US 3006793 A
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Description (OCR text may contain errors)
Oct. 31, 1961 3. WHEELER Ill ADHESIVE PRODUCTS 2 Sheets-Sheet 1 Filed Aug. 19, 1960 FIG. 2
w m m mm m M w IE A H a W H H S L DZ Oct. 31, 1961 5. WHEELER m ADHESIVE PRODUCTS 2 Sheets-Sheet 2 Filed Aug. 19, 1960 FIG.
INVENTOR. SETH WH EELER, IE, BY 7' ATTORNEYS FIG. 6
linited States Pater 3,036,793 ADL ESIVE PRODUCTS Seth Wheeler IH, Painesville, Ohio, assigncr to Avery Adhesive Froducts, inc, Monroria, Califl, a corporation of Caiiicrnia Filed Aug. 19, B69, Ser. No. 59,637 2 Claims. (*Cl. 154-535) This invention relates to web combinations for the manufacture of adhesive articles, such as labels, stickers, tapes and the like. More particularly the invention relates to web combinations for the manufacture of articles of the above type which have backings for protecting and for accomplishing containment of the adhesive coating which is to be employed in mounting the article in its end use.
Fibrous materials such as paper, clot-h and-the like have been commonly employed as backings to protect and contain the adhesive coating or adhesive surface for roducts such as labels, stickers, tapes and the like. One of the requisites for such backings is that they remain securely in protecting and containing relationship with the adhesive surface during manufacture and distribution of the articles while also being capable of easy and convenient removal by the end user when the article is to be mounted or afiixed on the surface with which it is to be associated in its ultimate end use.
Of importance to an aspect of the present invention is an appreciation that partially degraded zones in a fibrous backing web can satisfactorily accomplish adhesive containment and remain capable of transmitting relatively high transverse tensile stresses under no bending when such zones are degraded to an extent that (1) allows the web material within the zones to remain capable of transmitting the relatively low transverse tensile stresses necessarily encountered during separation from a backing web while under a degree of bending necessarily encountered during such separation but (2) results in ready rupture of the web material within the zones when the web is bent to a degree greater than that necessarily encountered during such separation. Such relatively high tensile strength under no bending may be su-fliciently higher than the relatively low tensile stress encountered during separation of the backing webs to permit the pulling forces for causing separation of the backing web across a long zone to be transmitted across a short zone of only a fraction of the length of the long zone.
it is particularly advantageous to provide stock for the manufacture of self-adhesive articles, such as labels, stickers, tapes and the like, with web combinations which will provide for easy removal of the protective backing by the end user without any substantial departure from the conventional production processes and apparatus of the manufacture of such labels, stickers, tapes and the like.
It is even more particularly advantageous to provide for manufacture of even the sheet stock (from which the label, sticker or tape manufacturer will make the end use article) in such a manner that the feature of easy removal of the protective backing may be accomplished on-line in such conventional web combining and web processing production runs without substantial production cost increases.
The present invention makes it possible to realize these advantageous results in such a manner as to inherently result in the provision on the end use article of latent starting tabs of small, conveniently graspable width.
Other advantages and features of the invention will become apparent from the following detailed description and drawings illustrating an example of the invention.
FIGURE 1 is va view of a length of stock material exemplifying the invention.
FIGURE 2 is a greatly enlarged detail view of the portion of the right band edge of the stock material shown in FIGURE 1.
FIGURE 3 is a schematic sectional view taken from line 33 in FIGURE 2, assuming that the structure shown in FlGURE 2 has been severed along line 30 and the thickness of the webs being exaggerated for clarity.
FIGURE 4 is a view similar to FIGURE 3 showing the illustrated web combination in a bent position.
FIGURE 5 is a view similar to FIGURES 3 and 4 showing the removal of a portion of the protective backmg.
FIGURES 6 and 7 are diagrammatic representations of one stage in the manufacture of products contemplated by the invention.
A fibrous backing sheet it} is provided which is in apposite relationship with the adhesive coating 11 on a base web 12, the web 10 constituting means for protetcting and for accomplishing containment of the adesive coating 11.
