Summary of the invention
The purpose of this invention is to provide a kind of freeze proof full Eucalyptus lamination decoration panel and production method thereof, is to improve the humidity resistance of full Eucalyptus wood-based plate by production method of the present invention on the one hand, makes it be suitable for manufacturing office furniture, is to reduce burst size of methanal on the one hand.
Technical scheme of the present invention is as follows:
In the production process of base material, adopt cold pressing for three times, three hot pressing, twice standing health of thermostatic chamber overcome bulging phenomenon with the method for heat radiation health.Concrete production technology is as follows:
Manually select Eucalyptus veneer of the same size, coat above-mentioned adhesive, resin added is 250~300g/m
2, assembly (3~15 layers), cold pressing for the first time, and temperature is normal temperature, and pressure is 0.8~1.0MPa, hot pressing for the first time, temperature is 120~125 ℃, pressure is 1.5~2.0MPa; 60~80 ℃ of standing healths of thermostatic chamber 4~6 hours, the naturally ventilated cooling of thermostatic chamber, heat radiation health 3~4h; Cold pressing for the second time, temperature is normal temperature, and pressure is 0.8~1.0MPa, hot pressing for the second time, and temperature is 115~120 ℃, pressure is 2.5~3.0MPa; The standing health of thermostatic chamber for the second time, thermostatic chamber temperature are 60~80 ℃, time 90~120min, the naturally ventilated cooling of thermostatic chamber, heat radiation health 3~4h; Cold pressing for the third time, temperature is normal temperature, and pressure is 0.8~1.0MPa, hot pressing for the third time, temperature are 125~130 ℃, and pressure is 1.5~2.0MPa, fixed thick with coarse sand and fine sandpaper polishing, paste low face side, the polishing face side, face side sticks the alundum (Al2O3) abrasion-proof paper, hot pressing, and temperature is 160 ℃, pressure is 1.5~2MPa, heat radiation arranges, and beats limit, obtains freeze proof full Eucalyptus lamination decoration panel.
Prepare adhesive: reduce the burst size of formaldehyde, at first will from improving adhesive-preparing technology, by improving adhesive-preparing technology, make raw material formaldehyde almost or complete reaction, reduce the residual quantity of formaldehyde.This adhesive-preparing technology adopts the disposable formaldehyde that adds, and adds at twice urea, and the method for a melamine promotes the complete reaction of formaldehyde.In reactor, add formaldehyde, with the first acid for adjusting pH value, be 2~2.5, the polyvinyl alcohol that adds formaldehyde weight 0.5~0.6%, the urea that adds formaldehyde weight 10%, be warming up to 50 ℃, insulation reaction 30min, the pH value of conditioned reaction liquid is 8~8.5, the urea that adds formaldehyde weight 25%, the melamine that adds formaldehyde weight 1%, 1% polyvinyl acetate emulsion, be warming up to 90~95 ℃, insulation reaction 90min, reaction checks after finishing, if also contain formaldehyde, add appropriate urea or melamine to continue reaction, until detect the content<5mg/L of formaldehyde, the pH value that adds the alkali conditioned reaction to finish liquid is 7.2~7.5.Amino generation polycondensation reaction on aldehyde radical on formaldehyde molecule and urea or melamine molecule, generate macromolecular compound, along with constantly carrying out of condensation reaction, the molecular weight of the material that polycondensation reaction generates constantly increases, cause reactant liquor viscosity to increase, the mobility variation, reduced the probability of the collision of the formaldehyde that do not react and urea, and the high polymer gel formaldehyde and the urea that generate, cause the outer formaldehyde of high polymer and urea effectively to inside, not to supplement, cause the inner polymer molecular weight generated low.Polymer molecular weight is low, easily degraded, release formaldehyde.Therefore the one-step technology before, namely disposable formaldehyde and the urea of adding, easily cause the reaction in early stage violent, and gelatin phenomenon is very serious.So-called gelatin phenomenon is exactly in polymerisation, the high molecular polymer generated encases polymerization single polymerization monomer, and the monomer of high molecular polymer the inside is polymerization reaction take place also, but because the monomer of outside can't give the reaction of the inside supplementary, therefore, the polymer molecular weight that wraps of high molecular polymer is very little.The polymer substance molecular weight distribution that this phenomenon causes polymerisation to obtain is very wide, and level of residual monomers is very large.Because one-step method is reacted acutely in earlier stage, reaction polymer molecular weight in early stage is very large, and the later stage molecular weight is little, the formaldehyde of complete reaction is not many, the adhesive molecular weight distribution of making is very wide, and the artificial board formaldehyde burst size made from this adhesive is very large, has greatly endangered the healthy of user.The new technology that adds urea by gradation, avoided reaction in earlier stage too violent, and the polymer molecular weight that adds for the first time the urea afterreaction to generate can be very not large, because add for the first time the amount of urea seldom, the polymer generated is few, and viscosity is low, the good fluidity of material, do not have the phenomenon of gel, therefore the molecular weight distribution of polymer is more even, adds for the second time urea, because the concentration of formaldehyde in reactant liquor has reduced much, react more steady, so gelatin phenomenon not very serious yet.
