Process and apparatus for producing synthetic decorative covering

A process and apparatus for manufacturing synthetic decorative coverings is presented in which at least one powder (generally a polymeric resin) is selectively deposited, in accordance with a pattern or decoration, onto a base material. The power deposition is carried out under gravity without contact between the means of applying the powder and the base. At least one of the deposited powders contains particles which are fusible at a temperature below the distortion temperature of the base and which is compatible with the base material. At least one thermal treatment is then carried out at a temperature below the distortion temperature of the base so as to fix the decorative pattern produced by deposited powders. The apparatus for applying the powders consists of a continuous screen printing frame, in particular, a screen printing roller which is fed by a device providing uniform distribution of the powder into a hopper located inside the roller. The hopper has two longitudinal blades which are adjustably separated and are in contact with the inner surface of the screen.

BACKGROUND OF THE INVENTION 
This invention relates to the field of synthetic decorative coverings. More 
particularly, this invention relates to an apparatus and process for 
manufacturing synthetic decorative coverings and the products obtained 
thereby. It should be appreciated that "synthetic coverings" may be any 
coverings produced from organic components which may, if appropriate, 
include inorganic materials in their formulations (for example, asbestos 
or glass voile) or other organic materials of plant origin (i.e., jute). 
The manufacture of products for synthetic decorative coverings, 
particularly for floors and walls, which are based on synthetic materials, 
usually polyvinylchloride (PVC), has been the subject of major 
developments in recent decades. Typically, these synthetic decorative 
coverings consist of a base material, such as, for example, jute fibers, 
asbestos, nonwoven glass fibers, synthetic foam or the like. Next, a sheet 
or layer of PVC is applied to the base. Finally, the face of the PVC 
receives a desired decoration or pattern and which thereafter, is usually 
protected by a transparent film covering. 
A plurality of alternative methods for producing such decorative coverings 
have been utilized. However, all of these alternative processes relate to 
printing techniques which use a relatively viscous liquid product. Another 
technique, also derived from printing techniques, consists of localized 
application of plastisol studs by screen printing. 
Because printing products are commonly used in the above discussed 
alternative processes, a pasty printing ink is also utilized in 
conjunction with these techniques. This ink is typically comprised, in 
part, of a liquid, i.e., water or solvent. 
Generally, in order to produce the final decorative surface, known 
processes involve several successive applications, via printing 
techniques, of various components of the decoration. Each printing 
application requires a drying step after which, a transparent protective 
covering is employed. 
It will be appreciated to those skilled in the art, that the above 
processes provide only mediocre results, particularly when attempting to 
imitate ceramic glazes such as floor tiling or wall tiling. Various 
improvements in the above processes, involving the use of foaming agents 
in conjunction with simultaneous and localized application of chemicals 
which retard or accelerate foaming, have been proposed in an effort to 
produce a localized expansion (for example, see FR-A No. 1,411,338). 
However, even in this French patent, it has been found that while the 
geometrical configuration and appearance of the tiling can be accurately 
reproduced, the surface conditions peculiar to glazed products is 
reproduced only sporadically and the appearance of a depth (also peculiar 
to these ceramic products) is not achieved. 
Patents DE-A No. 2,260,788 and FR-A No. 2,263,893 disclose "handicraft" 
processes for producing patterns by the deposition of fusible substances 
on a base made of metal, glass, ceramic or of any other material which is 
stable at the temperature for carrying out the subsequent thermal 
treatment. These processes are intended for use in the non-continuous 
production of colored patterns in the form of, for example, tourist 
souvenirs or the like. 
Patent FR-A No. 74/37,741 describes a process for printing textile 
surfaces, particularly deep pile materials, wherein coloring products 
having a powdered form are applied to the surface which is to be printed 
in accordance with a corresponding decorative design. A portion of the 
colored product is then fixed. Any particles which were not fixed are 
subsequently removed. This French patent relates solely to textile 
surfaces and does not in any way teach or suggest a process for providing 
a covering which imitates the glazing effects generally obtained with 
ceramic materials. To the contrary, the printing process described in FR-A 
No. 74/37,741 relates to depositing a dye on a piled textile by a 
technique involving disposing powdered colorants in the interstitial 
spaces of the textile fibers. It will be appreciated that this process 
essentially depends on the base material and the preparation thereof. The 
purpose of the process is to provide a final decorative effect which is 
restricted to introducing coloring into textile fibers without providing 
any three dimensional effects. 
