US2337348A - Printed packaging material and method of making same - Google Patents

Description

Dec. 21, 1943. K. E. PRINDLE PRINTED PACKAGING MATERIAL AND METHOD OF MAKING SAME Filed Feb. 2, 1940 INVENT OR. /(A /?L 5 PR/AwLE 67%;;

ATTORNEY.

Patented Dec. 21, 1943 PRINTED PACKAGING MATERIAL AND METHOD OF MAKING SAME Karl E. Prindle, Shaker Heights, Ohio, assignor to The Dobeckmun Company, Cleveland, Ohio, a

corporation of Ohio Application February 2, 1940, Serial No. 316,895

8 Claims. (Cl. 117-15) This invention relates to moistureproof materials. More specifically, it relates to printed moistureproof materials suitable for wrapping and packaging purposes and the method of making the same.

Transparent moistureproof materials are today extensively used for the wrapping and packaging of articles which ar desired to be maintained in their original state or condition. In order to enhance the appearance of the package and also for the purpose of identifying the contents of the package, the wrapping tissues in many cases are now being attractively printed in one or more opaqu colors in accordance with the desired indicia. This is particularly true when the transparent moistureproof material is formed into a bag and the latter is used in the packaging of the articles.

When the wrappingorpackagingmaterial,either in the form of a wrapping tissue or a bag, is formed of transparent moistureproof regenerated cellulose sheeting, such as is sold under the trade name of Cellophane, I- have found that the printing operation deleteriously affects the properties of said moistureproof regenerated cellulose. Specifically, I have found that the printing operation materially reduces the original moistureproofness of the material, particularly at those areas or surfaces to which the printing ink has been applied. As a consequence, when the printed transparent moistureproof regenerated cellulose is used for wrapping or packaging purposes, either as-a tissue (sheet) or in the form of a bag, the contents of the package are not maintained in the original state Or condition for the period of time between the packaging of the contents and that when it reaches the ultimate consumer. This is especially true when the contents of the package are products or articles desired to be maintained in their original dry condition.

In addition to the foregoing defect, the areas or surfaces of the wrapping tissue or bag formed thereof on which th opaque indicia has been applied are characterized by an undesirable dull, non-lustrous or mat appearance.

An object of this invention is to provide a printed moisturepro'of wrapping or packaging material, either in the form of a tissue or ba characterized in that the printed areas or surfaces are at least as moistureproof as the original transparent moistureproof material.

Another object of this invention is .to provide a printed moistureproof wrapping or packaging material wherein at least the printed areas are treated to render the moistureproofness thereof at least equal to that of the original moistureproof material.

Another object of this invention i to provide 'a method of preparing a printed transparent moistureproof material in which the printed areas have a moistureproofness at least equal to the original non-printed transparent moistureproof material.

Other objects will appear from the following description, appended claims, and accompanying drawing forming a part of this specification and wherein:

Figure 1 is a diagrammatic view illustrating the method constituting one phase of this invention;

Figure 2 is a plan view of an illustrative bag blank produced in accordance with this invention;

Figure 3 is an enlarged section taken on the line 3-3 of Figure 2;

Figure 4 is a rear view of a bag formed from the blank shown in Figure 2 with the indicia omitted; and

Figure 5 is a side view of the bag shown in Figure 4.

In accordance with on embodiment of this invention, transparent moistureproof regenerated cellulose sheeting is printed in one or more opaque colors by either the gravure or anilin processes in accordance with the desired indicia. It is to be understood that the term indicia is used herein to define numbers, letters, characters, illustrations, designs, etc., either alone or any combination thereof produced by the printing operation. The product at this stage of the process, as shown by exhaustive tests performed by me, is characterized in that the surfaces or areas bearing the printed indicia are of a moistureproofness considerably less than the original moistureproofness of the areas or surfaces bearing the indicia. In other words, the printing operation deleteriously affects and specifically materially reduces the moistureproofness of those areas of the original material on which the printed indicia is applied. Also, the printed indicia -is characterized by a dull, mat appearance.

