US3751320A

US3751320A - Composite pressure sensitive adhesive sheet structure and process of making the same

Info

Publication number: US3751320A
Application number: US00225668A
Authority: US
Inventors: H Buck
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-05-11
Filing date: 1972-02-11
Publication date: 1973-08-07
Anticipated expiration: 1990-08-07

Abstract

A process in which a carrier strip has a release coated web marginally secured thereto, the latter releaseably adherently mounting a longitudinally extending tape having a pressure sensitive adhesive on its underside. The release coated strip is longitudinally severed with the line of severance being spanned by the adhesive coated tape. Subsequently, the combined span of the tape and a marginal portion of the release coated stock that is freely superposed on the carrier strip, are transversely slit defining a plurality of discrete pressure sensitive adhesive backed sections of tape, each provided with a corresponding tab by means of which each discrete section of tape can be peeled from the composite structure for application to another article. The process produces a roll of individually dispensible, pressure sensitive adhesive tape sections, each with its corresponding tab being so angularly related to the length of the composite structure as to facilitate winding up of the product, in the process of manufacture, to protectively enclose the tabs between successive coils of the carrier strip. Upon unwinding of the roll through a specially adapted guide means of a dispensing apparatus, each tab is individually projected out of the plane of the carrier strip to provide clearance for grasping a free end of the tab stripping the associated adhesive backed sheet article from the roll. The carrier strip and tape may have different characteristics of light reflectivity, controlling an automatic feed system for the dispensing apparatus, cooperatively associated with a photoelectric light cell or the like.

Description

United States Patent 1 1 Buck I COMPOSITE PRESSURE SENSITIVE ADHESIVE SHEET STRUCTURE AND PROCESS OF MAKING THE SAME Homer G. Buck, 803 S. Rimpau Ave., Los Angeles, Calif. 90005 Feb. 11, 1972 [76] Inventor:

[22] Filed:

' 21 Appl. No.1 225,668

Related U.S. Application Data [62] Division of Ser. No. 36,209, May 11, 1970, Pat. No.

Primary Examiner-Douglas J. Drummon d Atl0rneyFulwider, Patton, Rieber, Lee & Utecht [57] ABSTRACT A process in which a carrier strip has a release coated 1 Aug.7, 1973 web marginally secured thereto, the latter releaseably adherently mounting a longitudinally extending tape having a pressure sensitive adhesive on its underside. The release coated strip is longitudinally severed with the line of severance being spanned by the adhesive coated tape. Subsequently, the combined span of the tape and a marginal portion of the release coated stock that is freely superposed on the carrier strip, are transversely slit defining a plurality of discrete pressure sensitive adhesive backed sections of tape, each provided with a corresponding tab by means of which each dis crete section of tape can be peeled from the composite structure for application to another article. The process produces a roll of individually dispen sible, pressure sensitive adhesive tape sections, each with its correspending tab being so angularly related to the length of the composite structure as to facilitate winding up of the product, in the process of manufacture, to protectively enclose the tabs between successive coils of the carrier strip. Upon unwinding of the roll through a specially adapted guide means of a dispensing apparatus, each tab is individually projected out of the plane of the carrier strip to provide clearance for grasping a free end of the tab stripping the associated adhesive backed sheet article from the roll. The carrier strip and tape may have different characteristics of light reflectivity, controllingan automatic feed system for the dispensing apparatus, cooperatively associated with a photoelectric light cell or the like.

5 Claims, 7 Drawing Figures COMPOSITE PRESSURE SENSITIVE ADHESIVE SHEET STRUCTURE AND PROCESS OF MAKING THE SAME BACKGROUND OF THE INVENTION 'ously manufacturing a roll of a composite strip structure providing a series of individually dispensible pressure sensitive adhesive backed sheet articles, the resulting product, and improvements in apparatus for dispensing the same.

SUMMARY OF THE INVENTION The article of manufacture of this invention includes a base or carrier strip having a parallel strip or web mounted thereon in contacting superposition, the latter having a release coated top side on which a length of pressure sensitive adhesive backed sheet material is releasably adherently mounted. One edge or marginal portion of the release coated stock is secured to the underlying corresponding marginalportion of the base stock, the remaining width of the release coated stock remaining in freely contacting superposition on the base stock. The release coated stock is longitudinally severed but the separate portions are held in contiguous abutment and against relative displacement by the pressure sensitive adhesive backed underside of a tape. Discrete sections of the tape are formed by a transverse slitting operating which simultaneously forms discrete areas of the free marginal portion of the release coated stock to provide tabs by means of which each separate label or the like can be peeled from the marginally secured portion of the release coated stock. The area of mutual contact of each discrete section of tape with its corresponding tab is so adjusted, taking into consideration thenature of the release coating and the tackiness of the pressure sensitive adhesive, that after the freed end of the tape section is placed in its finally intended position, the tab can be withdrawn from adherent contact with the underside of the article by laterally sliding the tab out of contact with the underside of the tape article, afterwhich the then unadhered portion of the article can be pressed into adherent contact in its final position. I

