US2007630A - Decalcomania paper - Google Patents

Description

July 9 H ATW E DECALGOMANIA PAPER Filed Feb. 11, 1933 ATTORNEY] Patented July 9, 1935 PATENT OFFICE DECALCOMANIA PAPER Henry Atwater, Bryn McLaurin-Jones 00.,

Mawr, Pa... assignor to Brookfleld, Mass, a corporation of Massachusetts Application February 11, 1933, Serial No. 656,312

8 Claims.

This invention relates to decalcomania papers. Such a paper as usually made heretofore comprises a relatively substantial sheet of backing paper coated on one side with an adhesive which is adapted to take printing ink, Frequently the adhesive coating is not entirely homogeneous but the layer next to the paper is more readily softened than is the outer layer or layers so that the latter can more easily be separated from the 10 backing sheet. In some cases also the adhesive layer includes other constituents in order to produce special results. For example, it may contain metal powders, pigments, or the like, in order to make this coating substantially opaque. Sometimes also the adhesive coatingcarries a thin film of some water insoluble material such as lacquer, cellulose nitrate, or the like, on which the print- .ing operation will be performed.

In printing the decalcomania design on such papers it usually is necessary to repeat the print- ,ing operation one or more times in order to apply the necessary thickness of ink. As a general rule the ink only is transferred to the work and it is therefore necessary that this ink shall be,

present in a fairly thick body. For the purpose of reducing the number of these printing operations so far as possible, it is customary to apply the ink heavily in each printing operation, and due to this fact there is a very serious tendency for the ink to offset or, in other words, to stick to the surface of the next adjacent sheet as the sheets are stacked up in coming from the printing press. While it has been attempted to minimize this difficulty by using driers in thesurface of the adhesive coating of the decalcomania paper, and by various other expedients, nevertheless this is still a serious practical difliculty, and it isalmost the universal custom toplace asheet of waxed paper or of paper treated in some other suitable sheets in connection with the stacking operation, these so-called slip sheets or interleaved sheets remaining in place until after the ink has dried. This operation is commonly called slip sheeting, and it involves the expenditure of a substantial amount of time, labor and material,

all of which tend to increase the manufacturing expense of the printed gi'ecalcomanias.v

The present invention deals with these considpapers" and the methods of making them that the I necessity for slip sheeting will be avoided.

The nature of the invention'will be readily understood from the following description when 65 read in connection with the accompanying drawmanner between each adjacent'pair' of printed.

erations. It aims so to, improve'decalcomania' ing, and the novel features will be particularly pointed out in theappended claims.

In the drawing,

Figure 1 is a perspective view, illustrating one embodiment of the invention; and

Figure 2 is a vertical, transverse, sectional-view through the sheets illustrated in Fig. 1.

' The decalcomania sheets shown in the drawing each includes a backing sheet 2 usually consisting of a fairly heavy sheet of paper containing relatively little sizing so that it readily absorbs water. One face of each sheet carries a coating 3, the surface of which is adapted to take decalcomania printing. This coating may be of any suitable nature, such, for example, as any of those -above described. It should, however, be bonded to the backing sheet by a union which can readily be dissolved in water or easily broken so that the backing sheet can easily be stripped from the coating. In a typical case the inner layer of adhesive consists of a mixture of starch and dxtrine. So far as these features are concerned the prior practice may be followed since the present invention is not especially concerned with them.

As above stated, this invention deals more especially with the problem of preventing the offsetting of the printing ink in connection with the printing process, or, in other words, with the transfer of the ink from the printed face of one sheet to the back of the next adjacent sheet. The invention contemplates that this object can be realized by so roughening'the rear face of the backing sheet 2, or, in other words, that face opposite to the adhesively coated face 3, that when the sheets are stacked, no substantial area of one sheet will come in contact with that of the next adjacent sheet. This result may be produced in several ways.

The preferred method consists'in embossing the rear surface of the backing sheet with some design which will producea multiplicity of raised portions'distributed substantially uniformly over the surface of the sheet, said portions being separated by intervening lower areas. Such projections or raised portions are indicated at 4 on the lower sheet in Figs. 1 and 2. This embossing operation can be performed by running the sheets of paper, either before or after the gumming operation, between steel rolls, one of which is engraved while the other is smooth. The engraved roll engages the rear face of the backing sheet 2 and produces the roughened efiect while the smooth faced roll runs on the front face of the sheet so that this face willbe left smooth to receive the printing. Any design having raised portions which will hold an adjacent sheet away from the main body of the backing sheet will serve this purpose.

