Ultra-high performance additive manufacturing dry powder and method of making, printed substrate and method

Abstract

The application relates to a preparation method of an ultra-high-performance additive manufacturing dry powder, comprising the following steps: providing a nanoscale silica gel and a micrometer-sized inert filler, and uniformly mixing to form a first batch of premix; drying the first batch of premix; adding a second batch of premix to the dried first batch of premix and uniformly mixing to obtain an additive manufacturing dry powder with printability in rheological properties and setting time, wherein the second batch of premix comprises PO425 cement, CSA cement, a superplasticizer and hydroxypropyl methyl cellulose. The application solves the problem of insufficient strength of a traditional 3D printing cement-based material.

Description

Technical Field

[0001] This invention relates to the field of 3D printing technology, and in particular to an ultra-high performance additive manufacturing dry powder and its preparation method, as well as a printing substrate and method. Background Technology

[0002] 3D printing (3DP), also known as additive manufacturing, is a rapid prototyping technology. It's a technique that uses 3D model files as a basis and employs bondable materials such as powdered metal, plastic, or concrete to construct objects layer by layer. Its main characteristics include rapid prototyping, reduced material waste, template-free operation, high design freedom, and significant reduction in carbon emissions. It is an innovative, environmentally friendly, and efficient new method of component manufacturing. Among the many 3D printing materials, cement-based materials have become the mainstream material for 3D printing substrates due to their wide availability, low cost, and stable physical properties. Furthermore, with the development of 3D printing technology, the demand for precision, high strength, and high durability in 3D printed building components is becoming increasingly significant.

[0003] The most unique advantage of cement-based materials lies in their ability to print highly customizable irregular structures. However, the low strength of cement-based materials limits the innovation of irregular structures printed with them. The low strength forces an increase in cross-sectional area in mechanical design, resulting in bulky and heavy components that significantly reduce their artistic appeal. For example, in 3D printing artistic lettering using cement-based materials as ink, doubling the strength of the printing material would reduce the minimum number of printing layers by half, resulting in a lighter and more aesthetically pleasing structure. Furthermore, 3D printed architectural structures are often used for outdoor architectural features, retaining walls, flower beds, and other open-air structures. Therefore, the quality requirements for printed components during their service life are high; insufficient material strength leads to poor durability and a short lifespan. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides an ultra-high performance additive manufacturing dry powder and its preparation method, as well as a printing substrate and method, which solves the problem of insufficient strength in traditional 3D printing cement-based materials.

[0005] This invention is achieved through the following scheme: a method for preparing ultra-high performance additive manufacturing dry powder, comprising the following steps:

[0006] Nanoscale silica gel and micron-scale inert filler are provided and mixed evenly to form the first batch of premix;

[0007] The first batch of premixed materials is dried;

[0008] A second batch of premix is ​​added to the first batch of dried premix and mixed evenly to obtain an additive manufacturing dry powder with printable rheological properties and setting time. The second batch of premix includes PO425 cement, CSA cement, superplasticizer and hydroxypropyl methylcellulose.

[0009] A further improvement of the preparation method of the ultra-high performance additive manufacturing dry powder of the present invention is that the micron-level inert filler includes primary fly ash and S95 silica fume.

[0010] A further improvement of the preparation method of the ultra-high performance additive manufacturing dry powder of the present invention is that the nano-sized silica gel in the first batch of premix is ​​0.01 to 0.03 parts by weight, the first-grade fly ash is 0.15 to 0.2 parts by weight, and the S95 silica fume is 0.2 to 0.4 parts by weight, wherein the weight of the nano-sized silica gel is the weight after deducting its own water content.

[0011] A further improvement of the preparation method of the ultra-high performance additive manufacturing dry powder of the present invention is that the PO425 cement in the second batch of premix is ​​1 part by weight, the CSA cement is 0.02 to 0.05 parts by weight, the superplasticizer is 0.01 to 0.03 parts by weight, and the hydroxypropyl methylcellulose is 0.001 to 0.005 parts by weight.

[0012] A further improvement of the preparation method of the ultra-high performance additive manufacturing dry powder of the present invention is that the concentration of the nanoscale silica gel in the first batch of premix does not exceed 40%.

[0013] A further improvement of the preparation method of the ultra-high performance additive manufacturing dry powder of the present invention is that, when drying the first batch of premixed material, stirring is maintained and the material is dried to constant weight at 100-110°C, so that all the moisture in the nanoscale silica gel is lost.

[0014] The present invention also provides an ultra-high performance additive manufacturing dry powder, which is prepared by the preparation method of ultra-high performance additive manufacturing dry powder as described in any of the preceding claims.

