MANUFACTURE
.f LINOLEUM* GILES B. COOKEt University of Maryland, College Park, Maryland
The history and development of linoleum from earlier types of floor coverings are briefly reviewed. A short discussion of the sources and chemical A MODERN L I N O L ~FLOUR M IN A NEWSPAPER OFPICE properties of each of the basic conSpecially designed insets add character and individuality to business floors. stituents of linoleum i s followed by a discussion of their contributions to the jinished product. The general processes in the manufac- a t Knightsbridge for t h e manufacture of a floorcloth lure of linoleum are described and the various ty$es by applying a mixture of rosin, pitch, Spanish brown, of linoleum discussed. Standard tests of quality which beeswax, and linseed oil in a molten state to canvas linoleum must meet are giuen and some of the many a p and rolling the mixture into the cloth by pressure. In 1763 the first patent (1) ever issued specifically for the plications of linoleum presented. manufacture of floorcloth was taken out by Smith. ++++++ This patent covered the above~process. That floorcloth was u ~ o nthe market in 1788 is shown by an adHISTORY ----~ ~ vertisement' in the Bristol Gazette and pub& AduerINOLEUM was first produced in England, having tiser (2) of that year by Messrs. John Hare and Combeen developed by Frederick Walton of Yorkpany. The Builder (3) stated that Smith was the first shire in 1863. It was an outgrowth of earlier manufacturer to use wood blockg in the printing of types of floor coverings. There is no record as to the floorcloth. Subsequent improvements to lower the actual origin of floorcloth and its early history is very cost of Smith's floorcloth resulted in the development of limited. Most of the information avaifable concerning modem floor coverings. its early development is contained in patent specificaIn 1844 Elijah Galloway (4) softened India rubber tions. In reviewing the literature some confusion by the application of heat and incorporated the plastic results from the fact that prior to the eighteenth century rubber with cork flour. This material was rolled into the term oilcloth was applied to floorcloth. Evidently sheets and sold under the name of "kamptulicon." It the first floorcloth was merely a fonn of oilcloth in was first merely cemented to the floor in this form but which a piece of cloth had been coated with oil paint. later was much improved by being pressed into a canvas Later, to render oilcloth more serviceable as a floor backing. Owing to the high cost of rubber a t that time covering, resins were added to the paint. "kamptulicon" proved to be too expensive for the averThe earliest patent in 1636 for "Painting with oyle age buyer and in 1863 Walton (5) developed a process cullers upon wollen-cloath" was followed by the use of for the oxidation of linseed oil to produce a floor covervarious mixtures of oils and resins. In 1751 a floor ing less costly. covering was produced by incorporating India rubber Walton called this new material linoleum. "linnm" with oils and resins and applying to a cloth backing. for flax and "oleum" for oil, since linseed oil is obtained Three years later Nathan Smith established a factory from the flax plant. Since Walton's time many imIllustrations furnished by courtesy of the Armstrong Cork provements have been made in the processing of linoCompany, Lancaster. Pennsylvania. t Formerly Research Chemist, Armstrong Cork Company. leum and today linoleum floors are found all over the world. Linoleum originally contained four essential Lancaster, Pennsylvania. 3
L
substance. It is this solid, spongy, resilient form of linseed oil that is employed in the manufacture of linoleum.
MOWING FLAXIN W R ~ T E RSIBERIA N
materials, namely, oxidized linseed oil, resins, cork, and a burlap background. Today in high quality linoleum are found these same basic raw materials, or alternate substances, together with other materials such as gums, wood flour, pigments, and inorganic fillers, for example, whiting. These additional materials improve the quality, increase the durability, and add to the beauty of the finished product.
P R E P A R I N G THE SOIL FOR THE
PLANTING OX. JUTE
The chemical composition of linseed oil is known only approximately. It is not a simple substance but a mixture of glycerides. It is believed to be composed of the mixed glycerides of the following fatty acids:
THE BASIC RAW MATERIALS
Palmitic acid, ClsHlzO,about 5%.
