US3063182A

US3063182A - Molded articles

Info

Publication number: US3063182A
Application number: US460708A
Authority: US
Inventors: William E Dowda
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-10-06
Filing date: 1954-10-06
Publication date: 1962-11-13
Anticipated expiration: 1979-11-13

Description

Unite States 3,063,182 Patented Nov. 13, 1962 ice 3,063,132 MOLDED ARTICLES William E. Dowda, 2162 Piedmont Road NE., Atlanta 9, Ga. Filed Oct. 6, 1954, Ser. No. 460,708 5 Claims. (Cl. 40-135) This invention relates to molded articles and, more particularly, to molded articles having at least one surface which includes a design or the like, lettering for example.

The present invention is directed broadly to the problem of providing a molded article having at least one surface which includes a design or the like, lettering for example, of substantially permanent nature. An example of such a molded article is a sign panel wherein one surface carries lettering, the lettering being of one color and the background for the lettering being of a diilerent color. In the making of signs and other displays it is, of course, common practice to paint a design, such as lettering, onto a background surface. However, a painted sign, and for that matter any sign wherein the design is attached to the background surface by adhesion, is subject to the objections that the design may become chipped, ycan be scraped oit, may separate from the background by splitting away from it, or may be otherwise damaged. In metal signs, highway markers, for example, `substantial damage occurs because of the susceptibility of such signs to damage by rocks and other articles and resultant weathering and rusting.

By following the teaching of the present invention, it is possible to provide a sign, among other articles, which is lightweight, relatively strong, and in which the surface design is substantially permanent and not easily damaged. In fact, the design is actually bonded into the surface on which. it appears and lies substantially flush with this surface. 'I'he design coheres with the background on which -it appears and is thus attached by a cohesion rather than an adhesion technique. Furthermore, such a sign can be produced at a cost competitive with other materials, such as metal, and requires much less maintenance, repainting, for example, than is required for signs made of metal, wood or the like.

It is accordingly an object of the present invention to provide a new and improved molded article having at least one surface including a design or the like-wherein the design, lettering for example, is intimately bonded with the article and extends into the body from the surface on which it appears.

It is another object of the present invention to provide such an article wherein the design, lettering for example, may be of different color from the background on which it appears.

lt is another object of the present invention to provide such an article wherein the design may be light reflective.

Briefly described, a preferred embodiment of the present invention is an article, a sign panel for example, of molded reinforced thermoset resin wherein at least one face of the panel includes a design, lettering for example, sharply outlined and of different color from the background surface on which it appears and wherein the design is actually bonded with the body of the panel and lies substantially flush with the surface on which it appears. In fact, the panel body and the design, although of different color, have the same basic chemical composition and molecular structure.

In making such a sign, a preferred procedure is to first screen process the desired design onto a sheet of porous material, a fiber glass mat for example, by applying a thermosetting composition, including polyester resin for example, onto the porous sheet until the resin penetrates substantially the full thickness of the sheet. The screenedon design is then allowed to gel partially.

A backing sheet of porous material and one or more intermediate sheets of porous material are then laid up in a mold. Another thermosetting composition, including polyester resin for example, is then spread over the exposed upper surface of the uppermost intermediate layer. Then, one or more additional intermediate sheets of porous material are placed over the spread-out thermosetting composition which is in the mold and, linally, Ithe sheet containing the design is placed on top with the design uppermost.

rfhe mold is then closed and heat and pressure applied to the sheets of porous material and the thermosetting compositions which are within the mold until a complete cure is obtained. When the sign is taken from the mold, it is found that the molding composition has penetrated from the middle throughout the entire body of the sign except in that portion of the body which is occupied by the screened-on design. The design lies substantially flush with the surface on which it appears, is Vsharply outlined with respect to the background, and is actually bonded into the body of the sign so that it is an integral part thereof. The polymerization of the polyester resins appears to achieve a molecular linking of the design with the rest of the body. It is to be understood, of course, that the quantity of the molding composition is suflicient so that it can penetrate throughout the body as described. It is to he further understood that the screening composition and the molding composition may have color pigments dispersed -therethrough so that the design is of one `color and the background of a contrasting color.

