CA1041845A - Thermoplastic ink decorated, polymer coated glass articles - Google Patents

Abstract

THERMOPLASTIC INK DECORATED, POLYMER COATED GLASS ARTICLES
Abstract of the Disclosure A glass article is decorated with a thermo-plastic ink which contains no frit. A finely divided heat fusible polymeric coating material is applied to the article over the ink. The article is heated to a temperature at which the particles of coating material fuse to form a smooth continuous film over the ink while the latter is in melted semi-liquid condition. The melted ink diffuses into (but not through) the polymer film over it, thereby forming a melt-melt bond. The polymeric film imparts a serviceability to the ink which it would not otherwise display.

Description

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The invention relates to the decoration of glass articles with thermoplastic inks which ordinarily would not be serviceable for such use, and the combining of such inks with a coating by which they are made serviceable.
In the manufacture of glass articles, it is of - -course often desirable or essential to apply a decoration to the article. (As used herein, the term "decoration" is used broadly to mean, without limitation, trademarks, labels, in-structions for use, contents, pictures, designs, or other written or printed material. The decoration may be translucent, transparent, or opaque, and may be of one or more colors including black or white.) Whatever the decoration, it must be serviceable for the normal use of the article; that is to say, the decoration should not smear, abrade, rub off, chip, or be removed by whatever type of rinse or detergent wash the article might be expected to encounter in its ordinary use or in the handling incidental to its manufacture or filling.
Thus, the standard decorating compositions used in labeling pop bottles, for example, are formulated to withstand abrasion in filling lines and in use, and to resist the usual washes and so on.

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1041~45 In order to provide such serviccability ox durability it is the most common practice to decoxate glass bottles with a frit-containing composition that includes a glassy component which is bonded to the glass surface by firing at high temper-ature. The fired,enamel-like frit fixes the coloring pigments on the article's surface. Organic inks for ylasses are kno~m, which also are united with the glass by firing.
Such compositions or "colors" are most frequently applied by the screen decorating process. For screcnability 10 the composition is often made up as a viscous, water-containing ~`
slip or, alternatively, as a hot melt or thermoplastic mater-ial which is solid at room temperature but becomes a screenable semi-liquid paste when heated to a temperature of about 120-200F.
The decorating material, whether water slip or hot melt, is ~ -applied to delineated regions of the glass article by being squeegeed through a stencil in the form of a screen of silk ~ or wire which is placed in registry on the surface of the 4 article. When the screen is separated from the article, the decorating material remains on the article in the delineated ~-20 area and dries by loss of water (if a slip) or quickly solidi-fies ~if a hot melt). At this stage, the decorating material -is very poorly and impermanently adherent to the glass surface, ~nd is a waxy, chalky or powdery layer which is not service-: .
able. It will smudge upon contact, and is too easily removable in washing. It becomes durable and serviceable only if heated so that it fuses and unites integrally to the glass. ~-Thus, in order durably to bond such colors to the glass surface, the screen decorated article has heretofore had to be subjected to a special, high temperature firing 30 ~tep which unites the decoration with the glass surface.
Inorganic frit-containing colors must be fired at a tempera-ture above 800F., and organic colors at temperatures of 350-,, .
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~041845 500F. For the inor~anic colors this reheating typically requires a cycle of roug'nly 45-60 minutes duration. For the organics, the firing cycle is shorter, but in ~ither case there is involved a substantial c~pital expenditure (and very substantial space requirements) for the heating equipment and conveyors. Moreover, there is a substan~ial operating cost in terms of fuel, articl~ handling and maintenance. How-ever, such firing has been necessary to bond the decoration so as to provide permanence.
The cost of such decorating materials is relatively high, in large part because of the expense of frit or other bonding components and the heat treatment necessary for bond-ing. This relatively high cost has had the affect of restrict-ing use of such materials to relatively small surface areas or portions of the decorated articles. (Organic colors, which do not require quite such high temperature firing, do not pro-vide the intensity of color of frit bonded colors, and hence are less useful.) Speaking generally, it has not been econo-mically practical to screen decorate a large percent of the ~-~ 20 decoratable surface area of glass containers, at least on the -high volume product. For that reason, frit decorated containers generally do not have large color panels, stripes or designs covering a high percent of their surface area, although from i~ a merchandising standpoint larger color areas would open up new possibilities for enhancing the appeal and visibility of , containers.
This invention is directed to a procedure by which

