European legislation, notably REACH, is prompting metalworking fluid makers/importers to substitute 'bad' chemicals for 'good' ones in their products. REACH stands for Registration, Evaluation and Authorisation of Chemicals, and also requires the communication of safety information in Safety Data Sheets (SDSs – see HSE website
) and provides for the restriction of chemicals.
It is increasingly commonplace for latest coolant and metalworking fluids (MWFs) to boast that they do not incorporate one or other chemicals – chlorinated paraffins, formaldehyde and, most recently, boric acid. 'Bad' substances.
Chlorinated paraffin is used as an extreme pressure additive in both neat oils and water miscibles; formaldehyde is employed in the creation of biocides for water miscibles; and boric acid is employed in the creation of corrosion inhibitors, also for water miscibles.
On chlorinated paraffin, it is only long chain chlorinated paraffins (LCCPs) that are employed in MWFs. Short chain chlorinated paraffins are restricted under REACH, with strict controls on how much can be employed in any product (it is restricted). Medium chain types (MCCPs) also exist and these are classified as dangerous to the environment, very toxic to aquatic organisms and may cause long-term adverse effects in the aquatic environment. LCCPs have no such EU-wide damning associations, but must be registered under REACH. That said, the UK's environment agency doesn't like them. Its website says of LCCPs, within the context of the Agency's Pollution Inventory: "A group of man-made chlorinated chemicals used in metalworking and other industrial applications. They are toxic to wildlife, long-lasting and build up in the tissues of living organisms".
Biocides created by reacting formaldehyde, together with corrosion inhibitors created by reacting boric acid, are perfectly legal and still employed in MWFs, while free formaldehyde and free boric acid are okay – nothing is banned. As it happens, neither boric acid nor formaldehyde exists as a free chemical in MWFs, under normal working conditions, according to Master Chemical's Peter Blenkinsop, technical director (see also Machinery article here
, and box item below).
Nevertheless, the inclusion of boric acid on the so-called REACH Candidate List (CL) last year has seen MWF SDSs highlighting the substance, bringing it to the greater attention of users. There are currently 53 substances named on the Candidate List, incidentally, formaldehyde is not one of them, but is a potential candidate, as are MCCPs.
While formaldehyde does not pop up on MWF SDSs, it is already classified as carcinogenic category 3, Risk Phrase R40 (limited evidence of a carcinogenic effect), hence there's a general whiff of unease associated with it, albeit that the risk is a very specific one, not related to MWFs explicitly.
So, with talk of REACH Candidate List nomination (with this also offering potential for phase-out under the Authorisation process), MWF SDSs drawing attention to 'bad' chemicals and with a sense of health or environmental unease surrounding others, users increasingly react negatively to such things. This is likely to be particularly so if the company has a social corporate responsibility strategy or ISO140001 accreditation. And while ISO 140001 doesn't set targets, it does encapsulate continual improvement. So who's been releasing products that demonstrate the trend to 'good' chemicals lately?
High pressure machining of titanium with Master Chemical's VHPE820
Master Chemical Europe (01449 726800) has created Trim E950, a boron and formaldehyde donor-free, chlorine-free, bio-stable cutting and grinding fluid that boasts Rolls-Royce approval.
The lubricity of Trim E950 contributes to exceptional surface finish and tool life on difficult-to-machine aluminium alloys, Inconel, titanium, stainless and high tensile strength steels.
Master Chemical's aim was to achieve the performance of previous generation highly chlorinated EP Trim fluids, but without chlorine. A UK aerospace subcontractor field tested Trim E950 against its highly chlorinated counterpart and it delivered a significant increase in tool life in the volume production of titanium and stainless steel parts, Master Chemical claims.
Trim E950 is a proprietary blend of new vegetable-based technology and premium, traditional lubricity additives, formulated, says the company, to yield a very high performance, low management metal removal fluid.
In addition, new product Trim Tec OE315 NS –a vegetable ester-based cutting oil – is said to be a highly cost-effective product. Part of a new and comprehensive family of renewable oil products from Master Chemical Europe, this heavy duty cutting oil is ideal for deep hole, gun and ejector drilling, as well as small parts turning.
MAG's new Cyclo Cool 900 and 5000 series synthetic coolants (0121 313 5300) are highlighted as being additive-free, as well as low foaming and specially formulated for machining titanium, Inconel, beryllium copper, hardened steels, stainless steels and other superalloys.