Prior art patent CH-A No. 595,145 discloses the deposition of powders 
through a screen printing frame which is in contact with the base material 
by means of a magnetic doctor blade. The technique of this patent does not 
permit a variable volume of powders to be disposed on the base. 
Finally, a process suggested by Patents FR-A No. 2,291,868 and FR-A No. 
2,210,148, involves the fixation of particles, fibrils or powders, under 
the effects of an electrostatic field onto a base coated with an adhesive 
material. 
It should be understood to those skilled in the art that the above 
discussed techniques and processes are not applicable in any satisfactory 
way to the manufacture of flexible multilayer decorative coverings for 
floors and walls having requirements which include, for example, high 
resistance to delamination and other stresses. 
SUMMARY OF THE INVENTION 
The above discussed and other problems of the prior art are overcome or 
alleviated by the process and apparatus of the present invention. In 
accordance with the present invention, a novel process is presented for 
producing synthetic decorative coverings having an appearance which is 
very similar to ceramics and other glazed coverings. These highly 
desirable ceramic-like decorative coverings are achieved by a process for 
manufacturing synthetic decorative coverings wherein at least one 
polymeric powder, typically a thermoplastic resin, is selectively 
deposited, in accordance with a pattern or decorative design, onto a base 
material. A novel feature of this invention is that the deposition of 
powder is carried out under gravity in the absence of contact between the 
means for applying the powder and the base. Preferably, the powders are 
deposited via a continuous screen printing frame, particularly a rotary 
screen printing frame. In accordance with the present invention, at least 
one of the deposited powders contains particles which are fusible at a 
temperature below the distortion temperature of the base material. These 
powders should be compatible with that of the base or at least close to 
the distortion temperature of the base. Also, in accordance with the 
present invention, at least one thermal treatment is carried out at a 
temperature below the distortion temperature of the base thereby fixing 
the pattern or decorative design which has been produced by the deposited 
powders. 
The fixation of the design or pattern onto the base is preferably, at least 
partially achieved by a co-fusion of the powder and the base material. It 
will be appreciated that co-fusion is defined as a homogeneous imbrication 
of the pattern with the base during the thermal treatment. The co-fusion 
being sufficent to prevent delamination. Thus, during the thermal 
processing mentioned above, the deposited powder should penetrate at least 
partially into the interior of the base material. 
Surprisingly, it has been found that the process and apparatus in 
accordance with the present invention provides products which are flexible 
and capable of being rolled, while also having a remarkable ceramic-like 
asthetic appearance along with good mechanical and wear properties 
suitable for covering floors and walls. These desirable results are 
obtained moreover, without the use of lining techniques, which are 
conventionally employed in plastics processing and which generally involve 
a combination of mechanical pressure and heat, i.e., calendering. 
In an alternative method of the present invention, the powder may be 
deposited onto a temporary intermediate base on which the thermal 
treatment is performed. Thereafter, the deposited powder maybe transferred 
to the above mentioned final base material. 
Thus, unlike the prior art, the present invention does not utilize 
conventional printing techniques in an effort to form decorative designs 
or patterns on the coverings, but instead, the present invention provides 
a novel method for applying powders and producing a three dimensional 
configuration. The present invention insures strong adhesion of the 
decorative components for a variety of floor and wall coverings heretofore 
not found in the prior art. 
The present invention permits the imitation of those desired colors and 
textures which are obtained by producers of ceramics through the use of 
powders which appear as ceramic glazes and enamals. The present invention 
also provides desirable mixing and spreading effects which also appear 
similar to (i.e., imitate) ceramic glazed products. Moreover, varying the 
method of applying the powder makes it possible to produce decorative 
designs of all types such as, for example, abstract patterns or those 
conventional patterns typically found in the decorative covering field. 
