US2827727A - Expandable beaded decorative printing - Google Patents

Description

March 25, 1958 H. LIPSIUS EXPANDABLE BEADED DECORATIVE PRINTING Filed April 19, 1956 INVENTOR, HERBERT LIPSIUS.

ATTORNEY.

United States Patent EXPANDABLE BEADED DECORATIVE PRINTING Herbert Lipsius, Brooklyn, N. Y. Applic'ation April 19, 1956, Serial No. 579,350 7 Claims. ((31.41-24) This invention relates to decorative -printing such as for greeting cards but it will become apparent hereinafter that greeting cards are only one example to'which the inventionis applicable.

In the graphic arts it is often desirable to have a design or printed matter stand out physically in relief. "With special equipment, thin stock to carry "the design may be embossed. When thicker stock is to be used embossing is too expensive except for a few specified uses. It has been proposed to applique cut out letters when much relief is desired. This too, has been found too expensivefor general usage. A small amount of relief is obtained by engraved printing and so-called imitiation engraving or thermographic raised printing wherein a fine fusible dust is applied to wet ink and is subsequently melted so that the dust particles coalesce and form a smooth'bnt only slightly raised surface.

I have also proposed in my co-pending application, Serial Number 569,131, ffile'd March 2, 1956 to lightly adhere glitter particles, sometimes beads, to paper stock and then dust the beads with raised printing powder and fuse the powder to adhere the beads together. This procedure can hardly ever give heights of more than three bead diameters and the greater the bead diameter, the

more diflicult the adhesion of the head to thestock, and the greater the decrease in flexibility.

To overcome the objections above mentioned and obtain relief of the order of 1/ inch and more I adhere expandable or pufiable beads to stock in the intended design or printing and then expand the beads.

Expandable or pufiable free-flowing spherical beads are known commercial-products. They are generally made from thermoplastics-in which is incorporated an expanding or putting agent which causes the beadto expand when heated. Such expandable compositions are described in United States Patent No. 2,681,321, issued June 15, 1954. They are described in detail in New expanded plastics, Plastics (London) 17, 313, November 1952, and in Popcorn plastic, Modern Plastics 31, 190 (May 1954). One such plastic in bead form is sold by Koppers Company, Inc., Pittsburgh, Penna., under the name Dylite the body of which is polystyrene, and can'be expanded to about 30 times its original volume by heating for about a half a minute at about 225 F. In my invention actual temperature need not be known for it is by far much easier merely to observe the expansion, regulate the heater to avoid scorching the paper and determine how long the beads must be heated to get the desirable expansion.

In the accompanying drawing showing, by way of example, one of many possible embodiments of the invention,

Figure 1 shows stock with adhesive applied in the form of an intended design;

Figure 2 shows stock and design covered with an excess of beads;

Figure 3 shows the removal of excess beads;

Figure 4 shows adhered beads subjected to heat, and

ice

Figure 5 shows roughly theform assumed by the ex panded beads.

For an example:

In carrying outniyinvention, adhesive 12 is applied 'to a'she'et of stock 10 to form a design 11 as shown in Figure 1. The adhesive maybe applied in any known manner, such as hand painting, stenciling as by silk screens, transfer 'from 'gluep'ots etc., so as'to leave a'wet -or 'tacky surface.

Wliile the "surface of the adhesive is still wet or tacky a "quantity of heat expandable spherical beads is applied to the surface 18 of the adhesive and the beads may pile up in a mound 16 as shown in Figure '2. The 'result'is -that'the"beatls'a're secured to the adhesive in substantially a 'monolayer 19. By tilting the stock 10 "substantially all the beads otherthan those of the'monolayer will easily roll off and the excess caught in a vessel or trough 20 for "reuse. The excess beads roll off even though the design is closed to leave an open space 14 (Figure 1) since"theheight of the 'a'dhesive'is "only a few thousandths of an inch thick, and the monolayer can hold back very few beads unless the angle of tilt is veryfslight. In practice, the 'normalmovement of the "stock is enough to dislodge any unadhered beads.

Spherical beads even 'in sizes down to about mesh readily roll on 'm'ost printing stock. This is in contrast to the action of fiat surfaced. glitter particles and thermographic raised printing powders which are held by a suction bond and must be removed by strong'vacuu'm cleansing or some form of sweeping action.

The monolayer of beads adhered to the stock is then subjectedto heat, as under a radiant heater '21, where the beads begin to expand .som'ewhat'as shown in Figure 4. After expansion the beads appear somewhat as in Fig- 'ure '5. It is to be noted that the beads expand laterally to form marginal portions 22 which overreach the side edges 24 'of the adhesive. This overhang is usually over inch on each side. The pulled up mound 25 of expanded heads is in fact not dense but contains microscopical small voids which render the expanded beads non-transparent and substantially opaque. 'The beads of course should not become truly melted so that surface tension of molten plastic'would smooth out the surface of the mound 25. Moreover substantial melting of the plastic or" the beads would permit loss of the expanding or pulling agent. As pointed out above, observation of the expansion or 'pufiiing up of the beads during the process is sufiicientt'o indicate the degree of heating necessary.

