US2888975A - Method of making a decorative surface covering product - Google Patents

Description

Q'g iQ E KR June 2, 1959 w.-E; BENEDKCT 2,383,975

maoa or MAKING A DECORATIVE SURFACE covaamc paonucr Filed July 22, 1958 r i g? a zzvmvrox.

HHWIIMIQWG ilnitcd States Patent nice.

Patented done 2, 1959 2,888,975 I. 91 MAKING A DECQRATH E SURFACE CQVERING PRGDUCT Walter E. Benedict, Newtown, Pa, assignor to Congoleum-Naim Inc, Kearney, NJ, at corporation of NewYork Application July 22, 1953, Serial N0. 750,240 14 (Zhims. (Ci. 154- 125) This application is a continuation-in-part of my pendlog application Serial No. 508,449, filed May 16, 1955 and now abandoned.

Composition material has been used very extensively for the decorative and wear-resistant layer comprised in flexible, smooth surface coverings. Composition sheets usually are'made adherent to a backing sheet such as bituminized felt or a fabric, but composition. sheet material can be used by itself, e.g., in the form of tiles. Cornposition sheets for such purposes may be manufactured by sheeting out a substantially homogeneous mixture of to produce a sh :et having a .1 and rode: material an... substantially uniform wlcr. Composition sheets having only a single color are must generally usocii in oflices, stores, and other public buildings. However, for such purposes, as well as in the field of multiple or single dwellings, more decorative effects are frequently desired wherein more than one color is utilized.

In the production of decorative effects using more than one color, coverings of the linoleum type have been made by depositing or inlaying pieces of different color and complementary shape onto a common backing sheet. 1 he decorative effects produced in this way are of the geometric type, e.g., a checkerboard arrangement of square pieces of contrasting color or polygonal pieces of one or more color that are inlaid in corresponding cutouts from a continuous sheet of contrasting color-- so as to form a predetermined pattern- The production. of coverings of the inlaid linoleum type involves the employment of a backing sheet such as bituminized felt on which pieces may he inlaid and the operation is one requiring the use of large and expensive equipment for cutting out the pieces from a plurality of calendered sheets of linoleum composition or the like, carrying the backing sheet of bituminized felt on a moving support, depositing the desired cutout portions or pieces of the cdendered sheets on the backing sheet at ditiercnt of travel of the backing sheet, rejecting and taking away the unwanted portions or pieces of the calcudered sheets, and finally merging or fusing together the edges of the pieces that have been deposited on the backing sheet in interfitting inlaid relation. Because of the nature of the apparatus and method employed in making inlaid linoleum, the decorative effects produced are limited to designs of the geometric repeat type. Moreover, because any changeover from one design to another requires very substantial and costly changes in equipment, the number of designs that may, as a practical matter, be placed on the market by a particular concernis very l mited. It is also a drawback to the inlaying method that a serious salvage probram is presented by reason of the unwanted portions of the calendered sheet material that do not enter nto the particular design being produced- For example. it not infrequently is the case that less than i6% of a calendered sheet having a par'icula: coloration is required for entering into the intended design, the remaining of the calender-ed sheet being essentially scrap. In many instances, the salvage of this scrap is inconvenient to arrange and problems of storage are encountered not only as regards storage space and handling expense but also as regards the limits of time that the composition may be stored without becoming unworkable. Heretofore, it has been impossible to adapt the above-described process for preparing coverings of the vinyl type.

More intricate decorative efiects haraheen produced on covering materials by applying pain, lace-per, or the like to a suitable backing sheet such as bituminized felt by means of block printing or other analogous operations. Since coverings of this type have a wear layer whose thickness is provided merely b the paint or lacquer that has been applied as a coating, their wearing life is much less than that of inlaid linoleum wherein the wear-resistant layer is provided by calendering linoleum composition :0 whatever thickness may be desired, such thickness being many times the thickness of paint or lacquer applied as a coating.

As distinguished from applying difierently colored pieces of calendered lincieunz composition to a backing sheet or applying paints or lacquers of dilicrent color to a base sheet, calendered sheets of composition material such as linoleum composition have been produced which are of variegated appearance by mixing together pieces of the composition material having different color and, while the mixed 'ecs are of a planic md moldable core sistency, subiecting them to one or more calendering operations under conditions which are suitably controlled for producing the appearance desired. For example, linoleum composition may be formed prior to calendering into pieces about to 1 inch in length and having a transverse dimension of about M. inch. Pieces of different color that have been so formed are mixed together until the relative proportion of the pieces of ditierent color is about the same in all portions of the mixture. The mixture is then fed into a calender and during passage through the calendar the pieces largely retain their individual colors but are subjected to very substantial distortional com ming ing. This distortional commingling is evidenced in the product of the first calendaring by the fact that the pieces have become stretched out into long streaks to provide a striated efiect that is commonly referred to as jaspc.

In addition to the iaspe efleet, a simulated marble efiect may be produced by further distortionrl. commiegling of the pieces ct dilierent color. This usually is accomplished by cutting a previously formed iaspe sheet into lengths, turning the lengths 9'), lappirg the turned lengths and carendering the lapped lengths. The lapped jaspe sheets me then cross calendered, that is, calendcred in a direction 90 to the direction of the jaspe streaks, and by so doing the iaspe streaks are spread sidewardly with resultant production of an appearance resembling marble.

