CN114890759B

CN114890759B - 3D printing light material containing wood aggregate and preparation method and application thereof

Info

Publication number: CN114890759B
Application number: CN202210621220.0A
Authority: CN
Inventors: 陈明旭; 李秋义; 王亮; 岳公冰; 郭远新
Original assignee: Qingdao Agricultural University
Current assignee: Qingdao Agricultural University
Priority date: 2022-06-01
Filing date: 2022-06-01
Publication date: 2023-03-17
Anticipated expiration: 2042-06-01
Also published as: CN114890759A

Abstract

The invention discloses a 3D printing light material containing wood aggregate and application thereof, wherein the material comprises the following raw materials: 60-100 parts of gelled base material, 5-20 parts of wood aggregate, 5-15 parts of stabilizer, 0.3-1.0 part of assistant and 30-45 parts of water. The wood aggregate is composed of a wood inner core and a coating layer coated on the surface of the wood inner core, and the coating layer comprises the following components: cement binding material: nano-materials: micro-nano material: micron material: butanediol dimethacrylate = 60-100 parts by weight: 5-15 parts by weight: 5-20 parts by weight: 0.1-0.4 parts by weight: 0.1 to 0.3 weight portion. According to the technical scheme, the structural stability of the 3D printing material is effectively improved by using the modified waste wood material, so that the printing material has excellent continuity and bonding performance required by 3D printing.

Description

3D printing light material containing wood aggregate and preparation method and application thereof

Technical Field

The invention relates to the technical field of 3D printing building materials, in particular to a 3D printing light material containing wood aggregate and application thereof.

Background

The information in this background section is only for enhancement of understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.

The intelligent manufacturing technology can greatly improve the production efficiency of products as an innovative preparation method and an innovative technical means, realizes the informationization, digitization and intelligent manufacturing of the products based on a computer, and is successfully applied to the fields of chemistry, special equipment, aerospace, high polymer, automation and the like. And 3D printing technology has begun to be gradually applied to the field of civil engineering as a new green smart manufacturing technology. Compared with the traditional construction preparation technology, the building material 3D printing technology not only can obviously reduce the construction cost, save materials and improve the construction speed, but also can avoid the pollution of building dust and building rubbish.

However, the 3D printing technology for building materials still has the following problems: (1) The dispersibility, uniformity and stability of the 3D printing paste are poor, and the performance of the 3D printed product is seriously affected. (2) The printable performance of 3D printing paste is difficult to accurately evaluate and regulate, and the forming quality and the structural accuracy of printed products are poor. (3) The interlayer interface and defects of the 3D printed concrete product are difficult to regulate, so that the durability is poor, and the practical application is difficult.

Disclosure of Invention

Aiming at the problems, the invention provides a 3D printing light material containing wood aggregate and a preparation method and application thereof. To achieve the above object, the technical solution of the present invention is as follows.

In a first aspect of the invention, a 3D printing lightweight material containing wood aggregate is disclosed, and the material comprises the following raw materials in parts by weight:

the wood aggregate comprises a wood core and a coating layer coated on the surface of the wood core, wherein the coating layer comprises the following components: cement binding material: nano materials: micro-nano material: micron material: butanediol dimethacrylate = 60-100 parts by weight: 0.1-0.4 parts by weight: 5-20 parts by weight: 5-15 parts by weight: 0.1 to 0.3 weight portion.

Further, the cement-binding material comprises: sulphoaluminate cement, portland cement, high belite sulphoaluminate cement, sulphate-resistant portland cement and the like.

Further, the nano material comprises at least one of nano montmorillonite, nano silica and nano calcium carbonate.

Further, the micro-nano material comprises silica fume and fly ash, and the mass ratio of the micro-nano material to the fly ash is 1: 1-2, and the particle size range of the micro-nano material is 0.1-10 mu m.

Further, the micron material comprises mineral powder and fly ash, and the mass ratio of the micron material to the fly ash is 1-3: 1, and the particle size of the micron material is in the range of 10-100 mu m.

In the invention, the surface of the wooden core is coated with the coating layer containing the micro-nano material, so that the bonding property and rheological property of the coating slurry can be effectively improved, and the slurry can be more easily coated on the surface of the wooden core. Simultaneously, through can also improving wooden aggregate with compatibility and matching nature between the gelatinization substrate change the contact surface of cement-based material and wooden aggregate into the contact between the cement-based material, eliminate the concrete interface transition district.

Further, the preparation method of the wood aggregate comprises the following steps:

(1) The wood material is crushed into grains to prepare the wood kernel for standby.

(2) Uniformly mixing the coating layer component with a liquid component to prepare a coating slurry for later use, wherein the liquid component comprises: 35 to 45 weight portions of water, 0.1 to 0.3 weight portion of butylene glycol dimethacrylate and 0.1 to 0.4 weight portion of water reducing agent.

(3) And coating the pulp coating material on the surface of the wood kernel and then drying to obtain the wood aggregate.

Further, in the step (1), the particle diameter of the wood core ranges from 0.5 mm to 5mm, and the wood core contributes to improving the viscoelastic property of the 3D printing concrete.

Further, in the step (3), the drying temperature is 50-70 ℃ and the drying time is 1-2 h.

Further, step (1) also includes a process for modifying the wood core, including:

(i) And infiltrating the wood kernel with a mixed solution of polyvinyl alcohol and methanol, and drying the wood kernel to obtain the first-level modified wood kernel.

