Plastic material for simulating engraved metal plates

A plastic material which is suitable for simulating engraving on metal has a substrate which is not deformed by the heat or pressure of a hot stamping process. A sheet or layer of thermoplastic material of limited thickness is laminated to the upper surface of the substrate. The opposite side of the thermoplastic material is covered by a containment film. Thus, within the limits of manufacturing tolerances, the layer of thermoplastic material may be subjected to any amount of pressure to produce a debossment which is no deeper than the depth of the limited thickness when a hot stamping die bottoms on the non-deformable substrate. Therefore, there is a much more predictable end product.

This invention relates to plastic material which is suitable for simulating 
engraving on metal by imprinting by a hot stamping process, and to methods 
of using this material. 
My above-identified parent applications described means for and method of 
making plastic plates which are hot-stamped and have the appearance of 
engraved metal plates. The basic structure is a laminate of plastic layers 
wherein a layer or plate of thermoplastic material is mounted on a 
substrate and covered with a thin containing film having a heat-resisting 
characteristic. The containing film has a decorative surface coating which 
simulates, for example, brushed brass, silver, or another metal. However, 
it is also possible that other attractive surface appearances could be 
used as, for example, the appearance of letters burned in wood. 
In operation, a heated die is pressed against the decorative surface of the 
containing film with a force which is sufficient to heat, displace and 
deboss the thermosetting plastic. A hot stamping foil is positioned 
between the die and the film surface, thereby transferring ink from the 
stamping foil into the bottom of the debossment. Since the surface coating 
usually has the appearance of brushed brass, or another metal, the end 
result closely simulates an engraved metal plate. By multiple-stamping, 
many colors may be successively superimposed to provide special effects. 
The end result of this invention has almost instantaneously enjoyed great 
commercial success. As a result, there was a need to reduce costs by 
mechanically performing some steps which had been an "art." Also, there 
was a need to provide a general purpose material which could be used in 
many different settings. 
For example, the heated die is pressed into the surface covering over the 
thermoplastic material. If the die is pressed too far, there is a chance 
that the ink from the hot stamping foil might color the plate outside the 
area of the debossment. Also, too much displacement of thermoplastic 
material could occur, causing a distortion of the surface appearance. On 
the other hand, if the die is not pressed far enough into the 
thermoplastic material, the engravement might appear faulty. 
In the material shown in my previous applications, it is relatively easy 
for an operator to learn how deeply the die must be pressed into the 
thermoplastic material, but use of farily expensive hand labor is 
required. An alternative method, which uses a control circuit to gauge how 
far to depress the die into the thermoplastic material, is also expensive. 
The prior parent applications concentrated on the design of special 
products such as monogram plates, wall or award plagues, or the like. Each 
of these items has a specialized use. However, since the inventive 
material has rapidly become popular, people have found many uses which fit 
their own special needs, but which would not normally occur to others 
without that need. For example, some people have made plastic business 
cards which look like engraved metal plates. Thus, there is need for sheet 
stock of the plastic material which is suitable for simulating engraving 
on metal which may be sold for creation of a user's own special product. 
Accordingly, an object of the invention is to provide new and improved 
plastic material which is suitable for simulating engraving on metal. 
Here, an object is to provide sheet stock for sale to people who use it to 
tailor-make their own products. Accordingly, an object is to reduce or 
eliminate the requirement for specially-skilled operators, and to reduce 
the process to simple and foolproof steps which may be successfully 
employed by first-time users of the material. 
Another object is to produce uniform engravement, almost regardless of how 
forcefully the heated die is pressed into the thermoplastic material. 
Yet another object is to more faithfully simulate metal engraving. 
In keeping with an aspect of the invention, these and other objects are 
accomplished by limiting the thickness of the thermoplastic material to 
the desired depth of debossment. The thermoplastic material is laminated 
to a substrate which is not affected by heat. Therefore, it limits the 
travel of the heated die to precisely the desired depth of debossment. The 
substrate thickness is adequate to prevent distortion of the plastic 
material which is suitable for simulating engraving on metal, uncontrolled 
flow of thermoplastic material, or the like. Thus, the built-in substrate 
eliminates the dependence upon a special form of substrate heretofore 
provided by a release paper backing or a wooden plaque backing. 