Variegated color effects likewise have been produced, particularly in connection with relatively heavy comp. sition sheets, e.g., suitable for tiles, l'y initially formin-x by passage between rolls a sheet having substantially uniform color throughout and than prior to further fern-ration of the finished sheet by pas age betw en rolls adding pieces of contrasting color which may be of the charac er aforesaid and of essentially the same plastic consistsicy as that of the sheet to which they are added. so that upon being subjected to calendaring with the irfiall? formed relatively to the surface of the sheet being calendered,

the dragging out of the colors in the direction of the calendaring can be accentuated, and particularly if the roll in contact with one of the surfaces is operated so as to be at a temperature which increases the superficial plasticity oi the composition in contact with the roll. a certain amount of surface smearing of the colors may be produced. However, in any case the variegated appearance that resulting from random and very extensive distortional commingling of portions of the finished sheet of composition material. Sheets having this type of decorative appearance are extensively used by causing them to adhere to abaclting sheet such as bituminized felt to produce linoleum of the well-known jaspe or marbleized types as well as in the production of asphalt tile. if desired in the case of linoleum, calendered sheet material of this type may be fed into an inlaying machine and pieces may be cut therefrom for providing certain of the pattern elements of inlaid linoleum. The heavier grades of such sheets likewise may be cut into tiles.

Polyvinyl composition has heretofore been employed for providing the wear-resistive layer or sheet comprised iu fiexibe smooth surface coverings. Thus calendered polyvinyl composition sheets have been bonded to backing sheets such as bituminized felt. The decorative features of polyvinyl composition coverings have been somewhat more limited as compared with coverings comprising linoleum composition due primarily to the fact that the workability of polyvinyl composition depends upon its thermoplastic properties whereas linoleum composition can be worked at room temperature while the drying oil component of the binder is in an only partially oxidized and polymerized condition. Thus in the case of polyvinyl compositions relatively high temperaturcs are employed of the order of 250 F. to 350 F. during the operations of mixing and sheet formation. For this reason vinyl composition coverings have either been produced in plain colors or with variegated appear ance such as jaspe or marbleized appearance when a con tinuous process has been employed. This has been a serious limitation on the decorative and ornamental effects that are obtainable using this type of covering. Eltorts directed to a oid this limitation usually involve a process wherein differently colored areas of granulated vinyl composition are physically placed on a backing or in a mold in a predetermined arrangement. Most frequently, this process is limited to providing thicker products, on the order of Ms inch, because of its slow operation and great expense. Polyvinyl sheets are frequently cut into tiles.

It is an object of this invention to provide a flexible smooth surface covering comprising a decorative sheet of composition material presenting surface areas of contrasting color, the sheet having extremely long-wearing charazteristics cmnparabl: to coverings of the inlaid linoleum type while at the same t me being capable of manufacture at much less cost both as regards processing 4 going -improvements in a composite sheet composed of polyvinyl composition.

Other objects of this invention relate to the provision of an improved method for making a composite sheet of vinyl composition having areas of contrasting color whereby sharply defined predetermined boundar es between the areas of difierent color are produced. Other objects of this invention are to provide a method of producing a composite sheet having the characteristics aforesaid that is economical and operable at a high production rate.

It is a feature of this invention that a decorative and wear-resistant sheet of polyvinyl composition is provided which is composite in that it comprises a matrix sheet and numerous pieces of contrasting color which are embedded within recesses in one of the surfaces of the matrix sheet in substantially spaced relation with respect to each other with the exposed surfaces of the pieces substantially flush with the surface of the matrix sheet. The embedded pieces may be of substantially uniform thickness substantially throughout and are fused to the matrix sheet at their interfaces therewith.

According to this invention, flat pieces are preformed from polyvinyl composition which is similar to that of the matrix sheet except for the contrasting color. The flat pieces may be produced in any suitable way as by cutting them from a calendered sheet or by transversely slicing an extruded body whose cross section has the desired shape. Preferably, the flat pieces are somewhat thinner than the matrix sheet and are caused to be pressed into the matrix sheet while the matrix sheet is at a temperature at which it is soft and readily deformable. The pressing is accomplished with virtrally no distortional committgling of the pieces with the matrix sheet and thereby they retain essentially their original predetermined shape and thickness. As a result, effects may be produced which in certain respects are similar to those obtained in the case of inlaid linoleum in that the original contours of the pieces remain essentially the same and likewise are sharply defined and in that the original surface pattern remains essentially the same during wearing away of exposed surface over very long periods of wear. On the other hand, ellects may be produced which ornamentally are distinctly different from those that are ordinarily produced in making inlaid linoleum in that arrangements and shapes can be obtained which are beyond the capacty of machines for making inlaid linoleum. Thus pieces which have curved or other irregular outlines may be utilized as conveniently as the more regular and simpler pieces which are our and placed in position in the manufacture of inlaid linoleum. Moreover. the pieces can be disposed in regularly recurring pattern repeat units or in scattered or random relation. In any such case both the manufacturing operation and the machinery for carrying it out are much less costly as compared with the manut'acture of inlaid linoleum.

In the practice of this invention, the pressing in of the preformed flat pieces into the matrix sheet without substantial distortions commingling is effected when the exposed surfaces of the pieces are at a substantially lower temperature than the temperature to which the matrix sheet is heated. For example, such temperature differential may be partially or entirely obtained by causing the pieces to be in contact with a surface that is maintained at a relatively low temperature. in addition, an initial temperature diiierential between the pieces and the matrix sheet may be employed. By use of a, pressing part maintained at a lower temperature, ditficulties due to sticking ikewise are overcome. During the pressing step, the matrix sheet preferably is maintained in contact with a surface presented by a body of substantial thickness composed of a yicldable resilient material such asmbber or a synthetic rubber although the conventional steel or chrome plated rolls can be used. The pressing step between surfaces is of such character that it can conveniently be carried out as a continuous operation using opposed rolls into which the matrix sheet having the pieces deposited thereon is fed after having been heated until the vinyl composition of which it is composed is rendered soft and deformable.

After the pressing step, the resulting composite sheet need only be cooled before use because during the pressing of the pieces into the matrix sheet the pieces become fused with the matrix sheet at heir interfaces therewith. If the surface of the matrix sheet opposite to that into which the pieces are pressed becomes bulged to some extent in the locations where the pieces are pressed in, the composite sheet can be passed in operative relation to a mechanism for planing off the bulges so that the composite sheet will be substantially of uniform thickness throughout.

Any of the polyvinyl compositions suitable for lamination with a backing sheet or for use in the form of tiles may be employed in the practice of this invention.

