Artificial Silk Fabrics

Chenille Voile.

The various stages in the construction of this fabric is indicated by a portion of an applied or "working" design on point paper, in fig. 1, in which black squares indicate warp threads raised over picks of cotton weft, while the shaded squares show the warp raised over picks of artificial silk weft. After the cloth was woven, the ribs of floating artificial silk weft were "cut" up the centre in order to sever the floats of weft, which immediately assumed a more or less vertical position, and thus constituted the tufts of cut velvet or plush pile, after the manner of forming the ribs of pile in corduroy and velvet cord fabrics (see FUSTIAN). However, "Chenille voile" fabrics were sometimes woven with plain ribs or cords of pile, uniformly, and afterwards embellished with printed designs in one, or more than one, colour.

Embossed Plush Pile Fabrics.

The charming decorative qualities of artificial silk were displayed to their greatest perfec tion in so-called "embossed" plush or velvet pile figuring devel oped on a delicate texture of natural silk georgette and which was formerly very popular. This example was embellished with a de sign developed with a rich plush pile figuring of artificial silk and subsequently printed with an effective colour scheme, display ing the artistic ability of the designer in conjunction with the handicraft skill of the weaver. The georgette foundation texture of this lovely dress material was produced from spun silk yarn with a high degree of twist, and with both the warp and weft threads twisted in "reverse" direction, i.e., "twist-way" and "wef t way" respectively, in order to develop the peculiar, crimped tissue which is a distinctive characteristic of voile and georgette textures. The artificial silk pile figuring warp threads and the spun silk ground warp threads were drawn through the shedding harness and reed in pairs, with a "two-and-two" end disposition, uniformly. The ground warp threads of spun silk were disposed in the order of one thread spun with a "right-hand" twist (or "twist-way"), and one with a "left-hand" twist (or "weft-way"), in alternate suc cession, uniformly; while the ground picks of spun silk weft were inserted with three picks of weft spun "twist-way," and three spun "weft-way," uniformly.

Embossed plush pile fabrics of this character were produced in a "double-plush" loom of a special type in which two distinct fabrics were woven together simultaneously, face to face, with the figuring pile warp threads passing vertically between the upper and lower foundation textures which were severed automatically (while in the loom) during the operation of weaving. When not

required for figuring purposes, the figuring warp threads were floated quite loosely as surplus yarn on the back of their respec tive foundation fabrics, from which they were afterwards brushed away as waste material. This method of pile weaving necessitated the winding of the plush figuring warp threads onto separate flanged bobbins that were supported in a bobbin-creel frame, whereas the foundation warp threads were wound onto an ordi nary warp beam.

Related to the artificial silk industries were the manufacture of artificial wool and artificial horse-hair, sheets, films and tissues and plastic masses. The solutions used for spinning artificial silk from spinnerets with, e.g., so or more minute orifices, were spun from spinnerets with one or more larger orifices and artificial horse-hair was thus produced ; or ribbon strips were similarly made. The spinnerets with fine orifices for artificial silk were usually made from alloys of gold, platinum and palladium, and glass was also used to some small extent ; for spinning horse-hair and ribbons glass spinnerets were employed.

These spinning solutions were also made into sheets, films and tissues. Thus nitro-cellulose, frequently mixed with camphor and pigments, was made into celluloid sheets and moulded articles and also into photographic and cinema (inflammable) film; cel lulose acetate was made into (non-inflammable) cinema film; vis cose into a thin tissue known as "Cellophane," used as a food wrapper, and into film caps, often pigmented, much in use as a closure for bottles, especially by pharmacists, for which they were well suited because their great shrinkage during drying gave a very tight closure. Nitro-cellulose, mixed with softeners and pig ments and dissolved in butyl or amyl acetate, was much used as a lacquer for motor car bodies and other high class out-door work; cellulose acetate similarly dissolved was the dope used for the wing fabric of aircraft, to which it gave a shrunk water-proof finish and for which the nitrate, being very inflammable, was unsuitable. (See also CELLULOSE.) See H. Nisbet, F.T.I., Grammar of Textile Design (3rd ed., 1927) ; a practical treatise on the principles of woven fabric structures, with a chapter on "The Decorative Value of Artificial Silk in Textile Fabrics." (H. N.)