By opening the mold before the screened-on design has completely cured, it is possible to dust very small glass beads onto the tacky surface of the screened-on design and then when the mold is closed and the cure completed the glass beads are held firmly in place. This results in a light reilective sign. Although the screened-on design is still tacky at the stage when the molding is interrupted, the background itself is quite hard due to the different time phase in the molding cycle. A more detailed description of this process is described in my application Serial No. 70,869.

Other objects and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the attached drawings wherein:

FIG. l is a front elevation view of a sign made according to the teaching of the present invention;

FiG. 2 is an exploded perspective view of a portion of the sign shown in FIG. l showing component parts of the completed sign; v

FIG. 3 is a sectional view taken on line 3 3 of FIG, 1;

FIG. 4 is a view showing a step in the process of making a sign like that shown in IFIG. 1 according to another teaching of the present invention;

FIG. 5 is an enlarged detail view in section of a portion of a light reective sign.

A molded article made according to the teaching o'f the present invention comprises, as its principal components, a material, or composition, which is initially liquid in character so that it can be used as an impregnating material and a material which is suiciently porous or otherwise absorbent to receive the rst-mentioned material and act as a filler or reinforcing medium for the molded article. A preferred reinforcing material is glass fiber in the form of mats `but any reinforcing or fortifying material is sufficiently porous or otherwise absorbent can be used, it being understood that the ultimate strength and physical properties of the molded article may vary quite considerably depending upon the strength and nature of the particular reinforcing material employed.

Examples of other reinforcing materials which may be used are cloth, paper, and even such substances as lloc, cork or sawdust in mat form.

The -impregnating material, or composition, i.e. the material which penetrates the porous reinforcing material is preferably a resin or varnish which may be polymerized under heat and pressure to a thermostat substantially infusible hardened state. A preferred thermosetting resin is a polyester which may be described generally as Abeing a polymerizable material consisting of a mixture of a maleic containing alkyd resin, a polymerizable monomer such as styrene or diallyl phthalate, and a light stabilizing vsubstance which has the ability to absorb ultra-violet light. The resinous component may contain other mono or dibasic acids than maleic, usually phthalic an/ or adipic, which have been reacted with polyhydric alcohols such as ethylene glycol or other glycols. The over-all mixture is polymerized by peroxide either with or without heat, and contains an oxidation inhibitor usually of the phenolic type to prevent spontaneous polymerization. Other resins or varnishes having properties substantially similar to a polyester just described may be employed within the broad teaching of the present invention but, as stated, a Vpolyester resin is preferred.

In `order to obtain a design or the like in an article, such as a sign, made according to the teaching of the present invention, a coloring pigment is added to the polyester.

By having one color in the polyester used to apply the -design to a surface mat of the reinforcing mats and by yhaving another color in the polyester which is used to impregnate the main body and background surface of the molded article, it is possible to obtain color separation in the article with actual bonding together and similar molecularrstructure of the portion of the article which includes ythe design and the remaining portion of the article. It is thus apparent why a design or the like formed according to the teaching of the present invention is so permanent in nature.

...As an example of an article made in accordance with the teaching of the present invention, reference is made to FIG. l of the drawings which shows a sign 1 having the word TELEPHONE at the front surface 2 thereof. In making this sign a screening on composition of thermo- -setting material containing a color pigment was applied to a vglass fiber mat of acommercial grade known as surface mat. The screening on composition was applied .according to the screen processing technique known gen- ,erally as thesilk screen technique, well known to those skilled in the art of sign and display making. The screening on composition was screen processed onto the front of the glass iiber surface mat until the resin penetrated into the mat substantially its entire depth. The screening ,on composition wasv then allowed to gel partially, which Aaction takes place in a period of from l2 to 24 hours after the screeningv on is done. Also, of course, the screening on design was such that the word TELE- PHONE was formed on the surface mat `as shown in ,FIGURE 1 of the drawings. The reference numeral 3 indicates the screening on composition forming the letter design making up the word TELEPHONE.

After the screening-on of the design was completed, the mat 4 containing the lettering was assembled with other reinforcing mats of the same length and width to make up the complete sign. The various mats are shown in .FIG. 2 where it will be noted that there is a front surface `mat-4 which includes the lettering, a back surface mat 5 v'of vthe commercialgrade known as surface mat. Mats 7 are glass fiber mats of the commercial grade known as reinforcing mats. The reinforcing mats are of much coarser texture than the surface mats but are quite suitable for use in the middle of the sign panel. The relatively ne pores of the surface mats give the front and back surfaces of the sign a smooth appearance.

