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6. Temperaturein burning cabinet 7. Preparation, handling, and past history of sample 8. Variations in operating technique, flame size, speed of operations, and direction of burning
Statutory requirements fer flame-resistant textiles in specific uses have created markets for fabrics processed with flameresistant finishes, but laws requiring limited flammability in fabrics have not significantly influenced the market for flamcresistant fabrics up to this time; the only regulation of this type is that of the state of California. Moreover, it is doubtful that this form of restriction will ever create a sizable market for flameresistant textile finishes, even if such regulations eventually prove
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workable. The real market for flame-resistant textiles lies in those fabric uses now considered hazardous under existing types of municipal and state laws. The trend toward broader coverage by these laws, and their wider acceptance, will be accelerated by developments in chemical and finishing technology through which better and cheaper flame-resistant finishes are made available. LITERATURE CITED
(1) Buck, G. S., Jr., Am. Dyestuf Reptr., 38, 7 8 (January 1949). ( 2 ) IIatl. Board of Fire Underwiiters, “01dnance Providing f o r Safety to Life in Places of Asuemhly,” Section 2. iiEcsIvcDSeptember 26, 1949
FIRE-RETARDANT T XTILES A G O N S U ER S T A N D P O I N T KENNETH H. BARNARD Textile Resin Department, American Cyanamid Company,
Bound Brook, N. J.
T
HERE is only one good reason for a consumer’s interest in &+retardant textiles, and that is his personal safety. Firehazardous clothing may cause him injury or even death. The possibility of such a fire may seem remote to the reader, but it seemed equally remote to 7000 people one sunny afternoon in Hartford, on July 6, 1944, sitting in a tent watching the clowns and the animals do their tricks. Maybe it was a cigaret butt in the dust-dry grass near the main entrance or a match tossed in the corner of the side wall, but whatever the initial cause the paraffin-soaked canvas wm quickly ablaze and with a great swish of smoke and flames the whole tent was a roaring funeral pyre for 163 people, mostly women and children. The greatest show on earth had a million dollars north of claims to settle, and five of its top executives were indicted for manslaughter, but no fineq, damages, or prison sentences can make up for the irreparable low of life, all of which could have been prcmnted by any one of scvera1 fire-retardant treatments. COCOANUT GROVE DISASTER
The reason for fire-retardant treatments on textiles was brought close to lo00 people who were celebrating the results of a Boston College-Holy Cross football game in a nightclub in Boston on November 28, 1942. To simulate its tropical name of “Cocoanut Grove,” the place was equipped with artificial palm trees, false walls of artificial leather, and a suspended fabric ceiling. I t is thought that a bus boy trying to locate a broken light bulb lit a match and started the conflagration. The tiny flame spread quickly through the fabric decorations and balls of flame rolled along the ceiling from one room to another, so that in a short time 489 people seeking pleasure there ended by losing their lives in a frightful way. Again, this tragedy could have been picvented by a proper fire-retardant treatment of textiles. These catastrophes, especially frightful because so many people were involved, are no more poignant to those left behind than that of a small boy in a cowboy suit of brushed rayon who played with a bonfre near Washington, D. C., and lost his life. This tragedy happened at the time California TVM passing a law prohibiting fire-hazardous clothing. However, passing a law under the pressure of some headline disaster is not the final answer to our problem. What is needed is better enforcement of the present laws, which in turn depends
on educating the general public to the hazards involved, along the lines of other drives for safety. The safety campaign conducted in the schools and newspapers for more careful automobile driving, the elimination of the hazards of the Fourth of July firecrackers, and the life insurance companies’ broadcasts on health and disease are the type of campaigns really needed to rcduce accidents from hazardous textiles. FIRE-RETARDANT REQUIREMENTS