Accordingly, the sheet stock may be adapted for many purposes, without 
regard to the need for a separate substrate backing.

The following principles shown in FIGS. 1-7 and described herein were 
originally set forth in the above-identified patent application Ser. No. 
454,166. 
As illustrated in FIGS. 1-3, the article 20 comprises a plastic pad 22 of a 
preselected size and shape, preferably having a pressure-sensitive 
adhesive 24 on the back 26 of the pad 22. The adhesive coating 24 is 
covered by a backing sheet 28, which is chemically treated, such as by 
silicone or wax to provide a release surface. 
A hot stamping foil 30 is superimposed over a plastic plate 40 forming a 
major part of the pad 22. A second adhesive coating 32 is located on an 
appendage 38 on the front 34 of the pad 22, to hold in place the hot 
stamping foil 30. Other suitable means, such as stapling, may also be 
employed for retaining the foil 30 on the pad. The appendage 38 is 
separated from the remainder or plate portion 40 by means of a slit 41. 
The backing sheet 28 maintains the appendage portion 38 in its original 
contiguous relationship with plate portion 40 so that the entire article 
20 is a self-contained unit during the hot stamping operation. 
The pad 22 comprises a polyester film 42 laminated on a thermoplastic 
material 44 (FIG. 4). Applicant has found "metallized" MYLAR to be a 
satisfactory polyester film (MYLAR is a trademark for polyester film of 
the DuPont Company). "Metallized" MYLAR which may have the aesthetic 
properties of gold or silver, for example, is readily available from 
various manufacturers, such as the Flexcon Company, Inc. One 
characteristic of MYLAR is that it has almost no heat-spreading 
capability. Therefore, the heat of the die does not spread out of the 
debossment area. 
The thermoplastic material 44 should be readily formable through an 
application of moderate heat and pressure, and a pressure-sensitive 
adhesive should adhere to it. The material 44 should also be sufficiently 
rigid to function as a printable plate. Applicant has found rigid 
polyvinyl chloride to be satisfactory. 
In one form, article 20 was constructed by using a pad 22 of MYLAR film 
with a thickness ranging from 1/2 to 1 mil, and rigid vinyl with a 
thickness of about 8 mils. Within this range, applicant has found that the 
pad 72 is sufficiently rigid and thick to withstand hot stamping and to 
provide a suitable imprinting surface. 
For the adhesive backing 24, a number of compositions can be used. These 
"pressure-sensitive adhesives" are various blends of natural and synthetic 
rubbers with resins, polyvinyl acetates, ethylene-polyvinyl acetate 
copolymers (EVA), polyterpenes, hydrogenerated resins, resin ester, 
acrylics, chlorinated paraffins, ethyl cellulose, and a variety of other 
substances. Common and well-known types of pressure-sensitive adhesives 
are exemplified by those used on transparent cellophane adhesive tapes. 
These materials may be applied as solutions using solvents such as 
naphthas, toluene, chlorinated hydrocarbons, and the like. An important 
property is that the adhesive is capable of adherence to metal, wood and 
other types of surfaces used for the products to which the plates of this 
invention are intended to be attached. The protective cover 28 may be 
paper, plastic, or other suitable material having desirable releasing 
properties. 
The hot stamping foil 30 includes a carrier supporting a coloring matter 
such as ink. Generally, the carrier may be MYLAR, cellophane or acetate, 
or the like. The foil is available in many colors so that various degrees 
of contrast between the lettering and the remaining plate surface may be 
achieved. Distributors of suitable hot stamping foils include Howard 
Corp., Franklin Corp., and Kingsley Corp. 
It should be noted that the rectangular shape of product 20 in this 
embodiment is merely an example, and the invention is not limited thereto. 
FIGS. 4-6 disclose an exemplary method of manufacture which may be used to 
produce the article of this invention. The method illustrated may be 
performed on a Webtron Printing Machine. 
