High area density fibre board and manufacture method thereof
Technical field
The present invention relates to fibre board and the manufacture method thereof of a kind of high area density, belong to wood-based plate and manufacture field.
Background technology
Medium and high density fibre panel be utilize fast growing wood or rice wheat straw etc. for primary raw material, by getting the raw materials ready, defibrator process, applying urea-formaldehyde resin adhesive, be dried, mat formation, wood-based plate that precompressed, hot pressing, cooling, the technique such as sanding manufacture.Area density after consolidated floor base material high density fiberboard requires sanding must not be less than 1.0g/cm3, furniture surfacing plate substrate medium density fibre board (MDF) must not require less than 0.8g/cm3。
When using urea-formaldehyde resin adhesive to produce fibre board, slab its top layer after hot pressing occurs " pre-hardening thickness " the most in varying degrees.The formation mechenism of pre-hardening thickness is: sending between heating platen at slab, when upper lower platen not yet completes to close boost process, slab surface fibre has received the heat from heating platen, and temperature drastically raises;When slab surface fibre temperature rises to urea-formaldehyde resin adhesive solidification temperature, the urea-formaldehyde resin adhesive imposing on fiber surface i.e. starts solidification, solidification process quickly (only 1~2s);Owing to slab surface fibre is very sensitive to conduction of heat, time not yet by hot press working pressure, the urea-formaldehyde resin adhesive on its fiber is cured, although and slab enters after formal hot pressing surface fibre by hot press working pressure, but the most cannot form bonding, adhesion process is only carried out at slab internal layer.
Top, plate face cured layer problem is worldwide technical barrier, and pre-hardening thickness is inevitable.Generally slab two sides pre-hardening thickness thickness is about 3~4mm.Pre-hardening thickness causes fibre board plate face soft, and fiber easily peels off, and only by sanding, removes the pre-hardening thickness in plate face, the dense layer of good bonding just can be made to be presented on plate face.This part that should form the volume of timber is become sanding powder, and the thin plate in causing enterprise to be difficult to produce, otherwise the ratio shared by sanding loss is bigger.Therefore, Fibreboard Production enterprise is highly desirable finds a kind of effective way to solve pre-hardening thickness problem.This problem is studied by many scholars, it is proposed that following corrective measure: (1) adjusts hardening time and the curing rate of urea-formaldehyde glue;(2) slab table, the resin added of sandwich layer and glue kind are changed;(3) hot-pressing process curve is changed;(4) Guan Bi of pressing plate, pressure rising time are reduced;(5) increase the moisture content of steel slab surface, reduce the moisture gradient inside and outside slab, make slab top layer heat up slowly.In actual production, most enterprises often uses the method at sprinkling on the surface of mat, but effect is the most undesirable.
Summary of the invention
The present invention is directed to the difficult problem that fibreboard surface pre-hardening thickness brings, the fibre board preparation method of a kind of high area density is proposed, the method can remove the sanding operation during Fibreboard Production from, pre-hardening thickness in Fibreboard Production is made full use of, reduce fiber loss, the high area density fibreboard product being directly produced out, can also reduce production cost simultaneously, effectively solves the defects such as fibre board hardness is low, wear no resistance.
The manufacture method of this high area density fibre board, comprises the steps: that a, upper and lower surface to the fibre board slab of sanding non-after hot pressing carry out vacuum cleaning;B, to slab upper and lower surface respectively showering modified adhesive predrying to applying glue face;C, the sheet material made a good job of in advance is placed on cold press flattens so that the area density of sheet material reaches 1.0g/cm3Above;D, to the upper and lower surface spraying modified adhesive of sheet material after flattening, make resin fill in plate surface completely, e, the sheet material after secondary applying glue put in hot press hot-forming.
