GB462976A - Improvements relating to dandy rolls for use in the paper making and allied industries - Google Patents

Abstract

462,976. Dandy - rolls. TROTMAN, W. E. K. Sept. 12, 1935, No. 25344. [Class 96] In a dandy-roll for use in paper-making and allied industries, the liquid permeable surface is composed of upper and under layers of non - woven or non - interlaced structure each formed of close set parallel courses of fine wire, the wire courses of the upper layer crossing those of the under layer without being interwoven or looped therein. The liquid permeable surface is formed of an under layer 1 comprising parallel lengths of fine wire, e.g. <1>/50" to <1>/64" diameter at a distance apart substantially equal to the diameter of the wire, and an upper layer 2 comprising a single length of fine wire, e.g. <1>/100" to <1>/128" diameter coiled around the layer 1 in the form of a spiral with a pitch preferably approximately equal to the diameter of the wire. If desired, one surface may be formed of lengths of wire disposed in parallel courses with a large pitch helical formation, or of close set circumferential wire rings. To simulate a wove surface, the top layer 2 may be embedded in the lower layer 1 so that their surfaces are substantially flush. The top layer 2 is positioned by being tinned and coiled on while the tinning coating is still hot. The supporting skeleton comprises a series of lightened longitudinal bars 4, carrying a coarse spiral 5 of stiff wire. Longitudinal lengths of coarse wire 6 are placed between the bars 4. Watermarks and wires for producing laid lines may be applied to the roll surfaces.