In the preferred embodiment, the pad 22 having adhesive 24 on one side, 
which is protected by the backing paper 28, is first manufactured in any 
convenient manner and rolled into a supply roll 46. Likewise, the hot 
stamping foil 30 is manufactured in any conventional manner and rolled 
into supply roll 48. 
In one form, the width of the material 22,30 on each of the supply rolls 
46,48, respectively, is 41/2 inches. This material is slit into four 
ribbons or strips 62 which are 11/8" wide. Each strip 62 includes plate 
material 40 which is 7/8" wide and appendage material 38 which is 1/4" 
wide. The finished product 20 is thus 11/8" wide, and the imprinted plate 
is 7/8" wide. 
The plastic laminate web 22 is drawn from supply roll 46 under slitters 50 
which cut only through the pad 22. The backing paper 28 is not cut; it 
remains intact. Next, adhesive impregnated rollers 52 apply adhesive 
between the cut or slitted areas 54,56. The supply roll 48 of hot stamping 
foil 30 is drawn into contact with the adhesive-coated laminated material 
22. Pressure roll 58 aids in assuring adhesion of hot stamping foil 30 to 
the slitted areas 54 and 56 of the plastic laminate 22. 
Cutting wheel 60 longitudinally divides the web into the four strips 62. 
Transverse cutting wheel 63 divides the strips 62 into the completed 
articles 20. It should be noted that the rectangular article 20 could be 
die cut into other desired shapes by suitable die-cutting apparatus (not 
shown). 
The article 20 may be hot-stamped on a conventional hot stamping machine 
69, as illustrated in FIG. 7. The machine 69 comprises support member 66 
suitably mounted on base member 88. The upper portion of the support 
member 88 has a ram-receiving aperture 70. Stamping means 71 includes a 
spring-biased ram 77 slidably mounted within ram-receiving aperture 70 and 
articulated by handle 74 through gear means 76. A heat conductive-type 
stick 78, containing preselected type, is mounted on a heat conductive 
mandril portion 80 of ram 72. A heating means 82 supplies thermal energy 
to the type stick 78. 
After the type has been set and the type stick 78 has been inserted into 
the mandril portion 80, the article 20 is aligned by suitable means on 
base plate 84. Responsive to the activation of handle 74, stamping means 
71 is forced downwardly onto article 20 and heat is concurrently applied, 
thereby debossing the article 20 while transferring ink from the hot stamp 
foil to the debossed letters. The temperature and time at which the 
stamping operation is carried out are related functions. If the 
temperature is increased, the time of contact between the stamping means 
and the object being stamped may be decreased or increased. It has been 
found that a hot stamp temperature range of between 150.degree. and 
300.degree. will give satisfactory debossing results. At these 
temperatures, the time range may vary from a fraction of a second to three 
seconds. At a temperature of 250.degree. F., a stamping time of between 
one and one-and-one-half seconds is satisfactory. The hot stamping foil 30 
selected for this process should accommodate the temperatures used and the 
materials being stamped. 
The film 42 is a heat-insulating covering film which withstands the hot 
stamping temperature, without acting as a heat conductor to spread the 
stamping heat across the upper surface. The covering film contains and 
follows the thermoplastic material as it debosses to form an imprintable 
surface. 
A further function of the stamping operation is to apply pressure to the 
stamping means. In hand-operated stamping equipment, normal hot stamping 
pressures may be satisfactorily applied. One feature of the embodiment of 
FIG. 7 is that it allows correction where too little or too much pressure 
has been applied to the plate being imprinted. If the operator exceeds the 
proper pressure or stamping time, either a conventional burnishing stick 
or a cleaning fluid may be rubbed over the surface of the plate to remove 
excess ink. If the operator uses too little pressure or time, the plate 
may be restamped. Thus, the process of FIG. 7 tends to become an "art" 
wherein the operator tends to have to learn how to stamp the pad. 
Once the article 20 has been hot-stamped, the backing sheet 28 is removed 
and the plate portion 40 is separated from appendage portion 38 and foil 
30 (as best illustrated in FIG. 3). The plate portion 40 may then be 
applied to a plaque or other object. 
