CN102632535B - Preparation method of aldehyde-free artificial board - Google Patents

Abstract

The invention discloses a preparation method of an aldehyde-free artificial board, and belongs to the technical field of wood processing. The invention provides a method for preparing an artificial board by adopting wood raw materials combing with an environment-friendly aldehyde-free adhesive, wherein the wood raw materials are pretreated by a bio-enzyme technology. The preparation process of the artificial board provided by the invention comprises the following steps of: pretreating the wood raw materials used for preparing the artificial board by the bio-enzyme technology; then sizing the treated wood raw materials by adopting the aldehyde-free adhesive; and then carrying out hot-pressing by adopting a two-section-type hot-pressing method, thereby obtaining the artificial board. The preparation method of the aldehyde-free artificial board provided by the invention has the advantages that through the pretreatment on the wood materials by bio-enzyme, the bonding strength of the artificial board is improved obviously, and the using requirements on the adhesive are lowered; formaldehyde-type adhesives are not added in the preparation process, the two-section-type hot-pressing treatment process is matched, the prepared artificial board does not emit free formaldehyde which is harmful to human bodies and the environment in the preparing and using processes, thus the preparation industry of the artificial board can break through the green barrier abroad and develop soundly.

Description

A kind of production method without aldehyde wood-based plate

Technical field

The present invention relates to a kind of production method without aldehyde wood-based plate, belong to wood processing technique field.

Background technology

In recent years, by the impact of timber resources growing tension, the development of China's forestry industry is subject to certain restriction.Development timber high-efficiency comprehensive utilization, makes full use of logging residue, industrial wood waste and inferior timber, is the effective measures solving wood material imbalance between supply and demand.

At present, most widely used in China's Wood-based Panel Production is formaldehyde series adhesive.But use the woodwork that formaldehyde series adhesive glueds joint, inevitably discharge the pernicious gases such as formaldehyde in manufacture and usage process, contaminated environment is also detrimental to health.

Certain progress is obtained recently with the research of the natural reproducible material production wood adhesives such as starch, lignin, tannin.But the application of these environmental-protection type adhesives in Wood-based Panel Production is at present also few, and this is mainly determined by the production technology of current wood-based plate.Existing Wood-based Panel Production technology conveniently applying glue and reduce drying time, require that adhesive solid content is high, viscosity is low and ensure adhesion strength, cause being used alone the impact of these environmental-protection type adhesives by performance or cost, formaldehydes adhesive cannot be substituted completely and be applied to the production of wood-based plate.

Summary of the invention

Technical problem to be solved by this invention is to provide a kind of production method without aldehyde wood-based plate, to solve the problem of the Form aldehyde release harm environmental and human health impacts existed in current wood-based plate manufacturing.

For solving the problems of the technologies described above, technical solution of the present invention is: adopt biological enzyme formulation to process Wood-based Panel Production wood material used, wood material after process is mixed according to a certain percentage with environmental-protection type adhesive, mixes thoroughly and manufactured Board embryo, institute's making sheet embryo being put into hot press adopts two-part pressure sintering to carry out hot pressing, namely obtains made wood-based plate after cooling.

Concrete steps are as follows:

The mass ratio 1: 4-1: 30 of wood material and soak, regulate pH to 3-6, biology enzyme addition 10-80U/g wood material, treatment temperature 30-60 DEG C, processing time 1-3h, the wood material after process after filtering under 60-100 DEG C of condition dry 1-6h obtain wood material pretreatment thing.By without aldehyde environment-friendly adhesive and wood material pretreatment thing in 1: 4-1: 20 ratio fully mix, the hot press warm table being warming up to 140 DEG C-190 DEG C is in advance put into after manufactured Board embryo, first under 6MPa-9MPa, be incubated 2min-5min, then be incubated 2min-5min under improving pressure to 10MPa-14MPa.

Biological enzyme formulation used can be laccase or laccase-medium system, cellulase or cellulose-medium system, lignin peroxidase or lignin peroxidase-medium system, manganese peroxidase or manganese peroxidase medium system and other white rot fungus degrading enzymes or white rot fungus degrading enzyme-medium system.Aldehyde-free cement used can be starch-based glue stick, lignin-base adhesive, tannin base adhesive, protein-base adhesive and other aldehyde-free cements.

The present invention's wood material used is primarily of cellulose, hemicellulose, lignin three kinds of material compositions, wherein cellulose and hemicellulose constitute the basic framework of wood material, lignin is then present between cellulose, hemicellulose and wood material surface, occurs and form parcel to cellulose and hemicellulose with shelly form.

Adopt enzyme preparation provided by the invention to wood material preprocess method, one electron redox reaction can be carried out by phenolic hydroxyl group in catalysis wood material, produce Phenoxy radical and water, make the shelly lignin cover layer degraded of wood material top layer, be conducive to the infiltration of glue, improve the internal bond strength of wood material goods.

Adopt environmental-protection type adhesive of the present invention, can guarantee that wood-based plate is producing and not discharging the free formaldehyde to human body and bad environmental in use procedure, is conducive to the expansion of wood-based plate range of application and the development of wood-processing industry.

Adopt two-part pressure sintering provided by the invention, plate embryo can be made to keep good form in the first stage of hot pressing, avoid causing because pressure is excessive plate embryo to cave in, reach re-set target in the hard-packed size that makes of the artificial intralamellar part of guarantee simultaneously.

