A process for producing a non-formaldehyde peeled full poplar shaving board

Abstract

The present application provides a kind of aldehyde-free peeling full poplar shaving board production process.The present application is by the core layer material poplar shaving of shaving board table different size complex, especially the addition of 0.4-0.6mm thin shaving, improves the shaving form, for reducing the shaving board density, reduces deformation, improves the condition of static bending strength and improves the edge compactness, combined with PMDI adhesive, and the waterproof agent and the deodorizing agent are modified treatment, under the process condition of keeping aldehyde-free addition, the static bending strength of shaving board is improved, and the density is as low as 600kg / m 3 , and reduces water absorption thickness expansion rate, improves moisture resistance, so as to obtain aldehyde-free peeling full poplar low-density high-strength shaving board.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of artificial board, and particularly relates to a formaldehyde-free peeling full poplar shaving board production process. BACKGROUND

[0002] The shaving board is a kind of artificial board material which is cut into a certain specification of fragments from raw materials such as wood, dried, mixed with adhesives, additives and the like, and pressed at a certain temperature. The raw material source of the shaving board is very extensive, the amount of glue used in the production process is small, the product has the characteristics of great strength and high stability, and has very broad development space in China. The adhesives of the shaving board are mostly urea-formaldehyde resin glue and phenol-formaldehyde resin glue. The aldehyde adhesive has good gluing effect on various plant materials such as straw and rice husk, the hot-pressing temperature is not high, and therefore is widely used in production, but has the disadvantage of releasing free formaldehyde to pollute the environment and harm the health of users; the mechanical properties of the shaving board are poor, the static bending strength is not high, and the bending resistance is significantly reduced after bearing, so that a reinforcing member is needed to assist in improving the bearing capacity; in addition, since the main material of the shaving board is wood, it is easy to absorb water and be damp, which causes the internal compacted part of the shaving board to easily expand and scatter, resulting in damage to the entire board. In summary, the existing shaving board has single performance, and cannot achieve low density, high moisture resistance and no deformation in furniture door surface, wall cabinet integration and decoration scene, and the performance in strength, odor, moisture resistance and bearing capacity is not as expected by the market.

[0003] Therefore, how to improve the static bending strength of the shaving board during use, expand the application scene, and reduce the water absorption thickness expansion rate and improve the moisture resistance while maintaining the non-formaldehyde release of the shaving board through innovative process and material selection, and meet the increasing demand for high-quality and environmentally friendly shaving boards in the market, has become a direction that needs to be focused on. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application aims to provide a formaldehyde-free peeling full poplar shaving board production process, which aims to solve the problems of single performance, poor mechanical properties, low static bending strength, difficulty in achieving low density and high strength of the existing shaving board, and easy water absorption and dampness, and insufficient moisture resistance.

[0005] The present application improves the shavings form by compounding different sizes of shavings of the core layer material of the shaving board, especially the addition of 0.4-0.6mm thin shavings, creates conditions for reducing the density of the shaving board, reducing deformation, improving the static bending strength and improving the edge compactness, combines with the PMDI adhesive, and modifies the waterproof agent and the odor removal agent, produces under the process condition of maintaining formaldehyde-free addition, improves the static bending strength of the shaving board while the density is as low as 600kg / m³, reduces the water absorption thickness expansion rate, improves the moisture-proof performance, and thus obtains the formaldehyde-free peeling full poplar low-density high-strength shaving board.

[0006] The technical scheme of the present application is as follows:

[0007] A formaldehyde-free peeling full poplar shaving board production process comprises the following preparation steps:

[0008] Step S1: preparing a surface layer material and a core layer material, the surface layer material comprising a first surface layer material and a second surface layer material, the first surface layer material being 20 parts of poplar shavings, the second surface layer material being 20 parts of poplar shavings, and the core layer material being 24 parts of poplar shavings I and 36 parts of poplar shavings II;

[0009] Step S2: separately gluing the surface layer material and the core layer material in step S1, uniformly mixing the surface layer material, PMDI, acidified paraffin and odor removal agent in a first mixer to obtain a glued surface layer material, and uniformly mixing the core layer material, PMDI, amidated paraffin and odor removal agent in a second mixer to obtain a glued core layer material;

[0010] Step S3: laying the glued surface layer material in step S2 to form a first board blank surface layer, laying a board blank core layer on the first board blank surface layer, and laying a second board blank surface layer on the side of the board blank core layer away from the first board blank surface layer to obtain a board blank;

[0011] Step S4: pre-pressing the board blank using a pre-pressing machine, and continuously flat pressing the pre-pressed board blank using a continuous flat pressing machine to obtain a formaldehyde-free peeling full poplar shaving board.

