Problem
A producer of Medium Density Fiberboard and Chipboard was experiencing excessive carryback on the conveyor system transporting wood chips to the screening process. On its way to the pressboard plant, wood is passed through a pre-chipper and screened to remove fine material. At that stage, the wood is damp and sticky, causing smaller particles to cling to the return side of the belt. The standard primary poly scraper was ineffective at removing adhered material from the belt, resulting in a high amount of carryback, which dropped along the belt path, piling around the mainframe. This required extra labor to clean the area 2 hours per day, raising operating costs and affecting workplace safety.
Solution
Examining the carryback issue and the material's physical properties, Martin Engineering UK technicians recommended that the company install a CleanScrape® Cleaner. Comprised of a matrix of tungsten carbide scrapers, the blade is mounted and tensioned against the belt using specially engineered stringers installed diagonally across the discharge pulley. This causes the blade to form a three-dimensional curve with extremely low contact pressure between the belt and cleaner, which easily passes over the splice but typically removes as much as 95% of difficult material. Designed to cover the entire width of the belt, the cleaner delivers double the life of most standard blades.
Results
The Cleanscrape® Cleaner was installed with a very compact footprint on the existing system and offered immediate results. Carryback has been reduced dramatically, and operators report that cleaning time has gone from 2 hours per day down to 1 hour per week. "We are truly amazed by how effective this blade is," an operator close to the project pointed out. "We had no idea just how inefficiently our previous blade had been performing." Managers were so pleased with the results that they have since installed a unit on another conveyor, providing the same impressive results.