In accordance with the present invention, the method of powder deposition 
"without contact" between the powder applying means and the base offers 
numerous advantages over conventional prior art printing processes. 
Thus, the process of the invention can be employed on any type of base 
material which is compatible with the powder employed or which is treated 
beforehand to make it compatible with the powder, (examples of which were 
mentioned earlier in the Background of the Invention). Moreover, those 
bases having uneven surfaces (deep reliefs), for example, as a result of a 
prior layer having been applied in a conventional process, may be utilized 
by the present invention. Furthermore, rigid organic or inorganic bases 
made compatible with the particular powder employed may also be used. Note 
that, as a result of the choice of the base material and of the powder 
applied, the products of the present invention may be flexible (rollable) 
and yet have an appearance resembling rigid ceramics. The novel decorative 
coverings of the present invention can be produced continuously and in 
strips capable of being rolled. The base material may be reinforced if 
desired. However, it should be understood that the base material must have 
a stability, including dimensional stability, which is sufficient at the 
temperature in which the powders are thermally treated. 
Another advantage of the "without contact" method and apparatus of the 
present invention is the capacibility of superimposing various layers of 
powders without, however, having to even partially fix the preceding layer 
or layers. This makes it possible to obtain the desired ceramic-like 
characteristics due to the mutual interpenetration or imbrication of the 
layers. This advantage, moreover, also provides considerable economic 
savings due to the elimination of the usually thermal fixing treatments 
carried out between depositions. Thus, only a single "final" thermal 
treatment is necessary with the present invention. Consequently, energy is 
further saved by use of only a single oven which is kept continuously hot. 
Energy is also saved by the avoidance of successively heating and cooling 
the decorative covering product during manufacture. It will be appreciated 
that to achieve certain special ceramic-like characteristics, it may 
nevertheless be advantageous to provide intermediate fixing operations 
between two successive applications of powders. 
The above discussed and other advantages of the present invention will be 
apparent to and understood by those skilled in the art from the following 
detailed description and drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
In accordance with the present invention, a process and apparatus for 
producing decorative synthetic coverings comprises, in part, means for 
applying or depositing powdered material onto a base without contact 
between the powder applying means and the base material. In a first 
embodiment of the present invention, the means for applying the powder 
consists of a screen printing frame having a mesh structure which is 
configured in accordance to a desired decoration or pattern, and through 
which the powders are distributed onto the base material. This first 
embodiment may be employed as a continuous process wherein the screen 
printing frame is a rotating roller, driven at a circumferential speed 
which is synchronized to the speed of the base material passing 
thereunder. An inner hopper having two lips, i.e., doctor blades, rub 
against the inner face of the roller thereby uniformly supplying powder 
over the length of the roller. By adjusting the spacing of the lips, it is 
possible to regulate the flow of powder as a function of (1) the 
rotational speed of the roller; (2) the size and shape of the mesh and (3) 
the fluidity of the powder. In the present invention, as a result of both 
the (1) absence of contact between the powder applying means and the base 
material, and (2) gravity deposition of the powder, the rate of 
application of the powders does not depend upon the volume released by the 
mesh, as is usually the case with screen printing frames which must be in 
contact with the base material in order to produce a pattern. 
Consequently, by carefully regulating and choosing the mesh sizes along the 
generatrix of the screen printing roll, the quantity of powder which is to 
be deposited may be precisely metered therefrom. 
By selectively superimposing one or more layers of powder, it is possible 
to obtain relief (3 dimensional) effects and also other special effects 
which vary in intensity, hue, depth, gloss and/or the iridescence of 
color. 