A further difliculty involved in the offsetting action above described is the fact that some times the fiber from the back of the sheet sticks to the inked surface. This difliculty can be minimized to a substantial degree by calendering the rear surface of the sheet before it is embossed. This tendency, however, should be borne in mind in selecting the design used in performing the embossing operation, care being taken to have-the projections or raised portions located sufficiently close to each other to give adequate support and to provide the necessary area. Designs similar to those used in imitating artificial leathers, coarse fabrics, and the like, have been used with satisfactory results. The upper sheet shown in Figs. 1 and 2 is like the lower sheet except that the raised portions 5 are not as well defined as are the projections 4 and are not regular in size or spacing.

This method of manufacture can be performed at an entirely reasonable expense. It produces an article in which the points of contact of the printed face of a sheet with the back of the next adjacent sheet are so scattered and their total area is so small that no substantial transfer of ink from the printed face of the sheet occurs. It does not materially reduce the water absorbing properties of the backing sheet. I have demonstrated by actual use that this invention makes it possible to do away with the slip sheeting heretofore required, while at the same time permitting the application of ink in as large quantities as has been customary even when the practice of slip sheeting has been followed.

In making decalcomania-paper by either of the methods above described, it is preferable to use a dryer in the surface coating of gum to which the printing ink will adhere, as has been proposed heretofore, so as to speed up the drying of the ink, so far as possible. The drying operation also is facilitated by the fact that the greater part of the inked surface is spaced from the back of the next adjacent sheet.

While I have herein shown and described a preferred embodiment of my invention, it will be understood that the invention may be embodied in other forms without departing from the spirit or scope thereof.

Having thus described my invention, what I desire to claim as new is: v 4

l. A decalcomania paper comprising a backing sheet of water absorbent paper carrying a coating on one face thereof adapted to take decalcomania printing and bonded tosaid sheet bya water soluble adhesive, the latter face of said backing sheet being smooth and the opposite face being provided with a multiplicity of raised elements, composed essentially of cellulosic material, distributed over the surface thereof and serving to hold the inked surface of a superposed sheet away from the main body of said backing sheet.

2. That improvement in methods of making decalcomania paper which consists in applying to the surface of a backing sheet of paper a coating readily separable from the backing sheet and adapted to take decalcomania printing, and at some stage in the process of manufacture producing, in the material of the sheet, a multiplicity of raised portions on the surface of said backingsheet opposite to said coating while leaving the coated side of the sheet smooth, said raised coated surface, said backing sheet and said rough-' ened surface having high water absorbing properties.

4. A decalcomania paper comprising a backing sheet having a smooth face on one side and carrying on said side a coating adapted to take decalcomania printing, the opposite side of said sheet having the material thereof roughened to present definite projecting areas spaced apart by intervening lower areas.

5. A decalcomania paper comprising'a backing sheet of water absorbent paper, having a smooth face carrying a coating adapted to take decalcomania printing, said coating being bonded to said sheet by a water soluble adhesive, the opposite side of said sheet having a surface characterized by the presence of a multiplicity of raised portions, integral with said sheet, projecting substantially beyond adjacent areas of said surface.

6. A decalcomania paper comprising a backing sheet carrying on one side thereof a coating adapted to take decalcomania printing, the lat ter side of said sheet being smooth and the opposite surface of said sheet being embossed to provide a multiplicity of raised portions distributed over the surface thereof and separated by intervening lower areas.

7. That improvement in methods of making decalcomania paper which consists in applying to the surface of a backing sheet of paper a coating readily separable from the backing sheet and adapted to take decalcomania printing, at some stage in the process of manufacture embossing the surface only of said backing sheet opposite to said coating, and producing by said embossing operation raised portions in said sheet of sufilcient height and so distributed as to hold the inked surface of a superposed sheet away from the main body of the backing sheet.

8. A decalcomania paper comprising a backing sheet of water absorbent paper, having a smooth face carrying a coating adapted to take decalcomania printing, said coating being bonded to said sheet by a water soluble adhesive, the opposite side of said sheet having a surface characterized by the presence of a multiplicity of projections having relatively small top areas and extending from said surface, said projections having high water absorbing properties.

- HENRY ATWATER.

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