[0015] The present invention also provides a 3D printing substrate, which is composed of the ultra-high performance additive manufacturing dry powder as described above and 0.25 to 0.3 parts by weight of water.

[0016] The present invention also provides a 3D printing method, comprising the following steps:

[0017] Before printing, a 3D printing substrate as described above is pre-formed;

[0018] During printing, the 3D printing substrate is pumped into the 3D printing equipment using a pump tube.

[0019] This invention also provides a 3D printing method, comprising the following steps:

[0020] A dual-head 3D printing device is provided, wherein the dual-head 3D printing device is equipped with a proportional dry powder nozzle and a water vapor nozzle;

[0021] During printing, the ultra-high performance additive manufacturing dry powder and water, as described above, are supplied to the dry powder nozzle and the water vapor nozzle respectively, so as to form the 3D printing substrate as described above through synchronous composite feeding during the printing process.

[0022] This invention uses micron-sized inert materials and nano-sized silica sol as the main materials for 3D printing substrates. Utilizing the maximum packing density theory, and supplemented by reinforcing additives to modify their rheological properties and setting time to achieve printability, it ultimately yields high-strength and high-durability additive manufacturing dry powder. This solves the problem of insufficient strength in traditional cement-based materials. Parts printed using this invention have a dense structure and high durability, resulting in a longer service life and reduced carbon emissions throughout their entire lifecycle. Attached Figure Description

[0023] Figure 1 A flowchart of the preparation method of the dry powder of the present invention is shown. Detailed Implementation

[0024] To address the issue of insufficient strength in traditional 3D printed cement-based materials, this invention provides an ultra-high performance additive manufacturing dry powder and its preparation method, as well as a printing substrate and method. The following detailed description, in conjunction with accompanying drawings, further illustrates this ultra-high performance additive manufacturing dry powder and its preparation method, and the printing substrate and method.

[0025] See Figure 1 As shown, a method for preparing ultra-high performance additive manufacturing dry powder includes the following steps:

[0026] Step 1: Provide nanoscale silica gel and micron-scale inert filler and mix them evenly to form the first batch of premix.

[0027] Step 2: Dry the first batch of premixed material.

[0028] Step 3: Add the second batch of premix to the first batch of dried premix and mix evenly to obtain additive manufacturing dry powder with printable rheological properties and setting time. The second batch of premix includes PO425 cement, CSA cement, superplasticizer and hydroxypropyl methylcellulose.

[0029] This method uses micron-sized inert materials and nano-sized silica sol as the main materials for 3D printing substrates. Utilizing the maximum packing density theory, and supplemented by reinforcing additives to modify rheological properties and setting time to achieve printability, it ultimately yields high-strength and high-durability additive manufacturing dry powder. The aforementioned maximum packing density theory refers to the optimal proportion of particles of different sizes in the constituent materials of a cementitious material to form the densest packing. Specifically, the gaps between millimeter-sized particles (aggregates) are filled by micron-sized particles (cement, fly ash, mineral powder), and the gaps between micron-sized particles are filled by submicron-sized particles (silica fume) or even nano-sized particles (nano-SiO2). Through these methods, the problem of insufficient strength in traditional cement-based materials is solved. Using the dry powder prepared by this method as a 3D printing material results in dense and durable printed parts with a long service life and reduced carbon emissions throughout their entire life cycle.

[0030] A preferred embodiment is provided below. Referring to the data in Table 1, in this embodiment, the dry powder is formed in two batches: The first batch is formed by uniformly mixing 0.01-0.03 parts by weight of nano-sized silica gel (SiO2) and micron-sized inert fillers (including 0.15-0.2 parts by weight of primary fly ash and 0.2-0.4 parts by weight of S95 silica fume; other micron-sized inert fillers can also be used as needed) to form the first batch of premix. It should be noted that the nano-sized silica gel is mixed in the form of a hydrosol, and the concentration is controlled to not exceed 40% to ensure its dispersion effect. The weights mentioned above are the weights after deducting the water content.

[0031]

[0032] The second batch is a reinforcing additive added to the first batch of premix to adjust the rheological properties and setting time, thereby enabling both to be printable. In this embodiment, the second batch of premix includes 1 part by weight of PO425 cement, 0.02 to 0.05 parts by weight of CSA cement, 0.01 to 0.03 parts by weight of superplasticizer, and 0.001 to 0.005 parts by weight of hydroxypropyl methylcellulose. The setting time can be adjusted by varying the amount of CSA cement added, and the rheological properties can be adjusted by adjusting the addition and proportioning of all components in the second batch of premix.

