GB1093314A - Improvements in or relating to the formation of felt - Google Patents

Abstract

A method of felting a preformed felt bar, or a mass of fibres packed into a flexible bag for formation into a felt bar, comprises restraining the bar substantially parallel to the face of a felting hammer which strikes the felt, or fibrous mass, to effect transverse compressions thereof, the position at which the bar is struck by the hammer being varied, preferably by intermittent or continuous rotation of the bar. The felting is preferably carried out by a pair of hammers arranged to strike the bar alternately in mutually perpendicular directions. When felting a tube of felt, a core is positioned within the felt, which core may be hollow and initially expanded by fluid pressure which is reduced as the diameter of the material decreases. Apparatus comprises a pair of hammers and associated anvils, the hammers striking substantially at right angles. The hammers are connected by a link so that when one hammer moves towards its anvil, the other moves away from its associated anvil, one hammer being connected to a reciprocating drive means. The distance between the hammer and its anvil may decrease in the direction of feed of the felt bar for the continuous felting or forming of felt bar or tubes. In the case of continuous formation of felt tubes a fixed progressively decreasing core may be provided between the hammer and its anvil. The apparatus may include a series of pairs of hammers arranged to strike at 45 DEG to the positions of strike of the preceding pair.