(ii) And adding the first-stage modified wood kernel into acrylic acid derivatives, styrene and ethanol, soaking under a vacuum condition, adding an initiator after the soaking is finished, and continuing to perform polymerization reaction under the vacuum condition to obtain a second-stage modified wood kernel.

(iii) And adding the secondary modified wood kernel into a mixed solution of triethylene glycol and epoxy vinyl resin for reaction to obtain the modified wood kernel.

(iv) And coating the modified wood kernel with the coating slurry, and drying to obtain the wood aggregate.

Further, in the step (i), the volume ratio of the polyvinyl alcohol to the methanol is in the range of 1. Optionally, the polyvinyl alcohol has a molecular weight of 1000 to 2000. The wood kernel is infiltrated by adopting the mixed liquid of the polyvinyl alcohol and the methanol, so that the inflation effect can be realized in the wood kernel, and the dimensional stability of the wood material is kept.

Further, in the step (i), the drying temperature is 40-60 ℃ and the drying time is 2-3 h.

In step (ii), the mass ratio of the acrylic acid derivative, styrene and ethanol is 1. Optionally, the acrylic acid derivative comprises: methyl methacrylate, ethyl methacrylate, butyl methacrylate, and the like. The modification of the step can lead the surface of the wood kernel to generate polymerization reaction, fill the pores on the surface of the wood kernel and improve the mechanical property of the wood aggregate.

Further, in the step (ii), the soaking time is 20-30 minutes, and the influence of oxygen and carbon dioxide in air can be avoided under the vacuum condition.

Further, in step (ii), the initiator comprises: potassium persulfate, dibenzoyl peroxide, and the like.

Further, in the step (ii), the reaction temperature is 100-120 ℃, and the reaction time is 3-6 h.

Further, in the step (iii), the mass ratio of the glycol to the epoxy vinyl resin is in the range of 1 to 2. Epoxy vinyl ester resin is a high performance thermosetting resin prepared by reacting epoxy resin with methacrylic acid and adding styrene monomer.

Further, in the step (iii), the reaction time is 1 to 2 hours. In the invention, after the secondary modified wood kernel is modified by epoxy vinyl resin, the bonding capability between the surface of the wood kernel and the coating layer can be effectively improved, and the coating layer is prevented from falling off.

Further, the gel base material is a composite gel material consisting of sulphoaluminate cement and ordinary portland cement. Preferably, the mass ratio of the sulphoaluminate cement to the ordinary portland cement is 1:1 to 2.

Further, the stabilizing agent consists of superfine quartz sand, vermiculite and diatomite. Preferably, the mass ratio of the superfine quartz sand to the vermiculite to the diatomite is 2-3: 1:1. more preferably, the superfine quartz sand consists of two grades of quartz sand of 50-100 μm and 100-200 μm, and the ratio of the two grades of quartz sand is 1:1 to 2. In the invention, the stability of the printing slurry in the printing process can be effectively improved by the incorporation of the stabilizer, the extrusion port blockage phenomenon is avoided, and the extrudability and the continuity of the printing slurry are improved. Meanwhile, the mixing of the stabilizer can avoid the occurrence of slurry sedimentation after printing, and the stability of the printing structure is improved.

Further, the auxiliary agent comprises: 0.1 to 0.4 weight portion of thickening agent, 0.1 to 0.2 weight portion of retarder and 0.1 to 0.4 weight portion of water reducing agent.

Further, the thickener includes: at least one of magnesium aluminum silicate, hydroxypropyl methylcellulose ether and kaolin, preferably the thickener is prepared from magnesium aluminum silicate, hydroxypropyl methylcellulose ether and kaolin according to the weight ratio of 1:1 to 2:1, in terms of mass ratio. In the invention, the internal friction force among particles in the slurry is improved through the composite thickening agent, the stability and the structural precision of the printing slurry are improved, and the slurry segregation and bleeding in the printing process can be prevented.

Further, the water reducing agent includes at least two of lignosulfonate, aliphatic series and polycarboxylic acid series.

Further, the retarder includes: tartaric acid, polyvinyl alcohol, and/or gluconic acid.

Further, the 3D printing lightweight material containing the wood aggregate further comprises 1-2 parts by weight of modified wood fiber.

Further, the preparation method of the modified wood fiber comprises the following steps:

(I) Crushing the wood material, soaking in water, collecting the deposited wood material, and drying for later use.

(II) the wood material obtained in the step (I) is boiled and softened, then polyvinyl alcohol and ethylene monomers are added to react under the heating condition, and after the reaction is finished, fiber separation treatment is carried out, and the wood fiber is obtained after drying.

Further, in the step (I), after the crushed wooden material is placed in water, the crushed wooden material is stirred for 5-10 min and then is kept stand for 30min or more, and soluble substances and light components in the wooden material are removed.

Further, in the step (I), the drying temperature is 50-60 ℃, and the drying time is 5-6 h. Preferably, heavy components such as metals in the wood material are removed by air-flow sorting after drying.

Further, in the step (II), the water boiling softening treatment time is 25-40 min. In the present invention, the wooden material can be macerated by the poaching softening treatment to facilitate defibration and loosening.

Further, in the step (II), the mass ratio of the polyvinyl alcohol to the vinyl monomer is 1:1 to 3. In the invention, polyvinyl alcohol and ethylene monomers are adopted to modify the surface of the wood fiber, which is beneficial to improving the bonding and mechanical properties with the gelled base material.

Alternatively, the vinylic monomer comprises any of acrylic acid, acrylamide, and the like.

Further, in the step (II), the length of the wood fiber is 1-9 mm.

