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Q1Which factors should we consider when choosing water-soluble cutting fluid?
A1

a. Type of water-soluble cutting fluid
b. Processing methods
c. Material of workpiece
d. Biological stability
e. Without skin irritation
f. Resistance to tramp oils
g. Safe, healthy and environmental friendly

Q2How to extend the life of water-soluble cutting fluid?
A2

a.    Control the spilling oil from machine strictly and clear up the tramp oils from the oil tank regularly.

b.    Avoid rags, tools, food residue and rubbish getting into the oil tank of machine.

c.    Turn on the pump to increase the oxygen content of fluid during long shutdown period.

d.    Well maintain the concentration of the cutting fluid at the recommended range.

Q3What problems will water-soluble cutting fluid of low-concentration cause?
A3

a.   Poor surface finish.

b.   Rust the iron workpiece and machine.

c.   Increase the wear of tools and grinding wheels, and reduce usage life.

d.   The fluid becomes spoilt and smelly easily.

Q4What will be caused in using different waters with water-soluble cutting fluid?
A4

a.   If the water is too soft, it may cause foaming problem and affect the processing.

b.   If the water is too hard, it may cause the separation of oil and soap which will affect the anti-rust performance of cutting fluid.

Q5What lead to the breeding of bacteria in water-soluble cutting fluid?
A5

a.     There are bacteria in the materials, such as the bacteria in the water.

b.     Bacteria in air get into the cutting fluid.

c.     Cutting fluid is infected when the workpieces are transferred between the processes.

d.     Bad habits of the operators to throw rubbish into the tank.

e.     Poor cleanliness of machines and workshops.

f.    Not following the recommended concentration of the cutting fluid.

Q6Why do some countries have explicitly banned the use of diethanolamine (DEA) in water-soluble cutting fluid?
A6

It is because the mists or droplets of diethanolamine (DEA) will irritate eyes, nose, throat and lung severely.  It may even damage liver and kidney.

Q7Why do some neat cutting oils induce color change on non-ferrous metals?
A7

Certain neat cutting oils contain active lubricant additives which cause color change in machining non-ferrous metals. Therefore, it is advisable to use neat oils without active lubricant additives for non-ferrous metal machining.

Q8What is the appropriate way of mixing water-soluble cutting fluid?
A8

a. Always add the neat oil into water to produce stable oil-in-water emulsion when manual mixing. Do not reverse the order to avoid the formation of unstable water-in-oil emulsion.

b. It is highly recommended to use fluid mixer which will enhance to form the stable oil-in-water emulsion at the preset dilution ratio.

c. If the concentration of the diluent is higher than recommended concentration, we should prepare moderate low concentration diluent by calculation and then add it to the sump. Do not add water to the sump directly and we may use the refractometer to correctly measure the concentration of the diluent.

d. If the concentration of the diluent is lower than recommended concentration, we should prepare moderate high concentration diluent by calculation and then add it to the sump. Do not add neat oil to the sump directly and we may use the refractometer to correctly measure the concentration of the diluent.

Q9Is it OK that we mix together two different cutting fluids for use?
A9

No. Different type of fluids has different chemical ingredients. The mixing may break the balance of their own system which may cause the separation of some chemical components that lead to the instability and the decomposition of the diluents and eventually affect the processing. If there is no alternative but mixing, please consult your supplier.

Q10What are the causes and treatment methods of rusting machine or workpiece?
A10

There are many causes of rusting and its mechanism is complicated. The typical causes and treatments are as follows but it may be caused by the combination of the following reasons.  Please consult your supplier if necessary.

a.   Low concentration of the diluents - Check the concentration with refractometer. Adjust and maintain it at the recommended range.

b.   Contamination - Identify and remove the contaminant causing the rusting, such as salts for heat treatment, floor cleaner or bacteria, etc.

c.   Poor water quality - Some rust-causing ions exist in poor quality water. Use water of better quality or purified water.

d.   High temperature / high humidity environment - Lower the temperature and the humidity, and/or apply rust inhibitor to the finished workpiece.

e.   Corrosive environment – Identity the source, enhancing ventilation and draining the corrosive fumes away.

f.    Low pH value - Add small amount pH-adjusting agent.

g.   Workpiece treatment/storage - Make sure workpiece are stored in a dry and well ventilated environment, separated by clean plastic parts if necessary. Rust inhibitor should be applied for long term storage.

