US3420405A

US3420405A - Package for copy sheets

Info

Publication number: US3420405A
Application number: US570195A
Authority: US
Inventors: William P Taylor
Original assignee: US Plywood Champion Papers Inc
Current assignee: US Plywood Champion Papers Inc
Priority date: 1966-08-04
Filing date: 1966-08-04
Publication date: 1969-01-07
Anticipated expiration: 1986-01-07

Description

Jan. 7, 1969 w. P. TAYLOR 3,420,405

PACKAGE FoR COPY SHEETS Filed Aug. 4, 1966 I. In, .m

III! I I I III III/I I II 11] II II]! II [III/II I 1 4- 3/ I I I I I I I I I I I 9 I A I United States Patent 3,420,405 PACKAGE FOR COPY SHEETS William P. Taylor, Hamilton, Ohio, assignor to U.S. Plywood-Champion Papers Inc., a corporation of New York Filed Aug. 4, 1966, Ser. No. 570,195 US. Cl. 22125 Int. Cl. B65h 3/58 7 Claims ABSTRACT OF THE DISCLOSURE This invention relates to making copies of images and more particularly the intention relates to a package of copy sheets which can be readily extracted from the package for immediate use in the copying process.

The copy sheets which are packaged in accordance with the present invention are of the type described in my copending applications Ser. No. 498,821 filed Oct. 20, 1965, and Ser. No. 570,294 filed Aug. 4, 1966. As described in those applications, each copy sheet comprises an impermeable base sheet which is preferably transparent and a very thin porous film on one surface of the base sheet. When used throughout this description and claims, the porous film on the copy sheet embraces discontinuous substances capable of sorbing a sensitizing liquid as well as gels which are swollen by the sensitizing liquid. The porous film is moistened with sensitizing liquid having the capacity to solvate the porous film and thus change its optical properties under certain conditions of exposure to printed paper. The sensitizing liquid, for certain film systems, is preferably constituted by water and a solvent for the material of which the film is formed while for other film systems, a plain water sensitizer is used.

The copy sheets as thus formed are ready for immediate copying. When placed against a printed cellulosic paper, the sensitizing liquid vaporizes and the vapor selectively diffuses or migrates into the printed paper to a greater extent in its non-image areas than in its image areas, thus creating a disparate amount of moisture retained in the corresponding areas of the copy sheet overlying the image areas of the printed paper. The different conditions thus created in the areas overlying the image and non-image areas of the printed sheet cause such changes in the optical properties of the copy sheet as to bring out an image. More succinctly stated, when the copy sheet is held against the paper for a few seconds, a discernible mirror image will appear on the surface of the copy sheet which can be read through the reverse side of the copy sheet if it is transparent.

The process involves the sensitizing of the-copy sheets with rather minute quantities of liquid. The film which retains the moisture is very thin and care must be exercised to avoid its being either too wet or too dry. If too dry, obviously the process will work imperfectly because of the insufficient moisture to effect the change in optical properties of the film. If too wet, it will cockle the printed paper to which it is applied, the process will take too much time to be feasible, and it may not even work at all if the copy sheet is so wet that the proper conditions for vapor diffusion are not present.

It is possible to moisten the sheets at the time of use, that is to say, immediately prior to their application to the printed sheet, but this operation requires carrying moistening equipment as Well as the sensitizing liquid along with the copy sheets wherever the copy sheets are 3,420,405 Patented Jan. 7, 1969 to be used. Further, as indicated above, a certain amount of precision is required in the moistening and the less skill-ed opera-tors might achieve rather indifferent or negative results. To provide a copy sheet which can be successfully used by even the most casual operators, it has been an objective of the invention to provide a package of premoistened copy sheets, the copy sheets being easily extracted from the package and ready for immediate use when extracted.

It has been a further objective of the invention to provide such a package in which the copy sheets will have a long shelf life. In this regard, even the best of moistureproof films will permit the escape, over a period of time, of at least some vapor, and even if there is no escape of vapor in the package, there will be a diffusion of vapor from the porous film to any overlying packaging material which might rob the porous film of enough moisture to decrease the effectiveness of the copy sheet.

To achieve the objectives of the invention, I provide a package of copy sheets in which each copy sheet has an overlying cover sheet, the cover sheet having on the surface adjacent the copy sheet a storage layer which holds a substantial amount of the sensitizing liquid. A package may be formed as a stack of copy sheets alternating with cover sheets or alternatively the package may be formed as a roll of a web having the moisture containing layer with copy sheets serially placed on the web. The copy sheets, in this embodiment, could, of course, be in the form of a single web with the container having means for cutting copy sheets of an appropriate length from the web.