The decorative coverings having a ceramic glaze appearance produced in 
accordance with the present invention may be provided on a base material 
which consists essentially of polyvinylchloride (PVC) having the usual 
additive ingredients, particularly stabilizers and plasticizers. When such 
a PVC base is used, preferable powders include polyester resin, polyamide, 
polyolefin, polyvinyl, polyurethane, polyacrylate, or a compatible mixture 
of the above mentioned resins. The particular powder chosen will generally 
have a selected color and will therefore contain certain inorganic or 
organic pigments or colorants. In the case of organic pigments or 
colorants, it may be appropriate to use those pigments which are stable at 
the temperature to which they will be subjected. 
Still further special decorative effects may be obtained in accordance with 
the present invention by the use of powders having varying physical and 
chemical properties. These varying properties may include, for example, 
different melting points, viscosity (when hot), wettability, or other 
physical (diffusion and/or solubility) or chemical characteristics. 
Still other decorative effects may be provided by incorporating into the 
powders certain substances which produce a heterogenity in the covering, 
particularly inorganic materials such as, for example, ground terracotta 
powder, textile fibers and the like. 
The process and apparatus of the present invention is compatible with 
conventional known techniques for the preparation, production and 
finishing of floor and/or wall coverings. The present invention is 
particularly well suited for producing decorative designs or patterns on 
said floor or wall coverings. Thus, the particular pattern produced in 
accordance with the present invention can be completed or finished with 
still another pattern in accordance with a conventional (i.e, printing) 
technique. Note that the finished product can receive a wear coat which 
may be transparent or colored if desired. Note also that conventional 
techniques for producing three dimensional relief, i.e., by embossing or 
differential foam expansion, may also be combined with the process of this 
invention. Accordingly, the present invention does not exclude additional 
process steps utilizing known methods for screen printing with the aid of 
a plastisol. 
As a result of the absence of contact between the base material and the 
powder applicator, the base material can be coated beforehand, either 
partially or completely, with liquid or paste in order to obtain still 
further decorative effects. As mentioned, if the decorative coating 
obtained in accordance with the present invention does not have the 
desired surface properties (i.e., wear, abrasion, indentation or 
scratching resistance), a suitable surface may be obtained by depositing a 
resistant coating. 
After the pattern or decorative design has been applied onto the base 
material, the thermal treatment will provide at least a partial, fusion of 
the powder. Of course, care should be taken not to displace this pattern 
during the thermal treatment process. It has been found that heating by 
means of infrared radiation gives preferable results. It should be 
appreciated, however, that it is also possible to use other advantageous 
heating means such as, for example, directly heating the base material. 
Through a selective choice of powders, it is possible to obtain a desired 
mattness. Thus, for example, a "Fully" fusible powder may be thermally 
treated during fusion to produce a brilliant glaze-like surface condition 
while a "slightly" fusible powder can be deposited at the tiling joints, 
in order to obtain a matt joint imitating cement. It is necessary, 
however, that the "joint" be fixed during the thermal treatment by a 
chemical reaction, slight fusion or by fusion of a component part of the 
powder deposited at the joints and/or by co-fusion with the base, in order 
to achieve adequate strength. Similarly, it is possible to incorporate an 
expansion or foaming agent in the powder in order to produce a foamable 
deposit wherein selected areas on the covering may have pronouced depth or 
height. 
Moreover, it is possible to obtain certain effects by, prior to thermal 
fixing, subjecting the base having powdered deposited thereon to 
controlled disturbances of a mechanical, pneumatic or electrical origin 
(i.e., vibrations, air blowing or electrical field). 
Referring now to FIG. 1, manufacturing apparatus for use in accordance with 
the process of the present invention is shown. In FIG. 1, the apparatus of 
the present invention comprises means for unrolling base material 6 shown 
generally at 1, means for applying powder shown generally at 2, an oven 3 
for use during thermal treatment of the covering, a cooling zone 4 and a 
device 5 for rolling up and cutting the processed decorative covering. 
In accordance with the present invention, the powder application means 2 
comprises at least one roller of the type shown in FIGS. 2 and 3. It 
should be understood that while four rollers for applying powder are shown 
in FIG. 1, any number of rollers may be used with the present invention. 