In accordance with the instant invention, the printed material is treated in a manner, more particularly hereafter described, to increase the moistureproofness of the printed surfaces or areas to a moistureproofnessat least equal to that possessed and exhibited by the original unprinted transparent moistureproof material. The treatment just referred to also imparts to the product, and

particularly the printed areas thereof, a highly brilliant sheen or luster.

The treatment of the printed material, in order to increase the moistureproofness of the printed areas or surfaces and impart thereto a highly lustrous sheen, is broadly effected by applying to at least said printed areas or surfaces 8. very thin coating formed of a transparent moistureproofing composition. The moistureproofing composition, more fully hereinafter described, also produces a highly lustrous and brilliant coating which possesses the necessary surface characteristics as will permit the product to be handled either manually or in automatic machinery. In other words, the coating is non-tacky and possesses the desirable surface (slip) characteristics. In addition, the composition, and hence the coating resulting therefrom, is adhesive to and firmly bonds to the moistureproof surface of the nonprinted areas of the material, if applied thereto, as well as to the printed areas thereof. Since the product must be handled and bent, the coating is also made sufficiently flexible and pliable to resist breaking during handling, flexing, etc.

The coating composition resulting in the coating contemplated by this invention and possessing the characteristics aforementioned comprises a film-forming substance and a moistureproofing agent, with or without a resin, and preferably also a plasticizer, dissolved in a solvent or solvent mixture, the solvent or solvent mixture being of a nature and type as will not deleteriously affect'the ink of the printed areas or the original moistureproof coating of the unprinted surface, if applied thereto.

As the film-forming ingredient, I prefer the polymerized long chain compounds, such as derivatives of rubber or synthetic rubber, for example, rubber halides or hydrohalides, and speciflcally rubber hydrochloride (Pliofilm) and depolymerized and cyclized rubber (Pliolite). The rubber hydrochloride (Pliofilm) may be of the type which is saturated with hydrogen chloride or partially saturated hubber hydrochloride, such as rubber hydrochloride containing 29 %-30.5% of chlorine. The polymerized and cyclized rubber (Pliolite) may be obtained by reacting rubber or a rubber solution with a halide salt or halogenated acid of a metal having a plurality of secondary valances, such as tin tetrachloride or tetrabromide, antimony pentachloride, titanium tetrachloride, boron trichloride, ferric chloride, antimony trichloride, boron trifluoride, fluoboric acid, chlorostannic or chlorostannous acid and the like, as described by Thies and Clifford in the Joumal of Industrial and Engineering Chemistryfvol. 26, page 123 (1934).

Polymerized vinyl compounds or conjointly polymerized vinyl chlorides and vinyl acetates may be used as the film-forming ingredient.

As the. moistureproofing ingredient, I prefer paraffin, and specially paraflin having a melting point of 60 C.

As the plast izer, I prefer to use diamy phthalate, buty stearate, or diamyl phthalate, though, of course, other plasticizers may be used.

When the composition is of the type which includesa resin, I prefer to use gum .damar (dewaxed) and East India gum, though, of course, other gums or resins, either natural or synthetic, may be used.

The solvent of the composition, as previously mentioned, is one which does not deleteriously aflect the ink of the printed indicia or the moistureproof coating of the original material. The

solvent or solvent mixture is one in which all the ingredients constituting the coating are individ- 35% by weight of the coating composition.

' In addition to the foregoing compositions, sat

The following table sets forth approximately the range of proportions of the solid ingredients constituting the composition:

Per cent by weight of solid ingredients Film-forming ingredient 30 to '70 Wax Up to 10 Plasticizer Oto 25 Resin Mo 20 Hereafter are set forth several specific illustrative examples which have given satisfactory results when applied to moistureproof regenerated cellulose film or sheeting which has been printed by the gravure or anilin processes:

Example 1 Per cent by weight Chlorinated rubber c. p 21.0 Damar 4.5 Diamyl phthalate 4.5 Paraflin 60 C 3.6 Benzol 36.4 Ethyl acetate 30.0