[0033] It should be noted that in order to obtain a dry and uniform powder that can be stored for a long time, it is necessary to remove the moisture from the dry powder. Therefore, in this embodiment, before performing the second batch operation, the first batch of premix is ​​dried while being stirred, and dried at 100-110°C to constant weight to ensure that all the moisture in the nanoscale silica gel is removed. All components in the added second batch of premix are dry and moisture-free.

[0034] A 3D printing substrate is prepared by mixing ultra-high performance additive manufacturing dry powder prepared by the preparation method described above with 0.25 to 0.3 parts by weight of water.

[0035] This 3D printing substrate can be used to 3D print intricate architectural components, with a layer height (vertical resolution) of less than 1 cm, and as low as 0.1 cm. There are two methods for using this 3D printing substrate:

[0036] A 3D printing method includes the steps of: pre-forming a 3D printing substrate as described above before printing; and pumping the 3D printing substrate into a 3D printing device using a pump tube during printing.

[0037] Another 3D printing method includes the steps of: providing a dual-head 3D printing device equipped with a proportionally proportioned dry powder nozzle and a water vapor nozzle; and during printing, supplying the ultra-high performance additive manufacturing dry powder and water as described above to the dry powder nozzle and the water vapor nozzle respectively, so as to form the 3D printing substrate as described above through synchronous composite feeding during the printing process.

[0038] The ultra-high performance additive manufacturing dry powder of this invention can reach a strength of C80 after 28 days, significantly improving the strength of 3D printed components. This, in turn, saves materials and enhances the innovation of component artistic design. It is ready to use after adding water, making it simple and quick to apply. Ordinary 3D printed building materials have coarse layering textures, while this ultra-high performance additive manufacturing dry powder does not contain coarse particles, resulting in stable printing performance and high printing resolution (1mm-10mm), suitable for 3D printing of delicate cement-based materials. Furthermore, the prepared 3D printed components have a dense internal structure, significantly improving corrosion resistance and freeze-thaw resistance.

[0039] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. Those skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention shall be defined by the appended claims.

Claims

1. A method for preparing ultra-high performance additive manufacturing dry powder, characterized in that, Including the following steps: Nanoscale silica gel and micron-scale inert filler are provided and mixed evenly to form the first batch of premix; The first batch of premixed materials is dried; A second batch of premix was added to the first batch of dried premix and mixed thoroughly to obtain an additive manufacturing dry powder with printable rheological properties and setting time. The second batch of premix included PO425 cement, CSA cement, superplasticizer, and hydroxypropyl methylcellulose. The micron-sized inert filler includes primary fly ash and S95 silica fume; The first batch of premixed materials contains 0.01 to 0.03 parts by weight of nano-sized silica gel, 0.15 to 0.2 parts by weight of primary fly ash, and 0.2 to 0.4 parts by weight of S95 silica fume, wherein the weight of nano-sized silica gel is the weight after deducting its own moisture content. In the second batch of premixed materials, the PO425 cement is 1 part by weight, the CSA cement is 0.02~0.05 parts by weight, the superplasticizer is 0.01~0.03 parts by weight, and the hydroxypropyl methylcellulose is 0.001~0.005 parts by weight; The concentration of the nanoscale silica gel in the first batch of premixes does not exceed 40%.

2. The method for preparing ultra-high performance additive manufacturing dry powder as described in claim 1, characterized in that, When drying the first batch of premixed material, stirring is maintained, and it is dried at 100~110℃ to constant weight so that all the moisture in the nanoscale silica gel is lost.

3. A high-performance additive manufacturing dry powder, characterized in that, It is prepared using the preparation method of ultra-high performance additive manufacturing dry powder as described in any one of claims 1 to 2.

4. A 3D printing substrate, characterized in that, It is made by mixing the ultra-high performance additive manufacturing dry powder as described in claim 3 with 0.25 to 0.3 parts by weight of water.

5. A 3D printing method, characterized in that, Including the following steps: Before printing, a 3D printing substrate as described in claim 4 is pre-formed; During printing, the 3D printing substrate is pumped into the 3D printing equipment using a pump tube.

6. A 3D printing method, characterized in that, Including the following steps: A dual-head 3D printing device is provided, wherein the dual-head 3D printing device is equipped with a proportional dry powder nozzle and a water vapor nozzle; During printing, the ultra-high performance additive manufacturing dry powder as described in claim 3 and water are supplied to the dry powder nozzle and the water vapor nozzle respectively, so as to form the 3D printing substrate as described in claim 4 through synchronous composite feeding during the printing process.

Images