Summary of test methods for powder resting angle
The angle of repose of powder is an important parameter in powder engineering, which evaluates the fluidity, compressibility and packing properties of powder. In the powder repose angle test, several common test methods are used: discharge angle method, injection angle method, sliding angle and shear box method.
1. Discharge angle method
The discharge angle method is a common testing method. The powder sample is formed at a certain angle through a funnel device, and then the angle at which the powder flows out of the funnel is observed. By measuring the angle of outflow, the angle of repose of the powder can be calculated. This method is simple and intuitive and suitable for many powder samples.
2. Injection angle method
The injection angle method is similar to the discharge angle method, but the injection direction of the powder sample is opposite to the discharge angle method. In this method, the powder sample is injected from the bottom into a funnel at a certain height, and then gas is injected from the top of the funnel at a certain angle. By measuring the angle of outflow, the angle of repose of the powder can be calculated.
3. Sliding angle method
The sliding angle method is another common testing method. The powder sample is placed on an inclined plane and the inclination angle of the plane is gradually increased until the powder starts to slide. By measuring the sliding angle, the sliding angle of the powder can be calculated. This method is suitable for evaluating the fluidity of powder. The larger the sliding angle, the better the fluidity of the powder.
4. Shear box method
The shear box method is a relatively new testing method. The powder sample is placed in a shear box and a certain amount of pressure is applied to cause shear deformation. By measuring the pressure and shear angle during shear deformation, the shear modulus and angle of repose of the powder can be calculated. This method is easy to operate and has high measurement accuracy, and is widely used in scientific research and production of powder engineering.
| Test Methods | difference |
| discharge angle method | The sample flows out of the top of the funnel. Measure the angle of flow out of the funnel. |
| injection angle method | Sample is injected into the funnel from the bottom and the angle of exit from the funnel is measured. |
| sliding angle method | The sample is placed on an inclined plane and the angle of inclination of the plane is gradually increased. The angle at which sliding begins is measured. |
| shear box method | Apply pressure to cause shear deformation of the sample and measure the pressure and shear angle during shear deformation. |
In summary, the discharge angle method, injection angle method, sliding angle and shear box method are common methods for testing the angle of repose of powders. Each method has its own unique advantages and disadvantages, and the appropriate method should be selected based on specific testing needs and sample characteristics. These test methods provide effective tools for powder engineering and help optimize the design and production process of powder materials.