Still referring to FIG. 1, oven 3 is intended for the thermal treatment, 
i.e., co-fusion of the fusible components of the powder and the base. This 
co-fusion is preferably conducted at a temperature below the distortion 
temperature of the base, material usually about 200.degree. C. The thermal 
treatment provides adhesion between the deposited powder and the base 6. 
The thermal treatment also provides smoothing of the powder surface 
(gloss) or at the least, the thermal treatment provides bonding between 
the individual grains of powder. Preferably, the heat source within the 
oven 3 is infrared radiation. As mentioned, oven 3 can also be used to 
heat the base material 6 so as to improve the adhesion or fixing of the 
powders thereto. It will be appreciated that an oven using any other means 
of heating, such as hot air, may similarly be used in accordance with the 
process and apparatus of the present invention. 
Cooling zone 4 may consist of simply passing through free air over the base 
material (which has been coated with powders and fixed during treatment in 
the oven). Alternatively, the cooling can be accelerated and improved by a 
stream of cooled air using suitable cooling means such as water heat 
exchangers. 
It should be understood that the cutting and rolling device 5 is well known 
to those skilled in the art and therefore does not require any additional 
description. 
As shown in FIG. 1, the apparatus in accordance with the present invention 
does not involve any intermediate thermal treatment between the successive 
rollers 2. However, it should be understood that larger number of rollers 
may be used together with intermediate fixing or thermal treatment stages 
(i.e., slight heating of the base) between successive rollers. 
Each of the four rollers 2 in FIG. 1 rotates at about the same 
circumferential speed. This speed is preferably equal to the linear speed 
of the base material 6 passing below the rollers. However, it should be 
appreciated that the rollers and the speed of the base material may 
differ, if desired, in order to produce certain special decorative 
effects. 
It will be understood that the manufacturing apparatus shown in FIG. 1 may, 
of course, be integrated wholly or partially into a conventional 
production line for the manufacture of floor or wall coverings. 
Referring now to FIGS. 2 and 3, a roller intended for the application of 
powders, commonly termed a rotary frame, is shown. The roller consists of 
a mesh screen 10 for screen printing, and a device for uniformly 
distributing powder. In this case, the uniform distribution device is a 
screw 12 which is capable of rotating in a feed channel 13. Screw 12 
distributes the powder uniformly into a hopper 14 inside the roller. Two 
longitudinal lips or blades 15 and 16 (FIG. 3) are provided within the 
hopper 14 and are adjustably separated to a preselected distance. Blades 
15 and 16 regulate the flow of powder which passes through the frame 10 in 
relation to (1) the speed of the rotating frame 10, (2) the fluidity of 
the powder, and (3) on the size of the mesh. As a result, deposits 17 of 
powder are formed at selected areas on the base material 20. Note that the 
separation of the lips 15 and 16 can be controlled by means of a screw 18 
(FIG. 3). 
In accordance with one embodiment of the present invention, the mesh screen 
10 is comprised of a foraminous material whose shape, size and/or density 
varies according to the desired pattern or decorative design. Accordingly, 
as a result of the absence of contact and of gravity deposition, the 
powder flow will be greater or lesser at selected areas on the base 
material 6 depending upon the size of the mesh and consequently 
differences in the intensity of color and/or relief of the pattern will be 
easily effected. 
The apparatus or equipment described in FIG. 1 is well suited for a 
continuous process. However, if a non-continuous process is desirable, a 
flat screen printing frame may be used, over which a hopper is provided 
having sliding lips (doctor blades) separated by a controllable distance. 
The present invention may be better understood with reference to the 
following examples. 
EXAMPLE 1 
Reference should be made to FIG. 4 in regard to the description of the 
first example of a wall covering in accordance with the process of the 
present invention. FIG. 4 is a cross-sectional view of a ceramic-like 
tiling design. The decorative pattern shown thereon consists of four 
successive deposits of powder, provided by a continuous production line in 
accordance with the apparatus of FIG. 1. Base 41 may be any suitable base 
material including, for example, stiffened paper coated with PVC, nonwoven 
fiber having a thermal setting binder and coated with PVC, a glass mat 
impregnated with PVC, or any other base material conventionally used for 
floor coverings and compatible with the particular powder employed. 