[0012] The following is a preferred technical scheme of the present application, but is not a limitation on the technical scheme provided by the present application. Through the following preferred technical scheme, the purpose and beneficial effects of the present application can be better achieved and realized.

[0013] As a preferred technical scheme of the present application, the poplar shavings I and the poplar shavings II are obtained by mechanical processing of poplar shavings, the thickness of the poplar shavings I is 0.4mm, and the length is 45mm; the thickness of the poplar shavings II is 0.6mm, and the length is 45mm.

[0014] The volume of the poplar shaving I is relatively larger, and can act as a main support of the shaving board, the poplar shaving II is small in size and is easy to compress, and can fill the gap position of the main support, so as to make the internal pore of the sample board smaller, the combination between the shavings is more compact, the modified wax is used to effectively reduce the density of the shaving board, and the static bending strength and the edge compactness are improved, and the water absorption thickness expansion rate of the shaving board is reduced.

[0015] As a preferred technical scheme of the present application, the preparation method of the acidified wax is as follows: 100 parts of emulsified wax is added into a reaction kettle with a stirrer and heated to 150 DEG C; then 20 parts of maleic anhydride is added, and stirred uniformly under nitrogen protection; then 10 parts of dibenzoyl peroxide is added, the temperature is controlled at 180 DEG C, and reaction is carried out for 1 h; and after purification, the acidified wax is obtained.

[0016] As a preferred technical scheme of the present application, the preparation method of the amide modified wax is as follows: 100 parts of emulsified wax and 200 parts of toluene are added into a reaction kettle with a stirrer and heated to 90 DEG C, and stirred for 0.5 h; 5 parts of ethylenediamine is added into 10 parts of benzene sulfonic acid solution (20% of mass fraction concentration), and stirred uniformly to obtain an amide modification reagent; 20 parts of the amide modification reagent is added into the reaction kettle, and stirred for 3 h under the condition that the temperature is 100 DEG C; after the reaction is completed, condensation and separation are carried out, and the amide modified wax is obtained.

[0017] The maleic anhydride groups of the acidified wax in the surface layer can react with the isocyanate groups of the PMDI, the PMDI in the core layer reacts with the amide modified wax to generate a urea compound, and the maleic anhydride groups of the modified wax in the surface layer and the amino groups of the modified wax in the core layer undergo cyclization reaction, a three-dimensional network structure is formed through the modified wax as a bridge, and the surface layer and the core layer are penetrated, so that the physical properties such as the static bending strength of the shaving board are significantly improved; meanwhile, the modified wax belongs to a hydrophobic substance, and the network structure formed by the modified wax can also block water, so that the water is prevented from entering the pores of the shavings, and the moisture resistance of the shaving board is improved.

[0018] As a preferred technical scheme of the present application, the deodorant is a nano metal-containing deodorant; and the preparation method of the nano metal-containing deodorant is as follows: 80 parts of deionized water is added into a reactor, the temperature is adjusted to 70 DEG C, 15 parts of polyethylene glycol is added, and stirred for 0.5 h; the temperature is lowered to 40 DEG C, 5 parts of alpha-cyclodextrin dissolving agent is added, stirred uniformly, and then 3 parts of zinc ricinoleate is added, and stirred at a speed of 4000 r / min for 1 h; the temperature is controlled to 50 DEG C, 10 parts of nano zinc oxide is added, and stirred at a speed of 4000 r / min for 0.5 h, the temperature is lowered to 25 DEG C, 3 parts of dodecyl dimethyl benzyl ammonium bromide is added, and stirred uniformly to obtain the nano metal-containing deodorant.

