Handheld Powder Spray Bulb for NDT Dry Magnetic Powder Application

Handheld Powder Spray Bulb for NDT Dry Magnetic Powder Application

The rubber ball dry powder applicator (Bulb Dry Powder Applicator) is a simple manual powder spraying tool based on the physical principle of air pressure difference. It is widely used in non-destructive testing (NDT), medical, pest control and other fields. The core function is to generate an airflow by squeezing the rubber ball, which then blows out the dry powder and evenly covers the target surface. 

I. Core Structure (Taking NDT Magnetic Powder Spraying Ball as an Example)
- **Rubber Ball (Bulb)**: High elasticity rubber material, providing the power source for the device. Compression generates airflow, and when released, it automatically retracts into the air chamber.
- **Powder Storage Chamber/Tube Body**: Internal space for loading dry magnetic powder, powder, and other powder materials.
- **Spray Head/Nozzle**: Front end with multiple holes (such as 32 φ0.9mm small holes), dispersing the airflow and ensuring uniform powder spraying to prevent blockage.
- **One-way Valve/Ventilation Structure**: Some models have a built-in one-way valve to ensure that air can flow in only one direction, preventing powder backflow and ensuring stable powder discharge each time during compression. 

II. Detailed Working Principle (4-step cycle)

III. Principle and Features
- **Pure mechanical, no power supply**: Completely relying on rubber elasticity and pressure difference, the structure is simple, with low failure rate and extremely low cost.
- **High controllability**: The squeezing force can control the powder output and spray distance. Light pressing results in a small amount, heavy pressing results in a large amount, suitable for precise local spraying.
- **Wide applicability**: Suitable for dry fine powders (magnetic powder, medicinal powder, insecticide powder, etc.), and is often used for dry powder application in NDT (non-destructive testing) for magnetic particle inspection.
- **Easy maintenance**: No complex components. When clogged, simply clean the nozzle and it can be reused repeatedly. 

IV. Adaptation to NDT Scenarios
In magnetic particle inspection, after the workpiece is magnetized, defects will generate a **leakage magnetic field**; by evenly spraying dry magnetic powder with this tool, the powder will be attracted and gathered by the leakage magnetic field, clearly revealing surface/near-surface defects such as cracks and pores, and the inspection can be completed with the aid of black light/white light observation.