While glass 'liber mats are a preferred reinforcing material employed in the practice of the present invention, other suitable porous materials may `be employed as has been mentioned above. Also, while a plurality of intermediate reinforcing mats has been referred to in the example being described, the sign panel could consist of fewer sheets of porous material if desired. Thus, one could eliminate some of the intermediate reinforcing mats and,- if desired, employ only a front mat and a backing mat. In the preferred practice of the present invention, more than merely a front mat and a back mat will be employed.

The various reinforcing mats were assembled by plac# ing them in a mold, placing the back surface mat 5 in the mold first, then an intermediate reinforcing mat 6 on top of mat 5, and then one of the coarser intermediate mats 7 on top of the intermediate mat 6.

At this point, a molding composition of thermosetting material similar to that used in the screening on process, but containing a different color pigment was spread substantially uniformly over the exposed upper surface of the intermediate reinforcing mat 7 in the mold.

After the molding composition was added, the other coarser intermediate mat 7 was placed on top of the molding composition, then the other intermediate mat 6 was placed on top of mat 7, and, finally, the front surface mat 4 was placed on top of mat 6 with the lettering uppermost. The mold was then closed, to compress the various mats and the thermosetting compositions all located in the mold, and pressure and heat was applied to the mats and the thermosetting compositions until the thermosetting compositions became fully cured.

At the end of this time, the mold was opened and the completed sign panel removed from the mold cavity. The molding composition penetrated from the middle to both the top and bottom, or front and back surfaces of the sign panel and flowed around the edges of the panel to close in and seal oif the projecting ends of the glass bers. Because of the relatively line porosity of the front and back surface mats 4 and 5, the outer surfaces of the panel were substantially smooth and uniformly colored.

The screened-on lettering retained its sharp outline and substantially its original yellow color. As has been mentioned above, the screened-on composition making up the lettering was in a gel condition when it was placed in the mold, which means that it was in a state of partial cure. When the mold was closed and heat and pressure applied to the lettering, it went from its gel condition to a liquid condition in approximately 11/2 minutes and then went back through a gel condition to a final cure or hardening. The latter phase occurred during the final portion of the two to three minutes that it took for the panel to be cured or polymerized. The molding composition went to a more liquid condition in from approximately 5 to 20 seconds after the mold was closed. It then started to gel and hardened in from one to two minutes after the mold was closed. The gelled lettering apparently prevents the quickly liquid molding composition from penetrating into that portion of the surface mat 4 which contains the lettering and this appears to account for the relatively sharp outline which the lettering retains in the finished article. Conversely, by the time the screened-on composition becomes liquid, i-.e., approximately 11/2 minutes from the time the mold is closed, the molding composition has gelled and appears to prevent the screened-on composition from spreading out in the surface mat 4 and creating fuzziness at the edges of the letters. When both thermosetting compositions are cured there appears to be an actual molecular linking due to the polymerization action which occurs.

It is found that polyester resins manufactured by a number of different manufacturers may be employed with success in the practice of the present invention. Naturally, the exact composition of a particular polyester resin will vary depending upon a particular physical or chemical property which the manufacturer desires the polyester to have. Consequently, it is possible to order polyester resins having a certain degree of flexibility or some other property and the range available on the market today is substantial. However, as a general proposition, polyesters generally may be employed in the practice of the present invention.

The process described above in connection with. the making of a sign wherein the design is different in color from the background adapts itself readily to making a reiiective sign. As was described above, the screened-on lettering goes from a gel condition to a liquid condition, then back through a gel condition to a hardened or cured condition. If the molding is interrupted while the lettering is going through its second gel condition prior to hardening or curing, the letters are still tacky but the background or body of the panel has cured.

At this point in the molding cycle small size glass beads, or other suitable light reiiective beads, may be dusted onto the tacky letters and will adhere thereto. The excess can be removed from the hardened -background surface by blowing them away with an air hose or by brushing them away. The mold is then closed to complete the cure.

This is illustrated in FIG. where glass beads 14 are shown as being applied to letter surfaces 15. The glass beads 14 are pressed into the surfaces 1S so that the greatest bulge or diameter of each bead is below the surface of the lettering (see FIG. 7). This insures that they will be gripped firmly by the cured screened-on composition.