In this example, the base material 41 consists of a glass voile with a 
weight of approximately 50 g/m.sup.2, bonded with a thermosetting resin 
and coated with a plastisol having the formulation: 
______________________________________ 
PVC emulsion 100 
Plasticizers 65 
Ground calcite 50 
Stabilizer 2 
Pigments: titanium oxide and 
11.2 
lampblack 
Weight deposited approximately 
420 g/m.sup.2 
Pregelling at 150.degree. .+-. 15.degree. C. 
______________________________________ 
The powders are initially prepared by providing a base powder, preferably 
having no color, in a fast mixer of the PAPENMEIER type and within a 
heating and coolant vat. 
The composition of the base powder is as follows: 
______________________________________ 
PVC suspension 
97 
Plasticizer 
40 
Stabilizer 
2 
Co-stabilizer 
3 
______________________________________ 
The red tiling background 42 has the following composition: 
______________________________________ 
Dry powder 100 
Chromophtal Red BRN (Ciba-Geigy) 
0.2 
______________________________________ 
The matt, tiling joint 43 has the composition: 
______________________________________ 
Dry powder 100 
Titanium oxide 4 
Ground calcite 3 
Lampblack 0.5 
______________________________________ 
The satin opalescent varnish 44 has the composition: 
______________________________________ 
Dry powder 100 
Titanium oxide 1.5 
______________________________________ 
The glossy orange decorative design 45 has the composition: 
______________________________________ 
Dry powder 100 
Chromophtal Orange 2G (Ciba) 
0.15 
______________________________________ 
During the powder deposition, the four application rollers 2 are fed via 
their internal hoppers 14 using the four colored powders mentioned above. 
The quantity of powder to be deposited is regulated by the opening of the 
lips 15, 16 of the inner hopper 14 so as to obtain the following mean 
thicknesses (after thermal treatment): 
______________________________________ 
Red tiling background 42: 
0.25 mm 
Matt joint 43: 0.25 mm 
Opalescent varnish 44: 0.12 mm 
Glossy orange decorative design 45: 
0.20 mm 
______________________________________ 
The total weight of the deposit is approximately 500.+-.30 g/m.sup.2. 
The total weight of the finished article is 500.+-.30 g/m.sup.2. 
The thermal treatment, which consists of a cure, is preferably carried out 
as a single operation in an infrared oven 3 carefully controlled so as to 
rapidly produce a temperature in the order of 190.degree. to 210.degree. 
C. This thermal treatment should last approximately 45 seconds in order to 
achieve the thickness and the weight set forth above. 
After leaving the oven, the tiling design is quickly cooled to at most, 
50.degree. C., whereupon it is rolled up. 
In the case of a floor covering (as opposed to a wall covering), the above 
formula and operating procedures are substantially identical, the 
essential differences being in the base 41, which is more suitable for a 
flooring application. 
EXAMPLE 2 
In this example, the base is made from a fine metal sheet. This type of 
base can impart better insulative properties to the final product. 
The base sheet used in this example is a sheet of 35-micron (.+-.280 
g/m.sup.2) electrolytic copper from Yates Industries, one surface of which 
has been subjected to a treatment which increases the porosity. 
The base powder and the coloring materials are prepared as in Example 1 and 
the decorative pattern is deposited as in Example 1. Unlike Example 1, the 
thermal treatment is slightly longer. 
The adhesion of the decorative pattern to the base is a function of the 
porosity of the base (Table 1). For example, the adhesion is zero on a 
smooth surface. Some further values of adhesions are given as examples in 
Table 1. The adhesion between the base and pattern can be improved by 
providing a preliminary coating having a component which is compatible 
with the base and the PVC powder. 
