The contents of the mixture results test
First, the setting of mixing uniformity test standards
This standard is not uniform, but is set according to the different requirements of various industries and enterprises. The setting of inspection standards should follow the following principles:
1. The higher the requirement of mixing uniformity, the smaller the sample measurement of inspection sampling;
2. The higher the mixing uniformity requirement, the smaller the allowable error value when testing.
Second, the steps of inspection and analysis
The detection of powder mixing uniformity can be roughly divided into three steps:
1. Select a number of representative positions (such as upper, lower, left, right, center, etc.) from the container after the mixing work is completed, and take out a number of powder samples with a special powder extractor (as shown below).
2. Carry out microscopic observation or chemical testing on the inside of the powder sample to ensure whether the powder is uniform at the microscopic level.
3. For the comparison of two or more samples with the formula, the difference test is carried out to identify whether the powder is uniformly up to standard in the macro.
3. Methods of inspection and analysis
1. Sensory test method:
This is a difficult test method, relying on people with rich experience to observe, particle feel, etc., to analyze and judge whether the mixing uniformity is up to standard. This is not scientific enough to quantify the results, but it is still commonly used.
2. Use standard methyl violet test method (as shown below) :
3. Microscopic observation (microscopic particle uniformity test) (as shown below):
Advantages are intuitive, the disadvantage is not easy to quantify the conclusions. And dark material is not easy to observe clearly.
4. Downstream product inspection method:
Using the quality of downstream products to test the mixing uniformity is also a common method, the advantage is convenient and direct, the disadvantage is that there is no qualitative and quantitative analysis means, and it is easy to cause greater losses after finding problems.