petroleum-derived products by their nature have low resistance against microbiological formations, using oil-free and emulgator-free products that are both environmentally favourable and have superior lubrication performance should be the first choice when it comes to select the most sustainable MWF’s.

Managing the fluid quality Once the product is selected, there is a specific procedure that must be followed when using the MWFs. Primarily all products should be transported and stored between 5°C and 40°C, kept indoors in their original containers with the lids closed, protected from direct sunlight and humidity, and be used before the expiration date. If it is stored outdoors, precautionary measures should be taken to avoid contamination by weather conditions, such as placing it horizontally, so moisture cannot infiltrate the bung or storing under a protective cover. Before use after a long storage period, it is recommended to first analyse the products due to the concern of the nitrosamine formation which is classified as carcinogenic.

Considering that approximately 90-95% of the water-based liquid sump consists of water, the water quality is as important as the choice of oil, which varies greatly depending on the source from which it is taken. It may contain dissolved minerals, organic matter, or microorganisms that can have health and safety implications as well as an effect on fluid performance. Therefore, it is vital to have a precise water quality not only to ensure emulsion stability but also to reduce both fluid consumption and disposal. The water used

for the preparation of the cutting fluid should be clean and, Total advises, neutral (pH approx. 7) and should be regularly tested to evaluate if it is following the reference values given below.

The closer the water properties to the ideal values, preferably to deionized, which of course also depends on the product, the longer the stability and lifetime of the bath.

Before using soluble cutting fluids, the system must be cleared of any kind of dirt, soap, and microbiological residues by adding 1% to 3% system cleaner to the sump that is going to be changed while the machine continues its operation. System cleaner must run on the system for at least 24 hours before the old sump is emptied to ensure the system is chemically purged. Prolonged contact with the cleaning agent is not recommended to avoid any skin irritation. It is highly recommended to rinse the system several times with water, preferably by adding 1% new oil to the water, after the tank has been completely drained of the lubricant and possible solid dirt and debris. If in doubt, ask your fluid supplier or refer to your machine manufacturer for advice and guidance.

As sump stability is the most critical property of the soluble MWFs, consequently there is a specific mixing procedure to be followed for preparing the sump. It is recommended that an automatic mixer is used if possible, at a minimum of 10°C ambient temperature to maintain a proper mixture that is balanced upon its alkalinity, acidity, and hydrophilic-lipophylic balance

* Nitrate concentrations are indicated by the German legislation (TRGS 611).

** The maximum values depending on the products

Continued on page 12 LUBE MAGAZINE NO.163 JUNE 2021 11

Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53