Q11How to manage and maintain water-soluble cutting fluids?
A11

a.   Concentration management - It is recommended to have daily checking of the diluent concentration in order to ensure timely adjustment of the concentration when it is out of the recommended range. Remember to implement the adjustment by preparing moderate high or low concentration diluents to add into sump. Do not add neat fluids or water to sump directly.

b.     pH management - Check the pH value of the diluents on a regular basis. Find out the reason of the variation of pH and solve it. pH value may have decrease drastically after use for some time.  Some pH stabilizer may help.

c.     Remove the tramp oil spill on a regular basis, using a professional skimmer if necessary.  Keep production environment clean, preventing tramp oils, debris or other contaminants getting into the diluent.

d.     A long downtime (two days or longer) will lead to the growth of bacteria and cause stink odor. We should pump the solution into circulation with air pump to increase its oxygen content.  Undermine the ideal environment for the growth of anaerobic bacteria while preventing the bacterial and fungal growth.

e.     It is proposed to assign a person to be in-charge-of fluid management to ensure the above measures are carried out strictly.

Q12Which factors should be considered when choosing stamping oil?
A12

a.     Stamping process

b.     Material of workpiece

c.     Thickness of workpiece

d.     Requirement of residue after volatilization

e.     Anti-rust requirement

f.    Oil application method

g.     Shape of workpiece

h.     Cleaning requirement of follow-up process

Q13Why do most customers choose volatile stamping oil for sheet stamping?
A13

The solvent based stamping oil will evaporate from the surface and won’t pollute the workpiece, benefit to the follow-up processing and cleaning.

Q14Why most drawing oils contain chlorine extreme pressure additive?
A14

Chlorine extreme pressure additive supplies strong adhesion and benefits the formation of film on the surface.  At the same time, the working temperature in drawing process is lower than that in cutting machining.  Drawing oils containing extreme pressure additives have better performance at this temperature.

Q15Why should we consider the NLGI level when choosing grease?
A15

NLGI defines grease in nine grades in 000、00、0、1、2、3、4、5、6 based on its working penetration. It stands for the hardness, consistency and mobility of the grease. The higher NLGI level, the more sticky the grease is and harder to fill the friction gap, as well as the larger friction; the lower of NLGI level, the better the mobility is but easy to lose.

Q16Why do steelworks, rolling mills and other steel companies choose calcium sulphonate complex grease as lubricant?
A16

Because calcium sulphonate complex grease has excellent water resistance and thermal stability, especially for the harsh conditions such as water rinsing, high temperature or high loading. It is perfect for the steel industry.

Q17What is the difference between H1 and H2 level in NSF certification?
A17

NSF is the short form for National Sanitation Foundation of US. NSF H1 level indicates that the lubricant is non-toxic and can be applied to the machines which have the opportunity to contact with food. NSF H2 level indicates that the lubricant is non-toxic, but not recommended for the machines which have the opportunity to contact with food.

Q18Shall we use kerosene instead of EDM oil for electro-discharge machining?
A18

No. The flash point of kerosene is extremely low and it is highly flammable. The flash point of typical EDM oil must be above 100℃.

Q19Why does the material still rust even though the workpiece has been coated with rust inhibitor?
A19

It may be due to improper use of rust inhibitor. If the surface of workpiece is not clean enough and dry completely, coating of rust inhibitor will trap the contaminants and moisture which in turn promotes rusting.

Q20Why can’t we spray the anti-rust spray close to the workpiece?
A20

Close spraying will make the active ingredient accumulate in the centre and proliferate around. There will be watermark and the spray cannot form a dense protective film to affect anti-rust performance. The proper spraying way is to put the aerosol can vertical and keep 15 to 30 cm distance from the mould, then spray in “Z” style evenly. You may repeat the action if