Linseed Oil.-Linseed oil is obtained from the seed Myrirtic acid, C M H Z ~ about O ~ , 5%. of the flax plant. Technically the domestic seed is Oleic acid. ClsHa40g,very small amount. Linolic acid, C I S H ~ ~from O ~ , 10% to 15%. called flaxseed and the imported seed is known as linLinolenic acid, CtsH3,,01,from 10% to 15%. seed. The flax plant is grown for both seed and fiber. Isolinolenic acid (not obtained in the pure state), from 55% If cultivated for seed the fiber is of little value, and if to 6.5%. cultivated for fiber the seed is immature. Tlie range The exact percentages of the glycerides of linolic, of climate under which flax can be produced is very wide. It is grown in Canada, the north-central part liuolenic, and isolinolenic acids present in linseed oil of the United States, northern Russia, Argentina, differ in the opinions of various investigators (6). These double-bond fatty acids-leic, linolic, linolenic, southern Russia, and India. Clean flaxseed contains from thirty-five to forty per and isolinolenic--are responsible for the characteristic cent. of oil by weight. The oil may be obtained by properties of linseed oil. In contact with the atmosone of several methods. The seed is ground, heated, phere they take on oxygen, undergo polymerizations and pressed in a hydraulic press. Or the seed is heated and possibly rearrangements, and become solid. This first and then crushed through a conical grating. A process appears to be continuous and probably is never complete. Heat, light, third method consists of . electliical energy, and mecrushing the seed and leachtallic catalysts hasten the ing out the oil with petrolsolidification of linseed oil. eum naphtha. The naphAmong the commonly used tha is distilled off and catalysts are the oxides of recovered. Commercially lead and manganese. pure raw linseed oil is Soaps and salts of lead obtained by all three of and manganese, and of these processes. other metals, are also of Linseed oil is a saponifivalue as catalysts (7). able oil. It contains radiRaw linseed oil is purcals of fatty acids in chemichased for the manufacture cal combination with glycof linoleum. The methods erin. The fatty acids of of oxidation which render linseed oil give it its charit suitable for use in the acteristicproperties. Some production of linoleum are of them are unsaturated described under the manuand they enable the oil to facturing process. absorb oxygen from the Cork.-Most of the air. increasing the s~ecific world's supply of cork is gravity and forming a crnr~~ JCTC c IX INDIA The fibers of the tall talks are used for weaving burlap. produced in Portugal, tough, spongy, rubber-like
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Spain, France, and northern Africa. Cork comes from the cork oak, being the thick, protective bark of this species of tree. When the tree is about twenty years old the cork bark is stripped from the trnnk and the larger branches and a t ten-year intervals thereafter. The bark is boiled to remove sap and tannins and to soften the cork. After boiling, the cork is carefully graded and baled and it is then ready for shipment. The finest grade of cork is used for the manufacture of bottle stoppers. After the cork stoppers have been punched about fifty per cent. of the cork is left in the form of scrap. This cork scrap which is of the very finest quality is ground to a dust and used in the manufacture of linoleum. The finer the cork is ground the better the finish of the completed linoleum. However, very finely ground cork makes the various manufacturing operations more difficult and results in a more expensive product. Cork is composed of tiny air-filled cells which are held together by a natural resinous binding material. Because of this structure cork is light, compressible, resilient, and impervious to water. Each particle of finely ground cork possesses these characteristic properties in just the same manner as the large pieces. Cork adds softness, resiliency, and durability to linoleum. Burlap.-Burlap suitable for linoleum production is imported principally from Scotland. Its manufacture is confined mostly to Dundee and the surrounding district where it forms a large and flourishing industry. Burlap is a loosely woven fabric manufactured from the fibers of the jute plant. Among the natural fibers jute ranks next to cotton and linen in commercial and techuical importance. The greater portion of the jute of commerce is pro-
A CORKOAKSTRIPPED OF ITS BARKTO THE LEGAL Srx FEET IN MAT'MORA FOREST,MOROCCO
duced in India and the East Indiin Islands. The fiber is prepared from the stalk of the jute plant by "retting" in water. Retting is simply a form of fermentation. The jute stalks often grow to a height of twelve feet. When the plant is full grown the. jute is cut close to the ground and allowed to soak in water on flooded fields for about two weeks. Under these conditions retting takes place. When the fermentation has progressed sufficiently the fibers can be separated readily from the remainder of the stalk. Native Hindoos, stripped to the waist, beat the jute stalks until only the fibers remain. As i t appears in commerce the jute fiber is from four to seven feet in length. Most of it is yellowish brown although some qualities are of a silver-gray color. Jute has considerable luster and a high tensile strength. Instead of being composed of relatively pure cellulose the fiber of the jute plant consists of a modified form of cellulose
cork flour, can be used satisfactorily as a replacement material where a finished product of light or bright colors is desired. For this reason the use of wood flour
commonly known as bastose. Because of this difference in chemical composition burlap combines directly with both acid and basic dyes while cotton and linen fabrics require mordants. Burlap forms a base for linolenm. It braces and strengthens the finished product. Other Constituents.-While linseed oil, resins, cork flour, and burlap are the original components of Walton's linoleum, other materials are now used with, 01 in place of, these first constituents to improve the wearing qualities and the design and general appearance of the finished product. Wood flour is used in varying proportions in most types of linoleum. Linoleum compositions containing cork are colored with difficulty. Wood flour of finely ground grade, while lacking some of the properties of
A PIECEOF OXIDIZEDLINSEEDOIL In this form linseed oil is tough and spongy.