3 color decoration can be applied to much larger glass surface ¦~ areas than would otherwise be economically feas1ble. MUCh 30 lower cost materials can be used, but the prolonged or high temperature firing cycle5 that have heretofore been necessary are avoided. At the same time, the decoration is fully , :

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~ 1041845 serviceable, even though it is not uni~ed with thc glass surface.
This is achieved with th~ utilization of colors which are not bonded durably to the article, and which do not require formula-tion with the expensive frit or bonding ingr~di~nts that have largely been responsible for the relatively lligh costs of the decorating colors pr~viously used. In g~neral, colors can be used which would not, in the absence of anything more, adequately resist the abrasion, water or alkali attack to which the article is subjected in its ordinary use.
A thermoplastic or hot melt color is used in carry-ing out the invention and is applied by the screen decorating technique. It solidifies very rapidly, almost instantly, on : .
the cooler ware. The color ~sometimes referred to hereinafter as an "ink") is formulated so as to become semi-liquid, with .. . .
a consistency suitable for screening, upon moderate heating.
It may be similar to known hot melt colors, except that it :
can be and desirably is compounded without the heretofore conventional frit binding ingredients. Such components are not necessary for bonding and, while they are not harmful, they are not necessary. -Hot melt colors or inks are well known per se and usually include as the vehicle a wax or waxlike material having a melting point between about 120 and 200~F. Examples of such waxy vehicle constituents are carnauba wax, parafin wax, microcrystalline wax, beeswax, palmitic acid, stearic acid, --and solid soaps. This is preferably the bulk of the vehicle, .
e.g., about 60-85~ by weight. The vehicle may also include a binder for adhering the ink to the glass. For example, about 5-25% re8in or the like is useful as a binder and hardener.
30 Ethyl cellulo~e- may also be present ~e.g., 2-15~ of the vehicle) , ~ as a v~scosity promoter and hardening agent.

-~ The pigment or coloring ingredient incorporated , '' Cb/ 5 ~'',' 104~t~45 with the vehicle may be particulate inorganic matcrial, e.g., Tio2 or Cr2O3, which is insoluble in thc vehicle, or it may ~e an organic dye, or ~ mixture of organic and inorganic color-ants. It is desirable to omit any volatiles which would have to be removed for solidification to occur and any solvents which would affect the coating resin when the latter is applied.
The ink itself does not comprise tl~e invention and its consti-tuents are not critical. From this disclosure those skilled in the art will readily be able to formulate a variety of ~` 10 suitable thermoplastic inks.
The ink sets up rapidly when applied to the surface i f ~tare which is at a temperature below the screening tempera-ture, for example at ambient temperature. Second or multiple colors having successively higher melting points can be . sequentially overprinted on the first color, in order to pro-j; yide a multi-color decoration. None of the layers of ink, however, are permanently bonded to the surface of the glass, and the process is characterized by the absence of any baking -~ or firing operation which would unite the decoration to the ;~ 20 glass surface as a frit is united. The decoration remains on '1~
the glass surface as a waxy deposit, and is easily removable.
`, A finely divided discrete particle fusible resin is applied over the ink. The article is preferably heated .~,. .
~`~ for this purpose so that upon contacting the article, the resin particles will soften or fuse sufficiently to become at ~`~ least partially adherent to it.~ -The article is then passed through an oven which does ~ not fire or bake the ink onto it, but which melts both the ~ -j ~ fu~ible resin and the ink, causing the resin particles to flow '.~, 30 together to form a smaoth, continuous film over the ink. At :
the ~ame time this heating operatlon causes some diffusion of .~ the lnk lnto the polymerlc film. However, it is important that ;-,,, s ~
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~04~845 the ink docs not mi(Jrate entirely throu-Jh the coatiny film, to the outside surface. In the final product the ink is pro-tected by a continuous layer of polym~ric coating over it, there being a melt-melt type bond between the sclidified resin and ink.
It might b~ expected that the fusion of a particulate resin over a fluid ink would cause undesirable loss of sharp-ness or blurring of the decoration. Nonetheless, I have found that this does not occur and a high degree of sharpness and distinctness is maintained, and thàt in fact the melted state of the ink during polymer fusion (and optionally, during poly-mer laydown) facilitates or improves the bond of the polymer ~ to the ink. In this connection, it is advantageous to apply `~ the ink throuyh a screen which is 200 mesh or finer (U. S.
- Standard) screen. Ordinarily, for applying glass frit type decorations, 165 mesh screens are used. This results in a ¦- relatively thick lay-down of decoration and thus utilizes `i~ a greater amount of material per unit decorated area. Use i of screens of smaller mesh sizes has been found feasible in 20 this invention, by reason of the omission of particulate frit component. This reduces the cost of materials used and also contributes to maintaining sharpness of definition in the product, in that the relatively thin layer of ink tends - -to blur less around the edges than a thicker layer when the polymer particles impinge on the ink and are fused over it.
The application of polymeric coatings on glass articles, including carbonated beverage bottles, is known -~ per se. Such coatings are useful to protect the glass surface -; from surface abrasion which otherwise would inevitably occur 30 in manufacturing, labeling, filling, packing, and/or use.
' ~ The polymeric coating prevents scratching of the underlying gla8s, Which would reduce its strength. Thé coating also Cb/ - 7 -", , ....................................... .