Formaldehyde almost completely reacts, the molecular weight of polycondensates narrowly distributing, and molecular weight is high, difficult degradation, as the adhesive of veneer, burst size of methanal is naturally low.
Lauxite adds polyvinyl acetate emulsion as modifier, can reduce the fragility of Lauxite, under low temperature, keeps flexible, and can improve tack and the resistance to ag(e)ing of Lauxite.
The good effect that the present invention produces is:
Freeze proof full Eucalyptus lamination decoration panel production technology of the present invention adopt cold pressing for three times, three hot pressing, the production technology of twice standing health of thermostatic chamber and twice heat radiation health, can eliminate the internal stress of Eucalyptus plate, after avoiding finished product to be heated, expand with heat and contract with cold to act on and hold yielding situation generation, and reduced the possibility that finished product chance water, the moisture absorption play drum, are out of shape.Use the technique in the present invention, can also reduce the finished product burst size of methanal, protected consumer's health.
2. the urea-formaldehyde resin adhesive that adopts of freeze proof full Eucalyptus lamination decoration panel of the present invention is to adopt gradation to add the technique of urea, the formaldehyde monomers less residue, in conjunction with the repeatedly cold, hot pressure technique that the present invention adopts, the burst size of methanal of finished product still less, more environmental protection.
The specific embodiment
Embodiment 1
At first prepare adhesive, in reactor, add formaldehyde, with the first acid for adjusting pH value, be 2~2.5, the polyvinyl alcohol that adds formaldehyde weight 0.5~0.6%, the urea that adds formaldehyde weight 10%, be warming up to 50 ℃, insulation reaction 30min, the pH value of conditioned reaction liquid is 8~8.5, the urea that adds formaldehyde weight 25%, the melamine that adds formaldehyde weight 1%, 1% polyvinyl acetate emulsion, be warming up to 90~95 ℃, insulation reaction 90min, reaction checks after finishing, if also contain formaldehyde, add appropriate urea or melamine to continue reaction, until detect the content<5mg/L of formaldehyde, the pH value that adds the alkali conditioned reaction to finish liquid is 7.2~7.5.
Manually select Eucalyptus veneer of the same size, coat above-mentioned adhesive, resin added is 300g/ ㎡, and 3 layers of assemblies, cold pressing for the first time, and temperature is normal temperature, and pressure is 0.8MPa, hot pressing for the first time, and temperature is 120~125 ℃, pressure is 1.5MPa; 60~80 ℃ of standing healths of thermostatic chamber 4~6 hours, the naturally ventilated cooling of thermostatic chamber, heat radiation health 3~4h; Cold pressing for the second time, temperature is normal temperature, and pressure is 0.8MPa, hot pressing for the second time, and temperature is 115~120 ℃, pressure is 1.8MPa; The standing health of thermostatic chamber for the second time, thermostatic chamber temperature are 60~80 ℃, time 90~120min, the naturally ventilated cooling of thermostatic chamber, heat radiation health 3~4h; Cold pressing for the third time, temperature is normal temperature, and pressure is 1.0MPa, hot pressing for the third time, temperature are 125~130 ℃, and pressure is 2.0MPa, fixed thick with coarse sand and fine sandpaper polishing, paste low face side, the polishing face side, face side sticks the alundum (Al2O3) abrasion-proof paper, hot pressing, and temperature is 160 ℃, pressure is 1.5MPa, heat radiation arranges, and beats limit, obtains freeze proof full Eucalyptus lamination decoration panel.