Suitable polyvinyl compositions are disclosed in Patent No. 2,558,378. While, as s ated in this patent, various polyvinyl compounds may be employed, that which is must generally employed is vinyl chloride-vinyl acetate copolyrner containing from about 80% to about 98% by weight of vinyl chloride. The resinous polyvinyl compound is plasticized by any of a number of plasticizers such as tricresyl phosphate, dioctyl phthalate and chlorinated parafiin. The plasticized polyvinyl compound binder is mixed with suitable fillers and p gments which may constitute fiom about 20% to about 76% by weight of the composition, e.g., calcium carbonate, clay, silica flour, etc., as well as pigments which are selected depending on the color desired. Generally it is preferable to employ a substantial amount of a fibrous filler such as short asbestos fiber. Typical formulation comprises from about 20% to about 50% of polyvinyl resin, about 10% to about 30% of plasticizer and about 20% to about 70% of filler including pigments. Such and similar composition material is referred to herein and in the claims as polyvinyl composition, and may be utilized in the practice of this invention.

In the practice of this invention, the thermoplastic properties of polyvinyl composition which in certain respects present diiiiculties in the successful manufacture of flexible smooth surface coverings have been utilized to advantage and; in fact, this invention involves a novel utilization of thcpeculiar properties of polyvinyl compositions. Thus while polyvinyl composition generally is mired and sheeted attemperatures in the range from about 259 F. to about 350 F., a sheet which has been formed as by calendering may be heated to still higher temperatures ranging from about 350 F. to about 390 F. and while the composition at such temperatures becomes soft and readily deformable, it can be handled and even passed between roiis while retaining its desired be pressed into a matrix sheet hat has thus been highly heated with little or no deformation of the preformed pieces. This is especially the case if the temperature of the pieces is held down at least at and adjacent the exposed surfaces thereof. When the matrix sheet is at such elevated temperatures, and even though the pieces are not substantially deformed, the pieces become fused to the matrix sheet so that there is no discontinuity of.

It is an advantage and unique attribute of this invention that the pressed-in flat pieces may be of any shape and may be of any size consistent with the capacity of the pieces to be pressed into the matrix sheet while the matrix sheet is heated to a emperature at which it is deformable and fiowable when the pieces are pressed into the matrix sheet. In order to permit the pieces to be pressed into the matrix sheet in an operation which may be readily carried out comercially, itis usually desirable that the pieces not have an area greater than about 2% square inches. It has been found that pieces of this size and smaller are actually imbedded in the matrix sheet and result in only a minimum amount of lateral or longitudinal displacement of material of the matrix sheet. On the other hand, if the total surface area of the pieces exceeds about 2% square inches, the pieces are laminated to the matrix sheet and considerable displacement of material occurs. This seriously disturbs any pattern which may be present on the matrix sheet and tends to create areas of unevenness on the final composite sheet. When pieces having a surface area less than about 2% square inches are imbedded in accordance with the invention, there or no discernible lateral or longitudinal displacement of material of the matrix sheet. Apparently the composition is compacted or pressed to the hack of the sheet. E en when using pieces measuring over about 1 square inch, care should be exercised to avoid close placement of the pieces to each other as the small amount of lateral and/or longitudinal displacement which does occur will result in slight surface unevenness of the final sheet. It is for this reason that the use of fiat pieces having a surface area of 1 square inch or less is most preferred in the practice of the invention. In addition, pieces which have a greatest surface dimension which greatly exceeds any other dimension, such as length compared to width, are somewhat difficult to handle in processing particularly in connection with placementand control of decoration other than of the random type. The pieces may be made so as to have a relatively small area if desired. as for example if an effect of the type which is commonly referred to as a salt and pepper effect is desired. However, the pieces should be such that when deposited on the matrix sheet they will lie fiatwise thereon so that after the pieces have been pressed into the matrix sheet, the surface of the pressed-in pieces will lie substantially flush with the surface of the matrix sheet and in the same plane so that the covering will present an over-all smooth surface. when reference is made to the area or dimension of the pieces, the reference is to the area or the linear dimensions of the exposed surface unless otherwise clearly defined.

he thickness of the matrix sheet and the thickness of the pieces depends upon the desired thickness or the composite sheet for use in the commercial product for which the composite sheet is intended. For example, in the production of a laminated covering comprising a decoratlve and wear-resistant layer which is bonded to a backing sheet such as bituminbed felt, the decorative and wear-resistant layer when made according to this invention may typically be about 0.025 inch in thickness. Usually it is desirable that this layer not be below about 0.029 inch in thickness. On the other hand, heavier grades of such coverings may be produced if desired. If

" thc composite sheet is to be used in the manufacture of tiles without a backing composed of nonvinyl material. the sheet that is produced is usually about 0.080 inch or greater in thickness.

The pieces which are pressed into the matrix sheet preferably are substantially thinner than the matrix sheet. For example, the pieces may desirably be about one-third the thickness of the matrix sheet. If the pieces are thinner, then the serviceahility of the covering is not as good. If the pieces are flicker than about one-half the thickness of the matrix shoot, them greater difficnlty is encountered in pressing them into the matrix sheet without the production of an undesirably large amount of bulging at the opposite surface of the matrix sheet. How

ever, pieces have been successfully pressed into the matrix sheet which are nearly the same thickness as the matrix sheet and which have been over 75% or the thickness cf the matrix sheet. As is apparent it is usually necessary to reduce the gauge of the matrix sheet while pressing in the pieces to produce a smooth, glossy surface on the sheet. By way of more specific example, when the composite sheet is to be about 0.025 inch in thickness, the pieces may be about 0.015 inch in thickness and the matrix sheet prior to pressing about 0.035 inch in thickness.

