SONG W,ZHANG K Q,CHEN Z H,et al.Effect of xylanaselaccase synergistic pretreatment on physical-mechanical properties of environment-friendly self-bonded bamboo particleboards[J].Journal of Polymers and the Environment,2018,26(10):4019-4033.DOI:10.1007/s10924-018-1275-7.
[8]刘芳延,郭明辉,张帆,等.木质素磺酸铵的糖含量对无胶中密度纤维板性能的影响[J].林业科学,2014,50(6):175-180.DOI:10.11707/j.1001-7488.20140623.LIU F Y,GUO M H,ZHANG F,et al.Influence of sugar content of ammonium lignosulfonate on the properties of binderless medium density fibreboard[J].Scientia Silvae Sinicae,2014,50(6):175-180.
[9]张亚东,顾继友,郑志锋,等.木材用大豆油基异氰酸酯胶黏剂的制备与表征[J].林业科学,2013,49(4):110-116.DOI:10.11707/j.1001-7488.20130416.ZHANG Y D,GU J Y,ZHENG Z F,et al.Preparation and characterization of isocyanate adhesive based on soybean oil for wood bonding[J].Scientia Silvae Sinicae,2013,49(4):110-116.
[10]LEI H,PIZZI A,DU G B.Environmentally friendly mixed tannin/lignin wood resins[J].Journal of Applied Polymer Science,2008,107(1):203-209.DOI:10.1002/app.27011.
[11]YE D Z,ZHANG M H,GAN L L,et al.The influence of hydrogen peroxide initiator concentration on the structure of eucalyptus lignosulfonate[J].International Journal of Biological Macromolecules,2013,60:77-82.DOI:10.1016/j.ijbiomac.2013.05.016.
[12]SONG W,ZHAO F,YU X F,et al.Interfacial characterization and optimal preparation of novel bamboo plastic composite engineering materials[J].BioResources,2015,10(3):5049-5070.DOI:10.15376/biores.10.3.5049-5070.
[13]LV S Y,FU F,WANG S Q,et al.Novel wood-based all-solidstate flexible supercapacitors fabricated with a natural porous wood slice and polypyrrole[J].RSC Advances,2015,5(4):2813-2818.DOI:10.1039/c4ra13456g.
[14]LV S Y,FU F,WANG S Q,et al.Eco-friendly wood-based solid-state flexible supercapacitors from wood transverse section slice and reduced graphene oxide[J].Electronic Materials Letters,2015,11(4):633-642.DOI:10.1007/s13391-015-5023-z.
[15]TANG Q H,FANG L,GUO W J.Investigation into mechanical,thermal,flame-retardant properties of wood fiber reinforced ultrahighdensity fiberboards[J].BioResources,2017,12(3):6749-6762.DOI:10.15376/biores.12.3.6749-6762.
[2]SONG W,ZHU M H,ZHANG S B.Comparison of the properties of fiberboard composites with bamboo green,wood,or their combination as the fibrous raw material[J].BioResources,2018,13(2):3315-3334.DOI:10.15376/biores.13.2.3315-3334.
[3]任一萍,唐启恒,郭文静,等.催化剂JSB1对UF树脂制备纤维板力学性能的影响[J].粘接,2017,38(10):43-47.REN Y P,TANG Q H,GUO W J,et al.Effect of catalyst-JSB1on mechanical properties of fiber board prepared with UF resin[J].Adhesion,2017,38(10):43-47.
[4]陈秀兰,王俊伟,朱光华,等.改性脲醛树脂中三聚氰胺添加量对中纤板防潮性能的影响[J].木材工业,2015,29(4):40-42.DOI:10.19455/j.mcgy.2015.04.009.CHEN X L,WANG J W,ZHU G H,et al.Effect of melamine usage in melamine modified urea-formaldehyde resin on moisture resistance of medium density fibreboard[J].China Wood Industry,2015,29(4):40-42.
[5]崔举庆,全清豪,韩书广,等.MUF胶黏剂的稀释对降低纤维板施胶量的影响[J].林业科技开发,2015,29(2):63-65.DOI:10.13360/j.issn.1000-8101.2015.02.015.CUI J Q,QUAN Q H,HAN S G,et al.Influence of dilution of melamine-urea-formaldehyde resin on lowering adhesive consumption in fiberboard manufacturing[J].China Forestry Science and Technology,2015,29(2):63-65.
[6]SONG W,CAO Y,WANG D D,et al.An investigation on formaldehyde emission characteristics of wood building materials in Chinese standard tests:product emission levels,measurement uncertainties,and data correlations between various tests[J].PloSONE,2015,10(12):e0144374.DOI:10.1371/journal.pone.0144374.eCollection 2015.
[7]SONG W,ZHANG K Q,CHEN Z H,et al.Effect of xylanaselaccase synergistic pretreatment on physical-mechanical properties of environment-friendly self-bonded bamboo particleboards[J].Journal of Polymers and the Environment,2018,26(10):4019-4033.DOI:10.1007/s10924-018-1275-7.
[8]刘芳延,郭明辉,张帆,等.木质素磺酸铵的糖含量对无胶中密度纤维板性能的影响[J].林业科学,2014,50(6):175-180.DOI:10.11707/j.1001-7488.20140623.LIU F Y,GUO M H,ZHANG F,et al.Influence of sugar content of ammonium lignosulfonate on the properties of binderless medium density fibreboard[J].Scientia Silvae Sinicae,2014,50(6):175-180.
[9]张亚东,顾继友,郑志锋,等.木材用大豆油基异氰酸酯胶黏剂的制备与表征[J].林业科学,2013,49(4):110-116.DOI:10.11707/j.1001-7488.20130416.ZHANG Y D,GU J Y,ZHENG Z F,et al.Preparation and characterization of isocyanate adhesive based on soybean oil for wood bonding[J].Scientia Silvae Sinicae,2013,49(4):110-116.
[10]LEI H,PIZZI A,DU G B.Environmentally friendly mixed tannin/lignin wood resins[J].Journal of Applied Polymer Science,2008,107(1):203-209.DOI:10.1002/app.27011.
[11]YE D Z,ZHANG M H,GAN L L,et al.The influence of hydrogen peroxide initiator concentration on the structure of eucalyptus lignosulfonate[J].International Journal of Biological Macromolecules,2013,60:77-82.DOI:10.1016/j.ijbiomac.2013.05.016.
[12]SONG W,ZHAO F,YU X F,et al.Interfacial characterization and optimal preparation of novel bamboo plastic composite engineering materials[J].BioResources,2015,10(3):5049-5070.DOI:10.15376/biores.10.3.5049-5070.
[13]LV S Y,FU F,WANG S Q,et al.Novel wood-based all-solidstate flexible supercapacitors fabricated with a natural porous wood slice and polypyrrole[J].RSC Advances,2015,5(4):2813-2818.DOI:10.1039/c4ra13456g.
[14]LV S Y,FU F,WANG S Q,et al.Eco-friendly wood-based solid-state flexible supercapacitors from wood transverse section slice and reduced graphene oxide[J].Electronic Materials Letters,2015,11(4):633-642.DOI:10.1007/s13391-015-5023-z.
[15]TANG Q H,FANG L,GUO W J.Investigation into mechanical,thermal,flame-retardant properties of wood fiber reinforced ultrahighdensity fiberboards[J].BioResources,2017,12(3):6749-6762.DOI:10.15376/biores.12.3.6749-6762.