Along the length of the backing sheet 10 are a succession of narrow cmbn'ttled zones 14 which are integrally included in the backing sheet '10 and thus integrally form a part of the means for protecting and for accomplishing containment of the adhesive coating 11.
As most clearly shown in FIGURE 1, the zones 14 (which for clarity are indicated in FIGURE 1 merely as lines) extend across the backing sheet 10 from side to' side thereof and in skewed relationship to both the lengthwise and w-idthwise directions of the web combination.
The backing material 10 may be any suitable conventional backing material such as paper, cloth, or the like. The narrow zones 14 are produced by subjecting the backing 10 to treatment with an agent which causes the treated portions of the backing to become brittle. The embrittled zones may be produced by applying heat, a flame, a chemical substance such as sulfuric acid or ultraviolet radiation, or the like to partially degrade or decompose the treated portions of the backing.
By way of example, if the embrittled zones are pro duced by applying a fiuid such as for example sulfuric acid, the embrit-tled zones may be continuously produced by an operation which is essentially a printing operation where a roll with helical printing ridges formed thereon is contacted with the backing web 10 before or after its combination with the Web 12 to thereby print the series of narrow embrittled zones 14 in an endless manner and in an on-line relationship with the remainder of the web combining and processing steps in the manufacture of the stock shown in FIGURE 1. This is indicated diagrammatically in FIGURES 6 and 7 where the backing web 10 is shown moving in the direction of the arrow shown in FIGURE 6 past the printing roll or plate roll 21 having a plurality of raised helical ridges 22. The crowns of the ridges 22 are coated with the printing liquid, for example sulfuric acid, by a form roll 23 which in turn is supplied by a fountain roll 24 which is in contact with a bath of the printing liquid 25.
The web 11) may be supported during the printing operation by a backing roll 27. V
The partial degradation contemplated by the invention may be accomplished for example by providing a relatively dilute bath of the liquid 25 and then progressively adding the active agent therein, as for example sulfuric acid, until on a trial basis it is determined that a condition has been reached where the backing web material 10 will rupture at the printed zones when bent to a degree greater than that necessarily encountered during transmitting such relatively highrstresses.
Accordingly, it will be clear that the. web combiner who manufactures the stock shown in FIGURE 1 may include therewith by low-cost, on-line methods, the succession of narrow embrittled zones 14 within'the backing :web 10. The combined stock comprising the adhesivecoated web 12 and the backing web 19 may then be supplied to manufacturers of labels, stickers, tapes and the like as for example by being provided in rolls of considerable length. Such rolls are arranged so that the curvature of the rolled stock does not exceed the curvature which'will result in rupturing of the embrittled zones 14.
.:When the stock is die cut or otherwise severed by the manufacturer of labels, stickers, tapes or the like, the skewed orientation of the embrittled zones 14 will result in the provision of latent starting tabs in the end product of small conveniently graspable width which ma be Y very conveniently manipulated. Assume now that the combined stock in FIGURE 1 is severed by the end user along the equally spaced lines 28, 29 and 3G and an indefinitely long succession of additional lines of severance to thereby form a plurality of rectangular web portions 3134 and a long succession of additional rectangular web portions. Starting tabs will thereby be formed at both the upper right hand corner and'the lower left hand corner of such rectangular web portion, references to direction being with respect to the product as viewed in FIGURE 1. Thus, for example, the line of severance 30 will define a small triangular corner portion 35 in the rectangular web portion 34. Such triangular portion 35 is seen on an enlarged scale in FIG- URES 2 and 3. The backing sheet 10 may be easily and simply removed from the label, sticker, tape or the like represented by the base Web 12 in FIGURE 3 by first bending the composite product at or near one of the embrittled zones 14 to such a degree that, as shown in FIGURE 4, the embrittled zone 14 is caused to rupture dividing the backing 10 into two parts. The divided backing is then removed by grasping the edge of the backing at the point of rupture and peeling the major part of the backing from the adhesive surface as shown in FIGURE 5. Other embrittled zones such as the particular zone 14 shown in FIGURE 5 Will remain intact as the backing is peeled from the adhesive sufiace because the embrittled zones 14 are self-sustaining under the tensile stress and limited bending required to peel the backirn sheet from the adhesive. As previously mentioned, they are also self-sustaining under no bending, even when subjected to higher tensile stresses. In these connections it will be understood that as the stripping operation progresses from the upper right hand corner of the particular rectangular web portion 34, progressively greater pulling force is required to further continue the stripping operation because the line of cleavage between the webs 16 and 12 becomes progressively longer, at least during the initial portion of the stripping operation. As cleavage proceeds past each succeeding zone 14, the tension per unit area through each succeeding Zone does not increase significantly for the reason that the lengths of the succeeding zones 14 increase in proportion to the increasing length of the line of cleavage. However the shorter zones 14 through which cleavage first occurs must carry progressively higher tensile stresses as the line of i by the user.