Assuming an interest in slow-burning textiles, either based on new l a m about to be passed or old ones t.hat are better undcrstood and enforced, what’ other characteristicx sbould such a textile have to interest the consumer? In general, unless it closely approximates all the characteristics of the goods before treatment, for fire retardancy, a textile will lose its original customers. To be salable, in addition to its fire-retardant properties it must meet the following requirements. Dermatitis. The treatment must not cause dermatitis if the textile is to be used for clothing or is to come in contact with the skin. This test is second nature to all reliable chemical companies interested in producing new finishes, but as it is expensive to perform, requiring a minimum of 200 individual patch tests, the average consumer depends on his supplier to make it for him. Almost equally bad, although not so damaging as dermatitis, is the possibility of the formation of a bad odor. This too is a problem of n-hich the chemical manufacturer is well aware. Tensile Strength. Many fire-retardant treatments are durable because there is a chemical rcaction between thc chemical applied and the cellulose. It is almost impossible for cellulose to react without being veakened, so that some loss in tensile strength is to be expected. If the loss can be held under lo%, there is no harm done. Unfortunately, with the litghtcr and more open goods such as lawns and voiles, the reaction is more severe, as more surface is exposed per unit weight and the loss in tensile strength is, thcrefore, greater. As light goods are n a t u r d y weaker goods originally, any loss at all becomes a serious matter. Some testing laboratories also make tensile strength tests on wet cloth. It has been observed that :I loss in wet tensile strength may indicate degradation of cellulose when dry tensile strength may be but little affected. The life of a treated fabric exposed to outdoor conditions would certainly be shortened if the
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INDUSTRIAL AND ENGINEERING CHEMISTRY
431 drape, tearing rcsistance, comfort, life, and color substuntially unchanged. MARKET FOR FIRERETARDANT TEXTILES
Assuming now that a consumer can get a fire-retardant textile Lvith the qualifications defined above, how badly does he uant it and how much of it will he use? The potential sizejof a textile market and the demand for a new product are difficult to predict, but the following seems like a scientific approach toward making such a prophecy In the first place, information is published for each past year on how many pounds of cotton Cocoanut Grove Nightclub after tlle Fire goods went into shirting, into draperies, into work clothing, etc. Now, if the five largest mills making original wet tensile strength was low compared with that of the addressed one of these items-draperies, for instance-are untreated samples. Drape and Hand. Both clothing and draperies must meet these tests. Clothing must not be stiffened, draperies must hang well. Most consumers test these properties by merely feeling of the fabric; the average woman buying in a store does just this. However, drape meters and stiffness testers are available for large users who want to put their requirements down in a written, numerically rated specification. Tearing Resistance. Surprisingly enough, very few large buyers check tearing resistance, although it can be low even if the tensile strength is high. Tearing resistance is a peculiar property, in that it gets better as the thread count gets lower, with the same yarns in each case. Therefore, a low tear can often be corrected by changing to a lower construction; as the treatment often adds weight and slightly lowers the greater air permeability of a lower count, the net result is something closely approximating the original cloth and finish. Comfort Factor. In wearing apparel this includes moisture absorption, air permeability, and heat conductivity. These are rarely measured, but more attention should be paid to them, especially in designing a fire retardant for work clothing. Effect on Colors. As the appeal of most clothing is to the eye, a successful fire retardant must not change the color seriously nor affect adversely the original fastness to light, washing, crocking, etc. A corollary of this is the maintenance of luster when a highly lustrous finish is desired. Effect on Useful Life. This question generally comes up on outdoor exposures where awnings, tarpaulins, canvases, etc., are under consideration. The textile chemists are still trying to produce a weatherometer that will duplicate outdoor exposures, but it is obvious that if a treated textile fails in either an accelerated test or an actual outdoor exposure, its field of interest to the consumer will be limited by this deficiency. Summing up these seven points, a textile after fire-retardant treatment must not only be safe-that is, slow burning-but it must &o have most of its original characteristics of strength. Artificial Palm Tree at Cocoanut Grove Nightclub
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432 Table I.
