Incoming inspection experience of metalworking fluid

September 13, 2022

For the metal processing industry, doing a good job in the incoming inspection of Metal Working Fluid will undoubtedly make the processing process more effective.

ISO9001 stipulates that the materials purchased by the factory for product production must be inspected at the factory. The general manufacturing industry basically has detailed assessment indicators and testing methods for its main raw materials, but the incoming inspection of chemicals used for production assistance is not so meticulously standardized. But in fact, these chemicals may also greatly affect the processing quality of subsequent key products, and there are many hidden dangers!

Here are some methods that can meet the requirements of on-site testing and are highly operational. This issue mainly introduces the incoming inspection standards and inspection methods of emulsifiable products. For example, cutting fluids commonly used in machining sites, forming fluids for forming, and emulsions for copper and aluminum wire drawing.

High energy ahead! The recommended testing items, testing methods and judgment methods are as follows:

1. Appearance

Everyone will definitely say "so easy", who doesn't know how to use visual inspection! But the inspection of appearance focuses on the selection of sampling points. In order to ensure the quality of the product, it is recommended to take a sample from the surface layer, the middle or the whole barrel, and the bottom of the barrel for comparison. If the three samples have differences in color, or differences in sensory viscosity, and there are floating objects in the surface samples, there is obvious sediment at the bottom. , all indicate that the product is not stable enough and uneven. Surface or bottom samples with >1% insolubles are unacceptable unless otherwise specified by the supplier.

2. Emulsion stability

This item is very critical and is recommended as one of the must-check items. The same as the appearance of the inspection, in order to verify the uniformity of the whole barrel of products, it is recommended to mix the three samples taken in the front with an emulsion with a concentration of 5-10% in tap water, and shake them well for observation. There is the phenomenon of oil separation and soap separation, and this product can be directly judged as unqualified (unless there is a special explanation from the supplier that the product is an unstable system). If there is no obvious change within half a day, it is recommended to place it for another night for observation. If the three samples are stable and the color and particle size of the emulsion are the same, it is qualified. Reminder: For products that are qualified in appearance and emulsification stability, when we conduct further testing and analysis, we can only test the whole barrel or the samples taken from the middle of the barrel, and there is no need to test samples from three sampling points in parallel!

3. pH value detection

Conditional manufacturers recommend using a pH meter for more accurate test results. If there is no pH detection instrument, it is recommended to use precision pH test paper, and it is not recommended to use 0-14 broad-spectrum test paper for detection. When testing, you can directly measure the pH value with the newly prepared emulsion before standing to observe the emulsion stability. Since the pH value specification of each manufacturer's product is different, it is recommended to evaluate whether it is qualified according to the supplier's specification.

4. Refractive reading

$Refractive reading$

The refractive index reading is equal to the assigned concentration divided by the refractive index. Different products have different refractive indices, so when the same concentration is used, the refractive index readings may be different. The purpose of emphasizing the detection of refraction readings here is to compare different batches to ensure that the same batch of the same product has consistent refraction readings at the same concentration, otherwise it can be basically judged as unqualified. The detection of this value is convenient for everyone to use the simplest test method to ensure the formulation stability of different batches of products.

5. Optional item: aluminum corrosion detection
Generally, the above four tests can ensure the adequacy of incoming inspection. However, for some enterprises that need to process easily discolored aluminum alloys, they can consider adding aluminum corrosion tests, especially when adding new products. The standard aluminum corrosion detection method is not introduced here, only the most practical parallel comparison method is recommended for reference. It is recommended to soak the aluminum parts directly in the prepared working solution to observe the discoloration time of the aluminum parts. The general observation period ranges from one week to two or three months; the soaked workpieces can also be placed in the factory to observe the aluminum parts during the placement period. The discoloration status can be used as a reference for the length of time between the workpieces after processing.

The above test items and methods may vary slightly due to different products, and are only for your reference. If you have any other thoughts on the incoming inspection of metalworking fluids, please leave a message to discuss with us, and look forward to growing together with you!

Author:

Mr. James

E-mail:

sales@cn-lubricantadditive.com

Phone/WhatsApp:

8613783582233