Apparatus for forming tubular fibrous insulatory articles

Abstract

Apparatus for forming the edges of mineral fiber blankets during their advance along a processing path. Guide means having surfaces shaped to continuously direct feathered or ragged longitudinal edges of an uncured mat of mineral fibers as it is introduced to forming apparatus causes a gathering of the fibers to control the uniformity of the density of the edge portion of the mass. The guide can comprise surfaces extending radially outward at the effective ends of a pressure roll cooperating with a rotatable mandrel in the formation of tubes of fiber mat. The first surface encountered by an advancing blanket raises the feathered edge. The raised edge is turned inward toward the major body portion of the blanket by a second surface. A third surface parallels the path of advance to establish the desired margin and maintain that margin as the blanket is compacted in its major face. Other surfaces can be provided to form or shape the marginal edges of the mass of mineral fibers to obtain a desired configuration, for example, square or chamfered edges.