US3503568A - Attaching tape - Google Patents

Description

March 31, 1970 H, T. G'AL. EY 3,503,568

' ATTACHING TAPE Filed Nov. 14, 1966 2 Sheets-Sheet 1 HOLLIS 7T GALLEY INVENTOR.

A TTOR/V Y5 March 31, 1970 H. T. GALLEY 3,503,568

nmcnme TAPE 2 Sheets-Sheet 2 Filed NOV. 14, 1966 7: GALLEY HOLL IS l%INVENTOR. +QW1% United States Patent U.S. Cl. 242-74 1 Claim ABSTRACT OF THE DISCLOSURE A tape adapted for detachably connecting the end of a web to a winding core. Both surfaces of the tape are coated with a pressure-sensitive adhesive for releasably attaching the web to a core such that the tape remains attached to the core when the web is unwound from the core.

This invention relates to means for detachably connecting the end of a web to a winding core, and particularly to a tape for releasably attaching webs of photographic paper and film to cores which insures that the tape always remains with the core when the web is unwound from the core.

Webs of photographic paper and film have been traditionally fastened to paper or cardboard windup cores by a single-sided adhesive tape applied over the starting end of the web and onto the core. As the customer removes the product from the core, the tape attaching the web to the core remains with the web, and to a greater or lesser degree delaminates the paper core. This tape, with the attached parts of the core, causes difficulties ranging from minor inconveniences to complete stoppage with various equipment through which the web is fed as it is unwound from the core.

The primary object of the invention is to provide a tape for releasably attaching the end of a web to a windup core which will insure that the tape always remains with the windup core when the web is unwound therefrom.

Another object is to provide a tape for the attachment of Webs to cores which is double coated with a pressure sensitive adhesive one surface of which is to be stuck to the core and the other surface of which is to be stuck to the end of the web. By making the adhesive characteristics of the two surfaces of the tape such that adhesion between the tape and the core is greater than that between the tape and the web, either by altering the pattern or geometry of the adhesive coating on the two tape surfaces, by using different adhesives on the two surfaces of the tape etc., one can assure that the tape will always remain with the core when the web is removed from the core.

And still another object is to make such tapes in a way in which one of the protective release sheets for the two adhesive coatings on the tape serves as a support and/ or a dispenser for a plurality of the tapes.

The novel features that I consider characteristic of my invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its methods of operation, together with additional objects and advantages thereof, will best be understood from the following description when read in connection with the accompanying drawing, in which:

FIG. 1 is an enlarged longitudinal section, in perspective, of an individual attaching tape constructed in accordance with one embodiment of the present invention;

FIG. 2 is an enlarged perspective view showing how the individual tapes shown in FIG. 1 may be fabricated by a continuous procedure and in a way which facilitates a dispensing of the individual tapes for their successive use;

FIG. 3 is a schematic view illustrating how the end 3,503,568 Patented Mar. 31, 1970 of a web is attached to a winding core by a tape constructed as shown in FIGS. 1 and 2;

FIG. 4 is a schematic perspective view of a winding core having attached thereto another and preferred embodiment of web attaching tape;

FIG. 5 is a schematic view illustrating the end of a web attached to a winding core by a tape constructed as shown in FIG. 4;

FIG. 6 is an enlarged perspective view showing how the individual tapes as shown in FIG. 4 may be fabricated by a continuous procedure and in a Way which facilitates a dispensing of the individual tapes for their successive use; and

FIG. 7 is a schematic view illustrating how the tapes fabricated according to the technique illustrated in FIG. 6 may be individually dispensed for use.

Referring now to FIG. 1, wherein an embodiment of the present invention is shown with the components thereof illustrated in a greatly enlarged and exaggerated scale for purposes of clarity, one of the tapes T constructed in accordance with the present invention comprises a narrow strip, e.g., /2" x 2", of polyester film base, or other suitable material, 10 completely coated on one surface with a layer 11 of an acrylic pressure sensitive adhesive and having half the length of its other surface coated with a layer 12 of the same acrylic pressure sensitive adhesive. The half coat of adhesive 12 is protected by a release sheet 13 stuck thereto. The layer of adhesive 11 on the other side is protected by a second release sheet 14 stuck thereto. In order to facilitate pulling the double coated polyester base 10 from the release sheet 13 the release sheet 14 is provided with a pull tab 16 which extends beyond the end of the film base 10. When one grasps this pull tab between his fingers and pulls upwardly, the double coated adhesive base 10 along with the release sheet 14 will be peeled off the release sheet 13 leaving the adhesive layer 12 exposed. Using the pull tab 16 as a handle the exposed adhesive layer 12 is first pressed against the end of the web W, see FIG. 3, and then the release sheet 14 is pulled off to expose the other adhesive layer 11. The web end is then stuck to the periphery of the winding core 18 by the adhesive layer 11, see FIG. 3. If the operator grasps the pull tab 16 between the thumb and forefinger in applying the tape to the end of the web after the lower release sheet 13 is removed, he is then able to use his thumb as an alignment device for applying the web end to the core. Preferentially the adhesive on the tape, particularly the layer 12 to be stuck to the web end, is colored black so that it may be readily seen when it is applied to the end of a photographic paper or film which is light colored. It should be pointed out that while the adhesive connection between the tape and the web should be such that it will give way before the adhesive connection between the tape and the core, the adhesive connection between the tape and the webmust be sufiiciently strong to hold while the tape is being initially pulled onto the core, otherwise windup of the web cannot be accomplished. It is in this respect that double coated adhesive tapes now on the market fail when an attempt is made to use them as web attaching tapes in accordance with the present invention.

