Basics of Wire Rope Lubrication (2% of wire rope weight should be comprised of the lubricant and more details hereunder) Wire rope lubrication serves two basic functions:

1. To reduce friction as individual strands (wires) move over each other, and lubricate the core;

2. To provide corrosion protection; prevent moisture and dust entry and wear protection from rubbing with external bodies during operation.

Wire rope lubricants are of two types: penetrating and coating. Penetrating lubricant contain a solvent that carries the lubricant into the core and then evaporates leaving behind a lubricating film to lubricate the core and individual strands. Coating lubricants penetrate slightly, sealing the outside of the rope from moisture, reducing wear and fretting corrosion from contact with external bodies.

Most wire ropes fail from inside. It is important to make sure that the center core receives sufficient lubricant. Hence a penetrating type lubricant is must. Coating (asphaltic) type lubricant may be used as supplementary. Wire ropes are lubricated during the manufacturing process. Relubrication is required from time to time due to loss of the original lubricant from loading, bending and stretching of the rope. Relubrication is necessary to minimize corrosion, protect and preserve the rope core and wires, and thus extend the service life of the wire rope.

Benefits of wire rope lubrication: Abrasive wear occurs on the inside and outside of wire ropes. Individual strands inside the rope move and rub against one another during normal operation, creating internal two-body abrasive wear. The outside of the cable accumulates dirt and contaminants from sheaves and drums. This causes three-body abrasive wear, which erodes the outer wires and strands. Abrasive wear usually reduces rope diameter and can result in core failure and internal wire breakage. Penetrating wire rope lubricants reduce abrasive wear inside the rope and also wash off the external surfaces to remove contaminants and dirt. Years of field experience shows that longer wire rope life can be obtained through the use of penetrating lubricants, either alone or when used in conjunction with a coating lubricant. Practical experience at a South African mine suggests that life cycles may be doubled with this approach. At one mine site, the replacement rate for four 44-mm ropes was extended from an average 18.5 months to 43 months. At another mine, life cycles of four 43-mm x 2073 meter ropes were extended from an average 8 months to 12 months. (Data from Machinery Lubrication Magazine, July 2002. (www.machinerylubrication.com) Properties of a good penetrating type lubricant: 1.Is flowable for easy penetration between adjacent wires in order to lubricate and protect them against wear and to keep the rope core from drying out; 2. Adhesive, does not get “fling off” during bending, loading, stretching during operation; 3. High load carrying capacity; 4. Good corrosion protection against rusting by acids, alkalis or salt water; 5. Resist softening or thinning out to the extent that throw-off or drippage occurs at high temperatures at which rope will operate; 6. Resist being washed off by water; 7. Form non-sticky films so that dust and dirt will not build up on ropes; 8. Be suitable for application by brush, drip feed, spraying, pouring on a running section of the rope, and running the rope through a trough or bath of lubricant. Molykote® technologies available for wire rope lubrication:

1. Molykote® LT 00 Semi-fluid Adhesive Grease: Penetrating type grease with 00 consistency, with complete resistance to water available in 25 kg packs for brushing onto wire ropes. Four ball load 3200N. Provides exceptional adherence, corrosion protection and maximum continuous resistance to extreme pressures and shock loading. Contains molybdenum disulphide for wear protection of individual strands and works well upto 120 deg C.

2. Molykote® S-1004/1014 Open Gear and Wire Rope Spray: Semi-synthetic open gear and wire rope in spray cans with

excellent adhesion, high load carrying capacity and good water and moisture resistance. 535 mm2/s viscosity at 40 deg C form a thick lubricating film separating metal surfaces. Four ball load 6000N. Service temperature upto 150 deg C.

Other Molykote® products that can be used for wire ropes: Underwater/ sea water wire ropes (Molykote® P40 paste), Multiple application product for wire ropes, chains and open gears (Molykote® 1122 Synthetic Grease spray), completely dry anti-friction coating lubrication for dusty environments (Molykote® 321R AF Coating Spray/bulk form).

Molykote® is a registered trademark of Dow Corning Corporation. Molykote® extends equipment life, simplifies yours. When you need to be absolutely sure, trust Molykote®. Call Dow Corning at 022-56966848 or fax 022 56946868