[0019] The nano zinc oxide in the deodorant has good heat conduction performance, and the high thermal conductivity enables it to effectively transfer heat, so that the surface layer material and the core layer material are evenly heated, which is more conducive to the reaction of isocyanate, and the full reaction of the PMDI adhesive improves the strength of the shaving board.

[0020] Preferably, the PMDI is added in an amount of 25 kg / m³, the acidified paraffin is added in an amount of 6 kg / m³, the amidated paraffin is added in an amount of 7 kg / m³, and the deodorant is added in an amount of 1 kg / m³ in the sizing of step S2.

[0021] Preferably, the water content of the first plate blank surface layer and the second plate blank surface layer is 17%, and the water content of the plate blank core layer is 4% in step S3.

[0022] Preferably, the thickness of the first plate blank surface layer and the second plate blank surface layer is 2-3 mm, and the thickness of the plate blank core layer is 4-8 mm in step S3.

[0023] Preferably, the pre-pressed plate blank is uniformly passed through the first zone, the second zone, the third zone and the fourth zone in sequence in step S4 when the continuous flat press machine continuously presses the pre-pressed plate blank; the maximum pressure of the first zone is controlled to be 500 N / cm 2 , and the temperature is 240℃; the maximum pressure of the second zone is controlled to be 400 N / cm 2 , and the temperature is 230℃; the maximum pressure of the third zone is controlled to be 200 N / cm 2 , and the temperature is 220℃; the maximum pressure of the fourth zone is controlled to be 200 N / cm 2 , and the temperature is 200℃; and the operating pressure of the hydraulic system of the continuous flat press machine is controlled to be 300 bar.

[0024] Compared with the prior art, the present application has the following beneficial effects:

[0025] (1) The present application uses PMDI adhesive and continuous flat pressing of peeled poplar shaving to produce a three-layer structure, through innovative process and material selection, with the addition of 0.4-0.6 mm thin shaving, the shaving form is improved, the internal pores of the sample board are made smaller, the combination between the shavings is more compact, the shaving board density is effectively reduced, the static bending strength is improved, and the edge compactness is improved, the process is produced under the condition of no formaldehyde addition, the no-formaldehyde peeled full poplar low-density high-strength shaving board is obtained, which meets the growing demand for high-quality and environmentally friendly shaving board on the market.

[0026] (2) The present application improves the internal bonding strength, increases the modulus of rupture, and reduces the water thickness swelling rate of the shaving board by compounding different sizes of shavings; the modified paraffin forms a three-dimensional interconnected network structure and penetrates the surface layer and the core layer, significantly improving the physical properties such as the modulus of rupture of the shaving board; in addition, the modified paraffin forms a three-dimensional interconnected network structure and penetrates the surface layer and the core layer, significantly improving the physical properties such as the modulus of rupture of the shaving board; the nanometer metal-containing odor removal agent effectively transfers heat to facilitate the reaction of isocyanate, and the sufficient reaction of the PMDI adhesive improves the strength of the shaving board. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of the present application, the present application lists the following examples. Those skilled in the art should understand that the examples are only to help understand the present application, and should not be regarded as specific limitations on the present application.

[0028] Some components in the examples and comparative examples are as follows:

[0029] Shavings: poplar shavings, purchased from Wanhua Jingzhou Company; poplar shavings I, obtained by mechanical processing (thickness of 0.4 mm, length of 45 mm); poplar shavings II, obtained by mechanical processing (thickness of 0.6 mm, length of 45 mm).

[0030] Adhesive: PMDI adhesive, purchased from Wanhua Chemical Group Co., Ltd.; urea-formaldehyde resin adhesive, purchased from Zibo Huasen Adhesive Co., Ltd.

[0031] Paraffin wax: emulsified paraffin wax, purchased from Hansheng Group (solid content of 42%).

[0032] Preparation of acidified paraffin wax: 100 parts of emulsified paraffin wax (purchased from Hansheng Group) were added to a reaction kettle with a stirrer, heated to 150℃; then 20 parts of maleic anhydride (CAS No. 108-31-6) were added, stirred uniformly under nitrogen protection; then 10 parts of dibenzoyl peroxide (CAS No. 94-36-0) were added, the temperature was controlled at 180℃, and the reaction was carried out for 1h, and after purification, acidified paraffin wax was obtained.

