Screening method for 3D printing powder

Abstract

The invention discloses a screening method for 3D printing powder. The screening method comprises the following steps that powder needing to be screened is prepared; s2, performing screening modes of different levels according to the powder attribute information of the powder: primary screening of the powder; powder is subjected to multi-stage screening; screening fine powder; the screening process is monitored, an alarm detection mechanism is installed, and whether blockage occurs in the screening process or not is judged according to the screening result; different grades of screening modes are carried out by detecting powder attribute information of powder, the alarm mechanism is arranged, whether blockage occurs in the screening process or not is judged according to the screening result, the alarm detection mechanism can be based on the weight of falling materials, when the weight of discharged materials reaches a certain pressure value, it is indicated that work is normal, and the working efficiency is improved. And if the pressure is lower than a normal numerical value, the blanking amount is small, blockage is caused, the blockage and accumulation phenomena of particle materials on the screen are effectively prevented, the continuity and the stability of the screening process are ensured, and the printing quality and the printing consistency are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of powder screening, and in particular to a method for screening powder for 3D printing. Background Art

[0002] With the continuous development of 3D printing technology, its application in high-end manufacturing, medical and other fields is becoming more and more extensive. However, in the 3D printing process, due to incomplete powder solidification, a lot of residues will be produced, including unsintered low-particle metal powder that meets the particle size requirements for printing.

[0003] Since metal powders used in 3D printing are usually very expensive, recycling metal powders from printing residues has become an important direction for reducing metal printing costs. Currently, traditional methods such as screening are usually used to recover low-particle-size metal powders remaining after 3D printing. The best screening methods corresponding to metal powders with different properties are different, and blockages are prone to occur during the screening process. Summary of the invention

[0004] The purpose of the present invention is to provide a 3D printing powder screening method. The present invention detects the powder property information of the powder to perform different levels of screening, and sets an alarm mechanism to determine whether the screening process is blocked according to the screening results.

[0005] To achieve the above object, the present invention provides the following technical solutions: A method for screening 3D printing powder, comprising the following steps: S1: prepare the powder to be sieved; S2: Screening methods of different levels are performed according to the powder property information of the powder: (1) Primary screening of powder; (2) Multi-stage screening of powder; (3) Screening of fine powder; S3: Monitor the screening process, install an alarm detection mechanism, and determine whether blockage occurs in the screening process based on the screening results.

[0006] Preferably, an ultrasonic vibrating screen is often used for primary screening of the powder in S2, and sieves of different mesh sizes are used for screening.

[0007] Preferably, the ultrasonic vibration screen uses a 60-mesh screen to remove coarse particles, and then uses 100-mesh and 270-mesh screens for classification.

[0008] Preferably, the powder is screened at multiple stages: a multi-stage powder screening method is used, a powder falling plate and multiple sieves are stacked in sequence, and then the metal powder is poured into the top sieve and scraped flat, and the powder is screened by a vibrating and rocking mechanism, and finally the multiple sieves are taken out and the obtained metal powder products are stored.

[0009] Preferably, the sizes of the sieve holes decrease from top to bottom.

[0010] Preferably, the fine powder screening can be equipped with an ultrasonic screening system for situations where finer powders are required, which transmits ultrasonic frequencies to the sieve, allowing screening as fine as 25m / 500 mesh while avoiding clogging of the sieve holes.

[0011] Preferably, the alarm detection mechanism in S3 can be based on the weight of the discharged material. When the weight of the discharged material reaches a certain pressure value, it indicates that the operation is normal. If the pressure is lower than the normal value, it indicates that the discharged material is insufficient and a blockage occurs.

[0012] In summary, due to the adoption of the above technology, the beneficial effects of the present invention are: The present invention detects the powder property information of the powder to perform different levels of screening, and sets an alarm mechanism to judge whether the screening process is blocked according to the screening results. The alarm detection mechanism can be based on the weight of the falling material. When the weight of the discharge material reaches a certain pressure value, it indicates that the operation is normal. When the pressure is lower than the normal value, it indicates that the falling material is small and blockage occurs, which effectively prevents the blockage and accumulation of particulate materials on the screen and ensures the continuity and stability of the screening process.

[0013] 2. Improve printing quality and consistency: Through screening, oversized or undersized particles, impurities and agglomerates can be removed to provide high-quality, pure printing powder, thereby improving printing quality and consistency.

[0014] 3. Improve printing efficiency: Using screened and graded powders can reduce downtime during printing, improve production efficiency, and simplify post-processing: By precisely controlling the particle size distribution of the powder, additional steps in the post-processing process, such as screening, cleaning, and sintering, can be reduced or eliminated, simplifying the production process and reducing time and cost investment.

[0015] 4. Improve screening accuracy and efficiency: The ultrasonic vibrating screen combines the advantages of rotary vibrating screen and ultrasonic technology. Through ultrasonic vibration, the particles on the screen produce tiny jumping movements, which effectively prevents fine particles from falling into the screen holes and improves the screening accuracy and efficiency.