Further objects, features and advantages of this invention will be apparent from the following description of the accompanying drawings which are illustrative of the practice of this invention and wherein:

Pig. 1 is a plan view on a reduced scale of a flexible smooth surface covering which illustrates certain of the effects that may be produced according to certain embodiments of this invention;

Fig. 2 is a fragmentary cross section of a flexible smooth surface covering comprising a composite sheet embodying this invention, the section being on an enlargcd scale for increased clarity in the showing;

Fig. 3 is a diagrammatic side elevation which is illustrative of one type of apparatus which may be used in the practice of this invention; and

Fig. 4 is a diagrammatic side elevation of a continua: tion of the apparatus shown in Fig. Swhich may be optionally used in the practice of this invention.

Fig. 1 illustrates the fact that the sheet-form pressedin pieces may be of virtually any shape such as rectangles, diamonds, crescents, elongated strips which may be either straight or curved, etc. The shapes of the pieces which may be readily used according to this invention provide much greater flexibility as regards the shapes of decorative design elements than is in any way practical in the case of inlaid linoleum, whose manufacture requires very complicated and expensive machinery for cutt ng out pieces from certain calendered sheets and fitting in pieces from other calendered sheets as to make up a mosaic. As shown in Fig. 1, the pieces are disposed in substantially spaced relation. By the term substantially spaced relation as used herein and in the claims, it is intended that the pieces are spaced so that a substantial portion of the matrix sheet is exposed. Ordinarily the major portion of the surface of the composite sheet is that of the matrix sheet. in Fig. l the exposed area of the matrix sheet is indicated by the reference character 10 and the reference character 11 is applied to the various pieces. The composite sheet as a whole is indicated by the reference character 9. The spaced relationship of the pieces is not, however, to be regarded as precluding the possibility of two or more of the pieces contacting each other as illustrated, for example, by the pieces 11a. Likewise, two or more pieces may overlap each other as illustrated by the pieces 1112. Such contact or overlapping of pieces is likely to occur when the pieces are distributed in the random fashion illustrated in the ieftlsand portion of Fig. 1. Very pleasing decorative effects can be produced such random distribution of the pieces. On the other example, be bituminized felt.v A layer of bonding material may he used and is indicated by the reference character 13 and may comprise one or more layers adapted to provide the necessary bond and, when desired, a seal to prevent migration of the binder in the backing sheet 12 into the composite sheet consisting of the matrix sheet ill and the pieces 11. It is to be noted in connection with Fig. 2 that the exposed surfaces of the pieces 11 are substantially flush with the surface of the matrix sheet 10. Moreover, the pieces 11 are substantially the same thickness substantially throughout. This results from the fact that the pieces 11 before being pressed into the matrix sheet it? are sheet-form in that they have the shape of a piece cut from a larger sheet or produced by cutting a thin layer of uniform thickness from an extruded body.

When the pieces 11 are pressed into the matrix sheet 10, they remain substantially unchanged and the interface between the pieces and the matrix sheet is sharply defined. This sharp definition is evident at the surface of the composite sheet and likewise is'apparent if the sheet is cut transversely so as to show a section such as that illustrated in Fig. 2.

In Fig. 3 there is illustrated one type of apparatus which may be used in the practice of this invention. Any suitable source of a sheet of polyvinyl composi ion may be employed. In Fig. 3 a calender is shown of the type which is adapted to produce a calendercd sheet from an unformed mass of vinyl composition. The unformed vinyl composition is indicated at 14 and may be vinyl composition which is of substantially uniform color throughout as, for example, a composition that results from mixing the ingredients of a polyvinyl composition in a Banbury mixer. The matrix sheet 10 is produced mm the mass 14 by passage between the rolls 15 and 16, between the rolls 16 and 17 and between the rolls 17 and is. If it is desired that the matrix sheet 10 have a iaspe appearance. then the mass 14, which is initially formed by passage between the roll 15 and 16, may he a mixture of pieces of vinyl composition of different color of the type hereinabove referred to. If a marbleized base sheet is desired, then previously formed and lapped iaspe sheets may be cross caiendercd as by passage through a 3-roll calender arranged in the manner indicated by the rolls 16, 17 and 18. Any other type of calender or sheet-forming apparatus may be employed foriniiial formation of the matrix sheet. Because of the nature of the polyvinyl composition, the matrix sheet as initially formed is at an elevated temperature which may be from about 250 F. to about 356 F. Since the step wherein the pieces are pressed into the matrix sheet is carried out when the matrix sheet is in a highly heated and softened condition, it is preferable to proceed with the incorporation of the pieces into the matrix sheet immediately after the matrix sheet has been formed at elevated temperature. As illustrated in Fig. 3, the ma rix sheet 10 immediately after having been formed has the pieces 31 deposited thereon from the feeding devices 19. This is conveniently done while the sheet 10 is being carried on the continuous conveyor belt 20 such as a steel mesh conveyor. The feeding devices 15 have been indicated schematically both because such suitable feeding devices are well known and because the particular feeding device employed may take a number of different forms depending upon the decorative effect desired. For example. the devices 19 may consist of a belt type feeder adapted to distribute the pieces in random fashion at a controlled rate in relation to the rate of movement of the matrix sheet 10. Alternatively, a feeding device of the sifting type may be employed for effecting random distribution of the pieces. If a predetermined pattern is desired, then the feeding devices 19 may be such as to deposit the pieces at predetermined locations on the matrix sheet as the matrix sheet 10 is moved in opere ative relation therewith. For example, a feeding device may be used of the known type in which a vacuum is used for picking up pieces on the surface of a rotat ing cylinder, the pieces thereafter being released for deposit on the moving matrix sheet at desired locations. While two feeding devices 19 have been shown, this has been done merely for the purpose of illustrating that either a single feeding device or a plurality of feeding devices may be employed depending upon the nature of the pieces to be deposited on the matrix sheet and the decorative effect that is to be produced.