[0033] Preparation of amidated paraffin wax: 100 parts of emulsified paraffin wax (purchased from Hansheng Group) and 200 parts of toluene (CAS No. 108-88-3) were added to a reaction kettle with a stirrer and heated to 90℃, and stirred for 0.5h; 5 parts of ethylenediamine (CAS No. 107-15-3) were added to 10 parts of a 20% mass fraction concentration of benzenesulfonic acid solution (benzenesulfonic acid CAS No. 3453-84-7), and stirred uniformly to obtain an amidation reagent; 20 parts of the amidation reagent were added to the reaction kettle, and stirred at a temperature of 100℃ for 3h; after the reaction was completed, condensation and separation were carried out to obtain amidated paraffin wax.

[0034] Preparation of nanometal-containing deodorant: 80 parts of deionized water was added into a reactor, the temperature was adjusted to 70°C, 15 parts of polyethylene glycol (CAS No. 25322-68-3) was added, and stirred for 0.5 h; the temperature was lowered to 40°C, 5 parts of α-cyclodextrin (CAS No. 51211-51-9) dissolving agent was added, stirred uniformly, then 3 parts of zinc ricinoleate (CAS No. 13040-19-2) was added, stirred at a speed of 4000 r / min for 1 h; the temperature was controlled at 50°C, 10 parts of nanometer zinc oxide (CAS No. 1314-13-2) was added, stirred at a speed of 4000 r / min for 0.5 h, the temperature was lowered to 25°C, 3 parts of dodecyl dimethyl benzyl ammonium bromide (CAS No. 7281-04-1) was added, stirred uniformly to obtain a nanometal-containing deodorant.

[0035] Example 1

[0036] The present embodiment provides a formaldehyde-free peeling full poplar shaving board production process, comprising the following steps:

[0037] Step S1: preparing a surface layer material and a core layer material, the surface layer material comprises a first surface layer material and a second surface layer material, the first surface layer material is 20 parts of poplar shaving, the second surface layer material is 20 parts of poplar shaving, and the core layer material is 24 parts of poplar shaving I and 36 parts of poplar shaving II;

[0038] Step S2: separately sizing the surface layer material and the core layer material in step S1, uniformly mixing the surface layer material, PMDI adhesive, acidified paraffin, and nanometal-containing deodorant in a first stirrer to obtain sized surface layer material, and uniformly mixing the core layer material, PMDI adhesive, amidated paraffin, and nanometal-containing deodorant in a second stirrer to obtain sized core layer material; the addition amount of PMDI in sizing is 25 kg / m³, the addition amount of acidified paraffin is 6 kg / m³, the addition amount of amidated paraffin is 7 kg / m³, and the addition amount of deodorant is 1 kg / m³;

[0039] Step S3: laying the sized surface layer material in step S2 to form a first board blank surface layer, laying a board blank core layer on the first board blank surface layer, and laying a second board blank surface layer on the side of the board blank core layer away from the first board blank surface layer to obtain a board blank; the moisture content of the first board blank surface layer and the second board blank surface layer is controlled to be 17%, and the moisture content of the board blank core layer is 4%; the thickness of the first board blank surface layer and the second board blank surface layer is 3 mm, and the thickness of the board blank core layer is 8 mm;

[0040] Step S4: pre-pressing the board blank using a pre-pressing machine, continuously flat pressing the pre-pressed board blank using a continuous flat pressing machine, and making the pre-pressed board blank pass through a first zone, a second zone, a third zone, and a fourth zone in sequence at a uniform speed; the maximum pressure of the first zone is controlled to be 500 N / cm 2, the maximum pressure of the second zone is 400 N / cm 2 , the maximum pressure of the third zone is 200 N / cm 2 , the maximum pressure of the fourth zone is 200 N / cm 2 , the maximum pressure of the fourth zone is 200 N / cm

[0041] Example 2

[0042] The present example provides a process for producing a non-formaldehyde peeled full poplar shaving board, comprising the following steps:

