Abstract: A method for cutting the bristles which form the sealing ends of a brush seal, in which the tightly packed bristles are infiltrated with a liquid binder which is then hardened to form a rigid composite of bristles and binder. The resulting rigid composite can then easily be machined (cut or ground) without damage to the bristles. For metallic bristles, conventional fine line cutting methods such as single point turning or milling, are employed. Ceramic bristles, are machined by conventional bore grinding. After machining, the binder material may be immediately removed by melting or dissolution. Alternatively, the binder may be left on the bristles to provide protection during subsequent machining or handling procedures. The method provides accurate, smooth cuts while offering a combination of low cost and high production rates.

Abstract: A long ribbon, composed of a multitude of fine wires, is placed at the requisite bristle angle onto a backing ring. A torch, welds the ribbon to the backing plate and simultaneously severs the ribbon--forming a first bundle of wires. The severed ribbon is repositioned, relative to the backing ring, adjacent to the first bundle, and the ribbon is again welded in-place and cut. The procedure of placement, welding and cutting is repeated until the backing plate (or the ribbon) has been repositioned over the desired length of the plate to achieve the requisite bristle array of the brush seal.

Abstract: For high temperature applications, ceramic coatings are plasma-sprayed onto various substrates. Plasma-spraying of ceramics onto non-conductive polymer surfaces often results in coatings which are poorly adherent. Adherent, non-spalling, ceramic layers can be achieved by first coating the non-conductive surface with an adhesively bonded, more conductive layer. It is postulated that the resulting more conductive coating is sufficient to prevent the build-up of electrostatic charges which can act to repel the plasma-sprayed particles. After the more conductive layer is applied (a bond coat may be employed, but is generally unnecessary), the ceramic powders are plasma-sprayed.