The process of this invention lends itself to high speed production of a longitudinal series of butt cut, contiguous, pressure sensitive adhesive backed sheet articles, each with its corresponding tab for removing each article from the assembly forultimate application. The carrier or base stock, the release coated stock and an adhesive backed tape, are fed at the same linear speed, continuously, to be sequentially brought into contacting superposition. An adhesive is first applied to an edge of the carrier strip after which the release coated stock is pressed thereonto, the two pieces of stock thereafter being adherently held against lateral displacement. Subsequently, the release coated stock is longitudinally severed adjacent the area of marginally applied adhesive to define first and second marginal portions of the release coated stock. The guide rolls and pressure rolls of the apparatus maintain the second marginal portion of the release coated stock in freely contacting superposition on the carrier stock until the adhesive backed tape is linearly applied across the line of severance of the release coated stock, the two marginal portions thereafter being tied against displacement by the tape. Subsequently, the second marginal portion of the release coated stock and the tape are transversely severed into discrete portions at intervals spaced longitudinally of the composite structure.

The lines of severance of the tape and second marginal portion of the release coated stock are preferably butt cuts and, preferably, disposed slant-wise, rather than along lines normal to a longitudinal edge of the composite structure. The lines of severance are so angularly related to the normal that during winding up into a roll of the completed product each discrete area of tape precedes its corresponding tab in entry into the roll. As a consequence, each coil of individual tabs is fed into the roll without deformation and is protectively enclosed between successive coils of the base stock or carrier strip.

The same preferred slant-wise severance of the tape and second marginal portion or tabs facilitates individual delivery of each section of tape and its corresponding tab, either manually or in an automatic dispenser. In unwinding from a roll of the composite product, each tab precedes its associated section of tape whereby the free end of the tape or tab can be grasped to peel the tape section from the first marginal portion of. the release coated stock. As thetabs formed out of the second marginal portion of the release coated stock are merelyin freely contacting superposition on the carrier strip, the latter may be deformed out of the plane of the tabs by an appropriate guide means, thus presenting each individual tab projecting forwardly in a position for easy pickup, with clearance, out of the plane of the base or carrier stock. By choosing a reflectivity of the base stock which differs from the reflectiv' ity of the sheet article the composite strip assembly can be advanced incrementally through an automatically controllable dispenser apparatus by properly optically orienting-a photoelectric cell system at the dispensing station of the apparatus.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic perspective view illustrative of the process of carrying out the invention;

FIG. 2 is a top plan view of a longitudinal segment ofthe completed composite product, portions of successive layers being broken away to illustrate distinct stages in the process of manufacture; I

FIG. 3 is a perspective view showing the means of application of a'pressure sensitive adhesive backed sheet article made'in accordance with the invention;

FIG. 4 is a view similar to FIG. 3 but showing the completed ultimate-and use of the adhesive backed sheet article;

FIG. 5 is a somewhat schematic sectional view of an apparatus adapted for dispensing the individual pressure sensitive adhesive backed articles;

FIG. 6 is a front view of the apparatus of FIG. 5; and

FIG. 7 is a transverse sectional view on the line 7-7 of FIG. 2, on an enlarged scale, showing the relationship of the several parts of a single unit of the composite structure.

DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention is useful in the manufacture of a wide variety of pressure sensitive adhesive backed flexible sheet articles, for example labels, markers,

tabs, bandages, film or tape splices, and other articles consisting of an essentially flexible segment of sheet material bearing a pressure sensitive adhesive on the underside thereof. For purposes of illustrating the process and resulting product of the invention, it will be described in conjunction with the manufacture of a metallic faced splicing tab of the type used in joining together adjacent ends of a sound recording tape.

Referring to FIG. .1, there are shown portions of strips of a carrier paper 10, a transfer adhesive tape 11, a release coated paper 12 and a pressure sensitive adhesive backed tape 13. While not shown, it will be understood that each of these strips is fed from an appropriately located supply roll thereof, all being mounted on an apparatus for synchronously feeding the various strips through rolls and dies mounted on the apparatus at the same linear speed.

The carrier strip is preferably made from a hard, die-cutting, calendered stock and is fed from its supply roll over a guide roller 15 whereon the transfer adhesive tape 11 comes into contacting superposition therewith, after having been trained over a guide roller 16. The adhesive bearing tape 11 is one of a variety of commercially available products, typically a release coated paper bearing a stripable layer of adhesive. It will be observed that the supply roll of the transfer tape 11 is so aligned with the carrier strip 10 that the adhesive is laid along one margin or edge portion of the carrier strip, in a relatively narrow swath.