While the matrix sheet 10 is preferably heated to a. temperature of the order of about 250 F. to about 350 F. when the pieces 11 are deposited thereon, the pieces 11 preferably are deposited while at ordinary room temperature After the pieces 11 have been deposited on the matrix sheet 10, the matrix sheet with the pieces deposited thereon is passed through the heating "unit 21, which may be of any suitable type adapted to raise the temperature oi the matrix sheet to the temperature desired for the pressing step. For example, if the matrix sheet already is heated to about 250 F., the heating unit 21 can readily raise the temperature of the base sheet to the desired temperature in only about to seconds. For this purpose the heating unit may be about 10 feet in length for a travel rate in the neighborhood of 40 feet per minute. Any suitable heating elements may be used and conventional infra-red heating elements 22 are very satisfactory. it is desirable to dispose the heating elements 22 underneath the matrix sheet 10 as well as above the matrix sheet 10, for the matter of primary concern is that of raising the temperature of the matrix sheet and it is preferable to do so while minimizing the heating of the pieces deposited thereon. It is usually desirable in order to obtain the desired plasticity and .tlowability of the matrix sheet by heating it to a temperature of about 330 P. to 390 F., namely, to the highest temperature that the matrix sheet will withstand without excessive decomposition and without such extreme softening of the polyvinyl composition as to render further handling of the matrix sheet impossible or impractical. The precise temperature to which the matrix sheet is heated will depend somewhat upon the composition of the matrix sheet. Thus increase in the amount of plasticizer enables the matrix sheet to be softened at a lower temperature than specified above. If the polyvinyl resin which is used has a lower softening point, this also results in lowering the temperature to which the matrix sheet may be heated. The proportion of the filler is also significant for increase in filler component tends to increase the temperature to which the polyvinyl composition should be heated in order to obtain good results.

The foregoing factors which affect the temperature at which the matrix sheet becomes softened also aifect the temperature at which the pieces become softened. Since it is desirablein the practice of this invention that the pieces retain as much as possible their original form this objective may be realized to somewhat better advantage by causing the pieces to be composed of polyvinyl composition having a substantially higher softening point than that of the matrix sheet, e.g., by the employment of less plasticizer in the formulation of the pieces.

While the heating of the matrix sheet has been shown in Fig. 3 as being effected after the pieces have been deposited on the matrix sheet, the sequence may be varied. For example, the matrix sheet may be passed through a heating oven prior to the deposit of the pieces thereon. By parially heating the matrix sheet before the pieces are deposited on the matrix sheet, the extent to which the pieces are heated in a subsequent'heating step may be minimized in relation to the final temperature to which the matrix sheet is heated prior to the pressing step.

sired spacing between the rails 23 and 24 and for maintaining the desired pressure to be applied. Such means are conventional and for this reason have not been shown in Fig. 3. The roll 23 presents a smooth, rigid surface suitable for imparting the desired finish to the composite sheet. Thus the roll may have a chromium finish or it may be a polished steel roll. Rolls of this type impart a high polish. If a surface finish of some other type such as a matte finish is desired, then the surface of the roll 23 may be appropriate for the production of such a finish.

The roll 24, as indicated in Fig. 3, is provided with a surface layer 25 of yieidable resilient material. For example, the layer 25 on the surface of the roll 24 may be about 1 inch in thickness and since this roll comes in repeated contact wth the highly heated matrix sheet, the material of which the surface layer 25 is composed desirably is one which will withstand use at relatively high temperatures. A synthetic rubber material such as chlorobutadiene polymer or butadiene-styrene copolymer is suitable for the purpose. However, since the gradual deterioration is minimized by maintaining the temperature of the layer 25 somewhat under 300 F, the roll 24 preferably has associated with it means for circulating a cooling fluid therethrougb. Rolls provided with means for circulating a cooling fluid therethrough are conventional in the art and for this reason such cooling means has not been shown in the drawing in the interest of clarity and simplicity. A similar comment is also applicable in the case of the roll 23 which is operated at a considerably lower temperature than the roll 24. It is to be tmderstood, however, that the cooling of the roll 24 is effected only in the interest of avoiding excessively rapid de erioration of the resilient surfacing layer 25 for it is preferable to run the roll 24 at as high a temperature as possible so as to keep the matrix sheet in a soft and deformable condition. Atemperature range of about 150 F. to an)" F. has been found particularly substantially below that of the matrix sheet 10 and it has been found to be desirable to maintain the surface temperature of the roll 23 at a temnezamre difi'erential of at least about 50 F. and preferably at least 75' F. By maintaining such temperature at the surface of the roll 23- any tendency of the composite sheet to stick to the roll 7.3 is avoided and any tendency to smear in the regions of the demarcation between the pieces and the matrix sheet is reduced to a minimum. Moreover, by maintaining the surface of the pieces which come in contact with the roll 23 at a relatively low tern perature, the amount of defamation of the pieces from their originally preformed shape during the pressing step s minimized. The tempera-hire and amount of the coolrng fluid passed through the roll 25 is controlled so as to mahxtain the desired surface tempermure at the surface of the roll 23. If necessary, water or brine at a temperature substzmtialiy below room temperature may be emp'foyed.

When the heat plasticized man-ix med with the pieces placed thereon is passed between the rolls 23 and 24, the surface-forming roll 23 is preferably arranged with reference to the feed of the matrix sheet so that it comes in initial contact with the exposed surfaces of the pieces, the roll 23 not coming incontact with the matrix sheet until the pieces have been pressed into the matrix sheet until their exposed surfaces are flush with the Surface of the matrix sheet; This is desirable bothfrom the point of view of keeping the pieces cool so as to retain their preformed shape and from the point of view of avoiding the cooling of the matrix sheetmnil thepieces have been pressed therein. The resiiientlayctzs enables tin matrix sheet and thepic-eestobetalrenintethr nipbetweenthe rolls 23 and 24 withoutbuildiugnp thank whemn ti:

softened polyvinyl composition becomes bunched or worked and results in more uniform pressure application.

