Featured in Marine Maintenance Technology International | April 2015

Columbia Industrial Products (CIP), of Oregon, USA, has developed a self-lubricated bearing material based on a composite suitable for long-term submersion in seawater.

CIP Marine is manufactured with polyester textile and a high-grade marine polyester resin. Solid lubrication additives PTFE and molybdenum disulfide are dispersed throughout the resin before the strong spun-fiber textile is run through it. Layers of the textile are then built up to the thickness required for the application, in tubes or sheets of material.

“The result is an ideal mix of material properties  a product that is harder than plastic and more stable”, says Ames Jacoby of CIP. “It doesn’t expand thermally as plastic would, or deform under loads, and because of the quality of the ingredients, it doesn’t swell in water. That is the number-one question that comes up – lots of other materials, whether wood, rubber or plastics, will swell in water, so you have to compensate to allow for expansion. Our product is very stable.”

However, says Jacoby, “CIP Marine is a little softer than metallic products, so it gives a little. That allows for a little bit more misalignment of the shaft and means that it absorbs vibrations and impact better.”

The molybdenum disulfide and polyester content in the material offers a very low start-up torque. “Our material is meant for dry-run applications, to eliminate grease and lubricants. It is a low-friction, slippery material by nature, so there are no noises or squeaks. And once the shaft is running at speed, water is doing most of the work.”

CIP has already gained class approval for the material from RINA and ABS. It says customer feedback is that the CIP Marine composite delivers quieter and smoother running and smooth start/stop and forward-to-reverse operations.

CIP produces the raw materials close to the size of the final desired machine bearing component. Tubes of the material are produced in three lengths, so that there is as little wasted material as possible. The other advantage is that it can send that raw material out in its basic sizes so that distributors and shipyards have it in stock.

“When a ship comes into drydock, the final measurements of the shaft can be confirmed and the material can be machined on site,” he said. “The material isn’t abrasive or toxic and can be fed into the lathe for cutting. Equally, if a bearing produced needs to be adjusted, it can be modified on site.”

Jacoby says the CIP Marine solution was developed to meet the needs of a time- and cost-pressured industry, as well as meeting environmental and other requirements. It is suitable for newbuilds and retrofits.

“In the marine marketplace, having materials available in a very short delivery timeframe is important from the service standpoint,” he said. “When the vessel comes out of the water, maintenance and other work has to happen quickly to contain overall costs.”