JOURNAL OF SYNTHETIC LUBRICATION J. Synthetic Lubrication 2006; 23: 167–176 Published online 18 September 2006 in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/jsl.19

Metalworking fluids from vegetable oils A. K. Singh* and A. K. Gupta Indian Institute of Petroleum Dehradun 248005, India

ABSTRACT The biodegradability of metalworking fluids has assumed very high priority. Biodegradable metalworking fluid formulations consist of vegetable oil, an emulsifier, co-surfactant, fungicide and additives. Non-edible vegetable oils such as neem, ricebran, and karanja oil are renewable, biodegradable and cheaper than synthetic fluids. Oleates and fatty-acid amides of these oils have been used as emulsifiers to eliminate biohard emulsifiers. Additives are used to achieve a high level of performance. Metalworking soluble oil formulations were evaluated for physicochemical characteristics such as emulsion and thermal stability, copper-strip corrosion, iron chip corrosion, deposit-forming tendency on hot metal surfaces, and lubricity. Oil–water micro-emulsions of these oils have higher stability. The emulsions were stable over a wide range of temperatures. Performance of formulations from all three oils are found at par with the ASTM specifications. Neem oil based formulation showed better characteristics than ricebran and karanja oil. Copyright © 2006 John Wiley & Sons, Ltd. key words: metalworking fluids; neem oil; karanja oil; ricebran oil; soluble oil; biodegradable lubricants

INTRODUCTION Machining speeds can be greatly increased if the cutting surface is kept cool and lubricated. Water can be regarded as the first cutting fluid, but modern developments have led to the introduction of advanced water–oil emulsion — soluble oil — incorporating special chemicals, which considerably improve its wettability, lubrication, high cooling power, rust inhibiting and detergency properties. Soluble oils are ideal for general machining processes where cooling, lubrication, cleaning, and extreme pressure characteristics are essential requirements [1]. The manufacture of cutting oil in 2001 amounted to around 200 000 kiloliters in India, of which the soluble type accounted for about 60–65%. There are no sizeable imports of cutting oils. Among the main consumers are engineering industries engaged in metal products, industrial machinery, automobiles, railway equipment, and heavy electrical equipment [2].

*Correspondence to: A. K. Gupta, Indian Institute of Petroleum, Dehradun 248005, India. *E-mail: [email protected]

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Traditionally, the mineral oils and petroleum sulfonates (as oil–water emulsifiers) have been the basic source of metalworking fluid formulations. Various additives are added to the soluble oils to improve the performance of the metalworking fluid [3]. However, petroleum based soluble oils are generally toxic to the environment, exhibit poor biodegradability and ever-changing characteristics with changes in crude oil composition [4]. Petroleum sulfonates also exhibit similar disadvantages. Several areas of development are under investigation but, typically, research effort is concentrated on biodegradable cutting fluids and methods for waste disposal [5]. As faster and more powerful machine tools are developed, an increased proportion of metal cutting involves high metal removal rates, which in turn leads to elevated cutting temperatures. As cutting temperatures increase, the primary role of a cutting fluid is that of coolant and to provide improved lubricity [6]. With the recently devised and introduced ISO 14000 environmental series legislation, consumption of metalworking fluids based on mineral oil is reducing. Companies are looking for a new type of cutting fluid to avoid recycling and disposal problems. However, the ultimate solution will be the use of biodegradable cutting fluids from renewable sources. There has been an increasing demand for environmentally acceptable products suitable for use as lubricants and emulsifiers. This demand has been met to some extent by vegetable oils [7]. These have the attraction of being natural, non-toxic, biodegradable, relatively non-polluting, cheaper than synthetics and derived from renewable raw materials. In the present study an attempt has been made to develop biodegradable or eco-friendly soluble oil from renewable and non-edible vegetable oil components such as neem, karanja and ricebran oil [8]. Vegetable oils are by their chemical nature long chain fatty acid tri-esters of glycerol and provide most of the desirable lubricant properties such as good boundary lubrication, high viscosity index, high flash point and low volatility. These advantages are mainly due to their polar ester structure and higher molecular weight in comparison to petroleum derived hydrocarbons. The major limitations with regard to the use of vegetable oils as lubricants are oxidative stability and low temperature behavior, which can be taken care of by chemical modification of vegetable oil into monoesters and use of performance additives. The fluidity in vegetable oils depends upon double bonds present in the fatty chain. The low temperature behavior, along with oxidative stability of vegetable oil triglycerols, depends on the structure of the fatty acids present. As per fatty acid typical composition of vegetable oils, it contains unsaturated acids such as oleic C18:1 as a major component. This reflects the fact that some of the carboxylic acids and/or esters are derived from naturally occurring materials and therefore contain a mixture of compounds the major component of which is the oxygen-carrying ester compounds. In Europe and the USA rapeseed, soybean, palm and canola oils are being exploited for biolubricants. In India the situation is little different, as the pressure for edible oils is heavy. This leaves only the non-edible oils as potential sources as feed stock for biolubricants. Neem, karanja and ricebran oils are potential candidates [9]. Neem (Mellia azadirachta, family Meliaceae) is a non-edible oil widely distributed in dry tropical parts of Asia. The major producing countries are India, Sri Lanka, Burma, Pakistan, Australia, and Africa. It comprises 40 different active compounds called tetranortriperpernoids or, more specifically, liminoids — the main one being azadirachtin. It exhibits antifeedant, insect repellent and insect sterilization properties. The fruit is ovoid and bluntly pointed (2 cm × 2 cm, weight 0.5 g). It has small amount of pulp and a hard bony endocarp. It contains a seed with a moderately brittle test. Each seed contains one kernel; multiple kernels are rare. The fruit yield per tree is 37–55 kg. The moisture in the commercial neem fruit is 6–7%, reducing to 5% on drying. The kernel, constituting about 45% of the Copyright © 2006 John Wiley & Sons, Ltd.