is increasing due to the greater production of highly colored linoleums as compared with the plain material which comprised the bulk of the production some years ago. The linoleum cement or hinder is prepared by blending or cooking the oxidized oil with rosin and gums. Rosin, or colophony, is the resinous residue remaining after the removal of turpentin~from the exudation of the southern long-leaf yellow pine, Pinus fialustris, or from the solvent extract of the stump of this tree. Kauri gum, now used to a much smaller extent than formerly, may be employed in conjunction with the rosin to give a higher fusion point to the finished cement. This gum is obtained fmm New Zealand. It is dug from the ground as the fossilized or semi-fossilized exudation of the tree, Agathis awtralis. Pigments of suitable color and strength are incorporated with the cork dust or wood flour and cement to give compositions of all the varied colors available in modern linoleum. Similar pigments are employed in the oil paints required for the manufacture of printed linolenm. Nitrocellulose lacquers are now used frequently as a finishing material, chiefly on plain linoleum. The advantage of lacquer on plain goods is the sealing of the surface to give protection to the linoleum during installation and to provide a good base for maintenance by waxing. THE MANUFACTURING PROCESS
The Oxidation of Linseed Oil.-Raw linseed oil is received in tank cars and stored in large reservoirs until needed. The oil is solidified to a spongy, rubber-like substance by exposure to air. This results from oxidation and polymerization, although the solidified oil is
generally referred to as oxidized oil. There are several processes by which linseed oil is oxidized. Two of the oldest and most common are described below. The scope of this article does not permit of a discussion of the more recent developments of this important phase of linoleum manufacture. The Scrim Process.-The initial treatment of the oil is boiling. The oil does not actually boil in the manner that water boils. Heating the oil causes it to foam and brings to the surface any impurities that may be present. The boiling is carried out in large kettles in fireproof rooms equipped with automatic fire extinguishers. Heating the oil effects the incorporation of metallic
D ~ s c ~ ~ n c rAN CEMENT c KETTLEINTO
A
COOLING PIT
oxidation catalysts and causes other desirable physical and chemical changes in the oil. Oxides of lead and manganese are the catalytic agents usually added to linseed oil during the boiling. The boiled oil is pumped from the kettles to traveling troughs a t the top of the oxidizing sheds. From these troughs the oil is periodically caused to flow over cotton scrims hung vertically. The scrims are usually about three feet wide and twenty-five feet long. They are spaced about four inches apart. A temperature of about 100°F. (about 38°C.) is maintained in the sheds and under these conditions the oil dries to a film on the scrims. Another flooding with the oil follows and so on until a t the end of from six to ten weeks the thickness of the oil sheets reaches about one-half of an inch. The scrims are then tom down and the oxidized oil ground preparatory to use in the manufacture of the cement. The Wood-Bedford Process.-Raw oil, with the addition of the DroDer oxidation catalvsts. , . is oxidized in jacketed horizontally arranged drums. These oxidizA
A
ers are equipped with axial shafts carrying a large number of spokes. A s the shafts are revolved air is drawn through the oxidizers which have been filled to onehalf of their volume with oil. Steam or water as required is used in the jackets to control the oxidation reaction, which, when once initiated, is highly exothermic. This treatment is continued until the hot oil attains the proper viscosity. The oil is then discharged into shallow containers where upon cooling it sets to a rubbery, dough-like consistency. Cement.-Proper proportions of the oxidized oil, resins, and gums are fluxed and blended in vertical, tilting, steam-jacketed kettles. The cementing operation is carried on a t approximately 300°F. over a period of from two to four hours. At the end of this time polymerizations and other chemical changes bring about a coagulation or gelatiou. The cement is then poured into cooling pits in which the material assumes the tough, plastic, and adhesive qualities evident a t
Prepared by cooking oxidized linseed oil with rosin and gums until gelation results.
