MAGIC CLOTH FROM TUBES

North Canterbury Gazette, Volume 7, Issue 58, 23 November 1937, Page 2

MAGIC CLOTH FROM TUBES

Accomplishments of Modern

Textile Chemists

CAN ALMOST MAKE SILK PURSES

FROM SOWS' EARS

gO many astonishing pink rabbits have been lifted out of the magic hat of modern research that a sopisticated twentieth century is apt to take startling new achievements all for granted. The average man's attitude toward them probably is a matter-of-fact,' 'Very interesting. I guess they've got something there!" Nevertheless, the technical investigators persist in drawing new wonders from the hat.

The machine and electrical age still produces its quota of surprises, though they cease to excite the imagination as they once did. Today, however, the whole world seems to have "gone chemical." Cloistered in university laboratories or in large industrial plants chemists are laboring to find ways to make things seem to be what they are not. Synthesis and metamorphosis appear, to the lay man at least, to be their watchwords.

From their bubbling retorts, these modern knights have brought forth surprises to make the textile world blink. By modifying the characteristics and properties of fibres used in weaving they have learned to impart a wide variety of striking, unique, and permanent finishes to familiar fabrics. Indeed, they are able to transform one type of fabric so that it looks and acts like an entirely different one. Until recently, there was little choice between wool that was too warm for summer wear and cotton or linen which fell into a mass of wrinkles after a few hours' use. And how many women have resisted the lure of velvet dresses because of the care they required! Today, spun rayons, cottons, linens and velvets are made permanently crease-resistant by the resin treatment, so that they snap back quickly after creasing, wrinkling, or crushing. Soft rayons in this way are converted into full-bodied, resilient dress goods By impregnating the rayon staples with resin and then distorting them to produce permanently curly fibres, the material is given the characteristics of wool. Sheer goods may be made more sheer and soft, or given a permanent crisp finish like organdie. Percales are

made to hold their iresnness ait-er it. peated washings. Weight and iustrt? of fabrics may be increased or decreased. In fact, almost any desired visible effect apparently may be achieved with resins and, in addition, the elasticity and wear resistance of the goods is improved and shrinkage and slippage is lessened.

Men's wear, too, comes in for a share of improvement. In addition to their crease-resistance, cotton suitings, shirtings, and underwear fabrics are made air-cool for summer comfort, when resin-treated to increase their porosity. The objectionable fuzz on shirting surfaces also is eliminated. Synthetic resins are being applied, as well, to silks and wools. With wools, it reduces shrinkage, increases their body and tensile strength, without added bulk, and gives new and distinctive finishes. The objectionable slippage, shrinkage, and sag of silk can be greatly reduced, and its lustre, softness, and wear resistance greatly increased.

The above examples illustrate but a few of the effects achieved. Probably 30 to 35 fabric finishes produced with synthetic resins are being marketed today, but it is possible to produce several hundred different effects, all of which last the life of the cloth, without needing to be "restored" periodically.

Before the application of chemical formulas to textile processing, the development of new fabrics was accomplished by a change of thread count, size, twist, or fabric construction, or tho introduction of new synthetic or natural fibres. This often necessitated the installation of expensive machinery. The resin process, by impregnating the fibres with synthetic chemicals, which last the life of the fabrics, permanently alters the yarn characteristics, and the new finishes become an integral part of the fibres.

Fabrics with these new finishes already are being produced in volume for the consumers' market. They are offered under special trade names intended to identify their particular features to retail shoppers. There is, incidentally, a strong movement among women's groups to obtain co-operation

of retailers in labelling garments made from unfamiliar fabrics, to inform shoppers of their characteristics and advantages, and to instruct in their proper care; also to instruct j'ardgoods salespeople to impart this essential information to customers.

Still a novelty, the advantages of permanently-finished fabrics sometimes bring a price premium of 25 per cent, or more over untreated goods, though some of the new finishes are offered at no price advance. Most of these finishes can be applied at manufacturing costs ranging from a fraction of a halfpenny per yard to several pence, the chemical makers say. The chemicals that produce these effects are applied on the regular textile equipment.

Development of synthetic resins has occurred only in the last quarter of a century. In their early days, resin products were dark coloured, brittle and unstable, with limited usefulness. Today, numerous synthetics are produced that are clear, glass-like, and even plastic, with compositions and physical characteristics that can bo controlled.

Chemists themselves have difficulty in defining resins, but those of most textile importance are usually organic condensations of resin-forming substances which, upon drying or upon the application of heat, are quickly converted into relatively insoluble products. About a dozen major classifications of resins are commercially available today, and their number is constantly increasing. Ways have been found to reduce their cost so that they are being used in many inexpensive articles. The familiar bakelite products are fashioned from resin compounds. Itesin compounds were confined largely to the paint and lacquer field until recently, however. Credit for their successful application to textiles is accorded to the British firm of Tootal Broadhurst Lee. Company, of Manchester, who have done an immense amount of investigation into resin impregnation of fibres in the last 10 years or more. Their triumphs, especially in producing crease-resistant properties in fibres, set research chemists to work in many countries to discover new things about resins and their uses, particularly in the textile field.

The original British patentees obtained a monopoly on processes using urea-formaldehyde condensations for anti-crease finishes, but other investigators have since achieved important results with such agents as acrylic acid esters, modified cellulose and others. In the United States, a position of leadership has been taken, in the production of resinous chemicals, by the Philadelphia house of Ilbhm and Haas.

The secret of the remarkable results obtained from these chemicals lies in working the resins between the fibres into lie fibres, penetrating them.

i.ous methods of application have

tea worked out. Use of a water solution is considered particularly advantageous where the fibres must be penetrated. This process is quite simple in its latest development. The cloth is dipped into the solution, the surplus liquid is squeezed out between rollers, like a common wringer, and the fabric dried over hot drums. Some resins must then be subjected to a heat of 280 to 300 degrees Fahrenheit for three- minutes to make the resulting impregnation insoluble. Still others require dipping in acid.