In the embodiment of FIGS. 1-3, the backing paper 28 is a substrate which 
keeps the thermoplastic plate from being distorted responsive to an 
application of heat and pressure, during the hot stamping process. Other 
embodiments in the above-identified parent applications used a wooden 
plaque as the stabilizing substrate. A difficulty with these substrates 
was that they led directly to specialized products which required backing 
paper, plaque board, or the like. Not all products will require these 
particular substrates. Moreover, the thermoplastic plate 44 of FIG. 2 is 
very thick relative to the depth of the debossment. Therefore, as 
explained above, if too much pressure is applied, the hot stamping ink is 
deposited onto the non-debossed areas. If too little pressure is applied, 
the printing is not crisp and sharp. 
According to the invention, both of these drawbacks are overcome by the 
structure shown in FIG. 8, wherein a substrate is built into the plastic 
material which is suitable for simulating engraving on metal itself, as 
distinguished from a separate substrate integrally laminated below the 
plastic material which is suitable for simulating engraving on metal. 
In greater detail, the laminate of FIG. 8 includes a release paper 90 
having a treated, plasticized, non-hydroscopic surface which peels off a 
layer of adhesive 91. Above the adhesive is a substrate layer 92 of 
material which withstands and does not deform under the pressure or heat 
of a hot stamping process. 
In one preferred embodiment, the substrate 92 is MYLAR film which is 0.005 
inches thick. 
Other embodiments may use many different forms of substrates. For example, 
various forms of metal may be used as the substrate 90. One such metal, 
which is easily available, is commonly called "engraving stock," which is 
the conventional material that the invention replaces. Other such metals 
may include any of many different sheet metals, such as: aluminum, steel, 
and various alloys. 
If these substrate materials have any surface texture, that texture appears 
on the surface of the inventive material. Therefore, it is possible to 
enhance the surface appearance of the inventive material by selecting a 
substrate with a particular texture. On the other hand, it is also 
desirable to have a substrate which is extremely smooth and free of any 
texture. One such material is currently used to make the walls of beverage 
cans because that metal is smooth enough to print labels, pictures, etc. 
directly on them, with conventional printing equipment. The walls of these 
beverage cans are also quite thin so that they are easily worked. For 
example, when this kind of metal is used as a substrate, the inventive 
material is easily stamped with a sheet metal stamping machine after the 
surface has been decorated with hot stamp engraving. 
Hence, the substrate is not necessarily limited to any particular kind of 
material, either metal or plastic. It should be selected on a basis of 
rigidity, pliability, mass, formability, and compatibility with existing 
machinery. 
Above the substrate 92, there is a layer 93 of thermoplastic material, 
which is a 0.004 inches thick layer of the vinyl used in the 
above-described embodiment of FIG. 2. Covering the upper surface of the 
thermoplastic layer 93 is a thin sheet or containment layer 94 of material 
which does not spread heat. Layer 94 contains and follows the flow of the 
thermoplastic material during debossment. In the preferred embodiment, 
this material 93 is MYLAR film, which may be 0.001 inches thick. Finally, 
a decorative color coating layer 95 coats the containment layer 94. If the 
MYLAR film 94 is metalized at 95 by aluminum, which is deposited in a 
thickness of a few molecules, the film will have the metallic appearance 
of silver or aluminum. Likewise, if the coating layer 95 is the color of 
copper, brass or gold, the metalized film 94 will appear to be copper, 
brass or gold, respectively. In the embodiment described herein, the 
coloring layer 95 may be 0.001 inches thick. 
As seen at 96 in FIG. 8, the heated die may be lowered until it bottoms on 
the top of the MYLAR substrate 92. Since the substrate is a material which 
does not deform under heat, the die cannot penetrate any further than the 
thickness of the material 93. Thus, within reason, it is almost irrelevant 
how much pressure is applied to the engraving material during the hot 
stamping process. 
If a cross section of an engraved metal material is examined under a 
microscope, it is found that a small rim is generally pushed up around the 
perimeter of the image pressed into the metal. In the embodiment of FIG. 