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seed, contains 40–45% oil. It is a medicinal plant and is used in toothpaste, bath soap, skin care and pharmaceutical preparations. Karanja (Pongamia glabra, family Leguminaceae) is a non-edible oil widely distributed in tropical Asia. The major producing regions are India, the Philippines and the East Indies. Karanja oil is believed to have insecticidal, antiseptic, antiparasitic and cleansing properties. It has been used in India to treat scabies, itching, herpes, eczema and various types of sores. It is mixed with equal parts of lime or lemon juice and used as a liniment for treating rheumatism. The kernel contains 27–39% oil, out of which 24–27.5% can be obtained by expeller. The freshly extracted oil is yellowish orange to brown and rapidly darkens on storage. It has a distinguishable odor and bitter taste. Rice bran (Oryza sativa, family Graminaceae) is mainly produced in Asia, Africa, and America. It is a by-product of the pearling process of rice and comprises the pericarp, aleurone layer, embryo and some endosperm. Crude ricebran oil is non-edible. The technology to produce ricebran oil is relatively recent, dating back some 50 years. During the early 1990s, nutritional studies demonstrated that stabilized ricebran, particularly ricebran oil, significantly reduces cholesterol levels. Despite its similarities to other common vegetable oils, ricebran oil offers several positive properties that make it unique. It has a light and delicate flavor and, once extracted, is extremely stable with extended fry-life. But perhaps its most notable feature is that this oil is trans fat free, heart-friendly, low in saturated fats, natural, not genetically modified, low in free fatty acids and non-hydrogenated. It also has a high level of components with nutraceutical value such as gamma-oryzanol and tocotrienols. Vegetable oils exhibit 70–100% biodegradability, as shown in Figure 1. Their fatty acid composition is well known in the literature and given in Table I. Vegetable oil is thus a desirable option that can solve the disposal problem as it is biodegradable, non-toxic and renewable.

EXPERIMENTAL DETAILS Commercial vegetable oils — neem oil, karanja oil, and ricebran oil — were first purified. Neem oil was dissolved in a mixed solvent containing heptane and ethanol in the ratio 85 : 15. The solvent to feed oil ratio was 3 : 1. The mixture of oil and solvent was cooled to 15°C and the temperature maintained for 5–6 hours. The mixture separated into two layers. The lower layer, containing about 25%

M

in

er

al o Ve il M go on il oe st er D ie st C om P er pl oly ex ol P s Po ol y ly o O ls le Ph ate s th a D late im s e Tr rate im s Py era ro te m s er at es

100 90 80 70 60 50 40 30 20 10 0

Figure 1. Biodegradability of various lube base oils. Copyright © 2006 John Wiley & Sons, Ltd.