provides a d~gr~e of cushion a~d th~rcby softens impact blows which might otherwlse cause breakage. Moreovcr, when applied to a glass container for pr~ssurized beverages, the coating resists scattering of glass fragments if the container is broken.
In the past, polymeric coatings have be~n applied over decorations which must first be physically united with the glass and bonded in place. That procedure was recently recommended in Ceramic Industry Ma~azlne, September, 1973, pp. 34-37. In that technique the decoration is not melted or semi-liquid during fusion of the polymer, and there is no Y
diffusion of the already hardened decoration into the coating such that a zone or layer of mixed decoration and coating is ~l provided between the decoration and the coating.
; -~ In accordance with this inyention, the coating mater-;~ ial which is applied over the ink is a finely divided resin `~ which is fusible at a temperature at which the ink itself is ,~ semi-liquid. By the term "fusible" as used herein in refer-- ~ ence to the coating, is meant that the coating particles will heat soften so as to flow together or coalesce to form a smooth, continuous film. Preferred for this purpose are the so-called ~ ~ ionomer resins which are ionic copolymers of alpha olefins ~
E``i and alpha, beta-ethylenically unsaturated carboxylic acids, --~3 for example of the type described in patent No. 3,264,272.
' One such ionic copolymer material which is formed from ethylene and methacrylic acid is available commercially from DuPont under their trademark "Surlyn", grade AD 5001. This material in particular has been promoted in the market by reason of it8 clarity, elasticity and degree of adherence to glass.
tl~ 30 It begin8 to fuse ~within the above meaning) at about 204F.
' It iB not a 801vent for the ink, and does not have an adverse chemical affect on the lnk. Other hea~-fusible resins which , ,,,: .
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1041~45 may be used include without limitation polyethylcne, poly-vinyl chloride ,and ethylcne vinyl ac~tate resins, in powder form. Such resins may also be prepared as sprayable emulsions, for gun application, with an emulsifier and a vehicle. In this case the resin particles are dispersed in t~e liquid, but fuse together upon heating, at a temperature at which the ink is semi-liquid. The resin may also be prcpar~d as a screenable liquid, for application on a screen dccorating machine.
The polymeric coatings can be applied to glass articles by a variety of coating techniques. In the coating technique which is presently preferred, dry fine particle resin is applied by the electrostatic dry powder spray process. The resin parti-cles are electrostatically charged oppositely to the glass article (which acts as a ground) and are projected toward the article by a relatively gentle air current. The attraction of opposite charges draws the charged particles to the article, to which they adhere electrostaticall~. For this purpose the article is desirably heated to about 150-360F., which improves the electrical conductivity of the glass. At such temperatures 20 the adhered resin particles will partially but not thoroughly -fuse together. A final higher heating is necessary to com-pletely fuse the particles so that they coalesce to form a smooth, continuous coating which is adherent to the glass surface.
Another useful method for applying the polymeric -coating to glass articles is the fluidized bed technique.
; The resin is maintained as an aereated or fluidlzed mass while ~ the article, heated to a temperature sufficient for at least i ! partial fusion of the resin particles, is moved through the ~ 30 bed so that it becomes coated, then is removed and heated at " ,~
higher temperature to coalesce or ~et the paxticles and form a gmooth continuous coating.
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~041845 ~ Still another type of coating proc~ss which can ~e - used is the electrostatic fluidi7.ed bed process. In that process the resin particles are maintained as a fluidized bed which is electrostatically charged. When the glass article to be co~ted (which is grounded) is passe~ through the bed of '' charged particles, the charge tends to adhere the particles to ~' it. Prior to coating, the glass container is heated for better conductivity to a point at which the ink ~ecomes mel~ed, but the heating is not sufficient to effect complete fusion of , 10 the resin particles on the article, and a final heating at higher temperature is used to set the plastic as a continuous , smooth coating.
,` A further description of the invention and its advan-tages is given in connection with the accompanying drawings, in which: -' Figure 1 is an axial section of a narrow neck glass bottle decorated and polymer coated in accordance with the '~ invention, with the relative thicknesses of the ink and the -polymer layers greatly exaggerated for purposes of illustration.
Figure 2 is an enlarged section showing the zone of interdiffusion of ink and polymer; and ' ' ~ Figure 3 is a flow diagram illustrating in abbreviat- :' -ed form the steps of carrying out a method in accordance with . ~ . .
,~ the invention. ' -The following examples set forth several alternative ~
~ techniques for carrying out the invention, but they should - -s, not be taken as representing the only specific processes for '--~ doing so. '~'--, , Example I This example constitutes the presently preferred 30 method of carrying,out the invention for screen decoration of - ' a conventlonal soda-lime glass pop bottle and the~ applying : a Su~lyncoating. The bottl~s may optionally have first been , ;~
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-1041~45 given a standar~ p~rol~tic metal oxide (TiO2 or SnO2) coating and olcfinic lubricity coating, for exampl~ as described in Patent No. 3,323,889, but this docs not affect the decorating or coating steps. - -The decorating color is a non-reactive ~lot melt ~r thermoplastic ink. It contains a vehicle whicll is a wax or waxlike material having a melting point of about 120-200F., preferably abollt 165F. No volatiles (requiring evaporation for the ink to solidif~) are present. ~n organic or inorganic pigment is mixed with the vehicle. No frit is needed and none is ~cluded. The ink would not be serviceable if not protected by the polymeric overcoat, being deficient in adherence and wash resistance. Such inks can be obtained from Drakenfeld Colors, Hercules Incorporated, Washington, Pa., under their designation Hot Organics, and from other sources. They are usually supplled in the form of a solid block which is melted on a heated screen for application, to establish a soft, melted-butterlike consistency for application through the screen.