[0043] Step S1: preparing a surface layer material and a core layer material, the surface layer material comprises a first surface layer material and a second surface layer material, the first surface layer material is 20 parts of poplar shavings, the second surface layer material is 20 parts of poplar shavings, and the core layer material is 24 parts of poplar shavings I and 36 parts of poplar shavings II;

[0044] Step S2: separately sizing the surface layer material and the core layer material in step S1, uniformly mixing the surface layer material, PMDI adhesive, acidified paraffin, and nanometer metal-containing odor-removing agent in a first mixer to obtain sized surface layer material, and uniformly mixing the core layer material, PMDI adhesive, amidated paraffin, and nanometer metal-containing odor-removing agent in a second mixer to obtain sized core layer material; the addition amount of PMDI in sizing is 25 kg / m³, the addition amount of acidified paraffin is 6 kg / m³, the addition amount of amidated paraffin is 7 kg / m³, and the addition amount of odor-removing agent is 1 kg / m³;

[0045] Step S3: laying the sized surface layer material in step S2 to form a first board blank surface layer, laying a board blank core layer on the first board blank surface layer, and laying a second board blank surface layer on the side of the board blank core layer away from the first board blank surface layer to obtain a board blank; the moisture content of the first board blank surface layer and the second board blank surface layer is controlled to be 17%, and the moisture content of the board blank core layer is 4%; the thickness of the first board blank surface layer and the second board blank surface layer is 2 mm, and the thickness of the board blank core layer is 4 mm;

[0046] Step S4: pre-pressing the board blank using a pre-pressing machine, and continuously pressing the pre-pressed board blank using a continuous press machine, so that the pre-pressed board blank uniformly and at a constant speed passes through a first zone, a second zone, a third zone, and a fourth zone in sequence; the maximum pressure of the first zone is controlled to be 500 N / cm 2 , the maximum pressure of the second zone is 400 N / cm 2 , the maximum pressure of the third zone is 200 N / cm 2 , the maximum pressure of the fourth zone is 200 N / cm2 temperature is 200℃; the hydraulic system operating pressure of the continuous press is controlled at 300bar; after continuous pressing, a full poplar shaving board without formaldehyde and peeled is obtained.

[0047] Example 3

[0048] The embodiment provides a full poplar shaving board without formaldehyde and peeled production process, which comprises the following steps:

[0049] Step S1: preparing a surface layer material and a core layer material, wherein the surface layer material comprises a first surface layer material and a second surface layer material, the first surface layer material is 20 parts of poplar shavings, the second surface layer material is 20 parts of poplar shavings, and the core layer material is 24 parts of poplar shavings I and 36 parts of poplar shavings II;

[0050] Step S2: separately sizing the surface layer material and the core layer material in step S1, uniformly mixing the surface layer material, a PMDI adhesive, acidified paraffin and a nano-metal deodorant-containing agent in a first mixer to obtain sized surface layer material, and uniformly mixing the core layer material, a PMDI adhesive, amidated paraffin and a nano-metal deodorant-containing agent in a second mixer to obtain sized core layer material; the addition amount of PMDI in sizing is 25 kg / m³, the addition amount of acidified paraffin is 6 kg / m³, the addition amount of amidated paraffin is 7 kg / m³, and the addition amount of deodorant is 1 kg / m³;

[0051] Step S3: laying the sized surface layer material in step S2 to form a first board blank surface layer, laying a board blank core layer on the first board blank surface layer, and laying a second board blank surface layer on the side of the board blank core layer away from the first board blank surface layer to obtain a board blank; the moisture content of the first board blank surface layer and the second board blank surface layer is controlled at 17%, and the moisture content of the board blank core layer is 4%; the thickness of the first board blank surface layer and the second board blank surface layer is 3 mm, and the thickness of the board blank core layer is 7 mm;

[0052] Step S4: pre-pressing the board blank using a pre-pressing machine, continuously pressing the pre-pressed board blank using a continuous press, and making the pre-pressed board blank pass through a first zone, a second zone, a third zone and a fourth zone at a uniform speed; the maximum pressure of the first zone is controlled at 500 N / cm 2 , the temperature is 240℃; the maximum pressure of the second zone is 400 N / cm 2 , the temperature is 230℃; the maximum pressure of the third zone is 200 N / cm 2 , the temperature is 220℃; the maximum pressure of the fourth zone is 200 N / cm 2 , the temperature is 200℃; the hydraulic system operating pressure of the continuous press is controlled at 300bar; after continuous pressing, a full poplar shaving board without formaldehyde and peeled is obtained.