Furthermore, the wood material for preparing the wood aggregate and the modified wood fiber can be waste wood materials, such as wood boards, modified wood fiber boards and the like, so as to achieve the purpose of high value-added utilization of wood wastes.

In a second aspect of the present invention, there is provided a method for preparing the 3D printing material containing wood aggregate, comprising the steps of:

s1, uniformly mixing the gelled base material, the stabilizing agent and the wood aggregate to obtain a solid mixture for later use.

S2, dissolving the auxiliary agent in water to obtain a liquid mixture for later use.

And S3, sequentially adding the liquid mixture into the solid mixture, and uniformly mixing to obtain the 3D printing material containing the wood aggregate.

Further, step S2 includes a step of adding the modified wood fiber to the liquid mixture.

In a third aspect of the invention, the application of the 3D printing lightweight material containing wood aggregate in the field of building engineering is disclosed, such as the fields of 3D printing large-sized profiled components, lightweight building materials and 3D printing decorative materials.

Compared with the prior art, the technical scheme provided by the invention at least has the following beneficial effects:

(1) According to the invention, the wood aggregate is added into the 3D printing material, so that the structural stability of the printed concrete can be obviously improved. The reason for this is that: the wood core of the wood aggregate has a large amount of hydrophilic surface groups, and the hydrophilic surface groups can absorb a large amount of free water in the printing slurry, so that the internal friction force among particles in the slurry is improved, the viscoelastic property of the 3D printing material is improved, and the 3D printing material has excellent continuity and bonding property required by 3D printing.

(2) The invention also carries out three-step modification treatment on the wood kernel of the wood aggregate, thereby achieving the purposes of easier material wrapping and mechanical property improvement, and the reason is that: (1) The modified materials (polyvinyl alcohol and methanol) are filled in the wooden core through infiltration to play a role of inflation, the dimensional stability of the wooden material is kept, the surface state of the wooden core can be greatly improved, the water absorption rate is optimized, and the structural deformation is reduced. (2) Acrylic acid derivatives and styrene are introduced to enable the surface of the wood kernel to generate polymerization reaction, so that pores on the surface of the wood kernel are filled, and the mechanical property of the wood aggregate is improved; (3) After the modified wood kernel is modified by adopting the epoxy vinyl resin, the bonding capability between the surface of the wood kernel and the coating layer can be effectively improved, and the falling-off of the coating layer on the surface of the aggregate is prevented; finally, the printing structure and the mechanical property of the lightweight concrete are improved. In addition, the wood aggregate is added into the 3D printing material, so that the unit mass of the 3D printing material can be greatly reduced.

(3) The wood aggregate adopted by the invention is prepared based on a pulp wrapping method, namely the surface of the wood core is coated with a coating layer to form a core-shell type wood aggregate. The coating layer composed of special components can effectively improve the compatibility, cohesiveness and matching property between the wood aggregate and the gelled base material, so that the contact surface between the gelled base material and the wood aggregate is converted into the contact between the gelled base materials, the transition area of the concrete interface is eliminated, and the mechanical property of the 3D printing lightweight concrete is improved.

(4) According to the invention, the modified lignocellulose is added into the 3D printing material, so that the structural stability and the mechanical property of the 3D printing material can be obviously improved. The reason for this is that: the modified lignocellulose has a large amount of hydrophilic surface groups, so that a large amount of free water in printing slurry is absorbed, the rheological property of 3D printing concrete is improved, and the deformation rate of a printing structure is obviously reduced. Meanwhile, in the preparation process of the lignocellulose, the surface of the lignocellulose is grafted with the monomers by adopting the polyvinyl alcohol and the ethylene monomers, so that the bonding and mechanical properties with the gelled base material are effectively improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. Embodiments of the invention are described in detail below with reference to the attached drawing figures, wherein:

fig. 1 is a graph of the effect of a sized wood aggregate prepared in the following first example.

Fig. 2 is a graph showing the effects of the modified lignocellulose prepared in the following fifth example.

Fig. 3 is a graph showing the effect of a 3D printed sample of a 3D printed lightweight material containing wood aggregate prepared in the following first example.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The experimental procedures, in which specific conditions are not noted in the following examples, are generally carried out according to conventional conditions or according to conditions recommended by the manufacturers.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The reagents or starting materials used in the present invention can be purchased from conventional sources, and unless otherwise specified, the reagents or starting materials used in the present invention can be used in a conventional manner in the art or in accordance with the product specification. In addition, any methods and materials similar or equivalent to those described herein can be used in the methods of the present invention. The preferred methods and materials described in this invention are exemplary only.

The 3D printing lightweight material containing wood aggregate of the invention will be further described in detail by combining the drawings in the specification and some preferred embodiments.

First embodiment

1. The preparation method of the wood aggregate comprises the following steps:

(1) Preparing a wood kernel: the waste wood boards are crushed into particles, the particles are screened after the crushing, the obtained wood particles are washed with water and dried, and the wood kernel with the particle diameter of 0.5-1 mm is obtained for later use.

(2) Preparing wrapping slurry: mixing sulphoaluminate cement and nano material: micro-nano material: the micron material comprises the following components in parts by weight of 70: 0.25 parts by weight: 17 parts by weight: adding the 10 parts by weight of the components into the liquid component, and stirring for 20min to obtain the coating slurry. Wherein:

the nano material is nano montmorillonite. The micro-nano material is prepared from silica fume and fly ash according to the weight ratio of 1:1, and the particle size of the mixture is 0.1-10 μm. The micron material is prepared from mineral powder and fly ash according to the weight ratio of 1:1, and the particle size of the mixture is 10-100 μm.