The decorating color is screened onto the container -, . : ",-, on a conventional screen decorating machine, fox example, as manufactured by Carl Strutz & Co., Mars, Pa., Applied Color Equipment Co., Sapulpa Okla.; and Star Equipment Co., Washington, .~ Pa. Depending on the particular sllk screening screen printing ~-~,~'A machine used, the ink may be applied at high rates, e.g., 200 bottles per minute. A further description of hot melt screen decorating is given in Patent No. 2,731,912. A 200 mesh to 300 me~h screen is desirable, for minimum ink usage and thickness.
The decoration may include a label, trademark, printed informa- -tion, a design, etc. The squeegeed compositlon will solidify ~ery rapidly after withdrawal of the screen stencil, on a bottle which i~ es8entially at ambient tempe~ature, e.g., 72F.
The æolidified material is a waxy, æomewhat chalky layer which . .

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1041t~45 is not united to or bondcd on the glass and can ~asily be washed or scratch~d off. Nonetheless, no fusion, bonding or firing step is used; in fact, th~ in~ would not form any better bond with the glass if it were fired at high temperature.
If the ink decorated but uncoated articles are exposed to a standard simulated line tester (such as the Amèrican Glass Research ~buse Line Simulator), the ink is so abraded as to be completely unacceptable; similarly, if exposed to a rinse test to simulate the exposure as given by industrial rinsers (such as the Emhart Rinser), the ink fails. The decoration ? iS not serviceable unless and until coated.
A number of different colors o~ ink can be super-imposed in quick succession on the article to produce intrica~e multi-color designs or decorations, using a multiple color decorating machine.
In accordance with the practice of this inventLon, the resin is applied directly over the decoration, without bonding reaction or curing of the ink. Preferably, Surlyn ~ -resin powder is applied by the electrostatic dry powder spray process. The bottles are carried on a continuous line by - chucks whlch grip them at the finish (i.e., the cap or closure end portion~. The bottles are first carried through an oven - :
and preheated to a temperature of about 300-360F. (surface temperature as measured by optical pyrometer). Such heating improves the electrical conductivity of the bottles so that . they can better act as grounds in the resin coating step, which improves the effectiveness of electrostatic coating step. -The resin is sprayed by a conventional dry powder spray appar-atus, for example a DeVilbiss Model No. 348, operated at 60 kv DC output. The 8prayed, charged particles adhexe to the f grounded bottles and partially fuse upon contact.