[0053] Example 4

[0054] This embodiment provides a production process for formaldehyde-free peeled poplar particleboard. The only difference from Embodiment 1 is that the 24 parts of poplar shavings I and 36 parts of poplar shavings II in the core layer are replaced with 60 parts of poplar shavings. Everything else is the same as in Embodiment 1.

[0055] Example 5

[0056] This embodiment provides a production process for formaldehyde-free peeled poplar particleboard. The only difference from Embodiment 1 is that the surface acidified paraffin wax is replaced with emulsified paraffin wax, and the core amide paraffin wax is replaced with emulsified paraffin wax. Everything else is the same as in Embodiment 1.

[0057] Example 6

[0058] This embodiment provides a production process for formaldehyde-free peeled poplar particleboard. The only difference from Embodiment 1 is that the nano-metal deodorizer is replaced with a zinc ricinoleate solution (4% by mass) deodorizer. Otherwise, it is the same as Embodiment 1.

[0059] Comparative Example 1

[0060] This comparative example provides a particleboard manufacturing process, including the following steps:

[0061] Step S1: Prepare surface material and core material. The surface material includes a first surface material and a second surface material. The first surface material is 20 parts poplar wood shavings, the second surface material is 20 parts poplar wood shavings, and the core material is 60 parts poplar wood shavings.

[0062] Step S2: Apply adhesive to the surface material and core material described in Step S1. In a first mixer, uniformly mix the surface material, urea-formaldehyde resin adhesive, emulsified paraffin wax, zinc ricinoleate solution (4% by mass concentration), and deodorizing agent to obtain the adhesive surface material. In a second mixer, uniformly mix the core material, urea-formaldehyde resin adhesive, emulsified paraffin wax, and zinc ricinoleate solution (4% by mass concentration) and deodorizing agent to obtain the adhesive core material. The amount of urea-formaldehyde resin adhesive added during adhesive application is 25 kg / m³, the amount of emulsified paraffin wax added is 6 kg / m³, and the amount of deodorizing agent added is 1 kg / m³.

[0063] Step S3: The adhesive surface material described in step S2 is laid to form a first slab surface layer. A slab core layer is laid on the first slab surface layer. A second slab surface layer is laid on the side of the slab core layer away from the first slab surface layer to obtain a slab. The moisture content of the first and second slab surface layers is controlled at 17%, and the moisture content of the slab core layer is controlled at 4%. The thickness of the first and second slab surface layers is 3 mm, and the thickness of the slab core layer is 8 mm.

[0064] Step S4: pre-pressing the slab using a pre-press, continuously flat pressing the pre-pressed slab using a continuous flat press, and making the pre-pressed slab pass through the first zone, the second zone, the third zone and the fourth zone at a constant speed in sequence; controlling the maximum pressure of the first zone to be 500 N / cm 2 and the temperature to be 240℃; the maximum pressure of the second zone to be 400 N / cm 2 and the temperature to be 230℃; the maximum pressure of the third zone to be 200 N / cm 2 and the temperature to be 220℃; the maximum pressure of the fourth zone to be 200 N / cm 2 and the temperature to be 200℃; controlling the operating pressure of the hydraulic system of the continuous flat press to be 300 bar; and obtaining an aldehyde-free peeled full poplar shaving board after continuous flat pressing.

[0065] Comparative Example 2

[0066] The comparative example provides a shaving board production process, which is different from comparative example 1 only in that the acidified paraffin wax is used to replace the emulsified paraffin wax in the surface layer.

[0067] Comparative Example 3

[0068] The comparative example provides a shaving board production process, which is different from comparative example 1 only in that the amide paraffin wax is used to replace the emulsified paraffin wax in the core layer.