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Table I. Fatty acid composition of vegetable oils. Type

Neem oil

Ricebran oil

Karanja oil

Saturated acids C12 — C14 — C16 14.0 C18 19.0

— 0.4 17.0 2.7

1.6 7.9 4.0 2.0

Unsaturated acids C18:1 49.0 C18:2 9.5 C18:3 — Ricinoleic — Erucic —

45.5 27.7 — — —

62.0 12.0 5.0 — —

8.3 10.14 6.1

Cost, USD/Quintal

43.4 68.03 23.8

Pour point, °C ASTM D 97

100°C

Acid value, mg KOH/g ASTM D 664

40°C

Sap.value, mg KOH/g ASTM D 94

Karanja Neem Ricebran

Kinematic viscosity, cSt ASTM D 445

Iodine value, gm/100 ml ASTM D 1159

OIL

Viscosity index ASTM D 2270

Table II. Typical physico-chemical characteristics of refined vegetable oils.

172 135 222

78 66 102

179 166 183

22 23 85

−9 +9 −3

60 100 62

of oil mass as gummy material, was removed. The upper layer, containing oil and solvent, was treated with clay to remove free fatty acid then distilled to remove the solvent. Ricebran oil and karanja oil, purchased from the market, were refined by dissolving in n-heptane and cooling the solution to 15°C for 5–6 h. The solvent to oil ratio used was again 3 : 1. The gummy mass, which amounted to abut 15% of the oil by weight, former the bottom layer and was separated off. The oil-bearing upper solvent layer was treated with clay to remove the free fatty acid, then the solvent was removed by distillation to yield the refined oil. The refined vegetable oils were characterized by methods prescribed in ASTM standards [10]. The kinematic viscosity, viscosity index, iodine value, saponification value, acid value, and pour point of the oils and their approximate cost are reported in Table II. The emulsifiers were analyzed as per standard method ASTM/IP. The estimation of oil and oleate was done by modified IP 74 (which is prescribed for sulfonates and where isopropanol/water 50/50 mixture is prescribed to dissolve sulfonate for oil extraction) in the sense that oleate was dissolved in isopropanol/water 75/25 mixture for the extraction of oil. Isopropanol/water 75/25 mixture is found suitable for fatty acid soap solubility and oil extraction. However, the rest of steps remain similar to IP74. Sodium carbonate, sulfate, hydroxide and water estimations were done as per IP 74 and reported in Table III. Refined vegetable oils (as base oils) were used to formulate the neat cutting oils [11]. Besides the procured oleates, some fatty acid soaps were also prepared in the lab [8]. Vegetable oil (neem, karanja Copyright © 2006 John Wiley & Sons, Ltd.

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Neem

Karanja

Ricebran

TEPA-oleate

TEA-oleate

Lithium oleate

Sodium oleate

Soap % wt/wt Inorganic % wt/wt Organic % wt/wt Water % wt/wt Alcohols % wt/wt

DEA-oleate

Table III. Fatty acid soap and oleate analysis.

95 — 3 1 1

94 3 1 1 1

93 4 1 1 1

93.5 4 1 1 0.5

94 — 4 1 1

95 — 3 1 1

95 2.5 1 1 0.5

94 2.5 2 1 0.5

Sodium salt of fatty acid

or ricebran) and sodium carbonate solution in water were mixed and boiled to saponify the glycerides into sodium carboxylates and glycerol. After separation of glycerin the carboxylates are concentrated by evaporating the water. Base oil 50% wt was mixed with emulsifier (sodium carboxylates, sodium oleate or other oleates) at 35% wt. The mixture was homogenized by heating at 30–100°C for 1 h and stirring to obtain clear solution. Then ligno sulfonate 5% wt was added as coupling agent. Also added were 2,6-ditertiary-butyl-4-methyl phenol (100 ppm) as antioxidant, cresylic acid (100 ppm) as fungicide, dibenzyl disulfide (100 ppm), sulfurized neem oil (100 ppm) and phosphosulfurized cardanol molybdate (100 ppm) as extreme pressure additive, 1H-benzotriazole (100 ppm) and sodium HAB sulfonate as antirust additives, and isobutanol (5% wt) as co-surfactant [12–15]. The mixture was further homogenized for 30 minutes. The pH of the solution was adjusted to 7–9 by adding sodium carbonate. The solution was cooled down to room temperature by stirring. The final composition is given in Table 4. The neat soluble oil was mixed with water in 20 : 80 to 80 : 20 ratio to produce oil–water emulsion. This emulsion was evaluated for its different characteristics (Table V) and some important stability characteristics (Table VI). The formulated soluble oils were evaluated as per standard methods prescribed in ASTM and results are reported in Tables VII and VIII. Kinematic viscosity, flash point, acid value, pour point, ash value and water. Performance evaluation was made to find out the suitability of the various soluble oil formulations by standard methods. The main characteristics evaluated were emulsion stability, thermal stability, corrosion, deposit-forming tendency on hot metal surface and lubricity. The evaluation results are reported in Table VII.