normal temperatures. After a suitable seasoning period, which is dependent on atmospheric conditions, the cement is evaluated to determine the particular grade of linoleum in which it will serve best as a binder. The Linoleum Mixture.-The mixing operation is an extremely important one. The tiny particles of cork dust, wood flour, and other materials must be thoroughly and intimately mixed and coated with the cement. The linoleum mixture must emerge from this operation in a homogeneous form. The various iugredients are given a preliminary mixing in a batch mixer of the Werner and Pfleiderer type. From this machine the mixture passes through the "german" mixer which resembles a large meat grinder. It is equipped with stationarv and rotating knives. the rotating knives being so.staggered as to cause 'the material to work
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through the machine. From the german the mixture is fed contiuuously into the "scratcher," a machine which consists of two rolls, one steam-heated and one cold. The material adheres in a thick layer to the cold roll. Adjacent to this cold roll is a high-speed revolving cylinder fitted with hundreds of sharp spikes. The spikes scratch off small particles from the layer of linoleum mixture, converting it to granular form. Calendering.-When the linoleum mixture comes from the scratcher it is ready for calendering. The granular mixture is fed into the opening or wedge between two large horizontal rolls or calenders. Burlap is led over the back roll and into the wedge, and the linoleum mix-
CALENDER WlllCH
SHEETS THE LINOLEUM MIXTURE ONTO
The length of the stoving period is variable and depends upon many factors. Atmospheric conditions, the thickness or gage of the linoleum, the composition of the linoleum mixture, the nature of the binder, and the temperature of the stoves all influence the duration of the maturiug process. Tests are made a t intervals during the maturing period to determine when the process is complete. If left too long in the stoves the linoleum becomes ---hard and brittle, and if removed before maturing is complete i t is ~~p ~~
THE
ture is sheeted into the burlap as a base. The rolls are cored and their temperatures are so adjusted as to give a smooth, thoroughly compacted sheet. The thickness of the linoleum is controlled by the opening between the calender rolls. As i t comes from the calender the linoleum is too soft to he satisfactory as a flooringmaterial. To transform i t into a tough, durable material i t is subjected to a treatment known as maturing. Maturing.-The linoleum sheet, whether formed by calendering or by pressing, as described later under "molded inlaid linoleum," next passes into tall narrow stoves or ovens in which it is festooned in large loops. The stoves are maintained a t elevated temperatures and it is this heat treatment that brings about the hardening and toughening or maturing of the linoleum.
