Study On The Performance Of Flame-Retardant Ultra-low Density Fiberboard

The ultra-low density fiberboard(ULDF)hadthe advantages of light weight,low transportation cost,low raw material consumption,small processing deformation coefficient,and good sound absorption.It could be widely used in interior decoration,furniture,hi-fi,composite board core material and other non-structural material.According to China's Fire Law,flammable materials for public places must be flame-retardant treated,because ULDF is generally used for interior decoration,etc.,therefore,improving the flame retardant performance of ULDFwas imminent.Polyphosphate(APP)applied to modify woody materials because of its good flame retardancy and low toxicity,but its flame retardant products were not widely accepted by the marketbecause of its high prices.Therefore,it is of great significance to study the flame retardant with good flame retardancy and affordable price.Vermiculite(EV)was cheap and had good flame retardancy,whichwas used as flame retardantsto modify high density polyethylene,rigid polyurethane foam,polyethylene,polypropylene and chemical products.The aim of this article is to manufacture the ULDF with the density of 0.2~0.4 g/cm~3,using Eucalyptus fiber and melamine modified urea-formaldehyde resin powder(MUF)as raw materials,using EV and APP as flame retardants.ULDF's flame retardant properties are investigated through the limit oxygen index and thermogravimetricanalysis.ULDF's physical and mechanical properties are investigated by measuring static bending strength(MOR),elastic modulus(MO E),water swelling rate,internal bonding strength(IB)and formaldehyde emission.ULDF's sound absorption performance and thermal insulation performance are investigated throughmeasuring the sound absorption coefficient and thermal conductivity,respectively.The results showed that:(1)With the increase of the addition of adhesive,MOR and MOE of ULDF tended to increase first and then decrease,IB and formaldehyde emission trendedto increase,whilethe2h and 24h thickness swelling rate of water showed a decreasing trend.Taking into account various properties,when the addition of adhesive was 20%,ULDF'scomprehensive performance is better.(2)With the increase of board's density,MOR,MO E,IB and thermal conductivity of ULDF obviously increased,whileits sound absorption coefficient obviously decreased.Considering various properties,when the board's density is 0.3 g/cm~3,the comprehensive performance of ULDF was better.(3)With the increase of EV content,MOR,MOE and IB of ULDF tended to increase first and then decrease,and its oxygen index(LOI)and thermal stability increased gradually.Considering various properties,when the EV content is 6%,the comprehensive performance of flame retardant ULDFwas better.(4)In EV and APP composite modified ULDF,with the increase of APP content,LOI of ULDF tended to decrease first and increase then,while its thermal stability tended to increase first and then decrease.Considering various properties,the EV and APP addition ratio was 1:1,the synergistic effect of flame retardant ULDF was best.