Techniques of Dalian Sandblasting Processing in Polishing Hardware Products

1、 Overview of Sandblasting Polishing Technology

As an important process for surface treatment of hardware products, Dalian sandblasting achieves the effects of cleaning, deburring, polishing, and surface strengthening by high-speed abrasive impact on the workpiece surface. Compared to traditional mechanical polishing, sandblasting technology has the advantages of uniform processing, high efficiency, and wide applicability, especially suitable for hardware components with complex shapes and high precision requirements.

The basic principle of sandblasting polishing is to use compressed air as power to form a high-speed jet beam that sprays abrasive at high speed onto the surface of the workpiece. Through the impact and cutting effect of the abrasive, the surface of the workpiece is cleaned and rough. This process not only removes surface oxide layers and impurities, but also forms a uniform matte surface, improving coating adhesion.

2、 Techniques for selecting sandblasting process parameters

1. Selection of abrasive type

Hardware products of different materials need to be matched with corresponding abrasives:

Stainless steel products: It is recommended to use glass beads or ceramic sand to achieve a delicate and uniform matte effect

Aluminum alloy products: suitable for using alumina or silicon carbide abrasives, with moderate hardness and not easily damaging the substrate

Copper products: It is advisable to use soft abrasives such as plastic sand or walnut shells to avoid excessive surface roughness

Steel products: Hard abrasives such as steel grit and brown corundum can be used, which have both cleaning and strengthening effects

2. Abrasive particle size control

Particle size selection directly affects surface roughness:

Rough polishing (Ra3.2-6.3 μ m): using 60-80 mesh abrasive

Fine polishing (Ra0.8-1.6 μ m): using 100-120 mesh abrasive

Ultra precision polishing (Ra0.2-0.4 μ m): using 180-220 mesh abrasive

3. Optimization of injection parameters

Pressure regulation: generally controlled at 0.4-0.7MPa, low pressure (0.3-0.5MPa) is recommended for thin-walled parts

Spray angle: Conventional processing uses 45-60 °, special texture requirements can be adjusted to 30 ° or 75 °

Spray distance: maintain 100-200mm, too close distance can cause excessive local wear

Moving speed: Move the spray gun evenly, with a speed controlled between 0.5-1.5m/min

3、 Sandblasting techniques for special hardware components

1. Precision small piece processing

For small hardware components such as screws and springs:

Using a dedicated rotary sandblasting machine to ensure uniform treatment on all surfaces

Reduce the air pressure to 0.2-0.3MPa to prevent part deformation

Use fine-grained glass beads (220 mesh or more) for micro polishing

Control the processing time within 30-60 seconds

2. Processing of complex structural components

For hardware components with holes and grooves:

Protect key areas with tape in advance

Adopting a multi angle alternating spraying method

Add auxiliary rotating devices to ensure uniform inner surface treatment

Appropriately extend the processing time (2-3 minutes)

3. Anti deformation techniques for thin-walled components

Adopting low-pressure slow injection mode

Choose spherical abrasive to reduce impact force

Double sided alternating treatment to maintain stress balance

Use specialized fixtures to fix workpieces

4、 Common problem solutions

1. Uneven surface treatment

Possible reasons and countermeasures:

Uneven abrasive mixing - regularly clean the sand storage tank

Irregular movement of spray gun - using mechanical automatic spray gun

Excessive abrasive loss - timely replenishment of new abrasives (old to new ratio 1:3)

2. Overly rough surface

resolvent:

Replace with finer grained abrasives

Reduce injection pressure by 0.1-0.2MPa

Increase the spraying distance by 50-100mm

Reduce processing time by 30% -50%

3. Abrasive embedding problem

Preventive measures:

Thoroughly remove oil from aluminum alloy parts before use

Control the environmental humidity between 40% -60%

Immediately clean with compressed air after processing

Perform secondary vibration polishing if necessary

5、 Sandblasting post-treatment and quality inspection

1. Post processing technology

Cleaning: First blow with compressed air, then clean with ultrasonic waves

Passivation: Stainless steel parts require acid pickling and passivation treatment

Protection: Spray temporary rust inhibitor or package

2. Quality inspection standards

Visual inspection: The surface is uniform without bright spots or residual oxide skin

Roughness test: Use a roughness meter to measure whether the Ra value meets the requirements

Adhesion test: Conduct a scratch test to verify the adhesion of the coating

Size detection: The change in key dimensions does not exceed 0.05mm

6、 Safety operation standards

Protective face shields, dust masks, and gloves must be worn

The sandblasting machine is well grounded to prevent static electricity accumulation

Maintain good ventilation in the work area

Regularly inspect the wear of sandblasting hoses

The pressure of the gas storage tank shall not exceed the rated value

Release pressure before maintenance after shutdown

7、 Process Innovation and Development Trends

Modern sandblasting technology is developing towards intelligence and environmental protection:

Robot automatic sandblasting system improves consistency

The recycling rate of abrasive materials reaches over 95%

New environmentally friendly abrasives (such as ice particles, dry ice) reduce pollution

Real time adjustment of process parameters by online monitoring system

Composite process (sandblasting+electrolytic polishing) improves efficiency

By mastering these sandblasting and polishing techniques, hardware product manufacturers can improve product surface quality, reduce production costs, and enhance market competitiveness. In practical operation, parameter optimization should be carried out based on specific product and equipment conditions, and standardized operating procedures should be established to achieve better sandblasting and polishing effects.