BURLAPBACKING
still too soft to be The printing surfaces of this parserviceable. ~h~ ticular block are fine lines made from brass strips. average time nec- , essary for proper maturiug varies from a few days to a few weeks. Maturing is the final process in the manufacture of all grades of linoleum. After maturiug the linoleum is given a final inspection, packaged in rolls of from forty to one hundred thirty square yards, depending upon the thickness and width of the material. The rolls are wrapped in paper, crated, labeled, numbered, and stored for shipment. Plain linoleum varies in thickness from a minimum of a little less than two millimeters to a maximum of six millimeters. Battleship linoleum, so called because of its use on the decks of
naval vessels, is a thick, plain, durable floor covering. There are three principal types of linoleum, namely, plain, printed, and inlaid. Within each of these general classes are various modifications which are briefly referred to in the following paragraphs. Plain Linoleum.-The description of the mixing, calendering, and stoving operations previously given covers in a general way the manufacture of plain linoleum. The material is made in varying thicknesses and widths and in black and white as well as brown and many other colors. J a p e is grained linoleum of two or more colors obtained by feeding scratched linoleum mixtures of different colors into the calender a t the same time. Printerl.Linoleum.-This nroduct is a relatively thin sheet of plain linoleum decorated with a wearing surface of oil paint. The material is manufactured and sold in roll form or as rugs. The partially matured linoleum base is taken from the stoves to the printing machine. These machines are of varying lengths depending on the number of colors they are to print. They are mounted on a movable base in order that they may be moved in front of the stove into which they are printing since the linoleum requires a second stoving or drying treatment to convert the paint to a serviceable condition. Printing is accomplished with wooden printing blocks which extend across the machine. They are usually eighteen inches wide and from six to twelve feet long depending on the width of the linoleum being printed. The pattern conceived by the designer is traced upon the printing block, the surface of which has previously been saw-cut to give a line block or a peg block. With the pattern thus traced for a given color of the design the block cutter chips away the unnecessary wood. For or in tin^ " fine lines strins of brass are shaped and embidded in the wooden block. When all of t i e blocks are ready impressions are taken to make certain the pattern is fitted together properly. The color scheme is also tested. Many color cotribinations are tried by the designer before a final choice is made. The value of this selection depends upon a knowledge of color harmony and the ability to sense the changes in public taste. After the-color scheme for the pattern has been selected the blocks are mounted at proper intervals on the various heads of the printing machine. As the partially matured linoleum passes through the printing machine in the form of a large ribbon, all of the blocks are pressed down a t the same time on the surface of the linoleum. The pressure is released and the blocks raised. When in this raised position paint of the proper color is applied to the blocks preparatory to the next dip or imprint. Applica~~
~
tion of the paint is effectedby means of rotating rolls partially submerged in the paint troughs. These are given a reciprocating horizontal movement tdsynchronize with the vertical reciprocating movement of the printing heads and the intermittent forward movement of the linoleum through the printing machine. The printed linoleum is taken off the end of the machine, festooned in the stoves for the final maturing, and is then trimmed, inspected, and packaged for shipment. Inlaid Linoleum.-Inlaid linoleum has every color extending through to the burlap backing. Regardless of how worn a piece of inlaid linoleum may be the pattern is always retained. For ~s reason inlaid linoleum can be used for a number of yeap. There are two general types of inlaid lmoleum-straight-line inlaid and molded inlaid. The name straight-line is derived from the fact that every block is died in geometrically straight lines. There are two methods employed in the manufacture of straight-line inlaid linoleum. Pieces of linoleum of the proper colors are cut into blocks from sheets of plain or marbleized linoleum composition calendered without the burlap backing. The sides of the blocks are straight lines and the pieces are fitted together by hand upon the burlap backing. In this way the desired pattern is formed. As the pieces are assembled into the finished pattern the linoleum passes under a hydraulic press. The heat and pressure applied in this operation form the individual blocks into a single sheet which is at the same time firmly attached to the burlap backing. Straight-lime inlaid linoleum is also manufactured entirely by machine. A giant rotary mechanism converts several linoleum mixtures into individual sheets, cuts