Example 2 Per cent by weight Chlorinated rubber 1000 c. p 10.0 East India gum 5.0 Diamyl phthalate 4.0 Paraffin 60 C 1.5 Toluol 79.5

Example 3 Per cent by weight Chlorinated rubber 125 c. p 21.0 Diamyl phthalate 6.0 Paraflin 60 C 1.2 Isopropyl acetate 25.0 Toluol 46.8

Example 4 Per cent by weight Pliolite resin 25.0 Paraffin 55-60 C s 1.5 Butyl stearate 4.0 Toluol 69.5

Example 5 Per cent by weight Pliolite resin 19.0

Paraflin 50-55 C 3.5 I'oluol 40.0 High-test gasoline 36.5

isfactory results have also been obtained when the composition is of the moistureproof lacquer types. As an illustrative example of such a mole.

tureproof lacquer .which has given satisfactory results, the following is set forth:

Example 6 v Per cent by weight Nitrocellulose 15-20 sec 10.0 Damar resin 6.5 Tricresyl phosphate 3.5 Paraffin 55-60 C 1.0 Ethyl acetate 40.0 Butyl acetate 3.0 Toluol 36.0

As hereinbefore mentioned, the thickness of the coating which is applied to the printed surfaces is exceedingly small and should not exceed .0001 inch. Satisfactory results have been secured when the thickness of the coating is approximately from .00002 to .00005 inch.

In carrying out the invention, the moistureproof material to be processed is printed by either the anilin or gravure process with inks in which the color thereof is obtained by pigments incorporated therein. In each of these processes the indicia of different colors is separately printed. After the last color has been printed, the protective coating composition is applied by a printing operation over the entire surface, except those portions or areas which are to be used in the formation of seams. The protective coating is then dried by passing the coated printed material through warm air. The last traces of solvents are driven off by means of gas burners, after which the dry coated material is chilled and finally wound up. The resulting product is then formed into a bag of suitable construction.

It is to be understood that the process may be applied to sheets or films of moistureproof material which are to be used for wrapping purposes or which are to be formed into bags.

In order to more clearly explain the invention, reference will now be had to the accompanying drawing wherein like reference numerals designate like parts.

Referring now ot Figure 1, the reference numeral designates a roll of transparent moistureproof material, such as moistureproof regenerated cellulose sheeting, which is to be printed and treated in accordance with this invention and thereafter converted into bags. The moistureproof regenerated cellulose sheeting is unwound and withdrawn from the roll 5 in any suitable manner and, after passing over a guide roll 6, is caused to pass onto a supporting cylinder I of the printing mechanism, generally designated by the reference numeral 8.

In the embodiment illustrated, three different colors are applied, the first color being applied by a printing roller l0, the second color by a printing roller II and the third color by a printing roller l2. It is, of course, understood that the printing surface of each of the printing rollers is of a form as will produce the desired indicia of the respective color.

Each of the printing rollers II], II and I2 is supplied with the appropriate ink by a transfer roller [5 which cooperates with a fountain roller l6 disposed in an ink fountain I1.

After the moistureproof regenerated cellulose has been printed with the three colors, the moistureproofing composition is then applied to the entire surface of the material. When the material is to be formed into bags, the moistureproofing composition is not applied to those portions which are to be utilized in the seams. The mechanism for this application of the protective composition is of the same type and construction as that utilized in the application of the different colors and is generally designated by the reference numeral 20. This mechanism 20 comprises a printing roller 2|, a transfer roller 22, a fountain roller 23, and an ink fountain 24.

After the protective coating has been applied, the material is fed through a drier (chamber) '30 maintained at a temperature to evaporate the solvent of the protective coating composition. In order to remove the traces of residual solvent, the coated printed film, after leaving the drier 30, is passed over gas burners 35, 36 and 31 disposed at predetermined positions along the path of travel of the coated film. It is to be noted that the flame of each of the gas burners applies heat to the film from the surface thereof which has not been printed and provided with the protective coating. If necessary, the material may be chilled, as, for example, by means of a fan 40, directing cool air onto the coated surface of the film. The film is then passed between tension or pull rolls 42 and then wound up onto a roll 43.

