What is antifreeze and what does it do?
Despite the name, antifreeze performs many important functions, not confined to preventing freezing. Mechanics and car owners add antifreeze to the cooling system of their vehicles. In cold weather, the antifreeze prevents the coolant from freezing; however, it also protects in other ways.
Antifreeze / engine coolant protects the engine against overheating and that is its principal function. In order to do this, it acts as a heat transfer fluid, absorbing heat energy from the engine, taking that heat away, and dissipating it to the environment. Moreover, the main heat transferring components of the engine coolant are water and glycol. Most coolant manufacturers, use mono-ethylene glycol; however, some producers use other glycol types for speciality applications.
What are the advantages and disadvantages of glycol?
Glycols typically have a lower specific heat capacity than water. This means that a water / glycol mixture has a lower cooling efficiency than water alone. Furthermore, vehicle manufacturers must compensate for this reduced efficiency by ensuring a sufficient circulation rate.
So, why do manufacturers add glycol to engine coolants?
Firstly, the glycol lowers the freezing point and raises the boiling point compared to those of water alone. This ensures that the coolant does not freeze in cold weather, and, also, prevents the coolant from boiling away. Consequently, it ensures that the coolant can flow and do its job; but, also minimises the risk of overheating.
Secondly, glycol/water mixtures are inherently less corrosive to the engine cooling system than water alone. A typical cooling system consists of the following parts:
- coolant reservoir
- water pump
Parts manufacturers use various different metals and alloys to make the components and fittings and it is important to minimize the risk of corroding each type.
Although the glycol reduces the corrosive potential of the coolant, the corrosiveness actually increases as the glycol degrades. Consequently, manufacturers add a super concentrate of additives to the fluid to inhibit glycol degradation and corrosion.
What is an antifreeze super concentrate?
Commercial antifreeze / engine coolant retails as either concentrate or ready-to-use (RTU). Accordingly, mechanics must, first, dilute the concentrate type with water; whereas, the RTU type can be added directly into the cooling system.
In contrast to an antifreeze concentrate, which is a retail product, a super concentrate is used by manufacturers of engine coolants / antifreeze.
A super concentrate is an additive package that performs two functions:
- to stabilize and inhibit degradation of the glycol
- to inhibit corrosion of the metals and alloy components of the cooling system
International standards and OEM specifications
Due to the multi-metal nature of the coolant system, super concentrates contain many different corrosion inhibitors. International standards specify the performance requirements of antifreeze /engine coolant. Moreover, these standards each comprise a battery of standardized tests, with specified limits. The coolant must pass all of these tests in order to meet the standard. Typically the standards include corrosion, freezing point and boiling point tests, all with strict spec limits.
Additionally, some vehicle manufacturers specify extra tests or OEM (original enquipment manufacturer) specifications. The coolant must also pass these tests in order to be used in certain makes of cars. For trucks and construction vehicles, the coolant must also pass international and OEM heavy duty standards.
Brad-Chem 557 is super concentrate for making long-life antifreeze /engine coolant that meets the ASTM D 3306 standard. Additionally, it meets the requirements of many other international and OEM specifications.
Manufacturers and suppliers generally refer to this type of coolant as long-life OAT antifreeze . OAT is an acronym for organic acid technology. Moreover, this type of technology is suitable for most vehicles manufactured after 1998.
Furthermore manufacturers can make heavy duty engine coolant by adding a booster package to antifreeze made with Brad-Chem 557.
Super concentrate for older vehicles
Antifreeze suitable for vehicles manufactured before 1998 utilises either inorganic acid technology (IAT) or a suitable replacement. In recent times, coolant manufacturers have started looking for alternatives to the older IAT engine coolant additives for a number of reasons. For example, these additives deplete in use and, consequently, this coolant type is not considered to be long life.
Furthermore, some of the additives traditionally used to make IAT type are hazardous chemicals. Brad-Chem 552 is a super concentrate that makes a British Standard BS 6580:2010 compliant antifreeze. Manufacturers can use this product to make a replacement for the IAT antifreeze types. This super concentrate is also approved for use in incidental food contact applications.
For further information on our antifreeze / engine coolant super concentrates, contact us