Abstract: An Ni-P (Nickel-Phophorous) undercoating is provided under particulate (spin-coated) magnetic media. Particulate media, largely due to the way it is applied to the disk, is less expensive than thin film media. Described are the systems and methods to utilize the undercoat for particulate media.

Abstract: The invention comprises a process for stripping disks coated by the process disclosed in the parent application described above. According to that process, the disks are rotated at high speed during a media application step, then immersed in an orienting magnetic field, and finally dried at low speed. If a flaw is detected after drying, according to the stripping and recoating process of the present invention, the disk is simply stripped and recoated by merely repeating the high speed coating step. During stripping and recoating, the nozzle starts at the outside diameter and moves toward the inside diameter. As the nozzle moves from outside diameter to inside diameter, the new media which is discharged from the nozzle onto the disk strips away the old media layer. Once the nozzle reaches the inside diameter, it moves back toward the outside diameter and applies a new layer of media to the disk.

Abstract: A disk is rotated at high speed on a spindle while fluid carrying magnetic medium material is applied to the disk through a dispensing nozzle which starts at the outside diameter of the disk and travels to the inside diameter, pauses momentarily, and then travels back to the outside diameter. As the fluid is applied, a thin film of medium material adheres to the disk while the excess fluid forms a protective coating over this thin film as it flows radially off of the disk due to the centrifugal force generated by the high speed of rotation. The nozzle discharge pressure and the high rotational speed of the disk result in a very thin film of magnetic medium material being applied to the disk. The rate of nozzle travel can be adjusted to vary the medium material film thickness. Immediately following the high speed coating application step the speed of the disk is substantially reduced and the disk is exposed to a magnetic orienting field during an orientation step.