[0016] 5. Improve powder performance: The powder particle size distribution after screening is more uniform and the fluidity is better, which helps to improve printing accuracy and effect while reducing material waste. Strong adaptability and easy maintenance: The control system of the ultrasonic rotary vibrating screen can adjust the speed of rotational vibration and the intensity of ultrasonic waves to adapt to different materials and screening requirements, and the equipment is easy to maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention, so that other features, purposes and advantages of the present invention become more obvious. The accompanying drawings of the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings: Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0019] In the description of the present invention, it is necessary to understand that the terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0020] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances of the specification.

[0021] The present invention provides Figure 1 A 3D printing powder screening method shown includes the following steps: S1: prepare the powder to be sieved; S2: Screening methods of different levels are performed according to the powder property information of the powder: (1) Primary screening of powders: Ultrasonic vibrating screens are often used for primary screening of powders, and are equipped with screens of different mesh sizes for screening. The ultrasonic vibrating screen uses a 60-mesh screen to remove coarse particles, and then uses 100-mesh and 270-mesh screens for grading; (2) Multi-level screening of powder: Use a multi-level screening method to stack the powder plate and multiple sieves in sequence, then pour the metal powder into the top sieve and scrape it flat, and screen it through a vibrating and swinging mechanism. Finally, take out multiple sieves and store the obtained metal powder products. The size of the sieve holes decreases from top to bottom. (3) Fine powder screening: For situations where finer powders are required, an ultrasonic screening system can be configured to transmit ultrasonic frequencies to the screen, allowing screening as fine as 25m / 500 mesh while avoiding clogging of the screen holes; S3: Monitor the screening process and install an alarm detection mechanism to determine whether the screening process is blocked based on the screening results. The alarm detection mechanism can be based on the weight of the discharged material. When the weight of the discharged material reaches a certain pressure value, it indicates that the operation is normal. A pressure lower than the normal value indicates that there is less discharged material and a blockage has occurred. Example

[0022] Step 1: Prepare the powder to be sifted; Step 2: Perform different levels of screening based on the powder property information of the powder: Primary screening of powders: Ultrasonic vibrating screens are often used for primary screening of powders, and are equipped with screens of different mesh sizes for screening. The ultrasonic vibrating screen uses a 60-mesh screen to remove coarse particles, and then uses 100-mesh and 270-mesh screens for grading: The specific steps are: 1. Raw material preparation: Select appropriate metal powder and perform pretreatment such as mixing, grading, and screening according to different requirements; 2. Equipment installation: Select appropriate ultrasonic vibrating screen equipment, and install, debug and inspect it according to the instructions to ensure stable operation of the equipment and appropriate vibration intensity; 3. Start screening: Add the pre-treated metal powder into the vibrating screen, turn on the equipment to start vibrating screening, and select the appropriate screen aperture and vibration intensity according to needs; 4. Collect products: After screening, separate, collect, package and store as needed.

[0023] 5. Equipment maintenance: Regularly perform equipment maintenance and care, clean the screen, check the working status of vibrators, motors and other equipment components, and ensure long-term stable and reliable operation of the equipment.

[0024] The benefits of ultrasonic vibrating screen mainly include the following aspects: 1. High screening accuracy: Ultrasonic vibrating screens superimpose high-frequency and low-amplitude ultrasonic vibration waves on the screen to keep the materials on the screen surface in suspension, thereby suppressing factors such as adhesion, friction, and flatness, and significantly improving the screening accuracy. Its screening accuracy can reach more than 95%, which is much higher than the 60%-70% of ordinary vibrating screens.

[0025] 2. High screening efficiency: The screening speed and output of ultrasonic vibrating screens are significantly improved, generally up to 0.5-10 times that of ordinary vibrating screens. This is mainly because the ultrasonic vibration waves make the material suspend in the low altitude on the screen surface, increasing the screening efficiency.

[0026] 3. Wide range of applications: Ultrasonic vibrating screen is suitable for screening various ultra-fine powders, such as flour, graphite powder, rubber powder, quartz sand powder, metal powder, powder coating, fluorescent powder, etc. Its mesh aperture range is wide, suitable for screening needs from 10 mesh to 635 mesh.

[0027] 4. Good dustproof effect: The top of the ultrasonic vibrating screen is equipped with a dustproof cover, which can effectively prevent dust from escaping and solve the dust pollution problem in the screening process of fine materials. In addition, its seal is made of high-quality silicone material, which further reduces dust leakage.

[0028] 5. Long equipment life: Although the price of ultrasonic vibrating screen is relatively high, its precise design greatly extends the service life of the equipment and reduces maintenance costs accordingly. In the long run, it can save users about 50% of equipment costs.

[0029] 6. No clogging: The ultrasonic vibrating screen uses an ultrasonic transducer to convert electrical energy into wave energy and transmit it to the screen surface, which can effectively break up the agglomerated materials, avoid clogging of the screen, and extend the service life of the screen.

[0030] In summary, ultrasonic vibrating screen has significant advantages in screening accuracy, efficiency, scope of application, dust prevention effect, equipment life and maintenance cost, and is particularly suitable for users of high-quality and fine powders.