Embodiment 2
Manually select Eucalyptus veneer of the same size, coat the adhesive of embodiment 1, resin added is 280g/ ㎡, and assembly (7 layers), cold pressing for the first time, and temperature is normal temperature, and pressure is 0.9MPa, hot pressing for the first time, and temperature is 120~125 ℃, pressure is 1.8MPa; 60~80 ℃ of standing healths of thermostatic chamber 4~6 hours, the naturally ventilated cooling of thermostatic chamber, heat radiation health 3~4h; Cold pressing for the second time, temperature is normal temperature, and pressure is 1.0MPa, hot pressing for the second time, and temperature is 115~120 ℃, pressure is 1.8MPa; The standing health of thermostatic chamber for the second time, thermostatic chamber temperature are 60~80 ℃, time 90~120min, the naturally ventilated cooling of thermostatic chamber, heat radiation health 3~4h; Cold pressing for the third time, temperature is normal temperature, and pressure is 1.0MPa, hot pressing for the third time, temperature are 125~130 ℃, and pressure is 2.0MPa, fixed thick with coarse sand and fine sandpaper polishing, paste low face side, the polishing face side, face side sticks the alundum (Al2O3) abrasion-proof paper, hot pressing, and temperature is 160 ℃, pressure is 1.8MPa, heat radiation arranges, and beats limit, obtains freeze proof full Eucalyptus lamination decoration panel.
Embodiment 3
Manually select Eucalyptus veneer of the same size, coat the adhesive of embodiment 1, resin added is 200g/ ㎡, and assembly (11 layers), cold pressing for the first time, and temperature is normal temperature, and pressure is 1.0MPa, hot pressing for the first time, and temperature is 120~125 ℃, pressure is 2.0MPa; 60~80 ℃ of standing healths of thermostatic chamber 4~6 hours, the naturally ventilated cooling of thermostatic chamber, heat radiation health 3~4h; Cold pressing for the second time, temperature is normal temperature, and pressure is 1.0MPa, hot pressing for the second time, and temperature is 115~120 ℃, pressure is 2.0MPa; The standing health of thermostatic chamber for the second time, thermostatic chamber temperature are 60~80 ℃, time 90~120min, the naturally ventilated cooling of thermostatic chamber, heat radiation health 3~4h; Cold pressing for the third time, temperature is normal temperature, and pressure is 1.0MPa, hot pressing for the third time, temperature are 125~130 ℃, and pressure is 2.0MPa, fixed thick with coarse sand and fine sandpaper polishing, paste low face side, the polishing face side, face side sticks the alundum (Al2O3) abrasion-proof paper, hot pressing, and temperature is 160 ℃, pressure is 2MPa, heat radiation arranges, and beats limit, obtains freeze proof full Eucalyptus lamination decoration panel.
The comparative example 1
Manually select Eucalyptus veneer of the same size, coat the adhesive of embodiment 1, resin added is 300g/ ㎡, and assembly (11 layers), cold pressing, and temperature is normal temperature, and pressure is 2MPa, hot pressing, and temperature is 120~125 ℃, pressure is 3MPa; 60~80 ℃ of standing healths of thermostatic chamber 5~8 hours, the naturally ventilated cooling of thermostatic chamber, heat radiation health 3~4h; Fixed thick with coarse sand and fine sandpaper polishing, paste low face side, polishing face side, face side stick the alundum (Al2O3) abrasion-proof paper, hot pressing, temperature is 160 ℃, and pressure is 1.5MPa, and heat radiation arranges, and beats limit, obtains freeze proof full Eucalyptus lamination decoration panel.