The several objectives and features of the invention will become more readily apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of a package formed in accordance with the invention,

FIG. 2 is a disassembled cross sectional view of the package taken along lines 2-2 of FIG. 1 and FIG. 3 is a cross sectional view through an alternative form of the invention.

Referring to FIGS. 1 and 2, the package indicated at 10 has a plurality of copy sheets 11, each having a sensitized film 12 on its upper surface. Overlying each copy sheet is a cover sheet 13 having a storage layer 14 containing the sensitizing liquid. The film 12 is very thin, preferably much less than one mil in thickness, as, for example, 0.0001 inch thick, whereas the storage layer 14 may well be at least 0.001 inch thick in order to contain a sufficient quantity of moisture to maintain the film 12 in a properly sensitized condition. As can be observed from FIG. 2, the moisture con-taining layer 14 has a margin 15 around its periphery which projects beyond the peripheral edge 16 of the sensitized film to insure against the drying out of the sensitized film around its marginal edge portions.

The cover sheets 13 have peripheral margins 17 eX- tending well beyond the edges of the copy sheets 11. The margins 17 are sealed together on a continuous line 18 (FIG. 1) so as to encapsulate a copy sheet between adjacent cover sheets. Preferably, the peripheral margins 17 are folded upon themselves as at 19 to compensate at the edges of the package for the bulk of the copy sheet and the moisture containing layer 14 of the cover sheet. Thus, the material thickness at the edge of the package is approxi mately the same as the material thickness through the central portion of the package.

The lowermost sheet 20 may simply be an impervious sheet of the same material as the cover sheets 13 but without having any moisture containing layer 14. The sheet 20 is sealed around its edges along the line 18 to package the lowermost copy sheet.

As illustrated in FIG. 1, tabs 22 may be associated with alternate cover sheets at one edge of the package and tabs 23 associated with cover sheets at an opposite edge of the package to facilitate the removal of the individual cover sheets to expose a copy sheet. By alternating the tabs, each tab is made more accessible. The tabs may be formed as separate inserts sealed to the cover sheets during the formation of the package or, alternatively, they may be integral extensions of the cover sheets.

The moisture containing storage layer is preferably a swollen, gelatinous but non-sticky material such as gelatin which has been tanned enough to make it insoluble, or polyvinyl alcohol which has been insolubilized by poly (vinyl methyl ether-maleic anhydride), or polyvinyl acetate which has been given a controlled amount of water receptivity by combining it with a hydrophilic colloid, or cellulose acetate which has been swollen or partially hydrolized, or regenerated cellulose, or silica gel, or the like. The cover sheet to which the layer 14 is adhered is preferably a sheet of aluminum foil coated with a heat sealing plastic. The cover sheet may, however, be a material such as saran, polyethylene, polystyrene, or the like, and such cover sheet may, if necessary or desired, be coated with a substance to provide a moisture barrier. If a thermoplastic material is used, there is no need to apply the coating of heat sealing plastic for the material itself is sufficiently thermoplastic to permit the joining of the cover sheet edges along the line 18 through the application of known sealing technique utilizing heat, ultrasonic energy or the like. The seal may preferably be made peelable in accordance with known techniques to facilitate the opening of the package. The moisture containing layer 14 may be secured to the sheet by any suitable adhesive.

In the operation of the invention, before the package is completed by sealing it around its periphery along line 18, the moisture storage layer 14 and the sensitized film 12 are moistened to the extent of their capacity to receive the sensitizing liquid but Without free liquid in the form of droplets or a continuous layer on the surface of either the moisture containing layer or porous film. The copy sheets and cover sheets are interleaved and heat sealed as described to form the package. At any time during the period of its useful life it is desired to make copies, the operator tears away the topmost cover sheet, thereby exposing the copy sheet. The copy sheet preferably has in its porous film suflicient moisture to require it to be dried for five or ten seconds before application of the copy sheet to the printed paper to be reproduced. This five or ten second drying time gives the operator a brief period in which to remove the cover sheet and to align the copy sheet with the printed paper before it is actually held in contact with the printed paper. It Will be found useful to leave the copy sheet in position at the top of the package when applying the copy sheet to the printed paper so that the copy sheet will be smooth when applied to the printed paper and will permit the use of the remaining portions of the package to apply the slight pressure of the copy sheet to the paper which is required for uniformity of results.

After a few more seconds, the copy sheet is removed from the printed paper and a discernible image will appear on the copy sheet, all as described in my copending applications.

An alternative form of the invention is illustrated in FIG. 3. In this form of the invention, the copy sheeting and cover sheeting are formed as described in the first embodiment except for the length of the cover sheet.