Merely by way of illustration, the roll 23 may be from about 18 to 24 inches in diameter and the roll 24 may be from about 12 to 18 inches in diameter. The length of the rolls may be varied depending upon the width of the composite sheet to be produced. Both rolls are dven at a rate adapted to receive the heated matrix sheet from the calendering and heating steps. Any suitable means (not shown) may be employed for driving the rolls 23 an 24 and synchronizing their rate of rotation with the other apparatus parts. a

While the operation preferably is carried out so that the pieces 11 are at a substantially lower temperature than the temperature of the matrix sheet, when the matrix sheet is caused to pass between the rolls 23 and 24, the pieces 11 wlere they come in contact with the man-it: sheet are raised to such temperature that fllSlOil occurs so that there is no physical discontinuity in the finished composite sheet but only a discontinuity as regards color between the matrix sheet and the pieces. The pressure exerted between the rolls 23 and 24 is preferably just sufiicient to result in embedding the pieces 11 until their exposed surfaces are substantially flush with the surface of the matrix sheet. A pressure of from about 200 to about 400 pounds per linear inch is ordinarily sufficient. 0minarily pressure is applied by urging the roll 24 upwardly by some suitable means (not shown) such as a pneumatic or spring means.

After the composite sheet has passed the zone of initial pressure Contact, it is preferably carried on the surface of the roll 24 for a substantial distance so that it may be cooled to a temperature at which it may more readily be separated from the surface of this roll. For example,

the composite sheet may be cooled while on the sur- 3 face of the roll 23 to a temperature of about 159 F. to 175 l and thereafter the composite sheet may be passed over cooling drums 26 on which it may be cooled to ordinary room temperature. It is preferable, however, to strip the composite sheet ofi of the surface of the roll while it is still hot to produce a glossy and polished surface.

The use of the process typified by the use of rolls 23 and 24 is greatly advantageous in the practice of the invention. In one operation the surfaces of the decorative pieces are cooled by the action of the metal roll contacting them prior to its contacting the matrix sheet; the overall sheet is rendered smooth by the pressing of the decorative pieces in the matrix sheet wifoout any substantial lateral or longitudinal displacement of material of the matrix sheet; the decorative pieces are immediately fused into the matrix sheet due to the heat contained therein yet there is little, if any, distortion of the decorative pieces or the decoration of the matrix sheet; the composite sheet is further cooled and set in its final form; the resilient bottom roll prevents a build up of material in the nip of the roll which would destroy the decoration of the matrix sheet; and, in addition, the bottom roll minimizes the removal of heat from the matrix sheet thus permitting the colder top mil to operate as described.

if desired, the composite sheet after havingpassed between the rolls 23 and 24 may be subjected to oneormore additional pressing steps carried out similarly and prior to substantial cooling of the composite sheet. However, if one or more additional pressing steps are utilized, the composite sheet may be subjected to reheating prior to any one or more of such repeated pressing steps.

v After the composite sheet 9 has become cooled by passage over the cooling rolls 26, the sheet is ready to be comprised in a commercial product. Thus the composite sheet may be bonded with a backing sheet such as full or a second vinyl sheet to provide a coming of the type gauge may be cut to form tile adapted for use without any backing.

Depending upon the operating conditions during the pressing step, including the temperature and composition of the matrix sheet and the area and thickness of the sheet-form pressed-in pieces, the matrix sheet may to some extent become bulged outwardly in back in those locations v where the pieces are pressed into the matrix sheet. When the finished composite sheet is caused to be laminated with a. sitznninous backing sheet that has been heated to a temperature at which it is substantially softened when the lamination is caused to occur utilizing substantial pressure, such bulges as may occur in the back of the matrix sheet may become absorbed by and counter sunk in the backing sheet so that notwithstanding the bulges the finished lam'nated covering of uniform gauge throughout. If, however, the l 'lges are regarded as excessive for such use or if it is desired that the composite sheet be of uniform gauge so that it may be used for the manufacture of tiles, for example, the bulges may be removed by planing them off as, for example, by a mechanism such as that indicated diagrammatically in Fig. 4.

As shown in Fig. 4, the composite sheet 9 may be taken from the cooling drums 26 so that the undersurface of the composite sheet will be passed in operative relation to an abrading means such as the roll 27 which has an ahrading composition, as, for example, sandpaper, on the surface thereof. In order that the sheet 9 may be held in proper relationship to the surface of the abrading roll 27, the roll 28 may be employed as an ordinary steel roll. By rotating the roll 27 so that its peripheral abrasivc-presenting surface is moved relatively to the undersurface of the composite sheet 9, any bulges are effectively planed 0E and removed, with the resultant production of a composite sheet that of uniform gauge throughout. Any material 39 that thus planed oil may be collected by suitable means such as that irdicarcd diagrammatically by the reference character 29 and, if desired may be incorporated with the composition material that is used either in the initial production of the matrix sheet or in the production of some or all of the fiat pressed-in pieces. The following example is given for the purpose of i lushation:

Example A vinyl composition matrix sheet six feet wide and; 0.035" thick was produced having the following composi-} tion: Parts by weight Copolymer of vinvl chloride and vinyl acetate 316 Dioctyl phthalate 126 Asbestos fiber 140 Wood hour 30 Dry ground limestone 100 1 Silica flour 215 Stearic acid 2 5 Basic lead silicate 6 Titanimn dioxide 50 Chrome green 15 rative elements on the surface of the sheet in spaced relationship so that they covered approximately 15% of the sufiace of the sheet. The matrix sheet carrying the decorative elements was then passed through a bank of infra red heating lamps wh ch raised the temperature of the sheet to 350 F. The heated matrix sheet was then fed at a rate of twenty-five feet per minute between two steel rolls having diameters of 24 inches. The top roll contactlag the decorative element ad the surfaceof the matrix sheet had a polished chrome surface and was heated to.

shown in Fig. 2. 0n the oflmr hand, sheets of heavia 75 275 F. 'lherollcomacting the back of the matrixsheet was maintained at a temperature about 195 F. The rolls were adjusted so that the sheet, upon passing from the rolls, had a thickness of about 0.025 inch. The sheet thus produced was allowed to travel with its surface in adherent contact with the surface of the chrome roll for approximately one-half revolution at which point it was stripped from the roll. The sheet was then passed over cooling rolls to reduce its temperature to about 100 F. and laminated to a bitumen impregnated felt having an adhesive coating. The product was then wound onto a collecting roll. The decorative sheet produced had a smooth, glossy surface with the design elements, having their original rectangular shape, firmly embedded in the surface of the sh .t to a depth of about two-thirds the thiclmcss of the sheet.