[0031] Powder ‌Multi-level screening: Use a multi-level powder screening method, stack the powder drop tray and multiple sieves in sequence, then pour the metal powder into the top sieve and scrape it flat, screen it through the vibration and swing mechanism, and finally take out multiple sieves and store the obtained metal powder products. The size of the sieve holes decreases from top to bottom: The specific steps are: 1. Prepare the sieve: Choose a suitable sieve, usually a stainless steel sieve, the aperture size is determined by the minimum and maximum size of the particles to be screened. The aperture of the sieve used for metal powder screening is generally 1-250 microns; 2. Assemble the sieve tower: stack the standard sieves in order according to the size of the aperture to form a sieve tower. There should be a receiving tray at the bottom of the sieve tower and a sieve cover at the top of the sieve tower; 3. Install the screening equipment: install the assembled sieve tower on the screening machine for screening; 4. Step-by-step screening: According to the required particle size, screens with different apertures are used for screening. Generally, the method of step-by-step screening from top to bottom is adopted to finally obtain screened materials of different sizes; 5. Record data: During the screening process, it is necessary to record the screening time, screening aperture, screening results and other data for subsequent analysis and use; 6. Drying treatment: If the metal powder needs to be dried, it should be done under vacuum or inert atmosphere; 7. Control moisture and viscosity: The moisture and viscosity of metal powder affect the screening effect, so it is necessary to control the moisture and viscosity; 8. Regularly replace and maintain the screen: The screen has a limited service life and needs to be replaced, maintained and cleaned regularly; Through the above steps, multi-stage screening can be effectively carried out to ensure that the screening effect of metal powder is stable and reliable, and improve production efficiency and quality.

[0032] ‌ Fine powder screening: For situations where finer powders are required, an ultrasonic screening system can be configured to transmit ultrasonic frequencies to the sieve, allowing screening as fine as 25m / 500 mesh while avoiding clogging of the sieve holes; The specific process of fine powder screening can be summarized into the following key steps: 1. Preparation stage: Make sure the screening machine is placed on a flat and level ground, check whether all parts are installed properly, the connection nozzles are kept tight, and the power supply is turned on and grounded reliably; 2. Choose a sieve: Choose a suitable sieve according to the screening requirements, such as the size of the sieve mesh, place it in the sieve seat slot and cover it with a lid; 3. Start sieving: Start the sieving instrument and sieve the fine powder on the sieve surface by mechanical vibration or sonic vibration. During the sieving process, fine particles will pass through the sieve holes, while coarse particles will remain on the sieve surface; 4. Screening completed: After the screening is completed, turn off the instrument, take out the materials on and under the screen, collect and process them separately. If needed, multiple screenings can be performed to achieve better screening results.

[0033] S3: The screening process is monitored. An alarm detection mechanism can be installed at the discharge port to set a normal discharge pressure value. The screening result can be used to determine whether the screening process is blocked. The alarm detection mechanism can be based on the weight of the discharged material. When the weight of the discharged material reaches a certain pressure value, it indicates that the operation is normal. A pressure lower than the normal value indicates that there is less discharged material and a blockage has occurred.

Claims

1. A method for screening 3D printing powder, characterized in that: The following steps are involved: S1: prepare the powder to be sieved; S2: Screening methods of different levels are performed according to the powder property information of the powder: (1) Primary screening of powder; (2) Multi-stage screening of powder; (3) Screening of fine powder; S3: Monitor the screening process, install an alarm detection mechanism, and determine whether blockage occurs in the screening process based on the screening results.

2. A 3D printing powder screening method according to claim 1, characterized in that: The primary screening of the powder in S2 is usually carried out by using an ultrasonic vibrating screen and equipped with screens of different mesh sizes for screening.

3. A 3D printing powder screening method according to claim 2, characterized in that: The ultrasonic vibration screen uses a 60-mesh screen to remove coarse particles, and then uses 100-mesh and 270-mesh screens for classification.

4. A 3D printing powder screening method according to claim 1, characterized in that: The powder is screened at multiple levels: a powder falling plate and multiple sieves are stacked in sequence using a multi-level powder screening method, metal powder is poured into the top sieve and scraped flat, screening is performed using a vibrating and rocking mechanism, multiple sieves are taken out, and the resulting metal powder products are stored.

5. A 3D printing powder screening method according to claim 4, characterized in that: The sizes of the sieve holes decrease from top to bottom.

6. A 3D printing powder screening method according to claim 1, characterized in that: For situations where finer powders are required, an ultrasonic screening system can be configured to transmit ultrasonic frequencies to the sieve, allowing screening as fine as 25m / 500 mesh while avoiding clogging of the sieve holes.

7. A 3D printing powder screening method according to claim 1, characterized in that: The alarm detection mechanism in S3 can be based on the weight of the discharged material. When the weight of the discharged material reaches a certain pressure value, it indicates that the operation is normal. If the pressure is lower than the normal value, it indicates that the discharged material is insufficient and a blockage occurs.

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