After removal from the spray apparatus, the adherent ,,~" . . ~ .
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104~845 p~rticulate resin particles are then set b~ hcating to form a smooth continuous ~ilm. This is done by passing the bottles through a continuous oven at a temperature of about 3~0 to 600F., for a period of 3 minutes to 45 seconds. This melts the ink to a semi-liquid state, however the melted ink does not "ball up" or run, but remains in place on the glass as a semi-liquid as the resin particles fuse over it. In the case of Surlyn, the resin also cures or cross-links as it j ~ forms the final hardened coating. The bottles are air cooled to 250, then quenched by a water rinse to about 200F. (this prevents hazing of the plastic coating).
In the final product, the decorating color is not united to the glass as a frit-containing ink would be. It adheres to the glass like a wax, and is further protected on the glass by the polymeric film over it, which is bonded to the glass in regions beyond those covered by the decorating color. The polymer coating adds a depth and brilliance to the decoration which an uncoated bottle does not display. The coating is much thinner than the glass wall, and is suitably . 20 about 5 mils thick, but this is not critical.
If the polymeric coating is carefully removed by stripping or peeling it from the bottle, it can be seen that -~
an area of ink remains on the bottle as a thin film, while some of the ink is pulled off with the polymer. It has . diffused into the polymer, not all the way through the latter, -but partially into it. A slanting or wedgelike slice through the film makes apparent the interdiffusion of the ink and J polymer. This is believed to improve the bond of the polymer through the ink. The ink is not brittle and retains its thermo-30 plastic chaxacter, but the coating protects it so that the . ink i8 not removed or affected by the ordinary use of the bottle, ,~ ~
i Cb/ - 13 -~, E~ple II In this example th~ polymeric coating is applied ~, , ', to a screen dccorated bottle by the electrostatic fluidized bed process.

The scr~en decoration is applied as in Example I.

After the decorating step, the bot~]~s are preheated to about 150-360E~. (surface t~mperature as measured by optical pyro-: ., meter).
The bottles are then carried through an electro-statically charged fluidized bed of the coating resin particles.
The charging apparatus is operated at 30,000 to 90,000 volts DC. After removal from the bed, the ad~erent particulate resin particles are,then set by heating to form a smooth continuous film. The in~ is melted and the adherent particulate material is fused over it by passing the bottles through an oven at a peak temperature of 390F., over a three minute period. The ', coating is complete after cooling.
If the plastic coating is carefully cut and peeled "', away from the bottle, again it is found that the decorating color is interdiffused with the polymeric coating. Application of too thick a decoration can cause difusion through the coat-ing, which is often detrimental to appearance.
Example III It should be understood that the invention is not limited to single color decorations. Where two or more ' colors are to be applied, they are applied sequentially as hot melts, and set up rapidly. In the subsequent resin fusion -step, all of the colors remelt, but they do not mix undesirably --or blur during the fusion.
~ t ~ ~ Example IV ~he coating provides maximum protection for the ~, ,~ - ..
~, ' article if it covers substantially the entire surface of the ', , 30 , artiCls excepting the fin~sh portion. However, where protection ~or the article is not a prime consideration, use of the ink , ' plu~ coating on even limited areas can provide a full service-, ~ , .
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~0~1845 ability of the ink, and a degree of protcction for the ylass surface, with minimal cost i.ncrease, For example, the coating may be applied only to a limited area, so as just to cover the decoration and a small adjaccnt glass surface area. For this purpose, it is advantageous to use a polymeric coating composi- ..
tion which itself is screenable, so that it can be screened or over the coating, preferably on the same decorating machine as that used to apply the ink. This has the advantage of elim-inating need for separate coating-applying spray or fluidized bed, or the like. The coating is heated until fused over the ink. :
While the foregoing examples illustrate various details ~:
of embodiments of the invention in order that others may prac-: ' tice the same, it will be understood that the invention is -not limited to utilization of these specific techniques set ~' forth therein, but may be carried out in accordance with other `~ techniques within the scope of the following claims. -.' , : ' ~ .

