PTFE was reinforced with PAN-based, Pitch-based (carbonized and graphitized) carbon fibers and vapor-grown carbon fibers and their tribological properties were examined. Aluminum alloy was used as the counter face material. The wear rate of PTFE was only reduced by the vapor-grown carbon fiber and the composite filled with the vapor-grown carbon fiber caused minimum wear amount of the aluminum alloy counter face. Aluminum alloy was easily abraded by the carbon fibers other than vapor-grown carbon fibers, and then the abraded rough surface promoted the wear of PTFE composites. There was a correlation between the abrasiveness of carbon fiber and the cylindrical surface area of carbon fiber.

It is tough subject to wash medical instruments with fine structure or tubular structure, though some exclusive accessories for WD and ultrasound washer are available now. This time, we would like to report newly developed washing method named as Vacuum Boiling Washer . The concept of this washer is application of physical energy of boiling water. This new washing machine has air sealed washing bath and it can reduce pressure to 10 kPa (0.1 bar). Water comes to boil at less than 50 degrees Celsius by reducing pressure to 10 kPa. And bumping can be generated by inducting air injection into the decompressed water. The strong physical energy of boiling water and bumping water generate effective washing ability. Furthermore, iteration of reducing pressure and revert back to the normal pressure makes strong circulating current of the washing agent into the fine structure or tubular structure of the instruments. We ve attained significantly good results of the washing experiments with some models of fine structure and tubular structure.