blocks from these sheets, fits them together on the burlap base, and finally presses the assemblage into a finished sheet of patterned linoleum. In this process each of the colored sheets is led under a revolving cutting cylinder. In the surface of the cylinder steel knives are embedded forming a pattern. Between the knives plungers operate selectively from the inside of the cutting roll and place oa-the burlap the t e s s e r ~of the particular part of the pattern required. The pieces that are not needed for the pattern are carried around between the knives and ejected. Normally four of such cylinders are spaced a t intervals around and adjacent to the large rotary e m over which the burlap is led. The pattern is thus b u ~ l t u pone color a t a time as the drum revolves past the cutting rolls. The burlap supporting the component parts of the finished sheet then passes over an inspection table to a continuous rotary press where heat and pressure finally consolidate the individual blocks into a homogeneous sheet and bond this sheet with the burlap backing. The rotary press consists of a cylinder against which hydraulically actuated pressure rolls operate. Molded Inlaid Linoleum.-This type of linoleum is manufactured by sifting or rubbing finely divided or granulated linoleum mixture through metal stencils onto the burlap backing. The stencils are arranged in a manner very similar to that in which pattern blocks are placed on the printing machine. One stencil is necessary for each color required in the completed pattern. The stencils are prepared with a high degree of accuracy in order that the colors may fit together properly. The colors are deposited one after another as the burlap intermittently passes from one stencil to the next along the molded table. The stencils are periodically raised
and lowered in unison to permit the intermittent forward movement of the burlap. The nature of the linoleum mixture and the requirements of the finished product have made i t advantageous to carry out this operation under artificially aeated constant atmospheric conditions. From the table the material is led to large hydraulic presses where final amalgamation of the individual particles is effected a t elevated temperatures. The molded linoleum process makes possible the manufacture of artistic creations which are not limited to the straight-lime configurations inherent in the straight-line process. Mottled colors may be employed. The surface of the linoleum may be embossed (patented process) to simulate depressed mortar lines and thus give relief or depth to an otherwise flat floor covering. Recently one manufacturer has combined the straight-line and molded processes by inserting straight-line blocks of marbled or grained character in the molded linoleum. Beautifully attractive and artistic designs have been created by this advancement in linoleum aaftsmanship. Embossing.-Embossing is a rather recent invention
linoleum, embossed inlaid lmoleum is matured in the stoves. Linoleum Tile or Linoti1e.-This material is essentially plain linoleum without the burlap base, cut into tile form. When applied to the floor in combinations of two or more colors it gives an inlaid flooring. Laid according to the individual taste this product makes possible the creation of many beautiful custom designs. CONTROL AND TEST METHODS
While the general manufacturing processes for making linoleum have been described, much other work which is essential for the production of high quality linoleum must be carried out simultaneously. All raw materials must meet a high standard of quality. Linseed oil must not contain adulterants, cork dust and wood flour must be free from dirt and hard particles, and the burlap must be evenly woven. Careful examinations of these materials are made before they are accepted for use in the manufacture of linoleum. Rosin, gums, inorganic fillers, pigments, and paints also must meet definite specifications of high quality. The finished linoleum must pass tests of quality specified by the United States Government. These tests have been developed jointly by the manufacturers and the government bureaus. They should be consulted for details. They are classified as general tests and detail tests. Under general tests are given specifications relative
The men in the picture are inspecting the finished product.
in the linoleum industry. The effect produced by embossing gives certain types of designs, for example, tile patterns, a haud-set appearance. After a pattern of molded inlaid linoleum has been made and pressed it is then ready for embossing. The embossing is accomplished in hydraulic presses which contain plates with raised portions fitted to particular parts of the design. As the press comes down on the linoleum a portion of the design is forced down below the other part. In this way a portion of the design is made to stand out in relief giving texture to the surface. Like all other
THIS LUXUR~OUS FRETWORK IN A SOUTHERN BANK OF DESIGNTHAT LINOT~LE EXEMPUKES THE FREEDOM
AFFORDS