While certain equipment has been illustrated in the drawings and described hereinauove which may be employed in the practice of this invention, it is to be understood that this ha been done in order to illustrate the practice of this invention so that an understanding thereof may be facilitated and that other types of equipment may be employed for providing a heated matrix sheet of polyvinyl composition having numerous sheet-form pressedin pieces distributed thereof in substantially spaced relation and for pressing the pieces into the heat plasticized matrix sheet in the manor: and for the purposes hereinabove described.

What is claimed is:

l. A method of mfiing a decorative and wear-resistant fierible surface covering for doors, walls and the like, which comprises d sposing in substantially spaced relation on the surface of a preformed sheet of thermoplastic pol 'vinyl composition numerous preformed fiat pieces of polyvinyl composition of contrasting color, heating said sheet to a temp-mature at which said szfiace is readily deformable and pressing said pieces flatwise into said heated sheet while said surface is deformable with a smooth surface maintained at a temperature substantially below the temperature of. said heated sheet until the exposed surfaces of said pieces are flush with the surface of said sheet thereby fusing said pieces to said sheet at their interfaces therewith without substantially distorting the shape of said pieces.

2. A method of making a decorative and wear-resistant flexible smooth surface covering for floors, walls and the like, which comprisfs disposing in substantially spaced rela ion on the surface of a preformed matrix sheet of polyvinyl composition numerous flat pieces of polyvinyl composition whose coloration contrasts with that of said matrix sheet and which are substautiflly thinner than said matrix sheet and have an area of less than about 2% square inches in scrim area, heating the sheet to a temperature at which said surface of said preformed matrix sheet is deformable and pressing said pieces flatwise into said heated sheet while said surface is deformable with a. smooth su'face maintained at a temperature substantially below the temperature of said heated sheet until the exposed surfaces t creof are flush with the surface of said matrix sheet thereby fusing said pieces to said sheet without substantially distorting the shape of said pieces to form a smooth and uniform sheet, said pieces during said pressing step being at least at the exposed surfaces thereof at a substantially lower temperature and of harder consistency than said mairix sheet.

3. Amethod of making a decorative and wear-resistant flexible smooth surface covering for floor, walls and the like, which comprises disposing in :ubstantially spaced relation on the surface of a preformed. sheet of polyvinyl composition mmrerous flat pieces of sheet material composed of similar polyvinyl cornposiiicn'- having coloration contrasting with that of said sheet, heating said sheet and fiat pieces to a temperamre at which said surface of said preformed sheet is defomrable between about 350 F and about 390 F, pressing said pieces into said sheet while said surface is deformable with a smooth hard sun -4 face maintained at a temperature substantially below the temperature of said heated sheet until the exposed surfaces thereof are flush with the surface of said sheet thereby formiry a smooth, uniform sheet and cooling the resulting sheet. 7

4. A method of making a decorative and wear-resistant flexible smooth surface covering which comprises disposing in substantially spaced relation on the surface of a preformed sheet of polyvinyl composition numerous preformed fiat pieces of polyvinyl composition whose coloration contrasts with that of said sheet, heating said sheet to a temperature at which said surface of said preformed sheet is deformable, passing said sheet while said surface is deformable between a first roll presenting a hard, rigid surface maintained at a temperature substantiaily lower than that of said heated sheet and a second roll comprised at least at and adjacent the surface thereof of yieldable resilient material, said first roll contacting c said pieces and pressing; them into said sheet while said sheet is supported by said second roll until the exposed surfaces of said pieces are substantially flush with the surface of said sheet thereby forming a smooth and uniform sheet without distorting the shape of said pieces.

5. A method according to claim 4 wherein said sheet is heated to a temperature in the range from about 3 0 F. to about 390 F. immediately prior to passage between said rolls, said preformed flat pieces are less than about one square inch in area, and the surface temperature of said first roll is not greater than about F.

6, A method of making a decorative and wear-resistant flexible smooth surface covering for iloors, walls and the like which comprises disposing in substantially spaced rela ion on the surface of a preformed matrix sheet of polyvinyl composition numerous preformed flat pieces of polyvinyl composition of contrasting color, heating said matrix sheet to a temperature at which said surface is deformable, pressing said matrix sheet with said pieces disposed thereon whilc said surface is deformable between a surface presented by yieldable resilient material in contact with said matrix sheet and a surface presented by hard, rigid material that is maintained at a temperature lower than that of said matrix she-ct until the surfaces of said pieces are flush with the surface of said matrix sheet I with resultant formation of bulges from the surface of said matrix sheet opposite to that into which said pieces are pressed in the places where said pieces occur, and thereafter planing off said bulges to provide a composite sheet of substantially uniform thickness throughout having a smooth upper surface.

7. A method according to claim 6 wherein said pieces are substantially thinner than said matrix sheet and are less than about one square inch in area, said matrix sheet is heated to a temperature between about 350 F. and 390 F. immediately prior to said pressing and said press ing of said matrix sheet with said pieces is effected between. a roll contacting said matrix sheet that presents a body of elastomer on the surface thereof and a hard, rigid, smooth surface metal roll that contacts said pieces and that is maintained at a temperature not above about 130 F., and said matrix sheet is cooled after said pressing step and prior to said planing off of said bulges.

