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Corrosion ControlHeat removal is one of the most
important functions of a metalworking fluid. Effective heat removal yields good tool life and dimensional accuracy of parts. Water has greater capacity for removing heat than oil. However, water alone in contact with
freshly machined metal leads to corrosion. Thus, corrosion is a problem faced by every manufacturer of water diluted metalworking fluids. The term "rust" applies only to iron and steel. The term
"corrosion" is more appropriate because this also includes nonferrous metals.
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Foam ControlFoam generally is considered to be an undesirable property in a metalworking fluid. Since most metalworking fluids have good cleaning properties to help keep machines clean,
they also foam when agitated. The quantity of foam that occurs, then, depends upon the chemical composition of a metalworking fluid product, the quality of the water used for mixing, and the degree of agitation in the
system. Top of Page
Importance of Water Quality on Water Dilutable Metalworking FluidWater is the major ingredient in a water-based
metalworking fluid mix. It may amount to as much as 80-99% of the mix as used. Therefore, its importance in product performance cannot be ignored. Corrosion, residue, scum, rancidity, foam, excess
concentrate usage, or almost any metalworking fluid performance problem can be caused by the quality of the water used in making the mix. Untreated water always contains impurities. Even rain water is more pure. Some
impurities have no apparent effect on a waterbased metalworking fluid. Others may affect it drastically. By reacting or combining with metalworking fluid ingredients, impurities can change performance characteristics.
Therefore, water treatment is sometimes necessary to obtain the full benefits of water-based metalworking fluids. Top of Page
Rancidity of Water Dilutable Metalworking Fluids - Causes, Concerns, Controls, and Corrective
ActionsRancidity is one metalworking fluid challenge which demands immediate attention. Employees will not tolerate a foul smelling fluid and even if they
would, the rust, loss of finish, poor tool life, and the generally poor performance that may accompany rancidity can be major concerns in metalworking operations. Rancidity can be prevented by
understanding the causes and by following a few simple control practices. Top of Page
Paint RemovalThe advent of water-based chemical metalworking fluids has led to some
concerns to their use because they can cause paint to soften and peel off the machine. This is not true of all water-based metalworking fluids. Paint does come off some machine tools that are not properly painted,
causing concerns. Top of Page
Overview of Precoat Types and Methods for Wire DrawingIn order to optimize lubrication during dry wire drawing, it
is important to have appropriately cleaned wire surface, to use precoating or carrier coating when appropriate, and to use cost effective dry powder wire drawing lubricants. Hot rolled steel rod has an oxidized surface
and since this oxide is very abrasive, it must be removed to allow proper lubrication during wire drawing. The two primary methods of removing the oxide are chemical or mechanical descaling. For chemical descaling, some
of the more common acids used: are hydrochloric or sulfuric acids for carbon steel and a mixture of nitric and hydrofluoric acids for stainless steels. For mechanical descaling, some of the methods employed are reverse
bending, shot blasting with an abrasive media, or surface removal with abrasive belts or brushes. Top of Page
A Suggested General Treatment Cycle for Skin Irritation in a Metalworking Environment
Dermatitis or skin irritation in a metalworking plant can arise from a number of causes, such as improper use of solvents or cleaners, abrasive hand cleaners, personal
hygiene, changes in weather conditions, contaminated metalworking fluid, etc. But, as mentioned, various other sources with the metalworking environment may cause skin irritation. In this regard, the
following steps may be beneficial should such skin irritation occur. Though these steps have been found to have favorable results, they are not meant to substitute for the consultation with a physician as a
precautionary measure if or when necessary. Top of Page
Metalworking Fluid Controls For Water Dilutable FluidsProlonging the life of
the metalworking fluid and optimizing its performance are very dependent on the control of the metalworking fluid system. This control includes maintenance of the mechanical components, as well as the metalworking fluid
and is as important as the selection of the proper fluid. The problems that beset metalworking fluids in central system applications are the same as those in an individual machine sump, only the magnitude is greater. A
program to accomplish this control should include the following steps. Top of Page
Definitions of Analysis Terms for Water Dilutable Metalworking FluidsA summation
of well defined definitions on the more common terms used in the analysis of water diluted metalworking fluids. Those included in this paper are: Concentration, pH, Dirt, Volume, Free Oil, Total Oil, Tramp Oil, Bacteria
Count, and Total Alkalinity. Top of Page
The National Toxicology Program (NTP) Dermal Study on Rats and Mice with DiethanolamineEtna Products,
Inc. has long been committed to understanding the potential health issues associated with the raw material and finished products that it produces and to communicating those concerns to our associates and customers.
Consistent with this commitment to product stewardship, Etna is a member of the Independent Lubricant Manufacturers Association (ILMA) which has a Health and Safety Taskforce that monitors the scientific data available
regarding raw materials used to formulate lubricants. In addition to participating as an active member of the Health and Safety Taskforce, Etna is also a member of the Metalworking Fluid Product Stewardship Group (MWFPSG
SM), which is an independent group of companies committed to product stewardship and to
funding research designed to identify and to understand the raw materials used to formulate metalworking lubricants.Top of Page
The Influence of Metalworking Fluids on Common ElastomersThe selection of elastomers for the metalworking industry requires balancing the elastomeric properties to suit the particular application. The key elastomer compounds to
consider are the polymer type, the cure system, and the filter content. The primary metalworking fluid components to consider are the oil, water, and alkalinity level. Many problems associated with
elastomers in metalworking fluids are the results of contamination. Simulated service testing can be a useful tool to judge the relative chemical compatibility of elastomers with the various types of metalworking fluids
. Top of Page
Formicary Corrosion of Copper TubeFormicary corrosion is a problem that has been known for years, although
relatively little work has been done to research this phenomena. Yamanchi, Motoyo, and others have conducted the bulk of the work in the 1980s. Description of the Problem Formicary corrosion
differs from typical copper oxidation in that the corrosion manifests itself as an ant nest (i.e. formicary) pattern within the metal. The end result of this tunneling effect can be pin hole leaks in copper tube.
Identifying formicary corrosion can in many instances be quite difficult. Microscopy is the most prevalent technique, with a blue/lviolet or gray/brown appearance being an indication of formicary corrosion rather than
the green/blue associated with more common forms of copper corrosion. Since the formicary corrosion mechanism can take place over a period of time, finished product at the mill can pass inspection and fail months later.
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General Clean Out Procedure For Water Dilutable Metalworking FluidsA clean metalworking fluid performs better and lasts longer than a dirty fluid. When
recharging an individual sump or central fluid tank, a clean out of the tank is beneficial so that the fresh charge of metalworking fluid can perform with maximum efficiency. If not removed, accumulated
shop waste, metal swarf oil, mold growth, and pockets of bacteria cause deterioration of the fresh mix. In a new system, construction debris in the trenches and tanks, the chemical waste, such as welding flux, from the
assembly of steel trenches must be removed. If the trenches are constructed of cement a good cleaning helps to season them. The clean out, therefore, is an essential first step. It insures that your
metalworking fluid has an "even chance" to give maximum performance with a minimum number of problems. The following clean out procedure should be used whenever possible, while no operators are
producing parts. Top of Page
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