It is to be noted that, either during the evaporation of the solvent or residual traces thereof. the coated printed film is subjected to a temperature at least equal to the melting point of the wax in the composition. This is for the purpose of making the coating glass-clear and inhibiting blush in the coating.

The various moving parts of the apparatus are designed to operate in synchronism and timed relationship so that the various operations may be performed and the final coated printed film in a dry state may be wound onto the roll 43.

The printing mechanism 20 for applying the coating composition is preferably so disposed with respect to the color printing rollers I0, II and i2 that the colored indicia is in a substantially dry state at the time the coating composition is applied thereto.

In the preferred embodiment of the invention, the coated printed material produced as previously described is fed through an automatic bag machine whereby the film is cut into a bag blank which is converted into a bag. It is to be understood that a bag of any form and shape may be produced. For purposes of illustrating the preferred embodiment of the invention, the latter will be further described in connection with the production of a fiat bag.

Referring now to Figures 2 and 3, the reference numeral 50 generally designates a bag blank severed from the roll material previously mentioned. The blank 50 bears on one face thereof printed indicia generally designated by the reference numeral 5|. For illustrative purposes only, and without any intention of restricting the nature of the printed indicia, each of the printed indicia 5| is composed of a three color design which, in the form shown, consists of three differently colored parallel stripes. The reference numeral 52 designates a red stripe which is printed by the printing roller ID. The reference numeral 53 designates a white stripe which is printed by the printing roller II. The reference numeral 54 designates a blue stripe which is printed by the printing roller l2.

The thin, transparent, moistureproof coating applied by the printing roller 2| is generally designated by the reference numeral 55. It is to be noted that the coating 55 is applied directly to and extends over. the entire printed indicia and also over the original moistureproof material which does not bear any printed indicia. As shown in Figures 2 and 3, the transparent coating 55 is so applied and disposed on the blank that at least the longitudinal marginal portions 56, and preferably also the transverse marginal portions 51, are not coated with the moistureprooflng composition. In other words, the blank 50 is provided with a margin adjacent its sides and top and bottom which are free of the protective coating. The portions of the blank which are not coated with the protective coating constitute the piles of the sealed joint in the ultimate bag.

In order to produce the bag from the blanks shown in Figures 2 and 3, the blank shown in Figure 2 is folded rearwardly on the lines designated by the reference numerals 60 and GI. It will be noted that the uncoated longitudinal marginal portions 56 will overlap to forma longitudinal joint 63 which is effected through the application of any suitable adhesive or solvent. After the blank has been folded as just described, the bottom portion is then backwardly doublefolded to produce the sealed joint generally designated by the reference numeral 65. It is to be understood that the sealed joint is effected through the application of a suitable solvent or adhesive. In the finishedbag the printed indicia willappear on the front panel thereof and will possess all the properties and characteristics hereinbefore described. It is to be noted that the unprinted surface is intended to be in inbefore referred to is of the type and nature which consists of a sheet or film of transparent regenerated cellulose coated on both sides thereof with a transparent moistureprooflng composition consisting of a cellulose derivative and a wax, with or without a resin, and, optionally, a plasticizer. The regenerated cellulose may be obtained by the viscose or the cuprammonium cellulose processes. It is to be understood that, though the preferred material is transparent moistureproof regenerated cellulose, other transparent moistureproof materials may be used. As illustrative examples of other transparent moistureproof materials which may be used may be mentioned moistureproofed cellulosic sheets or films, such as may be obtained by coagulation or precipitation from aqueous cellulosic dispersions, as, for example, glycol cellulose,- cellulose glycolic acid or other lowly etherified cellulose glycolic acid derivatives where there is only one substituent group for several glucose units of the cellulose, cellulose esters, such as cellulose nitrate, cellulose acetate or mixed esters of cellulose, cellulose ethers, mixed cellulose ethers, mixed ether-esters of cellulose, gelatin, casein, etc.