cleavage becomes progressively longer and the pulling force becomes progressively greater, but such relatively high tensile stresses occur substantially in the complete absence of bending and the fibrous web material within the zones 14 can carry such relatively high tensile loads in these conditions.
The above description relates in detail to the removal of the backing web 10 of the rectangular web portion 34.
It will be understood that the same considerations generally apply in the case of the other rectangular web portions 31-33 and in fact in the case of any rectangularly oriented labels, stickers, tapes or the like, which may for example be formed by die cutting in a conventional manner. For example, if three rectangular labels are die cut across the width of the web combination shown in FIGURE 1, each of them would be provided with a corner starting tab and the backing web would be separable therefrom in the same general manner as described above.
It is to be noted that the above description does not include the removal of the small triangular portion 35. This may be accomplished by grasping the edge of the triangular portion at the line of rupture and flicking oil the small triangle.
It is to be particularly noted that the boundaries of die-cut objects, or the lines of severance, such as the lines 28-31), need not be in any particular register with the pattern of zones 14. Thus, as illustrated in FIGURE 1, the lines of severance are out of register with the zones 14 so that the line 29 forms a small corner triangle 36 which it will be assumed is too small to be readily grasped In such an event, the user treats the nextsmallest cornentriangle as the starting tab, such nextsmallest corner triangle including the triangle 36 and being indicated by the reference numeral 37. The major portion of the backing sheet 10 is then removed by the end user as above described and the triangle 37 (including the portion 36) may be flicked off as a unit in the same manner as the triangle 35.
in still another case, a line of severance may exactly intersect one of the zones 14 as indicated at the line of severance 28. In this case the triangle 38 will obviously be larger than the triangle 35 and will be of sulficient size to form, at its hypotenuse, a conveniently usable starting tab. p
The invention is not restricted to the slavish imitation of each and every one of the details described above which have been set forth merely by way of example with the intent of most clearly setting forth the teaching of the invention. Obviously specific structural details may be changed or eliminated without departing from the invention.
What is claimed is:
1. An article of manufacture comprising a web combination extending in a long direction and including a base web having an adhesive coating on one surface and a protective flexible fibrous backing sheet in apposite relationship with said adhesive coating and constituting means for protecting and for accomplishing containment of said adhesive coating, said backing sheet having along its length a succession of narrow embrittled zones which are integrally included in said backing sheet to thereby integrally form part of said means for protecting and for accomplishing containment of said adhesive coating, said zones extending across said backing sheet from side to side thereof and in skewed relation to both the lengthwise and widthwise directions of said webcombination.
2. An article of manufacture comprising a web combination extending in a long direction and including a base web having an adhesive coating on one surface and a protective flexible fibrous backing sheet positioned in protectingand containing relationship against said adhesive coating and constituting means for protecting and for accomplishing containment of said adhesive coating, said backing sheet having along its length a succession 01': narrow embrittled zones which are integrally included in said backing sheet to thereby integrally form part of said means for protecting and for accomplishing containment of said adhesive coating, said zones extending across said backing sheet from side to side thereof and 5 of registration between said embrittled zones and said articles.
References Cited in the file of this patent articles cut from said web combination independently 10 ,73
UNITED STATES PATENTS Martin Nov. 5, 1901 Salfisberg Feb. 2, 1937 Salfisberg Dec. 28, 1937 Flood Dec. 1, 1942 Brady June 22, 1954