CROSS-WEAVING

This is a style of weaving which produces crossed thread effects such as gauzes and lenos (see lenos)

A name given to the shed made when weaving gauze (see gauze)

A fabric in which an open effect is woven by causing certain threads named doup threads to cross over one or more threads, termed standard threads. Very fancy and beautiful cloths are produced by combining this cross-weaving with other weaves. The term is applied generally to all light fabrics in which the cross-weaving principle is used.

The jacquard machine is an essential addition to looms intended for weaving ornamental designs that are beyond the scope of stave -work. The machine is made in many forms and sizes for different branches of the weaving industry, but its characteristic feature is that it furnishes the means whereby every individual thread in a design may weave differently from all the others. This permits the delineation of all forms and shapes and the fineness of the detail is only limited by the texture, e.g., the number of ends and picks per inch. The action of the jacquard machine is communicated to the warp threads through a system of cords known variously as the harness mounting and jacquard harness. Actually, loom harness ante-dated the jacquard machine by many centuries, and many draw loom harnesses were much more complicated than modern jacquard harnesses. An essential feature of a jacquard is that each hook in the machine can be lifted at will independently of the others. The selection of which hooks shall lift and which shall be left down is made by the designer, by painting marks on squared paper to indicate the hooks that must be lifted on each pick. In cutting the pattern cards, a hole is cut for every mark or filled square on the design paper, and a blank is left for every empty square on the paper. Assuming that each pattern card represents one pick of weft, when the card is pressed against the needles of the jacquard, the blanks push the unwanted needles and hooks out of the path of the lifting griffe; the holes allow the needles to pass through and thus remain stationary, so that the corresponding hooks remain in the path of the lifting griffe and cause the corresponding warp threads to be lifted. Jacquard: Single-lift, single-cylinder - In this machine there is only one griffe which lifts on every pick, and only one pattern cylinder, which strikes every pick. This restricts the speed at which the loom can be operated. Jacquard: Double-lift, single-cylinder - This is the machine in most common use for ordinary jacquard work. There are two lifting griffes and twice as many hooks as in a single-lift machine, but only the same number of needles and one card cylinder. The shed formed is of the semi-open type, which causes less movement of the warp threads, as any threads which require to be up for two or more picks in succession are arrested in their fall and taken up again. Double-lift jacquards give a greatly increased loom production as compared with single-lift machines, as they permit the speed of the loom to be increased to about 180 picks per minute for narrow looms, as compared with 120 to 140 picks per minute for single-lift jacquards. Jacquard: Double-lift, double-cylinder - In this machine there are two sets of hooks and needles, two lifting griffes and two card cylinders, odd picks in one set of cards and even picks in the other set. This permits maximum loom speed, it prolongs the life of the pattern cards, but is open to the serious drawback that spoiled cloth is caused whenever the two card cylinders get out of correct rotation. Jacquard: Cross Border - Fabrics with borders, such as tablecloths, bed quilts, etc., are woven with jacquards with two griffes, two sets of hooks and two card cylinders. The cards for weaving the border are laced together and weave on one cylinder, while the centre cards are on the other cylinder. The loom weaves at the speed of a single-cylinder, single-lift machine, and the change from the border to the centre cards can be made by hand or automatically

A movable bar on a loom over which yarn passes during weaving, the bar being caused to move inwards, e.g., towards the healds, in order to slacken the warp threads passing over it. When used as a slackener or easer for doup yarns in leno and gauze weaving there must be sufficient movement to allow the doup threads to cross to the other side of the standard threads. Vibrating backrests are used extensively in plain weaving to maintain a uniform tension on the warp threads.

The term applied in Yorkshire to the cross-rod system of tappet weaving (see Cross Road)

Viscose was discovered by two English chemists, Charles F. Cross and E. J. Be van, working in collaboration at Kew, near London, who found that when cellulose was treated with disulphide of carbon in the presence of caustic soda, it was converted into a golden yellow plastic compound which dissolved readily in water. A solution of the plastic was of such viscosity that it was named " viscose," a name that was destined to become world famous, seeing that round about 88 per cent of the world production of rayon is now made by the viscose process. In 1892 Cross and Bevan were granted a patent on the viscose process and it was applied to many purposes before the production of a textile thread was successfully accomplished. Fundamentally, the manufacture of viscose rayon is fairly simple. The raw material may be wood pulp, pulp from cotton linters, or a mixture of the two. The greater part of the world's viscose is made from wood pulp. Viscose rayon manufacture comprises seven distinct treatments as follows: - 1. Making and purifying the cotton or wood pulp which forms the cellulose base. 2. Caustic soda treatment of the cellulose base thereby forming alkali cellulose. 3. Treatment of alkali cellulose with carbon disulphide, forming cellulose xanthate. 4. Dissolving the cellulose xanthate in weak caustic soda to form cellulose solution or viscose. 5. Spinning viscose into yarn. 6. Bleaching, purification and finishing of the yarn. 7. Preparing the yarn for weaving and knitting.

Alpaca "wool" weft is obtained by disintegrating fabrics made of mixture materials, and may contain animal and vegetable fibres. The term is also applied to a lustre fabric woven with a cotton warp and alpaca wool weft, plain weave. When dyed in solid colours it is cross-dyed, the cotton warp being dyed before weaving, and the piece is piece-dyed after leaving the loom. The warp is usually 2/80's Egyptian. The cloth wears well and not liable to gather dust, so is used for linings and men's summer coats. A typical cloth is woven 56-in., 72 X 70, 2/80/ 28's alpaca. The true alpaca is a long, white or coloured smooth hair obtained from the Auchenia paco of South America (see Alpaca Wool)

The cross rail or roller at the back of the loom over which the warp threads pass to the healds and reeds. The American manufacturers call this rail " Slip-roll."

A quantity of yarn wound on to a flangeless paper or wood tube and usually cross wound (see Cheese Winding)

A lustre dress fabric made from two-fold cotton warp, yarn dyed, and mohair weft, cross-dyed after weaving, usually 30-in., 35/40 yards, 2/60's cotton warp and 16's mohair weft. The cloth is very similar to " Lustre Orleans," but of a closer texture.

In leno weaving, the warp threads over which the whip threads cross.