Developed for the aerospace industry, the new coolants are said to be an ideal replacement for semi-synthetics and soluble oils, delivering significant cost savings with lower initial cost, longer tool life, increased stock removal rates, reduced housekeeping, long sump life and freedom from biocides, fungicides or pH adjusters.
These new coolants are said to use unique synthetic formulations to provide boundary lubricant properties, while penetrating the heat barrier in the cutting zone, even at lower pressures (300 to 400 psi), to absorb heat from the tool and part, and minimise chemical reactions between tools and workpieces. Both coolants are clear in use, permitting excellent visibility in the cutting zone.
In the case of Cyclo Cool 5000, its unique EP package is said to provide heat-activated boundary lubrication, while eliminating chlorine, sulphur and phosphorus.
Containing a combination of 'synthetic' vegetable esters and polymers, and available from Angus MacInnes (01436 676913), Hangsterfer's S787 high performance, chlorine-free coolant emulsion is able to cope with any material or machining operation. S787 also forms a translucent micro-emulsion when mixed with water, which gives a better view of the workpiece.
With its 'synthetic' vegetable esters and polymers, S787 is said to be ideal when exceptionally high surface finish requirements on difficult-to-machine alloys are demanded. Despite the lack of chlorine, it is, in customer tests, outperforming chlorinated coolants, while tests have also shown it to outperform other vegetable oil-based coolants, says the company.
Importantly, the vegetable fractions have been synthetically altered to a structure not easily recognised by the type of bacteria found in coolants. Because of this, it operates with very low levels of bacteria.
Keeping it cool and bacteria-free
Blaser (Jemtech UK, 01825 767640) also has a 'vegetable' offering, its Vasco range. The performance of this vegetable oil-based range is claimed to be superior to most commonly available cutting fluids. And being produced from a totally renewable source, the environmental impact is minimised, says the company. Vasco is said to deliver the highest possible tool life and surface finish, particularly on difficult or exotic materials, such as Inconel, titanium and the tougher stainless steels.
BIO-CONCEPT, NOT BIO-STABLE
Blaser additionally offers an interesting take on the biocide issue. It is believed to be the only company in the UK offering so-called bio-concept metalworking fluids, as opposed to bio-stable (those using biocides). Offered through its Blasocut range, the approach makes use of the non-pathogenic (harmless) bacteria found in the water source to control and prevent the population of potentially harmful bacteria within the cutting fluid.
Controlling bacteria by adding additives such as biocides and monitoring with dip-sliding for bio-concept products is inappropriate, and at no time should biocides be added to Blasocut, says Blaser/Jemtech UK.
This approach and its requirements are highlighted in recent HSE guidance
. "These fluids require optimum conditions for the natural bacterial population to survive and need careful management, including close monitoring of pH levels and working concentration, to ensure they stay within the manufacturer's tolerances. The supplier/manufacturer evaluates premises before allowing its fluids to be used, and currently carries out monitoring of the fluid for its clients, to check that the necessary conditions are being maintained."
Clearly, the drive for the elimination of 'bad' chemicals continues, just as REACH intends. Product to product, that probably means higher cost, although with higher performance claims also made, it is not necessarily a clear-cut trade-off.
Boric acid and formaldehyde – the longer story
Box item 1
Boric acid and formaldehyde – the longer story
Master Chemicals' technical director, Peter Blenkinsop, offers this detailed overview of the boric acid/formaldehyde situation.
As a corrosion inhibitor and biostatic agent, boric acid has been a highly effective and cost-efficient constituent of metalworking fluids for many years. It is also a substance that is now on the REACH 'substances of very high concern' list. So, naturally, there has been regulation- and customer-driven movement away from fluids containing this product. Alternative technology doesn't come cheap though. Indeed, as well as being more expensive, the majority of boron- and formaldehyde donor biocide-free products are not as stable against bacterial growth as their forerunners.
Master Chemical Europe is one coolant developer, however, that has achieved good, and even superior, performance from its boron and formaldehyde donor biocide-free alternatives. Yes, they are more costly than the company's standard products, but they have proven to provide an even longer sump life and this helps counterbalance their higher purchase price.
As a company that serves Europe, Master Chemical can confirm considerable disparity in its markets. Although all coolant usage is governed by EU Directives, some countries are influenced to a greater extent than others by local regulation.
