| The valuable wood has been widely used in indoor furniture and decoration because of its excellent wood quality and unique beautiful color and texture.China’s massive dependence on import valuable wood has prompted the researchers to pay more attention on the study of the value-added processing and utilization of domestic plantation valuable wood and to solve the strategic safety of wood in China.In this work,wood veneer from valuable plantation was prepared by slicing four valuable wood species of Tectona（Tectona grandis）,Catalpa（Catalpa bungei）,Betula（Betula alnoides）and Castanopsis（Castanopsis hystrix）and the applicability of four veneers was studied to provide scheme for wood processing of valuable plantation tree species in China.In order to realize the value added utilization of veneer,its application in indoor wood fire doors is studied.According to the material composition of wood fire door veneer layer,internal solid wood frame and fire insulation layer,the fire retardant treatment of veneer and solid wood was carried out.At the same time,the performance of different insulation materials was selected and studied.The research route of this paper focuses on solving the surface flame retardant and anti-fire spreading performance of indoor wood fire doors,the carbon forming performance of internal solid wood in combustion and the lightweight of thermal insulation materials.Finally,based on the research materials,the process technology for the preparation of lightweight interior wood fire door were prepared.The application of valuable plantation in fire interior door will endow traits of the door not only fireproof but also beautiful.The main conclusions of this study are as follows:1.In view of the value-added processing of domestic plantation valuable wood and the applicability of veneer,four kinds of plantation valuable wood veneer prepared by two methods were studied.The results show that,Teak and Betula sliced veneers from small-diameter tree prepared by finger-jointed method has an obvious color difference and easy to be twisted.The appearance of large-diameter sliced Catalpa wood and Castanopsis veneer is not obvious different from the imported veneer except for the intrinsic color of the wood.The appearance of the four kinds of veneer can meet the decoration requirements.Domestic Teak and Betula finger-joined veneer have better anti-friction properties and tensile strength along the grain,while Catalpa veneer was the worst.The viscoelasticity is closely related to the embossing process.The viscosity of the four veneer in descending order is Betula>teak>catalpa>Castanopsis veneer at 160 oC.The veneer coating and bonding performance experiments show the surface bonding strength and film adhesion of four kinds of wood veneer can meet the requirements specified in GB/T 15104-2006《Decorative veneer wood-based panel》and GB/T 37005-2018《Paint finishing wood-based panels》.2.In order to solve the problem of flammability and treatment influence of veneer for wood fire doors on the performance of finishing,environmentally friendly phytic acid（PA）,cytosine（Cy）and vitamin C（VC）flame retardant system（PCV）were used for flame retardant treatment of teak fingered veneer.The results show that,After treated,the flame retardant performance of wood veneer was significantly improved.After ignition for 10 s,the fire could self-extinguishing.The smoke release rate and total smoke release amount of PCV-1W（veneer treated with Flame Retardant with PA,Cy,VC Ratio of 2:2:1）were the lowest.Compared with YM（untreated veneer）,PCV-1W has less difference in anti-friction properties and longitudinal tensile properties,and has better hydrophobicity.The color of PCV-1W is only slightly different,which does not affect when used.After the waterborne polyurethane coatinged,Only PCV-1W has better film-forming properties.The study of flame retardant mechanism shows that PA catalyzes the carbon formation of cellulose and VC in wood,forming dense and thick carbon layer.Under the action of flame retardant,the degree of graphitization of the carbon layer is enhanced and the flammability is reduced.At the same time,the N,P elements in the flame retardant and C elements produce cross-linking reaction,forming O=C-N,C-N,C-O-P and other groups,retain more C elements,heat resistance is improved,and could more effective to prevent heat transfer.3.In order to solve the problems of flammability,less carbon residual and poor integrity of solid wood inside fire doors,the flame retardant treatment of wood was carried out with biomass phytic acid,hydrolyzed collagen（HC）and glycerol（GL）.The results show that,the oxygen index increased significantly,and the LOI of PHG-C30/wood（wood treated with flame retardant with the ratio of PA,HC and GL is 3:1:1 and the concentration is 30%）reached 41%;The microscopic morphology shows that the inflatable foaming layer produced in the conduits when heated and plays a role in protecting wood.The results of TGA and CONE shows that PHG-treated wood absorbs heat earlier than pure wood and undergoes thermal decomposition,thereby protecting the internal wood matrix;The maximum decomposition rate(Rmax)of the PHG-C30/wood sample is 32.78%lower than that of untreated wood,the total heat release（THR）is47.7%lower,and the maximum heat release rate（p HRR）is also reduced by 54.7%.At the same time,the total smoke release（TSR）and smoke release rate（SPR）are also significantly reduced;Analysis of flame retardant mechanism found that PHG-C30/wood increased the graphitization degree of carbon residue in the condensed phase,and released H2O（steam）,CO2,NH3 and PO groups in the gas phase,which effectively dilutes the air and can capture H·and HO·free radicals.The condensed phase and gas phase work together to prevent the chain reaction of combustion and have a flame retardant effect.4.In order to reduce the weight of indoor wood fire door and achieve heat insulation effect,different lightweight filling materials were selected to study the heat insulation performance.The results show that,The density of the aluminum silicate ceramic fiber board（AC-Fb）and the soluble ceramic fiber mat（SC-Fm）are 79.5%and 39.4%of the perlite board（Peb）,respectively,which can effectively reduce the total weight as a filling material;The flame retardant hollow particleboard has strong moisture absorption and is prone to mildew.The SC-Fm does not absorb water,and the moisture absorption quality of AC-Fb does not increase significantly;At 800℃,the mass loss of flame retardant hollow particle board is 93.33%,while the mass loss of SC-Fm and AC-Fb is less,and there is basically no appearance change before and after calcination;The composite board filled with three materials has undergone a combustion test.The temperature rise of the back surface of the AC-Fb and SC-Fm is slightly higher than that of the perlite board（Peb）,but the difference is not large.5.The interior light wood fire door is invented with prepared flame retardant and insulation materials.Compared with the conventional fire door,the weight is reduced by 30%and its teak solid wood feeling and beautiful performance have been promoted.Fire test shows that the door has a fire resistance time of 82 minutes,which can meet Class B Fire door standards. |
