A method and device for use in the method for forming a reinforcing filamental network is the subject of this application. The network includes a pair of straight filaments (54, 56) which can extend generally parallely with respect to one another and be spaced at a given distance. A serpentine filament (58) is made to sinuate across the straight filaments (54, 56), and can be bonded thereto at intersections by means of a hot melt adhesive which impregnates the filaments (54, 56, 58) and which has a measure of flow potential when subjected to pressure.The device for forming the network includes a cylindrical cam (100) which is disposed for rotation about an axis generally parallel to the axis of one of two pressure rollers (76, 90) which effect cold flow of the hot melt adhesive with which the filaments (54, 56, 58) are impregnated. The cam (100) has a groove (110) formed in its outer surface. A shoe (108) of a reciprocating filament guide (102) rides in the groove (110). The groove (110) extends both circumferentially and axially in the outer surface of the cam (100). The cam (100) is geared to rotation of one of the pressure rollers (76, 90) so that, as the pressure rollers (76, 90) feed the filaments (54, 56, 58) therethrough, the reciprocating guide (102) will move axially along the rollers (76, 90) in order to effect sinuating of the serpentine filament (58).