Beneficial effects of the present invention: be placed on cold press by the sheet material made a good job of in advance by surface precompressed and flatten, by adhesive and the fiber compacting in pre-hardening thickness so that it is be adhered firmly on plate surface.The upper and lower pressing plate of cold press is polishing steel plate.The pressure of cold press selects according to the requirement of area density, it is ensured that area density reaches 1.0g/cm3Above.By sizing hot pressing the sheet material after secondary applying glue put into and hot press carries out sizing hot pressing by finger gauge requirements make adhesive solidify, formation case hardness layer.Upper lower platen in hot press is polishing steel plate, to ensure the flat smooth on composite two sides.Finger gauge size is customized by the sheet metal thickness of market demands, and hot pressing pressure is limited to be depressed into finger gauge, and hot pressing time and temperature depend on be coated with adhesive type.Generally, hot pressing pressure 0.8~1.5MPa, hot pressing temperature 110~180 DEG C, hot pressing time 10~40s/mm.The method can remove the sanding operation during Fibreboard Production from, pre-hardening thickness in Fibreboard Production is made full use of, reduce fiber loss, the high area density fibreboard product being directly produced out, production cost can also be reduced simultaneously, effectively solve the defects such as fibre board hardness is low, wear no resistance.
The manufacture method of above-mentioned high area density fibre board, modified adhesive refers to wear resistance adhesive agent, this wear resistance adhesive agent be by 80 mesh more than the inorganic material such as silicon dioxide, aluminium sesquioxide, aluminium hydroxide or carborundum add and low-molecular-weight resin stir and prepares, inorganic material and weight ratio 1:7-20 of low-molecular-weight resin, concrete addition depends on the hardness required by material and wear-resisting revolution.Inorganic material selects the inorganic material such as existing silicon dioxide on market, aluminium sesquioxide, aluminium hydroxide or carborundum, and kind does not limits, and particle diameter is typically more than 80 mesh.Low-molecular-weight resin all selects the market ripes such as Lauxite, phenolic resin, melamine resin and modified resin thereof.
The manufacture method of above-mentioned high area density fibre board, in step a during vacuum cleaning, the negative pressure of dust collecting system is-10kPa~-20kPa.Use fine vacuum dedusting absorption, it is ensured that dedusting is thorough.
The manufacture method of above-mentioned high area density fibre board, time predrying in step b, put into slab in drying machine and is dried applying glue face at temperature 80-120 DEG C, makes steel slab surface hands glue slightly hands when touching.
The manufacture method of above-mentioned high area density fibre board, in step b, the resin added to slab upper surface or lower surface is 300~420g/m2。
The manufacture method of above-mentioned high area density fibre board, in step e, the upper lower platen of hot press is polishing steel plate, and hot pressing pressure is 0.8~1.5MPa, and temperature is 110~180 DEG C, and the time is 10~40s/mm.
The manufacture method of above-mentioned high area density fibre board, in step d, the upper surface of sheet material or lower surface resin added are 100-200g/m2.Resin is made to fill completely in plate surface.
The manufacture method of above-mentioned high area density fibre board, slab is the fibre board of non-sanding after hot pressing cuts, long 2.44m, wide 1.22m, and gauge is 5mm-25mm.
Invention also provides a kind of area density >=1.0g/cm3, surface abrasion resistance reaches more than 6000 turns, and wearability is good, the high area density fibre board that production cost is low.
High area density fibre board of the present invention, it is to be prepared from according to the manufacture method of above-mentioned high area density fibre board.
Accompanying drawing explanation
Fig. 1 is the process chart preparing high area density fibre board of the present invention;
Fig. 2 is that slab drenches glue schematic diagram;
Fig. 3 is the product cross section schematic diagram of high area density fibre board.
In figure, 1 is modified adhesive, and 2 for drenching glue machine schematic diagram, and 3 is the fibre board slab of non-sanding, and 4 is fibreboard surface pre-hardening thickness, and 5 is modified adhesive layer.
Detailed description of the invention
Specific features and the technological means of the present invention is further illustrated below in conjunction with embodiment and accompanying drawing.
