Study On The Preparation Technology And Surface Properties Of Surface Decorated Plywood And Blockboard With Paper Impregnated Thermosetting Resins

The properties of impregnated decorative paper,the influence of the surface hot pressing process on the surface properties of surface decorated plywood and blockboard with paper impregnated themosetting resins and optimization technology of surface properties of decorative panels were studied In this thesis,The main conclusions are as follows:The precure percent and resin pick-up of impregnated decorative paper have a direct influence on the quality of the paper.When the amount of the precure percent and resin pick-up of impregnated decorative paper to meet the standard requirements,should be appropriately increased the content of both sides,to ensure that the surface of the impregnated decorative paper is covered by resin,there is no small pores.When the heating temperature o f impregnated decorative paper is 110?~115?,the resin in the paper starts to solidify rapidly,and the optimum curing temperature is 140?.The hot pressing process parameters have an influence on the surface bonding strength of surface decorated eucalyptus plywood and fir blockboard with paper impregnated themosetting resins.Experimental results show: Increasing hot pressing temperature from 110 ? to 160 ? significantly increased the surface bonding strength in the orthogonal test results(?=0.05).The influence of hot pressing process parameters on the surface properties of the surface bonding strength of surface decorated eucalyptus plywood and fir blockboard with paper impregnated themosetting resins was investigated by affecting the properties of impregnated decorative paper.Within the limits of t he hot pressing time 4~7min and hot pressing pressure 0.7MPa~1.3MPa,when the hot pressing temperature is 160?,the resin curing quality is poor in impregnated paper,the paper toughness decreased and the board surface prone to cracking.The board surface cracking not produced immediately,is a slow physical change,with the substrate size changes gradually stretching,tearing the impregnated decorative paper produced.Blister on the surface of the plate produced immediately in the hot pressing process.When the temperature is too high,the substrate and the impregnated decorative paper in the rapid evaporation of moisture and volatile matter formed large impact force,impregnated decorative paper can not withstand the impact force is broken,produced blister.Adding glass fiber cloth to eucalyptus plywood,can enhance the dimensional stability of eucalyptus wood plywood and the surface resistance to cracking.With the increase of the layers of glass fiber cloth,the size of eucalyptus plywood is more stable.When the layers of glass fiber cloth is more than 4 layers,with the increase of the layers of glass fiber cloth,it is not obvious to enhance the dimensional stability of eucalyptus plywood.Considering the factors such as comprehensive cost and dimensional stability,4 layers of glass fiber cloth were added to the 7 layer plywood.The best way was to close the upper and lower surface of the board.