8. A method of making a flexible smooth surface covering for floors, walls and the like, which comprises disposing on the surface of a smooth calendered polyvinyl composition sheet a. pluralit of fiat pieces of polyvinyl composition having a higher softening temperature than the sheet, heating the sheet and fiat pieces to a temperature at which said surface is deformable and pressing the pieces into said deformable surface .vith a smooth hard surface maintained at a temperature substantially below the temperature of said heated sheet until the exposed surfaces of the pieces are flush with the surface of the sheet thereby fusing the pieces to the sheet at their interfaces therewith without substantially distorting the shape of said pieces.

9. A method of making a flexible smooth surface covering for floors, wins and the like which comprises preheating a smooth calcndcred sheet of polyvinyl composition to a temperature between about 250 F. and about 356 R, disposing c-r; tn: upper surface of the preheated sheet a plurality of flat pieces of polyvinyl composition having colors that contrast with the color of the sheet, heatingair: street with the pieces disposed thereon to a temperature at which said upper snriace is deformable 'octwccr abort 356 F. and about 399 F. and pressing the picccs into the heated sheet while said surface is deforma'olby passing between a hard surface roll rna tained at a te- .pet" ture substantially lower than that of fire sheet and a second roll until J16 exposed surfaces of me pies are flesh wit: the surface of the sheet thereby fusing the pieces to the sheet at their interfaces therewith and forming a sheet having a smooth and uniform. surface, the rolls disposed so that the hard surface roll contac s the pieces during the pressing.

1 A method of making a flexible smooth surface covering for doors, wall; and the like which comprises forming a smooth sheet of polyvinyl composition comprising about 26 to 50 percent polyvinyl resin, about to 30 percent plastifier and about 20 to 76 percent pigments and fillers, d sposing on the upper surface of the sheet a plurality of fiat pieces of similar polyvinyl composition in colors which contrast with the color of the sheet and being less than about two and a quarter square inches in area and at least one third the thickness of the sheet, neatct to a temperature at which said upper surface is actor-stable, passing the heated sheet while said surface is deformable between two calender rolls, one calender roll having: a hard surface maintained at a tempcrature substantially lower than the temperature of the sheet which contacts the pieces, thereby pressing and {using the pieces so that the exposed surfaces thereof are substantially flush with the surface of the sheet and r'used to the sheet at their interfaces therewith and laminating the sheet thus formed to a felt backing material.

ll. 1; method of 2; king a decorative and wear-rsistant flexible surface covering for doors, walls and the like which comprises di posing in substantially spaced relation on the su ace of a preformed sheet of themeplastic poiyrlnyl chloride composition numerous preformed fiat pieces of polyvinyl chloride composition of contrasting col r,31eating said sheet to a temperature at which said sin-face is Kadily deformable and pressing said pieces fiatwise into said heated sheet while said surface is deformable win asmooth scrim maintained ata temperature substantially below. the temperature of said heated sheet until the exposed surfaces of said pieces are flush with the surface of said sheet thereby fusing said pieces to said rheet at their interfaces therewith without substmtially distorting the shape of said pieces.

12. A method of making a decorative and wear-zesistant flexible smooth sunace covering for floors, walls and the like, which comprises disposing in substantially spaced relation on the surface of a preformed sheet of polyvinyl chloride composition numerous fiat pieces of sheet material composed of similar polyvinyl chloride composition having coloration contrasting with that of said sheeL heat n said sheet and fiat pieces to a torn peratnrc at which sari-:2 surface of said preformed sheet is deformable between about 350 F. and about 390' F., pressing said pieces into said sheet while said surface is deformable with a smooth hard surface maintained at a temperature substantially below the temperature of said heated sheet until the exposed surfaces thereof are flush the surface of said sheet thereby forming a smooth, un form sheet and cooling t'ie resulting sheet.

13. A method of making a flexible smooth surface covering for floors, walls and the like which comprises disposing on the surface of a smooth sheet of polyvinyl composition a plurality of fiat pieces substantially thinner than the sheet of similar polyvinyl composi'ion having colors that contrast with the color of the sheet and having a thickness exceeding one-third the thickness of the sheet, heating the sheet to a temperature at which said surface is deformable, the temperature being less than about 390 F. passing the heated sheet while said surface is deformable between a hard surface roll maintained at a temperature substantially lower than that of the sheet and a second roll thereby pressing the pieces until the exposed snziaccs thereof are substantially flush with the surface of s sheet without substantially distoring the shape of s: to nieces the rolls being disposed such a way that the hard surface roll contacts the pieces before ihe sheet is passed between the two rolls.

14. The method of claim i3 wherein the thickness of the pieces is between one-third and one-half the thickness of the sheet, the sheet is heated to a temperature between about 350 F. and about 390 F. and the hard surface Fredrilzsen Dec. 12, 1933 l-leppes Aug. 31, 1937 Mondale no. r em, on...

Claims (1)

1. A METHOD OF MAKING A DECORATIVE AND WEAR-RESISTANT FLEXIBLE SURFACE COVERING FOR FLOORS, WALLS AND THE LIKE, WHICH COMPRISES DISPOSING IN SUBSTANTIALLY SPACED RELATION ON THE SURFACE OF A PREFORMED SHEET OF THERMOPLASTIC POLYVINYL COMPOSITION NUMEROUS PREFORMED FLAT PIECES OF POLYVINYL COMPOSITION OF CONTRASTING COLOR, HEATING SAID SHEET TO A TEMPERATURE AT WHICH SAID SURFACE IS READILY DEFORMABLE AND PRESSING SAID PIECES FLATWISE INTO SAID HEATED SHEET WHILE SAID SURFACE IS DEFORMABLE WITH A SMOOTH SURFACE MAINTAINED AT A TEMPERATURE SUBSTANTIALLY BELOW THE TEMPERATURE OF SAID HEATED SHEET UNTIL THE EXPOSED SURFACES OF SAID PIECES ARE FLUSH WITH THE SURFACE OF SAID SHEET THEREBY FUSIJG SAID PIECES TO SAID SHEET AT THEIR INTERFACES THEREWITH WITHOUT SUBSTANTIALLY DISTORTING THE SHAPE OF SAID PIECES.

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