In the making of a sign having the word TELE- PHONE., number 10 glass beads, i.e., those having a diameter of approximately .010` inch, were applied to the lettering While it was tacky and the sign completed according to the procedure just described. The resulting sign was found to be rugged in the sense that the glass beads are held firmly in place and even resist actual mechanical scraping to remove them. They areheld much more firmly in place than if they were retained merely by an adhesion process and yet they extend beyond the surface of the sign so as to be effective for light reflective purposes. The reflective properties of the sign are such that it will glow back at night when, for example, the light from an automobile headlights are directed toward the sign.

In the practice of the present invention in making sign panels, for example, both surfaces of the sign can have lettering thereon instead of only one surface. To make a double face sign it is simply necessary to screen on the desired lettering or other design onto the front surface mat and the back surface mat and then proceed to make up the complet sign in accordance with the procedure as described in making a sign with lettering on one surface only. Of course, the back surface mat is placed in the mold with the surface including the design being face down. Likewise, it is possible to make a sign panel wherein both surface mats have a screened-on design of one color and a screened-on background of a different color. A clear molding composition is used in the body of the panel. The resulting panel has 'colored faces, each bearing a design' such as lettering, and a translucent interior. Edge lighting can be applied to such panel to good effect since the panel body located between the opposite faces is essentially translucent and the lighting will pass edgewise through the panel body and enhance the appearance of the lettering or other design appearing at the surfaces.

It is thus seen that I provide molded articles wherein the articles include a design, such as lettering, which is essentially an integral Vpart of the completed article and is thus essentially permanent in nature. Such a design resists damage well and, as compared to a design painted on metal for example, is much less subject to damage from foreign objects. Highway markers are an example of a sign usually made of metal which is subject to damage from stones, bullets and the like. Being of metal, once they are struck by a bullet, stone or the like, they will rust where the paint is chipped off and much replacement is necessary in the course of a year. I have found that a molded sign panel made according to the teaching of the present invention may be literally peppered with riiie bullets and still retain essentially its shape and appearance. A rifle bullet will go through the panel cleanly, leaving only a small opening, and the panel will not rust.

While I have described and illustrated embodiments of my invention, I wish it to be understood that I do not intend to be restricted solely thereto but that I do intend to cover all modifications thereof which would be apparent to one skilled in the art and which come within the spirit and scope of my invention.

What I claim as my invention is:

l. A molded article comprising a surface layer of porous reinforcing material having an outer surface, a backing layer of porous reinforcing material, a first hardened material, a portion of said surface layer being impregnated by said rst hardened material, said impregnated portion including a portion of the outer surface of said surface layer and said first hardened material extending inwardly into -said surface layer from the outer surface thereof, and a second hardened material, said backing layer and the portion of said surface layer which is -not impregnated by said first hardened material being impregnated by said Second hardened material, said second hardened material bonding said surface layer and said backing layer together, and said hardened materials and said surface layer presenting a substantially smooth outer surface of said molded article.

2. A molding article comprising a surface layer of porous reinforcing material having an outer surface, a first thermoset polymerized material having a color pigment dispersed therethrough, a portion of said surface layer including a portion of the outer surface of said layer being impregnated by said first thermoset polymerized material, a backing layer of porous reinforcing material, and a second thermoset polymerized material having a color pigment dispersed therethrough and of different color from the pigment dispersed through said first thermoset polymerized material, said backing layer and the portion of said surface layer which is not impregnated by said first thermoset polymerized material being impregnated by said second thermoset polymerized material, said layers being bonded together by said second thermoset polymerized material.

3. A molded article comprising a glass fiber surface mat having an outer surface, a galss fiber reinforcing mat, a first thermoset polymerized mate-rial including a polyester resin in an amount of from thirty to sixty percent by weight of said material and a color pigment in an amount up to ten percent by weight of said material, said color pigment being dispersed throughout said material, a portion of said surface mat including a portion of the outer surface of said surface mat being impregnated by said first material, and a second thermoset polymerized material including a polyester resin in an amount from twenty-five to eighty percent by'weight of said second material and a color pigment in an amount up to ten percent by weight of said second material, said last named color pigment being dispersed throughout said second material and being of different color from the color pigment dispersed throughout said first material, said reinforcing mat and the portion of said surface mat which is not impregnated by said first material being impregnated by said second material, said second material bonding said mats together.