The liquid component consists of the following components: 41 parts of water, 0.2 part of butanediol dimethacrylate and 0.25 part of polycarboxylic acid water reducing agent.

(6) And (3) coating the aggregate with slurry: and (3) immersing the modified wood aggregate prepared in the step (4) into the pulp wrapping material obtained in the step (5), so that the pulp wrapping material is wrapped on the surface of the modified wood aggregate to form a wrapping layer, controlling the average thickness of the wrapping layer to be 2mm through multiple wrapping, and drying to obtain the wood aggregate (shown in figure 1) for later use.

2. The preparation method of the 3D printing lightweight material containing the wood aggregate comprises the following steps:

(i) Preparing the following raw materials (in parts by weight):

wherein: the composite cementing material is prepared from sulphoaluminate cement and ordinary portland cement according to the weight ratio of 1:2, and mixing the components in a mass ratio. The stabilizer is prepared from superfine quartz sand, vermiculite and diatomite according to the weight ratio of 3:1:1, wherein the superfine quartz sand is prepared by mixing quartz sand with grain sizes of 50-100 microns and 100-200 microns according to a ratio of 1:1, and mixing the components in a mass ratio of 1. The thickening agent is prepared from magnesium aluminum silicate, hydroxypropyl methyl cellulose ether and kaolin according to the weight ratio of 1:2:1, and mixing the components in a mass ratio of 1.

(ii) And mixing the composite cementing material, the stabilizing agent and the wood aggregate, and stirring for 30min to obtain a solid mixture for later use.

(iii) And dissolving the water reducing agent, the retarder and the thickening agent in the water, and then uniformly stirring to obtain a liquid mixture for later use.

(iv) And adding the liquid mixture into the solid mixture, and stirring for 20min to obtain the 3D printing lightweight material containing the wood aggregate.

Second embodiment

1. A preparation method of modified wood aggregate comprises the following steps:

(1) Preparing a wood kernel: crushing the waste wood boards into particles, screening after the particles are finished, washing the obtained wood particles with water, and drying to obtain wood kernels with the particle diameters of about 1-3 mm for later use.

(2) Modifying the surface of the inner core: and (2) dipping the wood kernel obtained in the step (1) into a mixed solution of polyvinyl alcohol (with molecular weight of 1500) and methanol according to a volume ratio of 1. And after the completion, taking out the wood kernel, and drying the wood kernel for 2.5 times at 50 ℃ to obtain the first-grade modified wood aggregate for later use.

(3) Adding the first-stage modified wood aggregate into a mixed solution formed by ethyl methacrylate, styrene and ethanol according to a molar ratio of 1.

(4) And adding the secondary modified wood aggregate into a mixed solution formed by triethylene glycol and epoxy vinyl resin (the viscosity is 800mPa & s, the solid content is 66%) according to the mass ratio of 1.

(5) Preparing wrapping slurry: mixing sulphoaluminate cement and nano material: micro-nano material: the micron material comprises the following components in parts by weight: 0.25 parts by weight: 17 parts by weight: adding the 10 parts by weight of the components into the liquid component, and stirring for 20min to obtain the coating slurry. Wherein:

the nano material is nano montmorillonite. The micro-nano material is prepared from silica fume and fly ash according to the ratio of 1:1, and the particle size of the mixture is 0.1-10 mu m. The micron material is prepared from mineral powder and fly ash according to the weight ratio of 1:1, and the particle size of the mixture is 10-100 mu m.

The liquid component consists of the following components: 41 parts by weight of water; 0.2 part by weight of butylene glycol dimethacrylate; 0.25 part by weight of polycarboxylic acid water reducing agent.

(6) And (3) coating the aggregate with slurry: and (3) immersing the modified wood aggregate prepared in the step (4) into the pulp wrapping material obtained in the step (5), so that the pulp wrapping material is wrapped on the surface of the modified wood aggregate to form a wrapping layer, controlling the average thickness of the wrapping layer to be 2mm through multiple wrapping, and drying to obtain the modified wood aggregate for later use.

2. The preparation method of the 3D printing lightweight material containing the modified wood aggregate comprises the following steps:

(i) Preparing the following raw materials (in parts by weight):

(ii) And mixing the composite cementing material, the stabilizer and the modified wood aggregate, and stirring for 30min to obtain a solid mixture for later use.

(iv) And adding the liquid mixture into the solid mixture, and stirring for 20min to obtain the 3D printing lightweight material containing the modified wood aggregate.

Third embodiment

1. The preparation method of the modified wood aggregate comprises the following steps:

(2) Modifying the surface of the inner core: and (2) dipping the wood kernel obtained in the step (1) into a mixed solution of polyvinyl alcohol (molecular weight is 1000) and methanol according to a volume ratio of 1. And after the completion, taking out the wood kernel, and drying the wood kernel for 2 times at 60 ℃ to obtain the first-grade modified wood aggregate for later use.

(3) Adding the first-stage modified wood aggregate into a mixed solution formed by propyl methacrylate, styrene and ethanol according to a molar ratio of 1.

(5) Preparing wrapping slurry: mixing Portland cement, nano materials: micro-nano material: the micron material comprises the following components in parts by weight: 0.4 part by weight: 20 parts by weight: adding 15 parts by weight of the components into the liquid component, and stirring for 30min to obtain the coating slurry. Wherein:

the nano material is nano silicon dioxide. The micro-nano material is prepared from silica fume and fly ash according to the weight ratio of 1:2, the particle size of the mixture is 0.1-10 μm. The micron material is prepared from mineral powder and fly ash according to the ratio of 3:1, and the particle size of the mixture is 10-100 mu m.

