Evening Republican, Volume 22, Number 51, Rensselaer, Jasper County, 1 March 1919 — DIFFERENT WAYS TO TEST FIBERS [ARTICLE]

DIFFERENT WAYS TO TEST FIBERS

Knowledge Given Will Save Housewife Money When Necessary to Buy Material. LINEN IS QUITE EXPENSIVE Office of Home Economics of Department of Agriculture Gives Practical Methods of Test for Adulteration of Fabrics. There is such a great variety of fabrics on the market now. and most_ of us understand so little about how they are made, that It is hard to know which ones will give the best value for the money. Our grandfathers used to buy pure virgin wool, but new processes have been devised which utb. Ilze shoddy along with the wool in such a way that the goods are sometimes handsomer and more durable than the old kinds. Linen Ims gone up so in price that many of us cannot afford it and must contenf ourselves with cotton or cotton-and-Hnen mixtures. A microscope is tin* most accuratemeans of distinguishing cotton and linen threads. Cotton fibers, under the microscope. have a ribbon-like appearance with frequent twists, ami a broad flat central canal : linen fiber? are round, jointed ami heavier than cotttm. .. ./ ~ If the fabric is without starch, oil makes linen translucent and eotthn opaque. The finish must be washed out of highly finished materials before the test can be used. A comparatively simple test which, after some experience. enables one to distinguish between linen and cotton is called the “tearing’" test. One must be an expert to detect cotton and linen mixtures hi this way. The linen weaves in general are more difficult to tear than cotton. * The torn ends of the linen threads appear uneven in length, and j the individual fibers of the threads are parallel; while the torn ends of the cotton threads are more even in length, and the individual fibers are twisted in every direction. The sound of tearing linen is shrill, ami that of cotton dull or muffled. Another simple test is to light the threads with a match, blow out the flame and examine, the burnt-ends. The cotton threads will haiV blunt ends, while the linen will be pointed.

An easy way of distinguishing between the highly sized and calenderedcotton damask and true linen damask is to boll a sample. After being dried and ironed, if it is cotton, it will have a dull and somewhat fuzzy appearance, while the luster and smoothness of real linen will not be affected by the treatment. Mercerized cotton damask keeps more luster than untreated cotton. but less than linen. Woolen and Worsted Fabrics. Since the price of pure, new wool is relatively high, other materials are often mixed with it. the most common being what is termed.“shoddy.” This is old woolen material, tailors’ clippings, etc., put through a special machine which tears them apart and reduces them to fibers. Such goods have many uses. It is stated by woolen manufacturers that the best grade of worsted shoddy, which is of long staple, i. e.. has long fibers, is superior to,the low grade, short staple, new or virgin wool * also that it is impossible to get the texture and finish required for some of the best grade goods without the use of some shoddy. As shoddy is made from wool fiber it gives the same chemical tests as pure wool, and small amounts are almost impossible to detect, except by the use of the miwoscope. Cotton is also used with wool. Such goods have many uses. It is a simple matter to detect the presence of cotton as wool is dissolved in alkalies and not affeetejd by acijis. while cotton is dissolved by acids and not affected by alkalies. Detecting Over-Weighted Silk. When the gum is removed from silk produced by a silk worm, the silk loses from 20 to 30 per eeht of its original weight.’ To_nmlm_uiLl<ir..this additi(]ns of various substances which do not change the looks, feel or structure of the silk, are often made. If no larger an amount than that of the weight of the gum boiled off is - added. It is considered legitimate: but much silk is made which has as high as from three to four times as much mineral matter added to. it as its original weight. This makes the silk brittle and wbak, so that It wears out quickly. It is easy to determine heavily weighted material by burning a small sample. Pure silk burns Rapidly, smells like, wool and produces a small amount of brittle curled-up ash. Material which is heavily weighted will have an ash which is stiff and which often holds the shape of the sampje. Cotton is frequently mixed with silk. Such “goods sold as mixtures have many uses. It is easy to detect Cotton in silk by'the mierpscope as the fibers iof silk areoround and smooth.- while ■ the cotton fibers are ribbon-like and I fuzzy.