The package of FIG. 3 comprises a container having rigid end walls 31, side walls 32, a top wall 33, and a bottom wall 34. The bottom wall 34 is provided with two spaced

slots

35 and 36 extending transversely across the width of the container. A pair of

spindles

37 and 38 are mounted on spaced parallel axes for rotation between the side walls 32 of the container. The spindle 38 has a crank handle 39 projecting outside of the container by which the spindle can be rotated. Wrapped about the spindle 37 are three plies of materials. The first ply is an elongated web 40 forming the cover sheeting, the web '40 having a moisture containing storage layer 41 adhered to one of its surfaces. The second ply is constituted by a series of copy sheets 42, each having a moisturized porous film 43 positioned against the moisture containing layer 41 of the cover sheeting. The third ply is a web 44 of impermeable plastic such as polyethylene, polypropylene, polystyrene, or the like which covers the copy sheets. Preferably, the cover sheet and impermeable web have longitudinal margins which project beyond the longitudinal edges of the copy sheets and are preferably heat sealed along the overhanging marginal edges to minimize the possibility of evaporation of moisture along the sides of the roll of material. The three plies of material are wound on the spindle 37 as shown and are fed through the slot 35. The impermeable web is fed across the bottom of the container and passes back into the container through the slot 36 and is wound around the spindle 38. A knife edge 45 is fixed to the corner of the container adjacent the slot 35 to permit the tearing away of used portions of the cover sheet. In the operation of the package of FIG. 3, the user turns the crank 39 in a clockwise direction as viewed in FIG. 3 to wind a portion of the impermeable web 44 around the spindle 38, thereby drawing a copy sheet with its cover sheet across the bottom of the container. The cover sheet is pulled away from the impermable web to expose the copy sheet and that portion of the cover sheet is pulled against the knife edge 45 to sever it from the web. The exposed copy sheet is applied to a printed paper as described above to form an image Where it is known or likely that either of the packages described above will have to be stored over a long period of time, it may be found desirable to enclose the packages in a glass, plastic, or metal container in which a supply of this sensitizing solvent is provided to maintain an essentially saturated atmosphere so that the moisture within the individual packets has little tendency to diffuse outwardly.

I claim:

1. A package of copy sheets comprising,

at least one impermeable base sheet having a moistened porous film on one of its surfaces, said film being capable of having its optical properties changed upon diffusion of said moisture to a printed sheet so as to reproduce the printing in said copy sheet, and

a cover sheet overlying said copy sheet, said cover sheet having a moisture containing storage layer on one surface thereof adjacent said film, said cover sheet being removable from said copy sheet film for exposure of said film to said printed sheet.

2. A package according to claim 1 in which said porous film is substantially less than one mil thick and in which said storage layer is at least approximately one mil thick.

3. A package according to claim 1 in which said porous film is not thicker than approximately 0.0001 inch and in which said storage layer is at least 0.001 inch thick.

4. A package of copy sheets comprising,

a plurality of copy sheets alternating with a plurality of cover sheets,

each said copy sheet having a thin porous film on one surface thereof,

each said cover sheet having a moisture containing storage layer, thicker than said film, on a surface facing said porous film, said cover sheets having peripheral margins projecting beyond the peripheral edges of said copy sheets, said margins being sealed together around the periphery of said package.

5. A package according to claim 4 in which said margins are folded upon themselves to provide a thick edge whereby the material thickness at the edge of the package is approximately the same as that through the central portion of the package.

6. A dispensing package for copy sheets comprising,

an elongated web having a moisture containing storage layer on one surface thereof,

copy sheet material covering said storage layer and constituted by an impermeable base sheet and a thin porous film facing said layer,

an impermeable web on said elongated Web and overlying said copy sheet material,

a container having a dispensing opening,

a spindle rotatably mounted in said container,

21 take up spindle rotatably mounted in said container on an axis parallel to said first named spindle and adapted to receive said impermeable web, and

said web and film being wound on said first named spindle.

7. A dispensing package for copy sheets comprising,

copy sheet material covering said storage layer and constituted by an impermeable base sheet and a thin porous film facing said layer, said copy sheet material is formed as separate sheets serially mounted on said web,

a container having a dispensing opening,

a spindle rotatably mounted in said container, and

said web and film being wound on said spindle.

References Cited UNITED STATES PATENTS 695,488 3/1902 Post. 3,049,836 8/1962 Weissman 206-47 3,203,798 8/1965 Muller 9649 3,255,007 6/1966 Kosar 96--4 MARTHA L. RICE, Primary Examiner.

US. Cl. X.R.