The liquid component consists of the following components: 45 parts of water; 0.25 part by weight of butanediol dimethacrylate; 0.4 part of polycarboxylic acid water reducing agent.

(i) The following raw materials (parts by weight) are prepared:

wherein: the composite cementing material is prepared from sulphoaluminate cement and ordinary portland cement according to the weight ratio of 1:1, and mixing the components in a mass ratio of 1. The stabilizer is prepared from superfine quartz sand, vermiculite and diatomite according to the weight ratio of 2:1:1, wherein the superfine quartz sand is prepared by mixing quartz sand with grain sizes of 50-100 microns and 100-200 microns according to a ratio of 1:2, and mixing the components in a mass ratio. The thickening agent is prepared from magnesium aluminum silicate, hydroxypropyl methyl cellulose ether and kaolin according to the weight ratio of 1:1:1, and mixing the components in a mass ratio of 1.

(iv) And adding the liquid mixture into the solid mixture, and stirring for 25min to obtain the 3D printing lightweight material containing the modified wood aggregate.

Fourth embodiment

(1) Preparing a wood kernel: the waste wood boards are crushed into particles, the particles are screened after the crushing, the obtained wood particles are washed with water and dried, and the wood kernel with the particle diameter of about 3-5 mm is obtained for later use.

(2) Modifying the surface of the inner core: and (2) dipping the wood kernel obtained in the step (1) into a mixed solution formed by polyvinyl alcohol (molecular weight is 2000) and methanol according to a volume ratio of 1. And taking out the wood kernel after the completion, and drying the wood kernel at 40 ℃ for 3 hours to obtain the first-grade modified wood aggregate for later use.

(3) Adding the first-stage modified wood aggregate into a mixed solution formed by methyl methacrylate, styrene and ethanol according to a molar ratio of 1.

(4) And adding the secondary modified wood aggregate into a mixed solution formed by triethylene glycol and epoxy vinyl resin (the viscosity is 700mPa & s, the solid content is 70%) according to the mass ratio of 1.4.

(5) Preparing wrapping slurry: mixing high belite sulphoaluminate cement and a nano material: micro-nano material: the micron material is prepared from the following components in parts by weight: 0.1 part by weight: 5 parts by weight: adding the 5 parts by weight of the components into the liquid component, and stirring for 20min to obtain the coating slurry. Wherein:

the nano material is nano calcium carbonate. The micro-nano material is prepared from silica fume and fly ash according to the weight ratio of 1:1.7, and the particle size of the mixture is 0.1-10 μm. The micron material is prepared from mineral powder and fly ash according to the ratio of 2:1, and the particle size of the mixture is 10-100 μm.

The liquid component consists of the following components: 35 parts by weight of water; 0.1 part by weight of butanediol dimethacrylate; 0.1 part by weight of polycarboxylic acid water reducing agent.

(i) Preparing the following raw materials (in parts by weight):

wherein: the composite cementing material is prepared from sulphoaluminate cement and ordinary portland cement according to the weight ratio of 1:1.6 in mass ratio. The stabilizer is prepared from superfine quartz sand, vermiculite and diatomite according to the weight ratio of 2.5:1:1, wherein the superfine quartz sand is prepared by mixing quartz sand with grain sizes of 50-100 microns and 100-200 microns according to a ratio of 1:1, and mixing the components in a mass ratio of 1. The thickening agent is prepared from magnesium aluminum silicate, hydroxypropyl methyl cellulose ether and kaolin according to the weight ratio of 1:1.5:1, and mixing the components in a mass ratio of 1.

Fifth embodiment

The preparation of the 3D printing lightweight material containing the modified wood aggregate is different from the second embodiment in the following steps: the liquid mixture in step (iii) further comprises modified lignocellulose. Specifically, the preparation method of the modified lignocellulose of the embodiment is as follows:

(I) And (3) putting the modified wood fiberboard into a crusher to be crushed for 10min to obtain the waste wood material.

(II) soaking the waste wood material into water, stirring for 10min at the rotating speed of 30rpm, standing for precipitation for 30min, removing upper solution and light components, collecting the waste wood material precipitated at the lower part, drying the waste wood material at 60 ℃ for 5 hours, and removing heavy components such as metal in the waste wood material through air flow separation to obtain the separated waste wood material for later use.

(III) placing the sorted waste wood materials in water, heating and boiling for 25min to perform water boiling softening treatment, adding polyvinyl alcohol and acrylic acid monomer (mass ratio = 1), boiling and reacting for 10min, and obtaining modified wood materials for later use.

(VI) defibrating the modified wood material by a mill and then drying at 50 ℃ for 1.5 hours to obtain modified wood fibers having a length of between 1 and 9mm (as shown in FIG. 2).

Sixth embodiment

The preparation of the 3D printing lightweight material containing the modified wood aggregate is different from the second embodiment in the following steps: the liquid mixture in step (iii) further comprises modified lignocellulose. Specifically, the preparation method of the modified lignocellulose of this embodiment is as follows:

(I) And (3) putting the modified wood fiberboard into a crusher to be crushed for 10min, so as to obtain the waste wood material.