Detailed description of the invention

Embodiment 1

The Aspen wood shavings 50g taking particieboard production is placed in 2000mL beaker, adds 1000g water and forms wood shavings-water slurry.Regulate pH to be 4, in above-mentioned suspension, add laccase with the enzyme concentration of 20U/g Aspen wood shavings, above-mentioned suspension is placed in 50 DEG C of water-baths and is incubated 2h, process terminates rear filtering soak, by wood material dry 3h under 60 DEG C of conditions.7g starch adhesive is added in dry backward gained wood shavings, the plate embryo of 8cm × 8cm breadth is made after mixing, plate embryo is put into the hot press being warming up to 170 DEG C in advance, improve pressure be incubated 3min under 8MPa after to 12MPa, after continuing insulation 3min, made particieboard (thickness is 7mm) is taken out and obtains in cooling.Internal bond strength and the expansion rate of water absorption of gained particieboard is measured according to method described in GB/T 17657-1999, result shows that the internal bond strength of made particieboard reaches 0.42MPa and exceedes the 0.4MPa required in particleboard production national standard, expansion rate of water absorption be 7.2% reach require in particleboard production national standard be no more than 8% requirement.

Embodiment 2

Get and produce glued board board using poplar board (thickness 1mm used, breadth 8cm × 8cm) 3 slices (quality 36g), be immersed in 100mL water and regulate pH to 5, to add manganese peroxidase in the enzyme concentration of 30U/g board using poplar board upwards soak, take out, by the board using poplar board dry 3h in 70 DEG C of baking ovens after process after filtering soak after 45 DEG C of insulation 3h.Dried board using poplar board surface is coated the starch adhesive (single spreading) of 0.5mm, the hot press being warming up to 150 DEG C is in advance put into after being stacked by three veneers, improve pressure be incubated 2min under 6MPa after to 11MPa, after continuing insulation 3min, made glued board (thickness 3mm) is taken out and obtains in cooling.Measure the surface bonding intensity of gained glued board with reference to method described in GB/T 9846-2004, the surface bonding intensity that result shows made glued board is that 0.65MPa reaches the requirement being not less than 0.6MPa required in medium-density plate national standard.

Embodiment 3

Take aspen fibers by using silicon 80g, be placed in 2000mL beaker and add 1000mL water, regulating pH to 3.5, in above-mentioned soak, add lignin peroxidase with the enzyme concentration of 40U/g fiber, filtering soak after 50 DEG C of insulation 2h, by the aspen fibers by using silicon dry 2.5h in 80 DEG C of baking ovens after process.9g protein adhesive is added in dry backward gained wood shavings, the plate embryo of 8cm × 8cm breadth is made after mixing, plate embryo is put into the hot press being warming up to 160 DEG C in advance, improve pressure be incubated 3min under 8MPa after to 13MPa, after continuing insulation 4min, institute's fibreboard (thickness is 7mm) is taken out and obtains in cooling.Internal bond strength and the expansion rate of water absorption of gained fiberboard is measured according to method described in GB/T11718-1999, result shows that the internal bond strength of institute's fibreboard reaches 0.62MPa and exceedes the 0.6MPa that in particleboard production national standard, Grade A requires, expansion rate of water absorption be 13.6% reach require in particleboard production national standard be no more than 15% requirement.

Claims (5)

1. the production method without aldehyde wood-based plate, it is characterized in that wood material adds biomass-based aldehyde-free cement and carries out two-part hot pressing production after cellulase treatment, its preparation technology comprises the following steps: be immersed in the water by wood material, regulate soak pH, add enzyme preparation, control soak temperature, after process a period of time, take out the dry Wood-based Panel Production pretreatment thing obtaining wood surface and soften; By above-mentioned pretreatment thing with carry out glue mixing without aldehyde living beings large molecular glue stick according to certain mass ratio, in hot press, adopt two-part pressure sintering to carry out hot pressing production subsequently; The described concrete formula without aldehyde wood-based plate and production method are: the mass ratio of wood material and soak is 1: 4-1: 30, pH is adjusted to 3-6, biology enzyme addition 10-80U/g wood material, treatment temperature 30-60 DEG C, processing time 1-3h, the wood material after process after filtering under 60-100 DEG C of condition dry 1-6h obtain wood material pretreatment thing; By without aldehyde environment-friendly adhesive and wood material pretreatment thing by 1: 4-1: 20 mass ratio fully mix, the hot press warm table being warming up to 140 DEG C-190 DEG C is in advance put into after manufactured Board embryo, first under 6MPa-9MPa, be incubated 2min-5min, then be incubated 2min-5min under improving pressure to 10MPa-14MPa.

2. method according to claim 1, its feature is laccase or laccase-medium system, cellulase or cellulose-medium system, lignin peroxidase or lignin peroxidase-medium system, manganese peroxidase or manganese peroxidase medium system and other white rot fungus degrading enzymes or white rot fungus degrading enzyme-medium system at biological enzyme formulation used, wood material top layer shelly cellulose and lignin cover layer is destroyed by pretreatment, softening wood surface, improves infiltration and the adhesive effect of living beings aldehyde-free cement.

3. method according to claim 1, is characterized in that aldehyde-free cement used is starch-based glue stick, lignin-base adhesive, tannin base adhesive, protein-base adhesive and other large molecular biosciences matter base aldehyde-free cements.

4. method according to claim 1, the two-part hot pressing that building board production process adopts is produced, it is characterized in that plate embryo first hot pressing a period of time at lower pressures, after adhesive segment solidification, raise hot pressing pressure, make plate embryo hot repressing a period of time at a higher pressure.

5. method according to claim 1, is characterized in that the production being applied to particieboard, fiberboard, glued board, core-board.