When the web is unwound from the core the tape T will always remain on the core 18 because the mechanical arrangement stresses the bond between the web and the tape in peel as shown by the angle 0 in FIG. 3, while the bond between the tape and core is stressed in shear. The shear strength of adhesives always exceeds the peel strength. In addition, the area of the bond under peel stress, that formed by adhesive layer 12, is one half that of the bond under shear, that formed by adhesive layer 11.

In order to facilitate the manufacture and the ultimate dispensing of these tapes they can be manufactured in a manner shown in FIG. 2. A long strip of polyester film base two inches wide is completely coated on side with a layer 11 of an acrylic pressure sensitive adhesive and has one half the length of the other side coated with a layer 12 of the same acrylic pressure sensitive adhesive. In covering relation with the adhesive layer 12 there is an elongated sheet 2" wide of release paper 13 which may be made of a heavy draft paper since this is to provide a support for a multiplicity of tapes. In covering relation with the layer 11 of adhesives there is an elongated sheet of parchment release paper 14 which is slightly wider than two inches to provide the pull tabs 16. This composite tape is then dinked in /2 widths, as indicated by lines 30 in FIG. 2, by means of a tool, not shown, which will cut through the parchment release paper 14, the film base 10 and the two adhesive layers 11 and 12 thereon but not through the kraft release paper 13. By manufacturing tapes in this manner a single strip of kraft release paper 13 will serve as a support for a plurality of tapes so that they can be rolled up for packaging and then each individual tape can be pulled from the kraft release paper as it is unrolled by merely pulling up on the pull tabs 16.

While I have shown and described, as one embodiment of the present invention, a double coated tape T, which is completely coated on one surface with a layer 11 of adhesive and one half coated on the surface with a layer 12 of the same adhesive, and which tape is first attached to the end of the web and then to the core, it will be appreciated that the two sides of the tape could be coated with a different pattern of adhesive and the order of attachment of the tape to the web and core could be changed without deviating from the scope of the present invention. For example, as shown in FIG. 4 the side of the tape T which is to be adhered to the web is provided with an adhesive area 12 which occupies approximately the center half of the full length of the tape. After removal of a release sheet, not shown, the underside of the tape T' which is completely covered with an adhesive layer 11' is first attached to the core 18. Then after removal of the release sheet for the adhesive layer 12, not shown, the end of the web is pressed against the adhesive layer 12 for attaching it to the core.

The geometry of the adhesive areas 11 and 12 on the tape T' results in an attaching tape which is more fool proof than tape T under certain conditions as will now be described. While a tape such as shown at T pulls from the web instead of the core under most conditions it has been found that if the web is left in a wound up condition for an abnormally long time before it is unwound from the core, then it is possible that a tape such as shown at T occassionally may stay with the web instead of the core upon unwinding. The reason for this may be due to the fact that the adhesion of the adhesive layers 11 and 12 increases with age and under certain storing conditions to an extent that when the web end is reached during unwinding, see FIG. 3, the tenacity between the adhesive layer 12 and the web increases to a point where instead of the web end peeling readily off the film base 10 it sticks firmly to the tape right up to the extreme end thereof. Under these conditions the pull on the web may tend to place the adhesive layer 11 between the film base 10 and the core under a peel stress so that it will give way before the web separates from the tape. This condition has evidenced itself at times by the tape T peeling off the core and doubling back upon the end of the web and becoming stuck thereto with the result that it stays with the web end and peels off the core.