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Claims (20)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A method for decorating a previously formed article of glassware, comprising, applying to a glass surface area of the previously formed article a thermoplastic ink which is solid at room tempera-ture but which becomes semi-liquid upon heating, said ink being screened onto the article as a semi-liquid but solidifying rapidly by cooling on the article, coating a layer of finely divided particulate polymeric coating material onto the article and over the ink thereon, said coating material being a resin which is heat fusible at a tempera-ture above the temperature at which the ink becomes semi-liquid, heating the article with the ink decoration and resin layer thereon to a temperature at which said ink again becomes semi-liquid, and said resin fuses to form a smooth continuous film over said article and melt-unites to said ink decoration, and cooling the coated, decorated article, thereby provid-ing a final decorated article of glassware wherein said film pro-vides a permanent outer coating which covers and protects said decoration on said glass surface area, the decoration being in solid but thermoplastic remeltable condition under the said outer coating.

2. The method of Claim 1 wherein said coating material comprises discrete solid resin particles which are fusible only at a temperature higher than the temperature at which said ink is applied.

3. The method of Claim 1 wherein said ink comprises a thermoplastic vehicle and a pigment carried by said vehicle.

4. The method of Claim 1 wherein said ink comprises a waxy vehicle which melts in the range of 120°-200° F., and a pigment, but contains no glass frit.

5. The method of Claim 4 wherein said pigment is an organic dye.

6. The method of Claim 1 wherein said coating is carried out by the electrostatic fluidized bed process, the article with the ink on it in semi-liquid state being coated as it passes in proximity to a fluidized bed of particles of said coating material which particles are electrostatically charged oppositely from said article.

7. The method of Claim 1 wherein said coating is carried out by an electrostatic dry powder spray process.

8. The method of Claim 1 wherein said ink displays abrasion and alkali resistance which, in the absence of the film overlying it, would be inadequate to withstand the abrasion and alkali attack incidental to ordinary use of the article.

9. The method of Claim 1 wherein a multiplicity of dif-ferently colored inks are applied to said article sequentially, at least one of such inks being applied over an earlier applied ink, all of said inks having thermoplastic characteristics.

10. The method of Claim 1 wherein said coating material is an ionic copolymer of an alpha olefin and an alpha, beta-ethylenically unsaturated carboxylic acid.

11. The method of Claim 1 wherein said coating material is fused at a temperature between 350° and 500° F.

12. The method of Claim 1 wherein said ink becomes semi-liquid at a temperature between about 120° and 200° F.

13. The method of Claim 1 wherein said ink is applied by the silk screen process and is permitted to solidify on said article, said article is reheated, prior to application of said coating, to a temperature at which said ink is semi-liquid, the particles of said coating are charged electrostati-cally in the application thereof, and said article is thereafter heated to a higher tempera-ture, with the coating particles adherent thereon, to fuse said coating over the semi-liquid ink.

14. The method of Claim 1 wherein said coating and ink are interdiffused while both are semi-liquid, but said ink is not diffused to an outer surface of the coating.

15. The method of Claim 1 wherein said ink is applied by hot melt screening through a screen which is 200 mesh or smaller.

16. The method of Claim 1 wherein said resin is coated onto said article by silk screening over said ink.

17. A permanently decorated, polymer coated hollow glass container, said container having a surface area thereof with at least one screen print decoration on it, said decoration being a thermoplastic hot melt ink which is solid at room temperature and which becomes semi-liquid upon heating, a polymer film coating on said container which overlies said decoration and which covers regions of said container ad-jacent to the said surface area on which the decoration is applied, said decoration having an adherence to the glass which is sufficient, in the absence of such polymer coating, to permit such coating to be applied over the decoration without smearing the latter, the adherence of the decoration to the glass being insufficient, in the absence of said polymer coating, to resist removal by such abrasion and alkali attack as is incidental to ordinary use of the container, said polymer coating being a smooth, continuous film of a heat fusible resin which is anchored to and supported by the glass surface regions with which it is in contact, the said decoration being meltable at a temperature below that at which the said polymer coating is fusable, the said decoration being melt-bonded with and diffused into the polymer coating which overlies it such that the decora-tion would be at least partially removed with the polymer coating if the latter were peeled away from the container, the film coating over the surface area of said con-tainer which is covered by said decoration being adhered to the glass surface through its bond to the said decoration, said decoration being captured by and between the film coating and the glass surface, said film coating providing a permanent outer coating which covers and protects the decoration, the decoration being in solid but thermoplastic remeltable condition under the said film coating.

18. The container of Claim 17 wherein said decoration includes a waxy thermoplastic vehicle and a pigment, said decoration containing no glass frit ingredient.

19. The container of Claim 17 wherein said decoration melts at a temperature between 120 and 200° F.

20. The container of Claim 17 wherein said decoration is diffused into said film, but not to the outer surface thereof.