Jacquard Weaving and Designing

by T. F. Bell

Fig. 176

A section through the weft of a piece of two-ply carpeting is given in [Fig. 176], showing the position of the threads when arranged to give the different effects of face cloth up as at A, back cloth up as at B, shot-about effect of red and olive on the face as at C, and shot-about effect of white and black on face as at D. The warp threads are marked W, O, R, B, the initial letters of the colours; and the numbers 1 to 32 give the order of picking. The shot-about effect is here produced with the opposite threads—that is, the first thread of one warp and the second thread of the other warp—as white and black; but it might be preferred to produce the effect the corresponding or mate threads (white and red, or olive and black) would give. In working with journals, two picks face and two picks back would be required to obtain this, and the needles of the jacquards would require to be acted upon by the cards for each shot, thus requiring double the number of cards. With a full harness any effect desired can be produced. Extra colours of weft may also be used (as drab) in addition to the white and olive—to work, say, white, olive, drab, olive, &c.; and dark green or blue in addition to the red and black, which would come in as red, green, black, green, &c., a shot of the light and one of the dark colours following each other in succession. Stripes of a bright colour may be introduced into the warp or weft and kept in the back cloth, only being brought to the face in small portions, at intervals, to sparkle up the centres of flowers, &c.

Ingrain carpets are made 36 in. wide, and with, say, 832 or 1088 threads of warp, according to quality. The former can be woven on a 200 jacquard (say 208=416), as the machine is double; and as there are two repeats of the pattern in the width of the cloth, 416 × 2 = 832 threads of warp. For the latter 272 needles are required = 544 × 2 = 1088 hooks.

When woven with journals, the jacquards used for figuring these carpets are similar to those explained under ‘Quilt Weaving’—that is, double machines with trapboards and knot cords; and when the card is pressed against the needles it is held in for two shots, one trapboard raising the harness for the first shot, and the other reversing the shed for the second shot. The journals are four sections of the cumber board, as shown in [Fig. 177]; each section contains two rows of the harness and one colour of warp. No. 1 journal controls the white warp, No. 2 the olive, No. 3 the red, and No. 4 the black; the draft is shown by the numbers 1 to 8 alongside the harness cords. These eight cords only represent half a row from each machine, as there are eight rows of hooks to the machine. One row of the two machines fills two rows across the journals, or 16 holes. A represents the trapboard of the machine for the ground or dark warp, and B that of the machine for the figuring or light warp.

The harness twines are furnished with large knots above the cumber board or journals, so that when one of the journals is raised the harness will be lifted with it. The journals may be raised by strong cords or wires from the machine, or by a tappet or shedding motion working either above or below them. If the machine is divided into two parts, four hooks in succession going to each colour of warp for each cloth, the cords from these four hooks making two rows of the journal, there will be no crossing of the harness in a straight or Norwich tie.

Fig. 177