[0069] The performance of the shaving boards provided by the above examples and comparative examples is tested, and the testing method is as follows:

[0070] Formaldehyde emission: tested according to the requirements of “GB 18580-2017 Indoor Decoration and Refurbishment Materials Limit of Formaldehyde Emission in Artificial Boards and Their Products”.

[0071] Static bending strength: tested according to the requirements of “GB / T 4897-2015 Shaving Board”.

[0072] Water absorption thickness expansion rate: tested according to the requirements of “GB / T 4897-2015 Shaving Board”.

[0073] Density: tested according to the requirements of “GB / T 17657-2013 Test Methods for Physical and Chemical Properties of Artificial Boards and Veneered Artificial Boards”.

[0074] The performance test data are shown in Table 1.

[0075] Table 1 Performance Test Results

[0076]

[0077] From the above, the present application obtains formaldehyde-free peeled whole poplar shaving board (Example 1-3) by compounding poplar shavings of different sizes in the surface and core layer of the shaving board, combining with PMDI adhesive, and modifying waterproof agent and odor removal agent, no formaldehyde release is detected, the static bending strength is 20.1-20.3 MPa, the water absorption thickness expansion rate is 2.2-2.4%, and the density is 600 kg / m3.

[0078] Compared with Example 1, if 24 parts of poplar shaving I and 36 parts of poplar shaving II are not used in the core layer, the static bending strength decreases, the water absorption thickness expansion rate increases, and the density increases (Example 4); compared with Example 1, if acidified paraffin is not used in the surface layer and amide paraffin is not used in the core layer, the static bending strength decreases and the water absorption thickness expansion rate increases (Example 5); compared with Example 1, if the nano-metal odor removal agent is not used, the static bending strength decreases (Example 6).

[0079] Comparative Example 1 does not use the technical innovation points of the present application, the formaldehyde release of the shaving board is 0.128 mg / m 3 , the static bending strength is 15.1 MPa, the water absorption thickness expansion rate is 5.2%, and the density is 650 kg / m3; compared with Comparative Example 1, if acidified paraffin is used in the surface layer, the static bending strength increases (Comparative Example 2); compared with Comparative Example 1, if amide paraffin is used in the core layer, the static bending strength increases (Comparative Example 3).

[0080] In summary, the present application improves the shaving form by compounding poplar shavings of different sizes in the surface and core layer of the shaving board, especially the addition of 0.4-0.6 mm thin shavings, which creates conditions for reducing the density of the shaving board, reducing deformation, improving the static bending strength and improving the edge compactness, combines with PMDI adhesive, and modifies the waterproof agent and odor removal agent, and the shaving board is produced under the process conditions of maintaining formaldehyde-free addition, which improves the static bending strength of the shaving board while the density is as low as 600 kg / m3, reduces the water absorption thickness expansion rate, improves the moisture resistance, and thus obtains formaldehyde-free peeled whole poplar low-density high-strength shaving board.

[0081] The applicant declares that the present application is illustrated by the above examples to explain the detailed process flow of the present application, but the present application is not limited to the above detailed process flow, that is, it does not mean that the present application must rely on the above detailed process flow to be implemented. It should be understood by those skilled in the art that any improvement of the present application, equivalent replacement of each raw material of the product of the present application, addition of auxiliary ingredients, selection of specific modes, etc. fall within the protection scope and disclosure scope of the present application.