2, there is enough thickness in layer 44 so that the thermoplastic 
material may be displaced in many directions. Therefore, the raised rim 
may or may not form, depending upon many random variables, and it may or 
may not be a faithful simulation of debossed metal. 
However, the inventive material of FIG. 8 does not have enough thickness in 
the layer 93 to absorb a substantial amount of plastic displacement. 
Therefore, some of the plastic material, displaced by the die will almost 
certainly flow upwardly to form the rim at 97,98. The amount of the 
material displaced around the rim has to be greatly exaggerated in FIG. 8 
in order to produce a drawing which can be seen and read easily. In 
reality, the rim is apparent only as subtle highlights and shadows formed 
around the perimeter of a debossment. 
By controlling the thicknesses of the various layers 92-95, these 
highlights and shadows may be made to closely simulate debossed metal 
whereas, in the order version of FIG. 2, it was easy to produce either too 
much or too little of these highlights and shadows, if a rim was produced 
at all. 
Principles described in connection with the embodiments of FIGS. 1-8 are 
employed in the inventive plaque, and in the process for fabricating it. 
The plaque and process are described in FIGS. 9-20. Among other things, 
the inventive process includes the use of a hot stamping machine, such as 
that shown in FIG. 7, and the product includes a laminate of polyester 
film on a thermoplastic material. 
The invention has a wide application in many fields. For example, jewel 
boxes, cabinets, doors, picture frames, product housings, dashboards, 
trays, and many other things may be made by the described processes. 
Accordingly, as used herein, the term "plaque" is to be construed to cover 
all devices which may incorporate the designs, features and processes 
described herein. 
The first step in the process for making the inventive decorative or award 
plaque or other panel is to cover the surface of a rigid board 100 with a 
finish coat 101 having any suitable surface. While any of many different 
suitable materials may be used to make the plaque blank of FIG. 9, it is 
presently thought that a wood grain vinyl sheet 101 bonded to a flake 
board panel 100 is the best material. Any of various plaque sizes and 
shapes may be used, one exemplary plaque being 4".times.6".times.0.5" 
(10.times.15.times.1.3 centimeters). 
After a suitable number of plaque blanks (FIGS. 9,10) are cut to size, 
their edges are finished in any suitable manner. For example, plaque 
blanks 102-108 are shown in FIG. 11 as being clamped together and passed 
over a roller 110 which is at least particularly submerged in any suitable 
paint or similar material 111. Thus, the edges of boards 107-108 are 
filled and painted or otherwise given an attractive end-product finish. 
Next, a laminated sheet of plastic material 113 is bonded to the wood grain 
vinyl 101. This sheet 113 is essentially the same film-covered plastic 
material described above in connection with FIG. 8. If desired, the 
plastic material may have a brushed golded metallic appearance. 
Thereafter, an ink (perhaps silver) on a hot stamping foil 119 is placed 
over, transferred and bonded to the metallic-like film surface 42, by a 
heating process. For example, in this particular drawing, the ink of a 
silver hot stamping foil 119 is transferred in the general form of a 
baseball catcher's mitt 115 and the tape 116 on a baseball bat handle. The 
outline 117,118 of silver ink already removed from the foil 114 indicates 
that a previous plaque was stamped with the same general form. The next 
plaque to be made will receive a transfer of silver ink presently carried 
in the area 119 of the hot stamping foil (FIG. 14). 
After the first hot stamping ink transfer step (FIG. 15) is complete, the 
appearance is a brushed gold surface 113 having polished silver surfaces 
at 120,121. In this particular example, a brushed gold disc or circle 123 
remains where no heat transfer occurred in the center of the silver patch 
120. 
The next step in the inventive process is to deboss the plaque of FIG. 16 
and to deposit a colored ink in the debossments. Here, in this specific 
example, a number of black lines 124 are debossed to provide the details 
of a catcher's mitt, a baseball bat, and a baseball. If desired, still 
more details could be added. For example, the baseball could be made white 
and its stitching could be debossed red lines. Obviously, the ultimate 
number of steps is limited only by the imagination, the desired design, 
and the acceptable limits of costs. 