It is further to be understood that the invention is not restricted to transparent moistureproof material since it is equally applicable to any moistureproof material, whether transparent, opaque or translucent, wherein the moistureproofness is reduced because of printing indicia thereon.

The term "solvent as used in the claims is intended to cover a single solvent or a solvent mixture.

Though the invention has been described in connection with printing on the exposed surface, it is to be understood that the principles of this invention are equally applicable where the printing is on the reverse or inner side. When the printing is on the inner orreverse side, the latter is treated with the selected moistureprooflng composition as hereinbefore described.

I claim:

1. A continuous method of forming transparent moistureproof wrapping material which comprises printing in multi-colors on predetermined areas of a transparent flexible sheet of regenerated cellulose, the latter being provided with a transparent moistureproof surface coating containing a cellulose derivative and a wax, said surface coating being deleteriously affected by the printing operation, directly printing a thin transparent coating over at least the printed indicia with a transparent moistureproofing composition containing a solvent which does not deleteriously afiect said printed indicia or the original moistureproof material, and evaporating the solvent at an elevated temperature to produce a thin lustrous transparent moistureproof coating not over .0001 of an inch thick and adhesively bonded to the printed indicia.

2. A continuous method of forming transparent moistureproof bag material which comprises printing in multi-colors on predetermined areas of a transparent flexible sheet of regenerated cellulose and in spaced relationship to correspond with bag blanks into which said sheet of regenerated cellulose is to be divided, said sheet of regenerated cellulose being provided with a transparent moistureproof surface coating containing a cellulose derivative and a wax, said surface coating being deleteriously affected by the printing operation, directly printing a thin transparent coating over at least the printed indicia corresponding to a single bag blank with a transparent moistureproofing composition containing a solvent which does not deleteriously affect said printed indicia orthe original moistureproof material, and evaporating the solvent at an elevated temperature to produce a thin lustrous transparent moistureproof coating not over .0001 of an inch thick and adhesively bonded to the printed indicia.

3. A continuous method of forming transparent moistureproof wrapping material which comprises printing in multi-colors on predetermined areas of a transparent flexible sheet of regenerated cellulose, the latter being provided with a transparent moistureproof surface coating containing a cellulose derivative and a wax, said surface coating being deleteriously affected by the printing operation, directly printing a thin transparent coating over at least the printed indicia with atransparent moistureprooflng composition containing a solvent which does not deleteriously affect said printed indicia or the original moistureproof material, and evaporating the solvent at an elevated temperature to produce a thin lustrous transparent moistureproof coating, said coating being adhesively bonded to the printed indicia and of a thickness not in excess of .0001 inch and comprising a moistureproofing agent and a rubber derivative selected from the class which consists of rubber halides and rubber hydrohalides.

4. A continuous method of forming transparent moistureproof bag material which comprises printing in multi-colors on predetermined areas of a transparent flexible sheet of regenerated cellulose and in spaced relationship to correspond with bag blanks into which said sheet of regenerated cellulose is to be divided, said sheet of regenerated cellulose being provided with a transparent moistureproof surface coating containing a cellulose derivative and a wax, said surface coating being deleteriously affected by the printing operation, directly printing a thin transparent coating over at least the printed indicia correprlsing a moistureproofing agent and a rubber derivative selected from the class which consists of rubber halides and rubber hydrohalides.

5. An article oi manufacture resulting from spending to a single bag blank with a transparent 5 the process defined in claim 1.

moistureprocfing composition containing a solvent which does not deleteriously aflect said printed indicia or the original moistureprooi' material, and evaporating the solvent at an elevated temperature to produce a thin lustrous transparent molstureproof coating, said coating being adhesively bonded to the printed indicia and of a thickness not in excess of .0001 inch and com- 6. An article of manufacture resulting from the process defined in claim 3.

7. A bag formed from the bag blank resulting from the process defined in claim 2.

8. A bag formed from the bag blank resulting from the process defined in claim 4.

KARL E. PRINDLE.

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