Metal Cutting Fluids Why do we need them?CoolingLubrication Also provides:- Swarf Flushing Corrosion Protection

Metalworking FluidsBasic Principles of Metal CuttingFluids ; What they are & how to use them correctly

What are neat cutting oils? The performance of a neat cutting oil is influenced by 3 factors:- Viscosity Additives Levels of additives

Viscosity Viscosity (at specific temperature)Measured in centistokes (cSt @ 40c)

Range from 5 to 40 cSt

Water = 1cStHydraulic = 32cSt

Effects of viscosityViscosity ViscosityLubricityCooling &Swarf Flushing

Lubricity additives Base Mineral OilsHighly refined oils of high, medium or low viscosity EstersNatural fatsVegetable oilsSynthetic esters

Anti-wear additivesTypically phosphorous compounds or ZDDPE.P. (extreme pressure ) additivesChlorinated paraffinsSulphurUsually sulphurised esters or polysulphidesLubricity additives

Neat Oils vsSoluble CoolantsCoolingLubricationNeat Oils SolubleCoolants

What are coolants? Emulsifiers & detergentsCorrosionInhibitors Bio-Protection LubricityAdditivesHOCUT ?Add to waterMetalworking coolant or emulsion

Oil in water emulsion

Coolant jargonConventional soluble oilSemi-syntheticSyntheticExtreme pressureBiostable

Factors affecting Coolant lifeMicro-OrganismsTramp oilWater QualitySystem DesignPeople

Micro-Organisms ( typically bacteria / fungi)Results in:-Bad smellsCoolant separationCorrosionIncreased disposal costs

Common Types Of Micro -OrganismsAerobic bacteria -live in the presence of air Anaerobic bacteria -live in the absence of air(bad eggs)Yeasts/ Moulds /Fungi -visible organism (rubber-like)

Tramp OilOil from positive lubrication & leaksOften resulting in:-Bacteria attackCoolant separationSmoke and fumeHigh disposal cost

Water QualityThe presence of inorganicsalts in coolant make up water will affect:-Coolant stabilityFoaming

Water QualityWater hardness expressed as ppm. (parts per million )as calcium carbonate.HighsaltsSoap formationCoolant instabilityCorrosionBacterial attack Ideal Water

Hardness = 100-200ppm. Chloride zero Sulphate zeroLowsalts Excessive foaming

Coolant mixing

Always add oil to water(use a mixing valve if possible)

Always mix coolant before adding to the coolant sump

Alwaysmaintainconcentrationbetweenspecified limits. Monitoring & control

Possible. skin irritationExpensive (product waste)FoamingMonitoring & control If concentration becomes too high.

Bacterial attackCorrosionIncreased disposalExpensiveMonitoring & control If concentration becomes too low.

How is concentration measured?

Refractometer --- on-siteTitration --- on-site / lab.Instrumentation --- lab.Monitoring and control

Fluid Concentration Chart

12

.0

R

E

F

R

A

10

.0

C

T

O

M

E

8

.0

T

E

R

R

6

.0

E

A

D

I

N

4

.0

G

B

R

I

2

.0

X

.0

0

1

2

3

4

5

6

7

8

9

10

FLUID CONCENTRATION (%)

Hocut B60

How is Condition Measured? pH readings4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0acceptable to skinfavours bacterial growthneutralalkalinegood corrosion protectionsoluble oilsacidic

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 )

Soluble Oil TrialsMachine 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.

Health and safetySkincareHandling concentratesConcentration controlHygieneProper use of skin creamsGood housekeepingHSE guide to metalworking

Environmental & H&S Issues There is an increasing demand for products that are FREE- from e.g.:-Nitrite-freeChlorine-freePCA -freePhenol-freeDEA-free

Environmental &H&S IssuesNitrite 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

Environmental & H&S IssuesChlorineDisposal by burning can form dioxin, a carcinogenSpecial incinerators needed for safe disposalDisposal cost is very high in Europe

Chlorine is an environmental issue, not health and safety

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

FLUIDCARE SERVICES Health risks and MWF mists

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