(II) soaking the waste wood material into water, stirring at the rotating speed of 30rpm for 10min, standing for precipitation for 40min, removing upper solution and light components, collecting the waste wood material precipitated at the lower part, drying at 50 ℃ for 6 hours, and removing heavy components such as metals in the waste wood material through air flow separation to obtain the separated waste wood material for later use.

(III) placing the sorted waste wood materials in water, heating and boiling for 40min to perform water boiling softening treatment, adding polyvinyl alcohol and acrylamide monomer (mass ratio =1 = 3) to perform boiling reaction for 10min, and obtaining modified wood materials for later use.

(VI) defibrating the modified wood material by a mill and then drying at 50 ℃ for 1.5 hours to obtain modified wood fibers having a length of between 1 and 9mm.

Seventh embodiment

A preparation of a 3D printing material, which is different from the first embodiment in that: and sand aggregate is adopted to replace the wood aggregate.

Eighth embodiment

(3) And adding the secondary modified wood aggregate into a mixed solution formed by triethylene glycol and epoxy vinyl resin (the viscosity is 800mPa & s, the solid content is 66%) according to the mass ratio of 1.

(4) Preparing wrapping slurry: mixing sulphoaluminate cement and nano material: micro-nano materials: the micron material comprises the following components in parts by weight: 0.25 parts by weight: 17 parts by weight: adding the 10 parts by weight of the components into the liquid component, and stirring for 20min to obtain the coating slurry. Wherein:

the nano material is nano montmorillonite. The micro-nano material is prepared from silica fume and fly ash according to the weight ratio of 1:1, and the particle size of the mixture is 0.1-10 mu m. The micron material is prepared from mineral powder and fly ash according to the weight ratio of 1:1, and the particle size of the mixture is 10-100 μm.

(5) And (3) coating the aggregate with slurry: and (5) immersing the modified wood aggregate prepared in the step (3) into the pulp wrapping material obtained in the step (4), so that the pulp wrapping material is wrapped on the surface of the modified wood aggregate to form a wrapping layer, controlling the average thickness of the wrapping layer to be 2mm through multiple wrapping, and drying to obtain the modified wood aggregate for later use.

2. Preparation of a 3D printed lightweight material containing modified wood aggregate, as in the second example, differs: the modified wood aggregate prepared by the embodiment is adopted.

Ninth embodiment

(1) Preparing a wood kernel: the waste wood boards are crushed into particles, the particles are screened after the crushing, the obtained wood particles are washed with water and dried, and the wood kernel with the particle diameter of about 1-3 mm is obtained for later use.

(2) Modifying the surface of the inner core: and (2) dipping the wooden kernel obtained in the step (1) into a mixed solution formed by polyvinyl alcohol (molecular weight is 1000) and methanol according to a volume ratio of 1. And after the completion, taking out the wood kernel, and drying the wood kernel for 2 times at 60 ℃ to obtain the first-grade modified wood aggregate for later use.

(3) And adding the first-stage modified wood aggregate into a mixed solution formed by triethylene glycol and epoxy vinyl resin (the viscosity is 800mPa & s, the solid content is 66%) according to the mass ratio of 1.

(4) Preparing wrapping slurry: mixing Portland cement, nano materials: micro-nano materials: the micron material comprises the following components in parts by weight: 0.4 part by weight: 20 parts by weight: adding 15 parts by weight of the components into the liquid component, and stirring for 30min to obtain the coating slurry. Wherein:

the nano material is nano silicon dioxide. The micro-nano material is prepared from silica fume and fly ash according to the weight ratio of 1:2, and the particle size of the mixture is 0.1 to 10 μm. The micron material is prepared from mineral powder and fly ash according to the ratio of 3:1, and the particle size of the mixture is 10-100 mu m.

(5) And (3) coating the aggregate with slurry: and (3) immersing the modified wood aggregate prepared in the step (3) into the pulp wrapping material obtained in the step (4), so that the pulp wrapping material is wrapped on the surface of the modified wood aggregate to form a wrapping layer, controlling the average thickness of the wrapping layer to be 2mm through multiple wrapping, and drying to obtain the modified wood aggregate for later use.

2. Preparation of a 3D printed lightweight material containing modified wood aggregate, as in the third example, differs: the modified wood aggregate prepared by the embodiment is adopted.

Tenth embodiment

(1) Preparing a wood kernel: crushing the waste wood boards into particles, screening after the particles are finished, washing the obtained wood particles with water, and drying to obtain wood kernels with the particle diameters of about 3-5 mm for later use.

(2) Modifying the surface of the inner core: and (2) dipping the wood kernel obtained in the step (1) into a mixed solution formed by polyvinyl alcohol (molecular weight is 2000) and methanol according to a volume ratio of 1. And after the completion, taking out the wood kernel, and drying the wood kernel for 3 times at 40 ℃ to obtain the first-grade modified wood aggregate for later use.

(4) Preparing wrapping slurry: mixing high belite sulphoaluminate cement and nano materials: micro-nano material: the micron material is prepared from the following components in parts by weight: 0.1 part by weight: 5 parts by weight: adding the 5 parts by weight of the components into the liquid component, and stirring for 20min to obtain the coating slurry. Wherein:

the nano material is nano calcium carbonate. The micro-nano material is prepared from silica fume and fly ash according to the weight ratio of 1:1.7, and the particle size of the mixture is 0.1-10 μm. The micron material is prepared from mineral powder and fly ash according to the weight ratio of 2:1, and the particle size of the mixture is 10-100 mu m.

The liquid component consists of the following components: 35 parts by weight of water; 0.1 part by weight of butylene glycol dimethacrylate; 0.1 part by weight of a polycarboxylic acid water reducing agent.

