How to optimize the process parameters of sandblasting in Dalian for better results

Dalian sandblasting is a widely used process technology for surface treatment, cleaning, and strengthening, and its processing effect is directly affected by process parameters.

1、 Overview of Basic Principles and Parameters of Sandblasting Processing

Sandblasting processing is the use of high-speed abrasive particles to impact the surface of the workpiece, achieving the purpose of cleaning, strengthening, or changing the surface roughness. The main process parameters include:

Abrasive type and particle size

Sandblasting pressure

spray angle

spray distance

Spray time/moving speed

Nozzle diameter and shape

Environmental conditions (temperature, humidity)

These parameters are interrelated and together determine the effectiveness and quality of sandblasting processing.

2、 Optimization strategy for key process parameters

1. Abrasive selection and particle size optimization

Abrasive is one of the core factors affecting the sandblasting effect, and should be considered when selecting:

Material matching: Select abrasive with moderate hardness according to the workpiece material. For soft metals such as aluminum, glass beads or plastic abrasives can be used; For hard alloys, hard abrasives such as alumina or silicon carbide should be selected.

Particle size control: Coarse particle size (such as Grit 16-36) is suitable for rapid removal of thick oxide skin; Medium grain size (Grit 60-100) is suitable for general surface treatment; Fine grained (Grit 120 or above) is used for fine surface treatment. The optimization principle is to use coarser abrasives as much as possible to improve efficiency while meeting processing requirements.

Shape selection: Sharp edged abrasives (such as alumina) have strong cutting ability and are suitable for cleaning; Spherical abrasives (such as glass beads) are more suitable for surface strengthening and finishing treatment.

2. Optimization of sandblasting pressure

Sandblasting pressure directly affects abrasive impact energy and processing efficiency:

Pressure range: usually 0.2-0.8MPa. Low pressure can lead to incomplete cleaning, while high pressure may damage the substrate.

Optimization method: Start testing at low pressure and gradually increase to achieve the desired effect at low pressure. For precision or thin-walled parts, lower pressure (0.2-0.4MPa) should be used; For cleaning thick oxide skin, 0.6-0.8MPa can be used.

Pressure stability: Maintaining pressure stability is key, and fluctuations should not exceed ± 5%. The use of stabilizing devices and regular inspection of pipeline sealing can effectively maintain pressure stability.

3. Optimization of spray angle and distance

Spray angle: usually between 45-90 degrees. Vertical jet (90 degrees) has stronger cutting force and is suitable for cleaning; A smaller angle (30-60 degrees) can produce a more uniform surface texture. For complex shaped workpieces, the angle should be dynamically adjusted to ensure uniform processing of each part.

Spray distance: generally controlled between 100-300mm. If the distance is too close, it will cause local overprocessing, while if it is too far, the efficiency will be low. The optimization method is to fix other parameters, test the processing effect at different distances, and select a distance with uniform processing and higher efficiency.

4. Spray time/movement speed control

For fixed sandblasting:

Time control: Determine the minimum time required to achieve the desired treatment effect through experimentation. Excessive sandblasting can cause damage to the substrate and waste of abrasives.

For mobile sandblasting:

Moving speed: It should be matched with the sandblasting pressure and abrasive flow rate to ensure that sufficient abrasive impact is received per unit area. Usually between 0.1-0.5m/s, a better speed can be determined through trial spraying.

5. Optimization of nozzle parameters

Nozzle diameter: affects abrasive flow rate and spray mode. Small diameter (4-6mm) is suitable for fine machining; Large diameter (8-12mm) is suitable for large-area processing. When choosing, the air supply capacity of the air compressor should be considered.

Nozzle material: Boron carbide nozzles have better wear resistance and a lifespan 2-3 times that of tungsten carbide, making them suitable for long-term continuous operation; Ceramic nozzles are low-cost but fragile.

Nozzle shape: Straight hole nozzle with concentrated jet, and Venturi nozzle with more uniform abrasive distribution. Select according to processing requirements.

3、 Parameter collaborative optimization method

The optimization effect of a single parameter is limited, and the interaction between parameters needs to be considered:

Orthogonal experimental method: Design a multi factor and multi-level experiment, and determine the optimal parameter combination through statistical analysis.

Response surface methodology: Establish a mathematical model of process parameters and processing effects (such as roughness and cleaning rate) to find better solutions.

Empirical formula reference: For example, the empirical relationship between sandblasting intensity (Almen test piece arc height), pressure, and distance is: I ∝ P · (1/D) ^ n, where n is approximately 1.5-2.

Real time monitoring and adjustment: Surface roughness meter, residual stress tester and other equipment are used for real-time monitoring and dynamic parameter adjustment.

4、 Optimization focus for different application scenarios

Surface cleaning: Emphasis is placed on cleaning efficiency, and higher pressure, larger abrasives, and shorter distances can be selected.

Surface strengthening (shot blasting): Emphasis is placed on introducing compressive stress, and accurate control of sandblasting intensity and coverage is required. Small abrasives (0.2-0.6mm) and medium to low pressure are usually used.

Surface texture treatment: Pursuing uniform and consistent surface morphology requires strict control of abrasive particle size distribution, spray angle, and movement speed.

Precision parts processing: With small parameter tolerances, it is necessary to use fine abrasives, lower pressures, and accurate nozzle positioning.

5、 Common Problems and Solutions

Surface unevenness: Check whether the abrasive flow rate is stable, whether the nozzle is worn, and whether the moving speed is constant.

Substrate damage: Reduce pressure, increase distance, and use softer abrasives or larger particle sizes instead.

Low efficiency: Check the air supply capacity of the air compressor, whether the abrasive is damp and clumped, and whether the nozzle is blocked.

Excessive dust: Optimize the dust removal system and consider wet sandblasting or using dust suppressants.

6、 Process parameter recording and management

Establish a comprehensive parameter recording system, including:

Workpiece material and condition

Use abrasive type and batch

Process parameter setting

Processing effect detection data

Equipment status information

Continuously optimize processes through data analysis and develop standardized operation manuals.

The optimization of sandblasting process parameters is a systematic engineering that requires comprehensive consideration of material characteristics, processing requirements, and equipment conditions. Through scientific methodology guidance, rigorous experimental verification, and continuous process improvement, it is possible to achieve better sandblasting processing results, improve product quality, and increase production efficiency. In practical applications, flexible adjustments should be made based on specific working conditions, and attention should be paid to experience accumulation and technological innovation.