Market for Fire-Retardant Fabrics
6,000,000 Brushed napped and pile fabric Lace curtains 12,000,000 Other curtains 30,000,000 Sheer goods 36,000,000 Cotton 9,000,000 Rayon 270,000,000 T o r k clothinn Chenille bedspreads 7,700,000 Chenille robes 160,000,000 Bed linens Upholstery 84,000,000 10,000,000 Seat cover cloths 625,600, 00 Total
50 75 50
3,450,000 9,000,000 15,000,000
75 75 5 0 75 2 25 25
27,000,000 6,750,000 13,500,000 5,000,000 3,200,000 21,000, 00 2,500,000 106,4 0,000
and the man in each mill who is responsible for this particular department is asked what proportion of his market iyould be interested in a fire-retardant finish, other things being equal, a pretty accurate guess as to the total market should be obtained. These estimates of the proportion of thc present market that might desire a fire-retardant finish were found to vary from zero for chenille bedspreads t o 7594 of the total market on lace curtains, for example. To show how these figures run, Table I is presented. COSTS
The possible market of 100,000,000 pounds of fire-retardant fabrics, mostly cotton and rayon, is of course a huge one, and the interest in such a finish covers so many classifications that it also is very broad. In making this survey, SO% of the men asked for their opinion replied, which is a very satisfactory percentage,
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as most market surveys get a response of only 20%. The price or cost of the treatment was not mentioned, but most mills based their estimates on a very low cost or one no greater than that of their regular finishes. Naturally, if costs were higher, and they are bound to be with any chemical finish, the market would be much smaller. I t is probable that a cost of 10 cents per pound of cotton treated would reduce the above estimate to one tenth of the figures given. However, even with this drastic reduction, there is a huge demand for fire-retardant cottons and rayons. Cost figures can be viewed from two different angles. To a fire chief or anyone responsible for keeping fire losses down, the cost of making the textile nonflammable would be of little concern, but to a retail merchant selling aprons, for instance, it is very important, for even a slight change in the price tag might turn a customer away to the next counter, or worse still, to the next store. It is said that a burnt child dreads the fire, and certainly the mother of such a child would be vitally interested in fire-retardant clothing a t any reasonable price; but, fortunately for children, perhaps only one in a thousand really gets burned in this way. CONCLUSIONS
The net result of all of this is merely that the average consumer is interested in just what interests you and me. We want to eliminate as many of the hazards of daily life as possible, but in this busy world we often do not rcalize such hazards exist, unless they are pointed out and properly impressed upon us. Furthermore, to be of any real buying interest, the cloth or clothing so treated must maintain most of its other useful characteristics and, finally, it must not cost too much. RECEIVED September 26, 1949.
COMMERCIAL APPLICATION OF F L A M E - R E S I S T A N T FINISHES ROBERT W. LITTLE' WITH JALVMESM. CHURCH AKU SYDNET COPPICIP Colunibia University, New York, N. Y.
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HE finishes commonly applied t o textile fabrics have for their purpose the improvement of the appearance or per-
formance of the final product. The qualities generally imparted are greater body or structural strength, resistance to soiling, and added stiffness, softness, luster, or drape. The latter are of prime importance, constituting a general enhancement of those characteristics which appeal to the eye and hand of the potential customer. The development of greatly diversified specialty finishes has addcd such properties a3 dimensional stability, crease resistance, waterproofness and water repellency, and resistance to moth damage and microbial attack. Flameresistant or flameproof finishes are unique in the field of tevtile processing in that their primary purpose is improvement of the personal safety of the consumer and that their use is required by law for certain fabric applications. Other papers of this symposium deal with mechanisms of flameproofing, the testing procedures employed in evaluating the flammability of fabrics, the value of flame-retardant fabrics t o the consumer, and legislative activity pertaining to fabric flammability. The following discussion reviews the nature of flame-retardant compositions and the methods by which they are applied commercially. 1 Present address, Experiment Station, Hercules Powder Company, Wilmington, Del. a P r w e n t address, Research Department, American Viscose Corporation, Marcus Hook, Pa.
NATURE OF RETARDANTS
A definition of the types of chemical compounds having flameretarding properties cannot be simply stated. In the final analysis, any noncornbustiblc material added to a flammable substance such as cellulose will serve as a fuel-diluent and hence reduce the flammability of the cellulose. This dilution effect often requires the presence of nearly IOO7, add-on of the additive, honever, before nonflammability is achieved and should not hc confused with the performance of true flame retardants which are effective at add-ons of 10 to 3OyO. The definition of retardants is further complicated by variations in the degree of combustibility of the substance to which they are applied. A compound which is effective in retarding the burning of wood may be relatively ineffective when applied t o a light-weight cotton fabric n-hich is both more easily ignited and more highly combustible because of its greater degree of subdivision. Although perhaps applicable to many other forms of cellulose, and to other substrata as well, the following discussion of retardants is based upon their effectiveness when applied to cellulosic teutilr fabrics. The many flameproofing compounds and treatments availalile couId be classified on the basis of the chemical nature of the active ingredients, the mechanisms by which they are thought to function, the permanence of the flameproof characteristics in terms of resistance to wet- and dry-cleaning operations, or the method of