RESULTS AND DISCUSSION Emulsion Stability (ASTM D 1479) Tables IV and V indicate that stable micro-emulsion of vegetable oils is formed with particular soaps only, for example, karanja oil with sodium oleate and ricebran oil with TEA oleate. No solubility problem was observed for any emulsifier in vegetable oils. Some combinations, however, show emulsion stability as a boundary case, that is, near to stable, showing slight separation; these formulations give stable emulsion with addition of small amount of heavy alkylate (LAB) but this option will reduce the biodegradability. Blending with HAB is therefore not advisable when the aim is to produce a Copyright © 2006 John Wiley & Sons, Ltd.

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Veg. oil ester

DEA-oleate

Sodium salt of fatty acid

TEPA-oleate

TEA-oleate

Lithium oleate

Sodium oleate

Water

HAB

Additivepack %

Co-surfactant

Coupling agent

NaOH

S. No.

Component %

Table IV. Metalworking soluble oil formulation.

60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60

27 — — — — — — 27 — — — — — — 27 — — — — — —

— 27 — — — — — — 27 — — — — — — 27 — — — — —

— — 27 — — — — — — 27 — — — — — — 27 — — — —

— — — 27 — — — — — — 27 — — — — — — 27 — — —

— — — — 27 — — — — — — 27 — — — — — — 27 — —

— — — — — 27 22 — — — — — 27 22 — — — — — 27 22

1.9 1.9 1.9 1.9 1.9 1.9 1.9 1.9 1.9 1.9 1.9 1.9 1.9 1.9 1.9 1.9 1.9 1.9 1.9 1.9 1.9

— — — — — — 5 — — — — — — 5 — — — — — — 5

0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1

5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

2

Neem oil

3

Ricebran oil

1

Karanja oil




DEA = di-ethalano amine, TEPA = tetraethylene pentmine, TEA = tri-ethalano amine, HAB = heavy alkyl benzene (a waste byproduct of detergent LAB).

oil : water → Karanja oil Karanja + HAB 5% Neem oil Neem + HAB 5% Ricebran oil Ricebran + HAB 5%

1 : 90 × × × × Ss St

1 : 45 × × × × ss St

1 : 90 × × × × × ×

1 : 45 × × × × × ×

1 : 90 × × × × × ×

1 : 45 × × × × × ×

1 : 90 ss St × × × ×

1 : 45 ss St × × × ×

1 : 90 ss St ss St × ×

Sodium oleate

TEA oleate

TEPA-oleate

DEA-oleate

Sodium salt of fatty acid

Emulsifier →

Lithium oleate

Table V. Emulsion stability test of metalworking soluble oil as per ASTM D 1479/64.

1 : 45 ss St ss St × ×

1 : 90 St St St St St St

1 : 45 St St St St St St

St = Stable, SS = Slightly stable, × = Non-stable.

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Friction coeffcient mm, ASTM D 5183

Wear scar diameter, mm

3

Temperature variation test ASTM D 3707/09

2

Biodegradability, % ASTM D 5864

Karanja oil + sodium oleate Neem oil + sodium oleate Ricebran oil + sodium oleate

Low temp Stability ASTM D 3709

1

Deposit on metal Federal Method 791-3464 — Panel cocker test

Formulation Iron chips rust test ASTM D 4627

SN

Copper strip corrosion test ASTM D 130

Table VI. Characteristics of metalworking soluble oil (emulsion).

Pass

Pass

Pass

Pass

90

Pass

0.075

0.542

Pass

Pass

Pass

Pass

93

Pass

0.085

0.525

Pass

Fail

Pass

Pass

93

Pass

0.078

0.521

Reactable sulfur, 100°C ASTM D 1275

3

Sap. value, mg KOH ASTM D 94

2

Flash ooint, °C ASTM D 92

Karanja oil + sodium oleate Neem oil + sodium oleate Ricebran oil + sodium oleate

Water % ASTM D 95

1

Ash % ASTM D 874

Formulation

Total acid no. mg KOH ASTM D 664

SN

K. Visc 40°C, cSt ASTM D 445

Table VII. Characteristics of formulated metalworking soluble oil (neat).