The following water absorption test is specified for battleship linoleum: The linoleum is placed in water for twenty-four hours a t 21°C. (7OoF.). The maximum absorption must not be over 5l/%% by weight for heavy, 4% for medium, and Z1/*% for light weight. These are but a few of the many tests that are constantly being made to maintain the high quality of linoleum. Research is also carried on to develop new compositions, new designs, and methods of manufacture necessary for the creation of novel artistic effects. Every year improvements and new patterns are offered to the public. Because of advancements over a period of many years modem linoleum is characterized by a beauty and durability undreamed of in the early days of its manufacture. THIS HOLLYWOOD
UTILITY
Linoleum floors are now in use to color, finish, width, burlap backing, key of the lino- in almost every country of the world. The many leum mixture to the burlap base, and hardness. The beautiful patterns and designs obtainable in almost latter is determined by an indentation test and is the every color and shade, coupled with lasting quality same for all kinds of linoleum. The government speci- and moderate cost, give linoleum a distinctive place fies that linoleum shall not show more than 0.01 of an in modern interior decorating. Linoleum floors are inch indentation a t the end of one hour, after being widely used in homes, public buildings, offices, stores, under eighty pounds of pressure for one minute by a and show rooms. Within the last few years a wall steel bar 0.282 inch in diameter. The burlap must covering of linoleum has been placed on the market. be deeply embedded and keyed to the linoleum mixture Combinations of linoleum wall covering and linoleum so as to be partially concealed by it. For battleship floors are offered in many attractive and pleasing arlinoleum a pull of six or more pounds is required to rangements. In library buildings linoleum is emseparate a strip three inches wide from the linoleum ployed as a cover for book shelves and the tops of mixture. The government specifies that the burlap reading tables. Card tables are manufactured with be finished with a backing paint. The linoleum must linoleum tops and the tops of'many office desks are be thoroughly matured. A cut a t an angle of forty-five covered with linoleum. degrees must show no difference detweeu the outer From one small, inadequately equipped factory in edge and the center. 1863 the manufacture of linoleum has developed and Detail tests refer to thickness, weight, pliability, and expanded until today it constitutes a world-wide induswater absorption. These vary with different kinds try. From all parts of the world-India, Siberia, and gages of linoleum. A minimum weight per Africa, United States, Eurppe, Argentina, New Zeasquare yard and a minimum and a maximum thickness land-are gathered the raw materials which are used in are required. The following example will illustrate the the manufacture of this modem floor and wall covering, and to all quarters of the globe the finished linoleum government specifications regarding weight. is shipped. Min. ?ul. Thickness in inches 4er so. Min. Max. . - vd. . Plain, A gage Printed, E gage Str.-line inlaid, A gage
6 . 8 pounds
0.137
3.6 pounds
0.064
0.147 0.074
6 . 8 pounds
0.110
0.120
Pliability is tested by bending the linoleum over mandrels. There must be no cracking or breaking during these tests. For straight-line inlaid the mandrels are five inches in diameter while for most of the other types of linoleum mandrels of three-inch diameters are employed.
ACKNOWLEDGMENT
The author is gratefully indebted to Mr. Edmuud Claxton, Director of the Laboratories of the Armstrong Cork Company, for corrections and suggestions in the preparation of this paper. LITERATURE CITED
1) NATHAN SMITH, British Patent No. 787. 2) Brwtol Gazette and Pzrblic Aduertiser. Thursday. Feb. 7. 1788.
t
3 ) Builder (British Jaumal). Jan. 16, 1858. 4) ELIJAH GALLOWAY. British Patent No. 10,054. (5) FREDERICK WALTON, British Patent No. 209. (6) J. I. LEWKOWITSCR, "Chemistry, technology, and analysis of oils, fats, and waxes," 6th ed., Macmillan & Co., London. 1922, Vol. 2. p. 61. (7) J. S. LONGAND OTHERS,''Studies in drying oils." Ind. Eng. Chem.,23, 53-7 (Jan., 1931); 23, 786-91 (July, 1931). BIBLIOGRAPHY
A. E. BWCHANAN, "An industry that g r e y from a paint pot." Sci. Am.. 143. 31%3 (Oct.. 1930). M. W. JONES." ~ i s t o r y and ' man"facture of floorcloth and linoleum." J. Soc. Chem. Ind., 38,2631T (Feb. 15,1919). ANON.,"Manufacture of floor covering." Chem. & Met. Eng., 32, 48O-5 (May, 1925). A. DE WAELE,"The manufacture of linoleum and its valuation," Ind. Eng. Chem.,9, 6-18 (Jan., 1917).
PEL= FRITZ, "Preparing Smoleum cement and the manufacture of linoleum flwr coverings," Textile World. 73,454-6 (Jan. 28,
1928). R. HESSE, "Recent advances in the linoleum industry," Nitrocellulose, 2, 9 2 3 , 115-6, 133-5 (1931). MAURICE DE KEGREL,"The manufacture of linoleum," Mat. plasligues, 3, 431-3, 626-8, 675-9 (1927). A. SCHWARTZMAN. "The chemistry of linseed oil," Can. Chem. Met.. 17. 36 (Feb.. 1933). J. A. N. FRI&. "~he'chemistrv of linseed oil." Gumev & - Jackson. London, 1917. "A story of floors," Armstrong Cork Company, Lancaster, Pa. GILESB. COOXE,"Cork and its uses," J. CAEM.EDUC.,8, 146392 (Aug., 1931). H. R. CARTER, "Flax and its products," J. Bale, Sons & Daniel..-.., ..-..--. ., ..- - . Woonnorsp. THOU.45. AN" KTLGOUS. "The jute industry from wed to finished cloth," I. I'urman & Sons, London, 1921. Fedxal Spcrificarimr. 1.I.L-L, 331+1 (Feb. 3, 1331).