The tape embodiment shown at T in FIGS. 4-7 overcomes this noted disadvantage by reason of the geometry of the adhesive layers 11' and 12. Looking particularly at FIGS. 4 and 5, since the adhesive layer 12 is located at the central portion only of the tape T there remains at each end of this adhesive layer clear areas 40 where there is no adhesive connection between the tape and the web. As will be evident from an inspection of FIG. 5 this means that as the Web is unwound from the core the web end will peel completely from the tape T before there is any chance of the adhesive connection between the end of the tape T and the core being placed under a peel stress rather than a shear stress. As a result the web end will always pull off the tape and the tape T will remain on the core regardless of how the adhesive characteristics of the layers 11 and 12' might change relative to one another, or their original states, due to the time and/or conditions under which the coated Web is stored. Leaving a clear area 40 on the tape on both sides of the adhesive layer 12 insures that the desired separating conditions between the web and tape will occur regardless of the circumferential orientation of the tape T on the core, and will prevent even the leading edge of the tape T from being placed under a peel stress during unwinding of the web, and which peel stress might tend to cause the tape to peel off the core rather than off the web.

These tapes such as shown at T may be fabricated so as to facilitate their being dispensed individually in much the same manner as described above in connection with tape T. Referring now to FIG. 6, a long strip of polyester film base 10 two inches wide is completely coated on one side with a layer 11 of an acrylic pressure sensitive adhesive and has the center half of the other side coated with a layer 12 of the same acrylic pressure sensitive adhesive. In covering relation with the adhesive layer 12 there is an elongated sheet of parchment release paper 14 which is the same Width as the film base. In covering relation with the adhesive layer 11 is an elongated sheet two inches wide of release paper 13 which may be made of a heavy kraft paper since this is to provide a support for a multiplicity of tapes. This composite sheet is then dinked in /2 widths, as indicated at lines 30'iin FIG. 6, by means of a tool, not shown, which will cut through the parchment release paper 14, the film base 10' and the two adhesive layers 11 and 12' thereon, but not through the kraft release paper 13. By manufacturing tapes T in this manner a single strip of kraft release paper 13 will serve as a support for a plurality of tapes T so that they can be rolled up for packaging and then each individual tape T can be pulled from the kraft release paper as it is unrolled.

As indicated in FIG. 7, if the roll of tapes T fabricated as shown in FIG. 6 is dispensed from a tape dispenser having a sharp edge about which the kraft release paper 13 is sharply bent as it is pulled out then no pull tabs are required on tapes T to permit their removal from relase sheet 13. When the release sheet 13 is sharply bent about a sharp corner 20 of a dispenser as it is pulled out in the direction indicated by arrow 21 it will be peeled from the leading edge 22 of the leading tape T as indicated in FIG. 7 thus leaving this leading edge of the tape available to be gripped by the fingers so as to be completely stripped from the release sheet 13. This peeling of the leading edge of the leading tape T from the release sheet 13' as the latter is pulled sharply about a short radius corner or edge 20 results because of the film base 10 of each tape T has a resistance to bending in a direction trans versely of its length which is sufficient to cause the adhesive layer 11' to peel from the release sheet 13 as shown in FIG. 7. As each tape T' is removed from the release sheet 13' it is stuck to the core 18 in the manner shown in FIG. 4 after which the release sheet 14' is then peeled off adhesive layer 12 so that the end of the web W may be stuck thereto as shown in FIG. 5. If the core 18 is black, as is often the case in practice, then the adhesive layer 12 can be made white so that the position of the tape T on the core will be clearly apparent.

It will be appreciated that the patterns and/or the adhesive characteristics of the adhesive layers on the two sides of the film base could be difierent from that shown in order to assure the tape remaining with the core. For example, the adhesive coating on the surface of the film base adapted to engage the web end could be made in a spaced dot or a stripe pattern while that on the other surface covers the complete surface. Also, adhesives having different adhesion characteristics but of the same pattern could beused on opposite sides of the film base, etc. Also, any web material having a sufficient flexibility and strength could be used instead of the film base 10 as disclosed.

I claim:

1. In combination with a web winding core, a tape secured thereto for releasably attaching the end of a web to said winding core so that the tape will remain on the core when the web is unwound therefrom, said tape comprising:

a flexible base adapted to embrace a portion of the periphery of the winding core, said base having a web surface and a core surface;

a pressure-sensitive adhesive on the core surface of said base for adhesively bonding said tape to the core; and

a pressure-sensitive adhesive on the web surface of said base for releasably bonding a web to said tape;

the pressure-sensitive adhesive on said core surface extending over the entire area of said core surface;

References Cited UNITED STATES PATENTS 2,765,998 10/1956 Engert 161--167 X 3,138,476 6/1964 Phipps 117-685 X 3,105,985 10/1963 Reid et al 117--68.5 X 2,900,868 8/1959 Gaffney 9678 X 2,455,146 11/1948 Tann 16147 2,292,024 8/1942 Dreher 16l-167 X ROBERT F. BURNETT, Primary Examiner M. A. LITMAN, Assistant Examiner US. Cl. X.R.

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