Metal Cutting Fluids Why do we need them?

1
Metal Cutting Fluids Why do
we need them?

• Cooling
• Lubrication
• Also provides-
• Swarf Flushing
• Corrosion Protection

2
Metalworking Fluids

• Basic Principles of Metal CuttingFluids What
  they are how to use them correctly

3
What are neat cutting oils?

• The performance of a neat cutting oil is
  influenced by 3 factors-
• Viscosity
• Additives
• Levels of additives

4
Viscosity

• Viscosity (at specific temperature)
• Measured in centistokes (cSt _at_ 40c)
• Range from 5 to 40 cSt
• Water 1cSt
• Hydraulic 32cSt

5
Effects of viscosity
Cooling Swarf Flushing
Lubricity
Viscosity
Viscosity
6
Lubricity additives

• Base Mineral Oils
• Highly refined oils of high, medium or low
  viscosity
• Esters
• Natural fats
• Vegetable oils
• Synthetic esters

7

Lubricity additives

• Anti-wear additives
• Typically phosphorous compounds or ZDDP
• E.P. (extreme pressure ) additives
• Chlorinated paraffins
• Sulphur
• Usually sulphurised esters or polysulphides

8
Neat Oils vsSoluble Coolants
Cooling
Lubrication
Neat Oils
Soluble Coolants
9
What are coolants?
Lubricity Additives

Add to water
Emulsifiers detergents
Metalworking coolant or emulsion
HOCUT ?
Corrosion Inhibitors
Bio- Protection
10
Oil in water emulsion
11
Coolant jargon

• Conventional soluble oil
• Semi-synthetic
• Synthetic
• Extreme pressure
• Biostable

12
Factors affecting Coolant life

• Micro-Organisms
• Tramp oil
• Water Quality
• System Design
• People

13
Micro-Organisms ( typically
bacteria / fungi)

• Results in-
• Bad smells
• Coolant separation
• Corrosion
• Increased disposal costs

14
Common Types Of
Micro -Organisms

• Aerobic bacteria
• -live in the presence of air Anaerobic
  bacteria
• -live in the absence of air(bad eggs)
• Yeasts/ Moulds /Fungi
• -visible organism (rubber-like)

15
Tramp Oil

• Oil from positive lubrication leaks
• Often resulting in-
• Bacteria attack
• Coolant separation
• Smoke and fume
• High disposal cost

16
Water Quality

• The presence of inorganic
• salts in coolant make up
• water will affect-
• Coolant stability
• Foaming

17
Water Quality
Ideal Water Hardness 100-200ppm.
Chloride zero Sulphate zero
High salts
Low salts
Soap formation Coolant instability Corrosion Bacte
rial attack
Excessive foaming
Water hardness expressed as ppm. (parts per
million ) as calcium carbonate.
18
Coolant mixing
Always add oil to water(use a mixing
valve if possible) Always mix coolant
before adding to the coolant sump
19
Monitoring control

• Always
• maintain
• concentration
• between
• specified limits.

20
Monitoring control
If concentration becomes too high.

• Possible. skin irritation
• Expensive (product waste)
• Foaming

21
Monitoring control
If concentration becomes too low.

• Bacterial attack
• Corrosion
• Increased disposal
• Expensive

22
Monitoring and control

• How is concentration measured?
• Refractometer --- on-site
• Titration --- on-site / lab.
• Instrumentation --- lab.

23
Fluid Concentration Chart
24
How is Condition Measured? pH readings
4.5 5.0 5.5 6.0 6.5 7.0 7.5
8.0 8.5 9.0 9.5 10.0
neutral
alkaline
acidic
soluble oils
favours bacterial growth
good corrosion protection
acceptable to skin
25
Monitoring corrosion protection

• IP 125
• Steel swarf on
• a cast iron plate.
• (overnight test)

• IP 287
• Cast iron swarf
• on a filter paper.
• (2 hour test )

26
Soluble Oil Trials Machine Cleaning

• Antisep Biocidal Cleaner (A.B.C.) kills
  bacteria dissolves dirt to ensure the new
  coolant has a good start.
• 2-4 A.B.C. circulated with coolant
  for 24/48 hours
• Empty rinse
• Refill with pre-mixed coolant at correct
  conc.

27
Health and safety Skincare

• Handling concentrates
• Concentration control
• Hygiene
• Proper use of skin creams
• Good housekeeping
• HSE guide to metalworking

28
Environmental HS Issues

• There is an increasing demand for products
  that are FREE- from e.g.-
• Nitrite-free
• Chlorine-free
• PCA -free
• Phenol-free
• DEA-free

29
Environmental HS Issues

• Nitrite
• Can react with amines to form
  nitrosamines (carcinogenic).
• DEA -diethanolamine
• Can react with nitrogen from the air
  to form nitrosamines.

Nitrite/DEA in fluids is a health and safety
issue, not environmental
30
Environmental HS Issues

• Chlorine
• Disposal by burning can form dioxin, a
  carcinogen
• Special incinerators needed for safe disposal
• Disposal cost is very high in Europe

Chlorine is an environmental issue, not health
and safety
31
FLUIDCARE SERVICES Health
risks and MWF mists

• HSE are demanding that metalworking fluids users
  should clearly demonstrate that they take every
  practicable step to control fluids, improve their
  condition and reduce exposure.
• We recognise that the new guidance on health
  risks especially regarding asthma and respiratory
  diseases will pose problems for users. We offer a
  package of services aimed at helping customers
  identify the risks and effective measures of
  prevention and control.
• Risk assessment
• Fluids testing and bio-audits
• Exposure monitoring
• Atmosphere control
• New Scandmist air filtration products are also
  available to remove both mist and bacteria from
  machine enclosures. Click on the download to
  learn more about the issues and to see Houghton
  products and services.
• Visit www.hse.gov.uk/metalworking for further
  information.

More Preventing respiratory diseases and
metalworking fluids ScandMist air filtration
equipment