27.56

Nil

0.01

2.0

211

175

Nil

26.2

Nil

0.02

2.0

218

165

Nil

18.15

Nil

0.018

2.0

228

172

Nil

completely biodegradable cutting oil. The test for stability under low and high temperature (ASTM D 3707 and 3709) reveals that the samples, which are stable at normal temperature of 20–30°C, also remain stable at high as well as low temperatures. This is the first requirement for soluble cutting oil. The selected vegetable oils are suitable for cutting-oil emulsion but with some particular soaps. The emulsions are stable over a wide range of temperatures. Stability increased by addition of alkyl benzenes may be due to its structure, which enhanced the size of oil–water micelles. Copper Corrosion (ASTM D 130) The results of the copper strip corrosion/tarnish test for neat oil at 100°C for 3 h in Table 6 indicate that all selected formulations passed the corrosion standard. Free fatty acids were responsible for the Copyright © 2006 John Wiley & Sons, Ltd.

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copper corrosion more than oils. This is an indication of de-coloring the cutting metals, and is probably due to ionization of oils or emulsifier. Care must therefore be taken during product processing to get rid of free fatty acid and easily hydrolyzable oil or emulsifiers. Rust Test (ASTM D 4627) The iron chip rust test was performed on emulsion (water–oil 80 : 20) for 24 h on emulsions and no rust spot was found on filter paper with samples. However, the ricebran based sample generated a spot. Rust test results are given in Table VI. All the formulations passed the rust test on iron chips but the ricebran sample failed. Failing the test, however, does not establish the unsuitability of the selected oil or emulsifier but indicates the need for suitable anti-rust additives. The additives used here were developed for mineral oils. The development of matching additives for vegetable oils and their derivatives may improve anti-rust performance. Deposit on Hot Metal Surface (Federal Method 791-3464) This method is very similar to ASTM D 3711 and is indicative of detergency, cooling ability and deposit-forming tendencies of the lubricants on hot metal surfaces. The panel temperature was kept at 250°C for 5 h. Deposit test is a Pass-Fail test. Deposit less than 20 mg on panel means pass and deposit more than 20 mg means fail the test. The formulations — emulsion (water–oil 80 : 20) passed the deposit test (Table VI). Generally deposits were in the range of 5–10 mg, indicatomh that these formulations will not produce any residual deposits during metalworking due to good detergency and cooling ability. Lubricity (ASTM D 5183) The lubricity test on emulsion (water/oil 80 : 20) was carried out on a four-ball machine, which is a standard method. The results were counter-checked on a high frequency reciprocal rig. The values of the friction coefficient and wear scar diameter at 120°C are given in Table VI. The selected formulations lubricate the metal surface nicely which is shown by the substantial reduction in wear scar diameter (WSD), meeting the requirements of the Indian Standard BIS 1115 and 3065. Biodegradability (ASTM D 5864) The typical biodegradability tests on ricebran neat cutting oil show (Table VI) that ‘soluble oil’ formulations based on karanja, neem and ricebran oils are more than 90% biodegradable. This is most valuable information, which will help in solving disposal problems. On disposal it will degrade rapidly and significantly. Toxicity (Bacteria Toxicity Test DIN 38 412, Part 8) This determines cell multiplication inhibition (EC10 and EC50 values). The pseudomonas type of bacteria used for the test is found in wastewater and in the soil. The test on neat oils indicates that all three vegetable oils at EC50 with 200 mg/L are practically non-toxic. On disposal it will not harm aquatic animals. Copyright © 2006 John Wiley & Sons, Ltd.

