Product category:
Lubricants
News Release from: Kluber Lubrication GB | Subject: Graphite-free adhesive lubricants
Edited by the Engineeringtalk Editorial
Team on 06 August 2002
Graphite-free formulation for adhesive
lubricants
Modern graphite-free adhesive lubricants can be applied by spraying, immersion or circulation lubrication, depending on the operating conditions.
The development of so-called adhesive lubricants started about 30 years ago, in order to meet requirements made by the industry This type of lubricant was supposed to provide reliable low-quantity lubrication for open girth gear and pinion drives in rotary kilns and tubular mills which rarely run under ideal operating conditions
Adhesive lubricants at that time were free of bitumen, but contained lead additives, chlorine and sometimes the solvent CFC.
The graphite contained in these lubricants protected the tooth flanks even under starved lubrication conditions, however it also gave the product its opaque black colour.
In the course of time, lead additives, chlorine and CFC were eliminated.
The products did and still do their job without any problem.
They have, however, remained opaque.
The trend to use modern, environmentally sound lubricants also affected adhesive lubricants, which led to the development of completely new products.
The aim has been to formulate products that contain neither bitumen, lead or chlorine, nor CFC, the latter being an ozone-depleting substance.
These products should be of a light colour in order to avoid the contamination that occurs with graphite products and to enable easier maintenance of the drives and lubricant disposal.
Now a range of partially or fully synthetic lubricants of high and very high viscosity have become available on the market that are free of graphite and contain different kinds of additives.
These new lubricants are also highly adhesive and offer excellent flank protection.
Modern graphite-free adhesive lubricants achieve a load stage of better than 12 with a wear rate of less than 0.2 mg/kWh in the FZG test A 8,3/90C according to DIN51354 and a welding load of 6500N in the VKA (four-ball wear test), DIN51350, point 4.
These lubricants can be applied by spraying, immersion or circulation lubrication, depending on the operating conditions.
With spray lubrication, consumption quantities can be reduced by up to 50% which also has a positive influence on lubricant disposal.
Experience gained in practice shows that also oscillations at the pinion bearings and tooth flank temperatures can be considerably reduced.
Another important aspect is that light, transparent lubricants make maintenance and inspection of drives much easier.
Tooth flank inspection by stroboscope is possible without having to stop the drive.
Costly and time-intensive cleaning of the drive is no longer necessary.
The transparent lubricating film makes any changes to the tooth flanks visible at once.
Disposal costs are reduced not only because of the lower lubricant quantities used, but also due to the fact that these lubricants are classified under the German directive of the Clean Air Act, class IV.
In view of the many advantages offered by light, transparent lubricants, it can be assumed that they will replace dark, graphite products in the long run.
The selection of the adequate lubricant, however, will always be based on the specific operating and application conditions as well as on the approvals from the manufacturers of machines and drives. Request a free brochure from Kluber Lubrication GB ...
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