Simultaneously, with the formation of the debossed lines 124, any suitable 
printing 125 may be formed. This printing could include a logo, a year, a 
person's name, or any other suitable message, such as, for example, "First 
Place." Likewise, any other suitable forms and styles of printing may be 
used. 
The images 120,121,124 may be formed by any suitable die, such as a 
low-cost zinc die made by a photographic etching process, which is 
well-known in the printing art. For use at the point of sale, dies with 
any of many different standard logos may be ordered, at the retailer's 
option. For example, the retailer may buy a Little League Baseball motif, 
as shown in FIG. 16. He may also buy patriotic, religious, civic, 
fraternal or organization symbols. Company logos, product symbols and 
words could be combined for a salesman's award. Many different 
one-of-a-kind plaques may be made in a low-cost manner from stock dies. Of 
course, any desired special die may also be made. The plaque may be 
further personalized by setting type for the debossment, at 125, with 
individually selected messages. 
Since the plastic 44 flows under heat, it may be heated and extruded once 
and then, within reason, reheated and re-extruded in a different manner. 
Also, the ink which is deposited in one step may be covered by other ink 
in a later step. Therefore, further customization may be achieved by 
overprinting. Thus, for example, religious symbols may be printed over a 
corner of an earlier printed flag, and then a motto may be printed over 
both the religious symbol and the flag. In a similar manner, many other 
combinations and modifications may also be made to customize decorative 
and award plaques. 
The next step of the process is to trim the surface layer 113 to the 
desired size and shape, and to remove the resulting selvage 130, as shown 
in FIG. 17. As illustrated, a die (preferably a steel rule die) 131,132 
has blades which are sharpened on only one side to provide a straight edge 
133 on the selvage side and a contoured edge 134 on the plaque side. If 
the contours were to be reversed with the straight edge on the plaque 
side, the plastic sheet 113 would be cut with a perpendicular edge 140 
which might be caught and lifted by a fingernail. Also, the laminated 
nature of the plastic 44 and film 42 is exposed to view at the vertical 
edge 140, and have an effect upon the illusion of a metal plate. 
To provide metallic-appearing edge contours which cannot be caught by the 
fingernail, the straight side 133 of the die edge faces the selvage 130, 
as shown in FIG. 17. Then, the tip of the die edge cuts the surface film 
42, the trailing die contour 134 rolls the underlying plastic 44 so that 
it becomes somewhat rounded. As the tip of the die penetrates and slits 
the wood grain vinyl 101, the metallic-appearing film 42 is inserted into 
the vinyl as at 143 (FIG. 19). When the die is raised, the memory 
characteristics of the vinyl 101 causes the slit formed by the die edge to 
grip and hold the film. 
The selvage is then peeled off the plaque and the plaque is complete (FIG. 
20). Any decorative hardware may be added, such as a hanger loop 145. 
Other hardware might include metal corners, frames, screws, rivets, or the 
like. An easel stand may be added to the back of the plaque. 
A preferred production line would include a conveyor with a sequential 
plurality of work stations, each performing one of the steps shown in 
FIGS. 9-20. The order of some of the steps may be changed for desired 
effects. For example, the order of the successive hot stamping processes 
of FIGS. 14 and 15 depends almost entirely upon the desired end product 
appearance. On the other hand, when the hot stamping involves debossing, 
the underlying plastic 44 is extruded and surplus material must flow 
someplace. Therefore, there may be an extrusion of layer 44 at an edge of 
the film 42, such as 140 (FIG. 18). If the edge of layer 44 is rounded and 
confined by film 42 before debossment, the plastic in layer 44 might not 
extrude freely, and less than desired results might follow. Therefore, if 
used, it is important that the die-cutting step of FIG. 17 should follow 
the debossing steps. 
It is to be understood that the embodiments of the invention which have 
been described are merely illustrative of the application of the 
principles of the invention. Numerous modifications may be made by those 
skilled in the art; therefore, the claims are to be construed to include 
all equivalent structures falling within the true spirit and scope of the 
invention.