Humble Wood and Cotton.

Waikato Times, Volume 121, Issue 20248, 17 July 1937, Page 15 (Supplement)

Humble Wood and Cotton.

Scientific Marvels :: A Chemical Age.

(From a Scientific Journal.)

IF YOU LOOK upon wood as wood, and coal as coal, you are living half a century behind the times. To modern life wood is cellulose, and as such responsible for many fine and valuable substances; coal may be fuel, dyes, or perfume, according to the needs of the moment.

And this because the world has hurtled suddenly into a chemical age. Hundreds of years have been spent in slow progress, each achievement making the next one easier, and the sum total providing the foundation for a revolution in industry. Take cellulose, the modem miracle discovery, which is really the fibre of wood. Let the scientist treat it with nitric and sulphuric acid, and he gets the basic ingredient of smokeless powder. Nitro-cellu-lose dissolves in many solvents and gives viscous solutions, which, when spread in thin layers while the solvent evaporates, becomes transformed into a transparent, flexible film. That thin, transparent, flexible film has Revolutionised the Motoring Industry. A few years ago cars were finished witli coat upon coat of slow-drying paints, enamels and varnishes. A car stayed in the paintshop for days and -weeks. Now a quick, long-lasting lacquer reduces the finishing time from days to hours. This amazing substance, which can be a high explosive base or a quick-drying lacquer at the chemist’s whim is still more versatile. By covering cloth with lacquer an American firm produces an impervious fabric which can be made to simulate the hide of any animal or the skins of reptiles. This material, used as “fabrikoid,” is used for everything—book-binding to travelling bags, brief cases, tablecloths which looks like damask but are soilproof, durable wallcovering, furniture upholstery, coated fabrics for automobiles, window shades which can be washed with soap and water, men ’3 belts, parts for shoes, and scores of other products. Blend camphor with nitro-cellulose and you get another material of a thousand uses, not a lacquer, but a plastic—“Pyralin.” When heated, this plastic can be worked like bread dough and it is produced in rods, sheets and tubes and in all the hues of the rainbow. It forms the “sandwich” between two sheets of shatter-proof glass, it is made into toilet articles of beauty and durability, tooth-brush handles, advertising novelties, bath fixtures, fountain-pen barrels, toys, automobile trim and articles of office equipment. The elephant and the tortoise should be grateful to the chemist bcause this inexpensive plastic in its myriad hues gives the Beauty, Durability, and Lasting Loveliness of ivory tusks and tortoise shells. “Pyralin” is tough, hard, solid, almost unbreakable, and can be cut, sawed, filed, blown, rolled, planed, hammered, drilled, turned in lathes, without cracking or splintering. Its surface can be dull or lustrous, smooth or rough; it can be transparent or opaque; it can be given any flat colour or mottled. It lends itself to exact simulation of mother-of-pearl, ivory, ebony, and other natural substances. Its uses are legion in everyday life. Think back again to cellulose, the base of all these products. Instead of treating it with nitric and sulphuric acid to produce nitro-cellulose, try caustic soda - lye to you. You now obtain—not nitro-cellulose, but a syrupy solution, known as viscose. Now extrude this syrup through a narrow slit and into a bath of sulphuric acid —sulphur plus water plus air—and you get not a viscous solution, but a solid—a oe'lulose film. You know this film as “Cellophane”— the transparent, shimmery, flexible, moistureproof wrapper which protects nearly everything you buy. Even new-born babies are wrapped in this protective covering to-day. At least one hospital encases the new-born in “Cellophane” for protection during handling immediately after birth. But this product of the stately spruce tree is more than a wrapper. It is used for decorative purposes in the arts and crafts; it :s made into rain canes and used in colours

on hats, shoes and belts and for printing purposes.

Now watch closely while the chemist performs another sleight-of-hand trick. Instead of extruding the syruo through a slit and into an acid bath, he merely squirts it through tiny holes, called spinnerets, and into the acid. And it emerges not as a film but as a filament—microscopic threads finer than human hairs, finer even than the silk of the silk-worm. Here you see the birth of rayon, the first man-made fabric. So fine are the tiny strands that one pound of them would Reach From the Atlantic to the Pacific, but when woven into a yard, it can be converted into a fabric of chalky crepe or transparent velvet, dull or lustrous, in solid colours or printed designs. Man at last has succeeded in doing mechanically what the silkworm does—making a filament from a plant. The difference is that man uses spruce wood or cotton and works under scientifically controlled conditions; the silkworm takes the mulberry leaves as they come. Moreover, the natural silk filament is a protein material, not cellulose. New and revolutionary things are being done with rayon to-day and so wide-spread have become its application that the United States alone used more than 250,000,000 pounds of this man-made fabric in 1935, four times the consumption of natural silk. In many minds rayon is associated only with cheap and inferior goods, but •ueb is not the case to-day, nearly every typ« of dress combining rayon with other materials. Rayon, for instance, originally was made highly lustrous. Styles changed and later rayon appeared with chalky and even frosty surfaces. With other yarns such a change would be impossible. The strength and uniformity of rayon yam have been improved to a point where it is claimed that rayon as irregular as the most regular natural yarns available would be unsaleable to-day. It is also true that more brilliant colour effects can be achieved with rayon than with other fabrics because its lustre in itself gives added brilliance. More than 700,000,000 yards of woven fabric were loomed from rayon in 1985, varying from sheer cloths of fine filaments to heavy ones of the wool type, delicate transparent and crushproof velvets, sturdv plushes, smooth sheers, durable rough crepes, satins with a bright glitter and others which were lustreless. Many fabrics are created to-day which could not be produced at all with other textile fibres and the list is growing. Spun rayon, composed of threads made from cut-up filaments, also, has opened up a completely new set of fabrics since it blends with natural fibres to make novelty wools, men’s tropical suitings and many other materials. And still more fabrics are bound to come from cellulose. Various other products besides rayon and “Cellophane” are produced from viscose. Put the syrup into a vat with chemical solids, stir it up and then dump it into the acid bath and it “freezes.” Treat the coagulated product to remove the chemicals, thus creating holes where the chemical was—and you have a sponge. Saw up this product and you obtain a sponge of regular shape in any size desired. Sausage casings and bottle caps also are made from the same syrup. Now, let’s return once more to our starting point—cellulose. Treat this cellule with acetic acid—which gives vinegar its taste—and you obtain, not nitro-cellu-lose and not viscose, but cellulose acetate and the Starting Point for a New Array of Produces Like nitro-cellulose, it dissolves in solvents to form viscous solution, but its solubility characteristics are different. One of its characteristics is that it is slow-burning and hard to ignite so it can be used to make products employed where fire would be a hazard. It goes into photographic film and safety film for movies and as a thin plastic sheet reinforced with wire mesh it is used instead of glass in poultry houses because it admits ultra-violet light. It is worked into a plastic somewhat like “Pyralin” and it is made into a fabric, acetate rayon and converted into high-styia women's wear.