Claims

1. A process for producing an aldehyde-free peeled full poplar flake board, characterized by, The preparation steps include the following steps: Step S1: preparing a surface layer material and a core layer material, the surface layer material includes a first surface layer material and a second surface layer material, the first surface layer material is 20 parts of poplar shavings, the second surface layer material is 20 parts of poplar shavings, and the core layer material is 24 parts of poplar shavings I and 36 parts of poplar shavings II; Step S2: separately gluing the surface layer material and the core layer material in step S1, uniformly mixing the surface layer material, PMDI, acidified paraffin wax and odor removal agent in a first mixer to obtain a glued surface layer material, and uniformly mixing the core layer material, PMDI, amidated paraffin wax and odor removal agent in a second mixer to obtain a glued core layer material; Step S3: laying the glued surface layer material in step S2 to form a first board blank surface layer, laying a board blank core layer on the first board blank surface layer, and laying a second board blank surface layer on the side of the board blank core layer away from the first board blank surface layer to obtain a board blank; Step S4: pre-pressing the board blank using a pre-pressing machine and continuously flat pressing the pre-pressed board blank using a continuous flat pressing machine to obtain a formaldehyde-free peeling full-poplar shavings board; The poplar shavings I and the poplar shavings II are obtained by mechanically processing poplar shavings, the poplar shavings I have a thickness of 0.4 mm and a length of 45 mm, and the poplar shavings II have a thickness of 0.6 mm and a length of 45 mm; The preparation method of the acidified paraffin wax is as follows: 100 parts of emulsified paraffin wax is added to a reaction kettle with a stirrer and heated to 150℃; then 20 parts of maleic anhydride is added, and the mixture is stirred uniformly under nitrogen protection; then 10 parts of dibenzoyl peroxide is added, the temperature is controlled at 180℃, and the mixture is reacted for 1 h; and after purification, the acidified paraffin wax is obtained; The preparation method of the amidated paraffin wax is as follows: 100 parts of emulsified paraffin wax and 200 parts of toluene are added to a reaction kettle with a stirrer and heated to 90℃, and the mixture is stirred for 0.5 h; 5 parts of ethylenediamine is added to 10 parts of benzenesulfonic acid solution, and the mixture is stirred uniformly to obtain an amidation reagent; 20 parts of the amidation reagent is added to the reaction kettle, and the mixture is stirred and reacted for 3 h at a temperature of 100℃; after the reaction is completed, the mixture is condensed and separated to obtain the amidated paraffin wax; The odor removal agent is a nano-metal-containing odor removal agent, and the preparation method of the nano-metal-containing odor removal agent is as follows: 80 parts of deionized water is added to a reactor, the temperature is adjusted to 70℃, 15 parts of polyethylene glycol is added, and the mixture is stirred for 0.5 h; the temperature is lowered to 40℃, 5 parts of α-cyclodextrin dissolving agent is added, and the mixture is stirred uniformly, then 3 parts of zinc ricinoleate is added, and the mixture is stirred at a speed of 4000 r / min for 1 h; the temperature is controlled at 50℃, 10 parts of nano-zinc oxide is added, and the mixture is stirred at a speed of 4000 r / min for 0.5 h; the temperature is lowered to 25℃, 3 parts of dodecyl dimethyl benzyl ammonium bromide is added, and the mixture is stirred uniformly to obtain the nano-metal-containing odor removal agent.

2. A process for producing an aldehyde-free peeled full poplar shaving board according to claim 1, characterized in that, In the gluing in step S2, the addition amount of PMDI is 25 kg / m³, the addition amount of acidified paraffin wax is 6 kg / m³, the addition amount of amidated paraffin wax is 7 kg / m³, and the addition amount of odor removal agent is 1 kg / m³.

3. A process for producing an aldehyde-free peeled full poplar flake board according to claim 1, characterized in that, In step S3, the moisture content of the first board blank surface layer and the second board blank surface layer is 17%, and the moisture content of the board blank core layer is 4%.

4. A process for producing an aldehyde-free peeled full poplar flake board according to claim 1, characterized in that, The thickness of the first slab surface layer and the second slab surface layer in the step S3 is 2-3 mm, and the thickness of the slab core layer is 4-8 mm.

5. A process for producing an aldehyde-free peeled full poplar flake board according to claim 1, characterized in that, The continuously flat pressing machine in the step S4 continuously flat presses the pre-pressed plate blank, and the pre-pressed plate blank uniformly passes through the first zone, the second zone, the third zone and the fourth zone in sequence; the maximum pressure of the first zone is controlled to be 500 N / cm 2 , and the temperature is 240℃; the maximum pressure of the second zone is controlled to be 400 N / cm 2 , and the temperature is 230℃; the maximum pressure of the third zone is controlled to be 200 N / cm 2 , and the temperature is 220℃; the maximum pressure of the fourth zone is controlled to be 200 N / cm 2 , and the temperature is 200℃; and the operating pressure of the hydraulic system of the continuously flat pressing machine is controlled to be 300 bar.

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