Embodiment 1
Surface after hot pressing is had the fibre board slab that thickness is 5mm of pre-hardening thickness 4, cut the slab 3 of rear length and width a size of 2.44m*1.22m, carry out vac sorb dedusting (negative pressure of dust collecting system is-15kPa) by high negative pressure system two surfaces upper and lower to slab.The particle diameter chosen at the inorganic powder silicon dioxide of 90 mesh, during the ratio of 1:10 is mixed into low-molecular-weight melamine resin by mass percentage, after stirring, make modified adhesive 1.Seeing Fig. 2, in slab 3 first surface (i.e. upper surface), (resin added is 300g/m by modified adhesive 1 showering to use pouring glue machine 22);Sending into temperature is to carry out predrying in the drying machine of 80-100 DEG C, makes the slab upper surface hands through drenching glue glue slightly hands when touching;Use same procedure, slab upset is carried out second (i.e. lower surface) showering, predrying, make sheet material second (i.e. lower surface) hands through drenching glue glue slightly hands when touching.The sheet material made a good job of in advance is placed on upper and lower pressing plate be polishing steel plate cold press on flatten so that plate surface density reaches 1.0g/cm3.(resin added is 140g/m to two surface even application modified adhesives again upper and lower to sheet material2), make resin fill completely in plate surface;Being put into by slab after spraying is good makes adhesive solidify in hot press, the upper lower platen in hot press is polishing steel plate, uses the finger gauge of 2mm to carry out sizing hot pressing, and hot pressing temperature is 180 DEG C, and hot pressing time is 100s (20s/mm*5mm).Hot pressing terminate after fibre board material can carry out quality inspection, grade, packing and storing etc., it is prepared as the fibre board of high area density, shown in Figure 3, it includes the fibre board slab 3 with pre-hardening thickness 4, on the upper and lower surface of fibre board slab 3, there is modified adhesive layer 5, modified adhesive layer 5 covers pre-hardening thickness 4, and modified adhesive immerses in pre-hardening thickness 4.
The fibre board that the method is produced, area density reaches 1.0g/cm3, surface abrasion resistance reaches more than 6000 turns, and all other physical mechanics properties are satisfied by respective country standard, can be used as house ornamentation surface lining, packaging material etc..
Embodiment 2
Surface after hot pressing is had the fibre board slab that thickness is 16mm of pre-hardening thickness 4, cut the slab 3 of rear length and width a size of 2.44m*1.22m, carry out vac sorb dedusting (negative pressure of dust collecting system is-20kPa) by high negative pressure system two surfaces upper and lower to slab.The particle diameter chosen at the inorganic powdered material aluminium sesquioxide of 100 mesh, during the ratio of 1:15 is mixed into low-molecular-weight melamine resin by mass percentage, after stirring, make modified adhesive.Seeing Fig. 2, in slab first surface (i.e. upper surface), (resin added is 350g/m by modified adhesive showering to use pouring glue machine2);Sending into temperature is to carry out predrying in the drying machine of 80-100 DEG C, makes the slab upper surface hands through drenching glue glue slightly hands when touching;Use same procedure, slab upset is carried out second (i.e. lower surface) showering, predrying, make sheet material second (i.e. lower surface) hands through drenching glue glue slightly hands when touching.The sheet material made a good job of in advance is placed on upper and lower pressing plate be polishing steel plate cold press on flatten so that plate surface density reaches 1.2g/cm3.(resin added is 180g/m to two surface even application modified adhesives again upper and lower to slab2), make resin fill completely in plate surface;Being put into by slab after spraying is good makes adhesive solidify in hot press, the upper lower platen in hot press is polishing steel plate, uses the finger gauge of 12mm to carry out sizing hot pressing, and hot pressing temperature is 180 DEG C, and hot pressing time is 25s/m.Hot pressing terminate after fibre board material can carry out quality inspection, grade, packing and storing etc., it is prepared as the fibre board of high area density, shown in Figure 3, it includes the fibre board slab 3 with pre-hardening thickness 4, on the upper and lower surface of fibre board slab 3, there is modified adhesive layer 5, modified adhesive layer 5 covers pre-hardening thickness 4, and modified adhesive immerses in pre-hardening thickness 4.
The fibre board that the method is produced, area density reaches 1.2g/cm3, surface abrasion resistance reaches more than 8000 turns, and all other physical mechanics properties are satisfied by respective country standard, can be used as fitment material for family, consolidated floor base material etc..