The comparative example 2
Manually select Eucalyptus veneer of the same size, coat the adhesive of embodiment 1, resin added is 300g/ ㎡, and assembly (11 layers), cold pressing for the first time, and temperature is normal temperature, and pressure is 1.5MPa, hot pressing for the first time, and temperature is 115~120 ℃, pressure is 2.0MPa; 60~80 ℃ of standing healths of thermostatic chamber 5~8 hours, the naturally ventilated cooling of thermostatic chamber, heat radiation health 3~4h; Cold pressing for the second time, temperature is normal temperature, and pressure is 1.5MPa, hot pressing for the second time, and temperature is 110~115 ℃, pressure is 2.0MPa; The standing health of thermostatic chamber for the second time, thermostatic chamber temperature are 60~80 ℃, time 90~120min, the naturally ventilated cooling of thermostatic chamber, heat radiation health 3~4h; Fixed thick with coarse sand and fine sandpaper polishing, paste low face side, polishing face side, face side stick the alundum (Al2O3) abrasion-proof paper, hot pressing, temperature is 160 ℃, and pressure is 1.5MPa, and heat radiation arranges, and beats limit, obtains freeze proof full Eucalyptus lamination decoration panel.
The comparative example 3
Manually select Eucalyptus veneer of the same size, coat the urea-formaldehyde resin adhesive of buying on market, resin added is 300g/ ㎡, assembly (11 layers), cold pressing for the first time, temperature is normal temperature, and pressure is 1.0MPa, hot pressing for the first time, temperature are 120~125 ℃, and pressure is 2.0MPa; 60~80 ℃ of standing healths of thermostatic chamber 4~6 hours, the naturally ventilated cooling of thermostatic chamber, heat radiation health 3~4h; Cold pressing for the second time, temperature is normal temperature, and pressure is 1.0MPa, hot pressing for the second time, and temperature is 115~120 ℃, pressure is 2.0MPa; The standing health of thermostatic chamber for the second time, thermostatic chamber temperature are 60~80 ℃, time 90~120min, the naturally ventilated cooling of thermostatic chamber, heat radiation health 3~4h; Cold pressing for the third time, temperature is normal temperature, and pressure is 1.0MPa, hot pressing for the third time, temperature are 125~130 ℃, and pressure is 2.0MPa, fixed thick with coarse sand and fine sandpaper polishing, paste low face side, the polishing face side, face side sticks the alundum (Al2O3) abrasion-proof paper, hot pressing, and temperature is 160 ℃, pressure is 2MPa, heat radiation arranges, and beats limit, obtains freeze proof full Eucalyptus lamination decoration panel.
According to GB/T15036.2-2001 " solid wooden floor board inspection and test method ", burst size of methanal, bonding strength and the expansion rate of water absorption of products obtained therefrom in embodiment are measured; The mensuration that plays the drum phenomenon of wood-based plate adopts water-boiling method, namely wood-based plate is cut out to the length for 80cm() * 30cm(is wide) specification, the thermostatted water of putting into 80 ℃ soaks, record wood-based plate and play the drum time used, the time is longer, illustrates that the quality of wood-based plate is better, under normal condition is used, more difficult drum.Wood-based plate is cut out and to be grown for 80cm() * 30cm(is wide) specification, put into the low-temperature test chamber of 25 ℃ of constant temperature and place 1h, give afterwards the cooling of low-temperature test chamber, near in 2 minutes-10 ℃, keep-10 ℃ of 30min, the low-temperature test chamber is warming up to rapidly 25 ℃ afterwards, checks the cracking situation of artificial flaggy and interlayer, and whether wood-based plate be out of shape, according to the craze and transfiguration situation, draw the anti-freezing property of wood-based plate.Each product detects three times, and data are averaged, and every testing result is as shown in the table:
It can be seen from the table, freeze proof full Eucalyptus lamination decoration panel of the present invention adopt repeatedly cold pressing, the production technology of hot pressing, the standing health of thermostatic chamber and heat radiation health, can eliminate the internal stress of wood-based plate, avoided wood-based plate because the situation that the effect of expanding with heat and contract with cold has produced the drum distortion occurs, and this production technology can reduce artificial board formaldehyde burst size.From the data table, find out, reduce burst size of methanal except relevant with Wood-based Panel Production technique, also relevant with the residual formaldehyde of adhesive, therefore in order to obtain lower burst size of methanal wood-based plate, except improving the production technology of wood-based plate, also need to improve the production technology of urea-formaldehyde resin adhesive.
Freeze proof full Eucalyptus lamination decoration panel of the present invention has good anti-freezing property, and good stability of the dimension under high temperature, high humidity environment is simultaneously met water, making moist has been difficult for drum, is out of shape, and is adapted at the north use of cold in winter.