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Table VIII. Typical biodegradability test results (ASTM D 5864-95) ricebran oil formulation. T21

CO2

33.1 39 31.7 36.2 36.1 37.2 42.9 39.1 36.7 42.8 51.7 52.8 40.7 0.6525 97.37 54.86 Sample

11.11 3.15 11.51 5.76 4.95 5.32 1.32 2.53 2.31 3.34 0.99 1.14

14.26 25.78 31.53 36.48 41.80 43.12 45.65 47.96 51.30 52.29 53.42

T2

ERBF

Cum. CO2

T22

CO2 evolved

Cum. CO2

34.8 37 32.3 35.6 63.7 40 42.4 40.4 38.2 46.2 39.2 40.3 40.3 0.653 96.49 73.83 68.74

9.24 5.35 10.85 6.42 4.29 2.24 1.87 1.10 0.66 −0.40 14.74 14.89

14.59 25.45 31.86 36.15 38.39 40.26 41.36 42.02 41.62 56.36 71.24

T23

CO2

40.9 36.8 31.8 32.9 35 39.1 44.1 39.1 37 39.2 43 40.1

2.53 5.57 11.40 9.39 6.16 3.23 0.00 2.53 1.98 7.30 10.56 15.11 40.8 0.653 97.689 77.54

Cum. CO2 8.10 19.50 28.89 35.05 38.28 38.28 40.81 42.79 50.09 60.65 75.75

Result: The sample is fairly biodegradable.

Discussion The study shows that it is possible to formulate the biodegradable metalworking soluble oil based on refined non-edible vegetable oil found in India without any chemical modification. Disposal problems are also eliminated. Due to the higher flash point of vegetable oil, it will be safe from fire hazards. It will reduce health hazards to the operators who are working in the oil mist during high-speed metalworking. CONCLUSIONS • As mineral oil is non-biodegradable, toxic and non-renewable, there are problems with its disposal. • Vegetable oils give stable oil–water emulsion with some specific emulsifiers. The stability of the emulsions is not affected by temperature variations. • Amongst the emulsifiers taken for the study, sodium oleate performed best. The formulations based on neem and karanja oil performed better than that with ricebran oil. • HAB, being an aromatic compound, enhanced the emulsification and stability when blended with vegetable oil. It can be used as an additive. However, it does reduce the biodegradability. • Matching additives and optimization of proportions of components in the soluble oil formulations need further study. • The vegetable oil based metalworking formulation will give enhanced performance. • It is possible to use the formulated biodegradable soluble oils commercially, which will eliminate the problems of disposal. Copyright © 2006 John Wiley & Sons, Ltd.

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ACKNOWLEDGEMENT

We are grateful to Dr. M. O. Garg, Director, Indian Institute of Petroleum, Dehradun, for providing facilities for carrying out this work and granting permission to publish it.

REFERENCES 1. Shell Petroleum Company. Cutting Oil (No. 6991). Alabaster Passmore: London, 1956. 2. Indian Institute of Petroleum. Market survey of cutting oil in India, IIP Reports 3255. Indian Institute of Petroleum, Dehradun, India, June 1974. 3. Olds WJ. Lubricants, Cutting Fluids and Coolants. Cahners: Boston, 1973. 4. Howes TD, Tönshoff HK, Heuer W. Environmental aspects of grinding fluids. Annals of CIRP 1991; 40:523–560. 5. Akagawa A. Development of cutting fluids which are environment- and human-friendly. International Journal of the Japan Society for Precision Engineering, 1997; 31:253–256. 6. De Chiffre L. The function of cutting fluids in machining. Lubrication Engineering 1988; 44(6):514–518. 7. Glenn TF, Van Antwerpen F. Opportunities and market trends in metalworking fluids. Lubrication Engineering 1998; 54(8):31–34. 8. Indian Institute of Petroleum. Biodegradable metal working fluids, IIP Reports CBD-5/2003. Indian Institute of Petroleum, Dehradun, India, July 2003. 9. Bringi NV (ed.). Non-traditional Oil Seeds and Oils in India, Oxford & IBH: New Delhi, 1987. 10. American Society for Testing Materials. Standard Test Methods for ATSM, Vol 05. 11. US Patent 4948521. Metalworking composition, 1990. 12. John J, Bhattacharya M, Raynor PC. Emulsions containing vegetable oil for cutting fluid application. Colloids and Surfaces A: Physicochemical and Engineering Aspects 2004; 237:141–150. 13. Perry PG, O’Dell GW, van Asten RWF. Cutting fluid. Journal of Cleaner Production 1996; 4:254. 14. US Patent 4882077. Metalworking fluid — formulation requirement, 1989. 15. Stanford M, Lister PM. The future role of metalworking fluids in metal cutting operations. Industrial Lubrication and Tribology 2002; 54:11–19.

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J. Synthetic Lubrication 2006; 23: 167–176 DOI: 10.1002/jsl