(5) And (3) coating the aggregate with slurry: and (3) immersing the secondary modified wood aggregate prepared in the step (3) into the pulp wrapping material obtained in the step (4), so that the pulp wrapping material is wrapped on the surface of the modified wood aggregate to form a wrapping layer, controlling the average thickness of the wrapping layer to be 2mm through multiple wrapping, and drying to obtain the modified wood aggregate for later use.

2. Preparation of a 3D printing lightweight material containing modified wood aggregate, which is different from the fourth embodiment in that: the modified wood aggregate prepared by the embodiment is adopted.

Eleventh embodiment

1. A method for preparing wood aggregate comprises the steps of crushing waste wood boards into particles, screening after the crushing is finished, washing the obtained wood particles with water, and drying to obtain a wood target with the particle diameter of 0.5-1 mm.

2. Preparation of a 3D printing lightweight material containing wood aggregate, which is different from the first embodiment in that: the wood aggregate prepared by the embodiment is adopted.

Performance test

Test pieces (as shown in fig. 3, which is a 3D printing sample diagram of the 3D printing lightweight material prepared in the first embodiment) were prepared from the 3D printing lightweight material prepared in each of the above-described examples by using a 3D printing technique, and then the test pieces were tested for the respective performance indexes, with the results as shown in tables 1 and 2 below. Wherein the viscoelastic modulus is measured using a Haake Mars 40 rheometer from Sammerfeil. The flexural strength and the compressive strength are obtained by testing with an American MTS universal tester. And calculating the average deformation of the 3D printing structure deformation rate in the three XYZ directions after the printing slurry is stable. And drying the test piece for 2 hours at the dry density of 100 +/-5 ℃, printing the mass of the test piece in unit volume, and weighing and calculating to obtain the test piece.

TABLE 1

Example number	First of all	Second one	Third step	Fourth step of	Fifth aspect of the invention	Sixth aspect of the invention
							Modulus of elasticity/Pa	65268	94812	96167	94205	99718	99125
Viscous modulus/Pa	26159	51897	52791	50663	53854	53016
							Structural deformation rate/%)	10.91	6.21	5.13	6.44	6.08	6.03
Compressive strength/MPa (3 d)	20.64	25.18	28.49	23.22	25.71	25.39
							Flexural strength/MPa (3 d)	3.13	3.97	4.54	4.26	4.98	4.92
Dry density/kg/m ³	1653	1707	1756	1792	1706	1723

TABLE 2

Example number	Seventh, a	Eighth item	Ninth item	Tenth item	Eleven points of the design
						Modulus of elasticity/Pa	156329	89624	93211	87094	12568
Viscous modulus/Pa	103659	47132	48369	42265	95224
						Structural deformation rate/%)	15.32	7.65	6.57	8.31	10.32
Compressive strength/MPa (3 d)	35.64	24.06	26.32	23.05	15.32
						Flexural strength/MPa (3 d)	4.99	3.59	4.01	3.92	2.65
Dry density/kg/m ³	2106	1712	1755	1788	1563

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The 3D printing lightweight material containing wood aggregate is characterized by comprising the following raw materials in parts by weight:

a gel base material: 60 to 100 parts;

wood aggregate: 5 to 20 parts;

a stabilizer: 5 to 15 parts;

auxiliary agent: 0.3 to 1.0 part

Water: 30 to 45 parts;

the wood aggregate is composed of a wood inner core and a coating layer coated on the surface of the wood inner core, and the coating layer comprises the following components: cement binding material: nano materials: micro-nano material: micron material: butanediol dimethacrylate =60 to 100 parts by weight: 0.1 to 0.4 parts by weight: 5 to 20 parts by weight: 5 to 15 parts by weight: 0.1 to 0.3 weight part;

the preparation method of the wood aggregate comprises the following steps:

(1) Crushing and granulating a wood material to prepare a wood kernel for later use;

(i) Soaking the wood kernel with a mixed solution of polyvinyl alcohol and methanol, and drying the wood kernel after the soaking treatment is finished to obtain a first-level modified wood kernel;

(ii) Adding the first-stage modified wood kernel into acrylic acid derivatives, styrene and ethanol, infiltrating under a vacuum condition, adding an initiator after the first-stage modified wood kernel is soaked, and continuing to perform a polymerization reaction under the vacuum condition to obtain a second-stage modified wood kernel;

(iii) Adding the secondary modified wood kernel into a mixed solution of triethylene glycol and epoxy vinyl resin for reaction to obtain a modified wood kernel;

(2) Uniformly mixing the coating layer component with a liquid component to prepare a coating slurry for later use, wherein the liquid component comprises: 35 to 45 parts of water, 0.1 to 0.3 part of butylene glycol dimethacrylate and 0.1 to 0.4 part of a water reducing agent;

(3) Coating the coating slurry on the surface of the modified wood kernel and then drying to obtain wood aggregate;

in the step (1), the diameter range of the particle of the wooden core is 0.5 to 5mm;

in the step (3), the drying temperature is 50 to 70 ℃, and the time is 1 to 2h;

the cement gelling material comprises: any one of sulphoaluminate cement and portland cement;

the nano material comprises at least one of nano montmorillonite, nano silica and nano calcium carbonate;

the micro-nano material comprises silica fume and fly ash, and the mass ratio of the micro-nano material to the fly ash is 1:1 to 2, and the diameter range of the micro-nano material particles is 0.1 to 10 mu m;

the micron material comprises mineral powder and fly ash, and the mass ratio of the micron material to the fly ash is 1-3: 1, and the particle size range of the micron material is 10 to 100 mu m.