Lateral expansion of thebeadsto form the overhanging portions is beneficial'in several ways other than the reduction in number of beads required to cover a given area. One benefit is that the expanded beads cover films of adhesive that are liable to extend beyond the intended limits and which are so thin that the films are not etfeetive for adhering beads. These films would become sticky, if glue is used, in the presence of moisture. Secondly, it is diflicult to obtain an adhesive which will not be notice able on the stock either due to difference in color or gloss.

Hence a minimum number of types of adhesives for a variety of stock colors and finishes is permissible and 01T- color cheap adhesives can be generally used. Thirdly, many adhesives which discolor with age and/or under heat (as is here required) yet are otherwise suitable may be used.

It will be realized that by my use of expandable beads complete coverage of the adhesive area in general is not necessary in the body of the design. This is important since silk screens may become plugged at points or the adhesive layer may not have been applied uniformly. If under such circumstances a few beads do not stick to the intended area, the lateral expansion will fill these spots.

Where lateral expansion is uninhibited it usually occurs at a faster rate than vertical expansion.

Since the lateral expansion is uninhibited, and the beads unsecured tend to expand spherically, the marginal prtions of the puffed mound assume a lacy edgelboundary. As a specific example of my invention I apply fish'glue which is thermosetting as the. adhesive "to paper stock,

assigns? to the adhesive in a substantially even layer thereon, and then applying heat to the beads'sufliciently to putt up the beads and withdrawing the heat before the pufied beads melt, to form a relief design having laterally expreferably through a silkscreen. Those skilled in. the

, art caneasily determine the required viscosity of glue for a given screen.

The wet glue is then covered substantially completely with a layer of free flowing'he'at expandable spherical polystyrene beads of about 50 mesh. Beads having a bulk density of about 0.5 g./cc. and expandable at about 225? F. to' 'a'h'ulk density of about 0.025g./cc:"are satisfactory. j The beads used were ,Dylite beads supplied by the Koppers Company as mentioned above, understood tended marginal portions of irregular lace-like appear.

ance.

2. A process as claimed in claim 1, said adhesive being fish glue. 7 V

3. A decorative article comprising a sheet of paper stock; an adhesive on the stock in the shape of a design;

' and a relief design in the form of a substantially integral to be essentially.polystyrene -in'which'a highly volatile 7 sive, ink or paper;

As one skilled in the art of printing, I have had no difliculty in obtaining satisfactory polystyrene beads when only physical properties are specified.

Preferably an excess of beads is spread over the glue, and stock, and the stock tilted to allow unadhered beads to roll off. Bead sizes of from. to 80 mesliare generally satisfactory. r

After the beads are adhered by the glue the beads are heated for several seconds to expand same,.but of course the heat treatment must not damage the stock. Ordinary stock is not damaged at temperatures necessary to expand beads normally expandable at 225 F.

While radiant heating from above is satisfactory, the stock with beads thereon may be disposed on a hot-plate or passed over a naked flame or even subjected to hot gases to expand the beads.

Sudden chilling of the hot heads is undesirable lest they tend to collapse. However the heating and cooling of the beads present no greater difficulties than are met with in conventional thermoplastic raised printing processes in allowance for variations in paper stocks and ink.

The invention claimed is:

l. A process for making greeting cards and the like bearing'relief effects in design comprising applying a thermosetting adhesive compatible with polystyrene to card stock in the shape of a design; then applying solid free flowing polystyrene thermoplastic beads thermally pufiable to a volume many fold over their pre-pufied size mound secured to the stock by the adhesive, said mound being of polystyrene thermoplastic material having irregular round bumps substantially "all over the surface and' lateral edge portions of the mound, the mound being substantially uniform throughout the interior but having a large number of microscopic voids to render the plastic opaque, said lateral edge portions projecting -,laterally past the adhesive in all zones thereof. v

4. An article as claimed in claim 3 said adhesive'bein'g a thermosetting adhesive.

5. A process for producing relief effects in design comprising applying a thermosetting adhesive compatible with polystyrene to paper and in the shape ofa design; then applying solid free flowing polystyrene thermoplastic beads thermally pufi'able to a volume many fold over their pre-pufr'ed size to the adhesive in a substantially even layer thereon, and then applying heat tothe beads sufficiently to puff up the beads and expand the beads laterallyand withdrawing the heat before the puffed beads melt to leave a mound of pufied beads having closelyspaced bumps protruding from the mound and paper in substantially all directions from the latter.

6. A process as claimed in claim .5 said beads being of between 20 and mesh before being pufied. J

7. An article as claimed in claim 3 the mound having' a bulk density of the order of 0.025 'g. per cc.

References Cited in the fileof this patent UNITED STATES PATENTS 1,739,492 Berndt etal. -Q Dec.. 17, 1929 2,153,755 Higgins Apr. ll, 1939 2,582,132 Kaphan Jan; 8, ,1952 2,644,883 .Schoenherr July 7, 1953 2,744,291 Stastny etal May 8, 1956 FOREIGN PATENTS 7 576,389 7 Germany May 10, 1933 670,230 Great Britain Apr. 16, 1952 V V OTHER REFERENCES Plastic World, Foaming-agent polystyrene beads, page 4, March 1954. j V

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