Spain and Italy are good examples. Water containing high amounts of boron is known to have a detrimental effect on citrus crops, so, naturally, countries which grow these fruits have historically been more focused on the adoption of boron-free metalworking fluids. In these markets, it is also often more cost-effective to choose a more expensive boron-free product, rather than meet the higher disposal cost of the standard product.
In the UK and other EU countries, we have demand for both fluids with and without boron. And this is where Master Chemical scores highly. As we have our own R&D chemists and development facilities, we are able to formulate products to suit the needs of individual markets. Our commitment to R&D allows us to meet everyone's needs.
So, although the take up for boron-free products in the UK may not be as high as in other countries at present, there is no doubt that larger manufacturers will ultimately fall in line with the wider European trend. Subcontractors will then follow suit. And when they do, Master Chemical will be ready. By that time we will have had many years experience of fine-tuning our boron-free products.
A bizarre fact about the development of the 'greener' boron-free fluids is that it is much more difficult to achieve a formulation that doesn't require a hazard label. This is because of the boron and free amine balance. Boron is a good buffer and soaks up a lot of amines, which are also added to the fluid to inhibit corrosion and stabilise bacteria. As a result, the product contains little free amine.
By minimising the boron content, a higher free amine contact can render the fluid hazardous, so it really is quite a fine line. We have invested a lot of R&D time in identifying the optimum combination of constituents that achieves the attributes we seek from a boron-free product without exceeding threshold levels.
Other problems facing metalworking fluid developers are tighter documentation and changing standards. Material Safety Data Sheets (MSDS now known as SDS) now require the developer to provide more constituent information than ever before, a move that can compromise the security of intellectual property. Furthermore, in 2015, when the Globally Harmonised System (GLS) comes into force, the current thresholds for irritancy, harmfulness and toxicity will reduce. At European level, GLS is reflected in the Classification Labelling and Packaging (CLP) Directive.
We have to be mindful of re-classification all the time. In the last few months, the classifications of several substances have been changed and this involves a great deal of re-formulation work to maintain our product's hazard-free label status. And with the GLS coming into force in 2015, the speed of reclassification is only set to increase.
Master Chemical Europe understandably attaches a great deal of importance to its ability to ride this tide of change through its high investment in R&D. We are unique in our ability to produce whatever the customer wants, whether it be driven by EU Directive, local regulation or industry trend.
Box item 2
Videos on the web
 Cimcool's importance of metalworking fluids video
 ExxonMobil's metalworking and lubricating fluids at work in Vodafone McLaren Mercedes' Woking technology centre
 Blaser Swisslube, cutting fluid monitoring and maintenance
 And on the HSE website, you can view a variety of videos on metalworking fluid understanding, use and handling
Box item 3
 Air Cleaning Systems helped Whitehill Spindle Tools eliminate dust from a linishing belt and grinding operations, as well as an oil mist problem on its machining centre
 Horn Cutting Tools now offers the GRAF GmbH high pressure coolant system for sliding-head, multi-spindle and other machines
 ExxonMobil's range of Mobilcut water-soluble metalworking fluids, alongside Mobilmet neat cutting oils, Mobil DTE hydraulic oils and Mobil Vactra slideway oils, are in use at the McLaren Technology Centre in Woking, Surrey
 The Waterhog from Jemtech (UK) will pay back the initial investment in just over 12 months for a typical machine tool user
 Fluid Maintenance Solutions has been appointed by RBM di Battistutta of Italy as the sole UK agent for its IFDR range of metalworking fluid filtration solutions for machine tools and grinding systems
 Mollart Engineering has developed a low-cost, spray mist coolant system for deep hole drilling applications that can be retrofitted to any machine tool. It uses a vegetable-based cutting oil
 As part of a multi-million single 5-axis machine installation for a UK aerospace company, turnkey supplier 2D CNC Machinery (Mitsui Seiki, 0844 871 8584), the customer, FSE (01562 60233) and machine builder Mitsui Seiki developed a fully programmable, totally media-free high pressure coolant system capable of providing up to 200 bar pressure around the spindle and 120 bar through the spindle>
 Walter Cryo.tec milling, drilling and turning tools use a special nitrogen cooling process to enhance cutting speeds and extend tool life
 Freddy Products' new Centrifuge system recycles oil, coolant and a multitude of additional fluids
 Quaker Chemical approach uses novel two-part metalworking fluid to slash energy, disposal and top-up
All links are to Machinery's website.
First published in Machinery, January 2012