2. The 3D printing lightweight material containing wood aggregate according to claim 1, wherein in the step (i), the volume ratio of the polyvinyl alcohol to the methanol is 1 to 2.

3. The 3D printing lightweight material containing wood aggregate according to claim 2, wherein the molecular weight of the polyvinyl alcohol is 1000 to 2000.

4. The 3D printing lightweight material containing the wood aggregate as claimed in claim 1, wherein in the step (i), the drying temperature is 40 to 60 ℃ and the drying time is 2 to 3 hours.

5. The 3D printing lightweight material containing wood aggregate according to claim 1, wherein in the step (ii), the mass ratio of the acrylic acid derivative, the styrene and the ethanol is in a range from 1.

6. The wood aggregate containing 3D printing lightweight material according to claim 5, wherein the acrylic acid derivative comprises: any one of methyl methacrylate, ethyl methacrylate and butyl methacrylate.

7. The 3D printing lightweight material containing wood aggregate according to claim 1, wherein in the step (ii), the infiltration time is 20 to 30 minutes.

8. The 3D printing lightweight material containing wood aggregate according to claim 1, wherein in the step (ii), the initiator comprises: potassium persulfate, or dibenzoyl peroxide.

9. The 3D printing lightweight material containing wood aggregate according to claim 1, wherein in the step (ii), the reaction temperature is 100 to 120 ℃, and the reaction time is 3 to 6h.

10. The 3D printing lightweight material containing wood aggregate according to claim 1, wherein in the step (iii), the mass ratio of the triethylene glycol to the epoxy vinyl resin is in the range of 1 to 2:1.

11. the 3D printing lightweight material containing wood aggregate as claimed in claim 1, wherein in the step (iii), the reaction time is 1 to 2h.

12. The 3D printing lightweight material containing wood aggregate according to claim 1, wherein the cementitious matrix is a composite cementitious material consisting of sulphoaluminate cement and ordinary portland cement.

13. The 3D printing lightweight material containing wood aggregate according to claim 1, wherein the mass ratio of the sulphoaluminate cement to the ordinary portland cement is 1:1 to 2.

14. The wood aggregate-containing 3D printing lightweight material as claimed in claim 1, wherein the stabilizer is composed of ultra-fine quartz sand, vermiculite and diatomite.

15. The 3D printing lightweight material containing wood aggregate according to claim 14, wherein the mass ratio of the superfine quartz sand to the vermiculite to the diatomite is 2 to 3:1:1.

16. the 3D printing lightweight material containing wood aggregate according to claim 14, wherein the superfine quartz sand consists of quartz sand of two grades of 50-100 μm and 100-200 μm, and the ratio of the two grades of quartz sand is 1:1 to 2.

17. The 3D printing lightweight material containing wood aggregate according to claim 1, wherein the auxiliary agent comprises: 0.1 to 0.4 weight part of thickening agent, 0.1 to 0.2 weight part of retarder and 0.1 to 0.4 weight part of water reducing agent.

18. The 3D printing lightweight material containing wood aggregate according to claim 17 wherein the thickener comprises at least one of magnesium aluminum silicate, hydroxypropyl methylcellulose ether, kaolin.

19. The 3D printing lightweight material containing wood aggregate as claimed in claim 18, wherein the thickener is prepared from magnesium aluminum silicate, hydroxypropyl methylcellulose ether and kaolin according to a ratio of 1:1 to 2:1, in terms of mass ratio.

20. The 3D printing lightweight material containing wood aggregate according to claim 17, wherein the water reducing agent comprises at least two of lignosulfonate, aliphatic series and polycarboxylic series.

21. The 3D printing lightweight material containing wood aggregate according to claim 17, wherein the retarder comprises at least one of tartaric acid, polyvinyl alcohol, gluconic acid series substance.

22. The 3D printing lightweight material containing the wood aggregate according to any one of claims 1 to 21, wherein the 3D printing lightweight material containing the wood aggregate further comprises 1 to 2 parts by weight of modified wood fiber; the preparation method of the modified wood fiber comprises the following steps:

(I) Crushing the wood material, soaking in water, collecting the precipitated wood material, and drying for later use;

23. The 3D printing lightweight material containing the wood aggregate according to claim 22, wherein the crushed wood material is placed in water, stirred for 5 to 10min and then left to stand for precipitation for more than 30 min.

24. The 3D printing lightweight material containing wood aggregate according to claim 22, wherein in the step (I), the drying temperature is 50 to 60 ℃, and the drying time is 5 to 6h.

25. The 3D printing lightweight material containing wood aggregate according to claim 22, wherein metal heavy components in the wood material are removed by air flow sorting after the drying.

26. The 3D printing lightweight material containing wood aggregate according to claim 22, wherein in the step (II), the boiling softening treatment time is 25 to 40min.

27. The 3D printing lightweight material containing wood aggregate according to claim 22, wherein in the step (II), the mass ratio of the polyvinyl alcohol to the vinyl monomer is 1:1 to 3.

28. The 3D printing lightweight material containing wood aggregate according to claim 22, wherein the vinyl monomer comprises any one of acrylic acid and acrylamide.

29. The 3D printing lightweight material containing wood aggregate according to claim 22, wherein in the step (II), the length of the wood fiber is 1 to 9mm.

30. The 3D printing lightweight material containing the wood aggregate as defined in any one of claims 1 to 29, which is applied to the field of building engineering.