Asbestos was added as an common ingredient to Brake Pads post-WWI, as car speeds began to increase, because research showed that its properties allowed it to absorb the heat (which can reach 500 °F) while still providing the friction necessary to stop a vehicle. However, as the serious health-related hazards of asbestos eventually started to become apparent, other materials had to be found. Asbestos brake pads have largely been replaced by non-asbestos organic (NAO) materials in first world countries. Today, brake pad materials are classified into one of four principal categories, as follows:
Non-metallic materials - these are made from a combination of various synthetic substances bonded into a composite, principally in the form of cellulose, aramid, PAN, and sintered glass. They are gentle on rotors, but produce a fair amount of dust, thus having a short service life.
Semi-metallic materials - synthetics mixed with varying proportions of flaked metals. These are harder than non-metallic pads, more fade-resistant and longer lasting, but at the cost of increased wear to the rotor/drum which then must be replaced sooner. They also require more actuating force than non-metallic pads in order to generate braking torque.
Fully metallic materials - these pads are used only in racing vehicles, and are composed of sintered steel without any synthetic additives. They are very long-lasting, but require more force to slow a vehicle while wearing off the rotors faster. They also tend to be very loud.
Ceramic materials - Composed of clay and porcelain bonded to copper flakes and filaments, these are a good compromise between the durability of the metal pads, grip and fade resistance of the synthetic variety. Their principal drawback, however, is that unlike the previous three types, despite the presence of the copper (which has a high thermal conductivity), ceramic pads generally do not dissipate heat well, which can eventually cause the pads or other components of the braking system to warp.However, because the ceramic materials causes the braking sound to be elevated beyond that of human hearing, they are exceptionally quiet.
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WSS launches marine boiler failure problem solution
Recently, Wilson Ship Service (WSS) has introduced a new device designed to solve marine boiler failure problems, reduce boiler downtime and reduce maintenance costs.
The boiler of the ship has failed, usually the boiler water is not properly handled. Rune Nygaard, manager of water operations at Wilson Marine Services, said that the company's digital, cloud-based, and automated boiler water dosing solution was the first such launch in the shipping market to respond to customer demand. Boiler failure is a dangerous thing, maintenance costs are often as high as 80,000-180,000 US dollars, and the relevant losses of ship shutdown have not been calculated. In addition, crew members should not risk boiler testing and maintenance on their own.
It is reported that this new device of Wilson Ship Service can provide ship-shore connection, realize data sharing, measure boiler water parameters, and then transmit the data to the command department. The program has been fully tested and will be finalized on 10 ships and is expected to be introduced to the market soon.