TABLE 1 
______________________________________ 
Adhesion 
Copper sheet Bonding Agent 
(daN/cm) 
______________________________________ 
Porous face -- 0.43 
Smooth face -- 0 
Smooth face EVAc 0.40 
Smooth face PU in solution 
0.32 
Smooth face PU in solution 
1.24 
Smooth face PU Latex 0.88 
Smooth face 2-component PU 
0.90 
______________________________________ 
EXAMPLE 3 
In this Example, the bases are chosen from a variety of paper bases which 
are typically used for floor and wall coverings. 
The Examples were conducted with both uncoated bases and bases coated with 
a PVC plastisol. The formulation of the PVC plastisol is identical to that 
given in Example 1. The weight deposited is 150 g/m.sup.2 and the coating 
is pregelled at 150.degree. C..+-.15.degree. C. 
The base powder and the coloring materials are prepared as in Example 1. 
The decoration is deposited in the same manner. The thermal treatment is 
identical except that the coated bases do not affect the coloring of the 
decorative pattern. 
EXAMPLE 4 
In this Example, the decorative pattern is prepared and deposited as in the 
preceding Examples, but on an incompatible intermediate base (for example, 
silicone paper). 
After the thermal treatment and subsequent cooling, the decorative pattern 
is separated from this intermediate base and deposited on a stable and 
compatible base material. The assembly is then subjected to a thermal 
treatment in an infrared oven which is regulated so as to rapidly increase 
the temperature to about 190.degree. to 210.degree. C. At the exit of the 
oven, the decorative article is rapidly cooled to less than 50.degree. C. 
and then rolled. The resultant decorative sheet shows no distortions or 
stresses. 
Alternatively, the base and the decorative pattern can be assembled on a 
machine known as a "combining" machine having a heating roller which is at 
a temperature of between about 120.degree. and 150.degree. C. 
The advantages of the process and apparatus of the present invention may be 
summarized as follows: 
The decorative synthetic covering of the present invention provides better 
dimensional stability to the final product. Thus, as there is no contact 
between the powder applicator means and the base material during 
application, and therefore no resultant pressure, there is consequently 
less pull on the base (which is only subjected to a fairly low driving 
tension). 
The present invention provides increased flexibility in terms of the 
physical state of the base surface. This is in distinct contrast to the 
prior art wherein printing on a non-planar or pasty surface has been 
practically impossible. Indeed, the polymeric resin powder itself may even 
be deposited on a liquid base. 
The process of the present invention also provides considerable savings in 
energy consumption since it is possible to produce a ceramic glaze effect 
at a temperature (200.degree. C.) which is much lower than that 
temperature which is conventionally employed for glaze finishes. Moreover, 
the present invention permits successive deposits of materials on a single 
production line without pregelling or intermediate thermal fixing. 
Because there is no contact between the powder applicant and the base, it 
is possible to provide a speed differential between the rotating rollers 
which apply the powder and the moving base material so as to create 
special and desirable distortion on the decorative pattern. Moreover, 
these distortions may be achieved without producing displacements, as is 
common in conventional superimposed printing patterns. 
Another feature of the present invention is the enormous degree of 
flexibility in achieving a plurality of decorative effects. Thus, as 
mentioned, it is possible to mix several powders having different 
properties, i.e., hue, melting point, expansion coefficient and the like, 
so as to produce different degrees of mattness, inclusions, crazes and/or 
pitting caused, for example, by internal stresses or chemical adjuvants 
(as for imitation terracotta and the like). 
The process of the present invention also makes it possible to produce 
imitation ceramic tiling which differs slightly from batch to batch, 
without having the repetition which accompanies conventional printing 
processes. 
Finally, the desirable effects achieved by the present invention are not 
restricted to the imitation of ceramic materials, but the novel process 
disclosed herein may also produce imitations of textiles, particularly 
cloths or yarn, or even non-skid effects and the like. 
It will be appreciated that in addition to floor and wall coverings, the 
products produced in accordance with the present invention may be broadly 
applied for use in connection with any decorative material. 
While preferred embodiments have been shown and described, various 
modifications and substitutions may be made thereto without departing from 
the spirit and scope of the invention. Accordingly, it is to be understood 
that the present invention has been described by way of illustrations and 
not limitation.