4. A molded article comprising a surface layer of porous reinforcing material, a backing layer of porous reinforcing material, a first thermoset hardened composition consisting essentially of, in lpercent by weight of said composition, from thirty to sixty percent of a polyester resin, from thirty to sixty percent of an inert granular filler, up to ten percent of a color pigment, and from one half to two and a half percent of a catalyst, said color pigment being dispersed throughout said first composition, a portion of said surface layer being impregnated by said first composition, and a second hardened composition consisting essentially of, in percent by weight of said second composition, from twenty-five to eighty percent of a polyester resin, from fifteen to fifty percent of an inert granular filler, up to ten percent of a color pigment, and from one half to two and a half percent of a catalyst, said last named color pigment being dispersed throughout said second composition and being of different color from the color pigment dispersed throughout said first composition, said backing layer and the portion of said surface layer which is not impregnated -by said rst cornposition being impregnated by said second composition, said second composition bonding said surface layer and said backing layer together.

5. A molded article comprising a surface layer of porous reinforcing material having an outer surface, a backing layer of porous reinforcing material, a first ltherlmoset hardened material, a portion of said surface layer -includinga portion of said outer surface being impregnated by said first thermoset hardened material, a second thermoset hardened material, said backing layer and the -portion of said surface layer which is not impregnated byzrsaid first thermoset hardened material being impregnated by said second thermoset hardened material, said second thermoset hardened material bonding said surface layer and said backing laye-r together, and a plurality of small glass beads embedded in the portion of the outer surface of said surface layer impregnated by said first thermoset hardened material, said glass lbeads projecting slightly outward from said outer surface portion, and the outer surface portions impregnated by said first thermoset hardened material and said second thermoset hardened material respectively being substantially flush and presenting a substantially smooth outer surface of said molded article.

References Cited in lthe file of this patent UNITED STATES PATENTS 1,014,472 Henriques Ian. 9, 1912 1,548,096 Persons Aug. 4, 1925 1,576,156 Swoba Mar. 9, 1926 1,717,738 Schwarz June 18, 1929 1,785,357 Levin Dec. 16, 1930 1,805,327 Carr May 12, 1931 2,056,928 Magdziarz Oct. 6, 1936 2,089,351 English Aug. 10, 1937 2,122,043 Pollard June 28, 1938 2,306,387 Huntley Dec. 29, 1942 2,365,034 Wirtz Dec. 12, 1944 2,390,663 Pollard Dec. 1l, 1945 2,541,497 Buxbaum et al. Feb. 13, 1951 2,621,432 Willner Dec. 16, 1952 2,624,967 Phillippi Jan. 13, 1953 2,659,170 Hill Nov. 17, 1953 2,670,554 Francis Mar. 2, 1954 l2,681,473 Carlson June 22, 1954

Claims

1. A MOLDED ARTICLE COMPRISING A SURFACE LAYER OF POROUS REINFORCING MATERIAL HAVING AN OUTER SURFACE, A BACKING LAYER OF POROUS REINFORCING MATERIAL, A FIRST HARDENED MATERIAL, A PORTION OF SAID SURFACE LAYER BEING IMPREGNATED BY SAID FIRST HARDENED MATERIAL, SAID IMPREGNATED PORTION ER AND SAID FIRST HARDENED MATERIAL EXTENDING INWARDLY INTO SAID SURFACE LAYER FROM THE OUTER SURFACE THEREOF, AND A SECOND HARDENED MATERIAL, SAID BACKING LAYER AND THE PORTION OF SAID SURFACE LAYER WHICH IS NOT IMPREGNATED BY SAID FIRST HARDENED MATERIAL BEING IMPREGNATED BY SALD SECOND HARDENED MATERIAL, SAID SECOND HARDENED MATERIAL BONDING SAID SURFACE LAYER AND SAID SURFACE LAYER TOGETHER, AND SAID HARDENED MATERIALS AND SAID SURFACE LAYER PRE-LDSENTING A SUBSTANTIALLY SMOOTH OUTER SURFACE OF SAID MOLDED ARTICLE.