Embodiment 3
Surface after hot pressing is had the fibre board slab that thickness is 25mm of pre-hardening thickness 4, cut the slab 3 of rear length and width a size of 2.44m*1.22m, carry out vac sorb dedusting (negative pressure of dust collecting system is-20kPa) by high negative pressure system two surfaces upper and lower to slab.The particle diameter chosen at the inorganic powdered material carborundum of 120 mesh, during the ratio of 1:15 is mixed into low-molecular-weight melamine resin by mass percentage, after stirring, make modified adhesive 1.Seeing Fig. 2, in slab 3 first surface (i.e. upper surface), (resin added is 400g/m by modified adhesive 1 showering to use pouring glue machine2);Sending into temperature is to carry out predrying in the drying machine of 80-100 DEG C, makes the slab upper surface hands through drenching glue glue slightly hands when touching;Use same procedure, slab upset is carried out second (i.e. lower surface) showering, predrying, make sheet material second (i.e. lower surface) hands through drenching glue glue slightly hands when touching.The sheet material made a good job of in advance is placed on upper and lower pressing plate be polishing steel plate cold press on flatten so that plate surface density reaches 1.0g/cm3.(resin added is 200g/m to two surface even application modified adhesives again upper and lower to sheet material2), make resin fill completely in plate surface;Being put into by slab after spraying is good makes adhesive solidify in hot press, the upper lower platen in hot press is polishing steel plate, uses the finger gauge of 20mm to carry out sizing hot pressing, and hot pressing temperature is 180 DEG C, and hot pressing time is 30s/m.Hot pressing terminate after fibre board material can carry out quality inspection, grade, packing and storing etc., it is prepared as the fibre board of high area density, shown in Figure 3, it includes the fibre board slab 3 with pre-hardening thickness 4, on the upper and lower surface of fibre board slab 3, there is modified adhesive layer 5, modified adhesive layer 5 covers pre-hardening thickness 4, and modified adhesive immerses in pre-hardening thickness 4.
The fibre board that the method is produced, area density reaches 1.5g/cm3, surface abrasion resistance reaches more than 9000 turns, and all other physical mechanics properties are satisfied by respective country standard, can be used as house ornamentation table top and furniture table, packaging material etc..
In brief, the manufacture method of the present invention is: fibre board blank plate (the length and width a size of 2.44m*1.22m of non-sanding after hot pressing being cut, gauge is 5mm-25mm), carry out vac sorb dedusting (negative pressure of dust collecting system is-10kPa~-20kPa) by high negative pressure system two surfaces upper and lower to slab.By drenching glue machine, by low-molecular-weight resin (Lauxite, melamine resin, phenolic resin or their the modified resin) showering that is mixed with inorganic powdered material, in slab first surface (i.e. upper surface), (resin added is 300-420g/m2);Feeding drying machine is carried out predrying, make the slab upper surface hands through drenching glue glue slightly hands when touching;Upset slab carries out second (i.e. lower surface) showering, predrying, makes sheet material second (i.e. lower surface) hands through drenching glue glue slightly hands when touching;The sheet material made a good job of in advance is placed on cold press and flattens, by adhesive and the fiber compacting in pre-hardening thickness.Pressure of colding pressing selects according to the requirement of area density, it is ensured that area density reaches 1.0g/cm3Above.The upper and lower pressing plate of cold press is polishing steel plate.(resin added is 100-200g/m to two surface even application modified adhesives again upper and lower to sheet material2), make resin fill completely in plate surface;After spraying is good, sheet material is put in hot press and require that carrying out sizing hot pressing makes adhesive solidify the (sheet metal thickness of finger gauge a size of market demands according to finger gauge, hot pressing temperature is 110~180 DEG C, hot pressing time is 10~40s/mm), upper lower platen in hot press is polishing steel plate, to ensure the flat smooth on composite two sides.Fibre board after hot pressing terminates can carry out quality inspection, grade, packs and storage etc., is prepared as high area density fibre board.
Sanding operation during using said method can remove Fibreboard Production from, pre-hardening thickness in Fibreboard Production is made full use of, reduce fiber loss, the high area density fibreboard product being directly produced out, also reduce production cost simultaneously, effectively solve the defect that fiberboard surface-density is little, hardness is low, wear no resistance, can be widely applied to the occasion that such as artifical board material is had higher requirements by construction material, furniture material, flooring material etc..
It is an advantage of the current invention that fibril plate slab need not carry out sand and cut processing, Processes and apparatus is simple, need not fibril board assembly line master operation is adjusted, only the relatively costly sanding operation in fibril board assembly line need to be removed, add dedusting, drench glue, cold pressing, the operation such as hot pressing.The high area density fibre board manufactured by the method, its area density can reach 1.0g/cm3Above, fibre board has the performances such as higher surface abrasion resistance and water resistance simultaneously.This preparation method and prepared product can be substantially improved the comprehensive serviceability of wood materials, reduce production cost, improve technology content and the added value of composite wooden material.