How to control the particle size and flow rate of abrasives during the sandblasting process in Dalian?

Dalian sandblasting processing is a commonly used surface treatment technology with high processing efficiency and good treatment effect, which can be widely used in surface treatment and processing of various materials. With the continuous advancement of technology and the expansion of application fields, sandblasting processing will be more widely used and developed in the future.

Sandblasting processing is mainly suitable for surface treatment of metal products, such as steel structural parts, aluminum alloys, copper parts, galvanized parts, etc. In the manufacturing industry, sandblasting is commonly used to remove oxide scales from welded structures, increase surface roughness, improve coating adhesion, and enhance product appearance quality.

How to control the particle size and flow rate of abrasives during the sandblasting process in Dalian?

1、 Control of abrasive particle size

Abrasive selection process

Select the appropriate particle size abrasive according to the processing purpose and workpiece material. If it is used to remove thick rust, oxide scale, or roughen the surface, larger abrasive particles are generally selected, such as 24-60 mesh (mesh refers to the number of holes that abrasive particles can pass through per inch of screen length). For example, when sandblasting and rust removal of large steel structural components, 24-36 mesh corundum sand can be used, as its larger particles can more effectively remove thick rust layers.

If surface finishing, cleaning thinner coatings, or requiring lower surface roughness, smaller abrasive particles such as 120-320 mesh should be selected. For example, in surface treatment of precision molds to prepare for subsequent electroplating, 180-220 mesh silicon carbide sand can be selected. This type of abrasive can achieve finer roughness on the surface of the mold.

Abrasive screening and grading equipment

Use vibrating screens and other equipment to screen and grade abrasives. The vibrating screen generates vibration through a vibration motor, causing the abrasive to move on the screen. Different particle sizes of abrasive are separated according to the size of the screen aperture. In sandblasting workshops, a complete abrasive screening system is usually equipped to classify and store abrasives according to standard particle size ranges.

For some high-precision sandblasting operations, airflow grading equipment can also be used. Airflow classification is a classification method that utilizes the different suspension velocities of abrasive particles in the airflow to more accurately separate abrasives that meet specific particle size requirements.

Monitoring during abrasive storage and transportation process

In the abrasive storage tank, it is necessary to prevent abrasives of different particle sizes from mixing with each other. Separate storage tanks can be used or abrasives of different particle sizes can be labeled and stored separately. Install a filter or screen in the abrasive conveying pipeline to prevent oversized abrasive particles from entering the spray gun. For example, in a pressure sandblasting system, setting a suitable mesh filter at the outlet of the pressure tank can effectively intercept abrasives that do not meet the particle size requirements.

2、 Control of abrasive flow rate

Adjustment function of sandblasting host

For the suction type sandblasting host, the abrasive flow rate is controlled by adjusting the control valve on the sandblasting gun. The opening size of the valve directly affects the amount of abrasive suction. During the operation, the operator can gradually adjust the valve opening and find the appropriate abrasive flow rate based on the surface treatment and processing requirements of the workpiece.

The pressure sandblasting host generally controls the abrasive flow rate by adjusting the flow control valve at the outlet of the pressure tank. Increase the opening of the regulating valve to increase the abrasive flow rate; On the contrary, the traffic decreases. At the same time, the flow rate of abrasive can be indirectly affected by adjusting the pressure of compressed air, as higher air pressure will increase the flow rate of abrasive in the pipeline, thereby increasing the abrasive flow rate per unit time.

Design and operational factors of spray gun

The diameter of the spray gun nozzle has a significant impact on the abrasive flow rate. Larger diameter nozzles allow more abrasive to pass through, thereby increasing abrasive flow rate. When selecting a nozzle, the appropriate diameter should be determined based on the type of sandblasting operation and abrasive particle size. For example, in large-scale sandblasting and rust removal operations, nozzles with larger diameters (such as 8-10mm) can be selected; In fine machining, nozzles with smaller diameters (such as 4-6mm) are used.

The angle at which the operator holds the spray gun and the distance from the workpiece can also affect the actual effect of abrasive flow rate. When the spray gun is perpendicular to the surface of the workpiece and at an appropriate distance, the abrasive can be more effectively sprayed onto the surface of the workpiece, and the utilization rate of abrasive flow rate is highest. If the angle of the spray gun is tilted or too far or too close to the workpiece, it will cause uneven dispersion of the abrasive, affecting the machining quality. At this time, it may be necessary to adjust the abrasive flow rate to compensate.

Flow monitoring and feedback system (for high-precision requirements)

In some situations with high automation or precise requirements for sandblasting quality, abrasive flow monitoring devices can be installed. For example, using electromagnetic flow meters or mass flow meters to monitor the real-time flow of abrasives in pipelines. These monitoring data can be fed back to the sandblasting host control system, which can achieve precise control of abrasive flow by automatically adjusting parameters such as valves or air pressure.

Sandblasting processing is a common metal processing technique, also known as sand blast processing or sand spraying. It sprays abrasives (such as quartz sand, diamond sand, etc.) onto the metal surface through a high-speed sandblasting gun to remove oxide scale, oil stains, dirt, and rough surfaces, thereby achieving surface smoothness and roughness adjustment, while increasing the adhesion and corrosion resistance of the metal surface.

The process flow of sandblasting mainly includes preparation work, selection of abrasives, equipment debugging and operation, sandblasting process, surface treatment, cleaning, and inspection. In the preparation work, it is necessary to confirm the material, shape, and surface condition of the processed object, select suitable abrasives, and check the operating status of the sandblasting equipment; During the sandblasting process, adjust the pressure of the sandblasting equipment, the flow rate of the nozzle and sandblasting agent according to the requirements, control the processing depth and roughness, and ensure that the processing effect meets the expected requirements.