Thereafter, the layers 10 and 11 pass under a pressure roller 17, adapted to firmly press the adhesive of the tape 11 onto the carrier strip 10, and around a series of

guide rollers

18, 19 and 20. A roller 21 takes the paper backing from the tape 11, leaving a swath of adhesive 22 deposited on the upper surface of the carrier strip 10. The paper backing of the tape 11 is spirally conducted away to be wound up on a waste roll 23.

The strip or web 12, on its upper side, is provided with a silicone release coating, which has relatively high release properties. As is shown in FIG. 1, the strip 12 is brought into parallel contacting superposition with the adhesive bearing carrier strip 10 between a pair of rollers 25 resulting in the two strips being secured together against displacement, although the major portion of the width of the release coated strip 12 is merely in freely contacting superposition on the carrier strip, rather than-being adhered thereto.

The marginally joined

strips

10 and 12 are now passed over a roller 26, positioned in opposition to a rotary die 27 that is formed adjacent one end with a circumferentially extending circular cutter 28. It will be observed that the cutter 28 is offset from the adjacent edge of the carrier strip 10 a distance slightly greater than the width of the adhesive strip 22, as best seen at the left hand end of FIG. 2. The cutter 28 is adapted to slit only through the stock of the release coated strip 12, thus severing the strip 12 into a first marginal portion 12a and a wider, second marginal portion 12b, that remain in contiguous abutment along the line of severance 29 produced by the rotary die 27. Thus, the first marginal portion 12a is essentially permanently adhered to the carrier strip 10 while the second marginal portion 12b remains in freely contacting superposition on the carrier strip.

The roll of tape 13 employed in this example comprises a strip of thin material coated with a pressure sensitive adhesive and covered with aluminum foil. The

tape may be a polyester film, such as Mylar, having the aluminum foil laminated to one surface thereof, the resulting laminated tape 13 thus having a pressure sensitive adhesive coated underside. The tape 13 is relatively narrow, as compared to the

strips

10 and 12, and the supply roll thereof is disposed in alignment with the line of severance 29. Accordingly, the tape 13 is fed onto the upper release coated side of the strip 12, beneath a roller 30, spanning the line of severance 29 to tie the portions 12a and 12b in contiguous abutment.

The composite of the

strips

10 and 12 and tape 13 is next passed over a roller 31 in opposition to a rotary die 32 that is formed with at least one longitudinally extending cutting edge 33. For simplicity of illustration, the rotary die 32 illustrated as being formed with but a single cutting edge 33. It will however be appreciated that a plurality of such cutting edges may be formed on the die and may take the form of straight rathern than helical cutting edges. In either event, the cutting edge 33 is adapted to slit the tape 13 and strip 12 transversely, without penetrating the carrier 10, thus producing a plurality of butt cut slits 34 at intervals longitudinally of the composite strip. The slits 34 may, if desired, be along lines normal to the longitudinal edges of the

strips

10 and 12. However, it is preferred to form the rotary die 32 with helically extending cutting edges 33 whereby to produce slant-wise slits 34 extending transversely of the tape 13 and strip 12, at angles other than normal to the longitudinal edges of the composite strip.

As a result of the slitting by the rotary die 32, the tape 13 is divided into a series of discrete sections 13a while the second marginal portion 12b of the strip 12 is formed into discrete sections 12c providing a pull tab for each section of the tape 13.

Finally, the composite product is wound into a roll 35. As the roll 35 is turned in the take-up direction, the successive coils of the carrier strip 10 receive the tabs 12c therebetween to protectively enclose them. In this connection, the slant-wise orientation of the slits 34 is such that each tape section 13a precedes its corresponding tab 12c in entry into the roll 35. As a result, the otherwise free tabs 112a are successively brought into the roll without deformation thereof and the roll 35 can be handled during transportation and in a dispenser without danger of deforming the tabs.

It will be seen that the process just described provides a roll of individually dispensible pressure sensitive adhesive backed sheet articles 130. Referring to the righthand end of FIG. 2, it can be seen that each of the articles 13a may be individually removed from a length of the roll 35 merely by grasping the free end of a tab 12c to turn and pull it in a direction to peel the section 13a from the release coated surface of the marginal portion 120, the latter, of course, remaining glued to the carrier 10.

In this connection, attention is drawn to the different areas of adhesive contact between the underside of the section 13a and the marginal portion 120, on the one hand, and the end of the corresponding tab 12c, on the other hand. Preferably, the greater area of contact is with the first marginal portion 12a in order to insure peeling the section 13a from the marginal portion 120, rather than accidentally separating the tab 12c from its associated section 13a. At the same time, it is desirable to determine the optimum area of contact between a tab 12c and the underside of a tape section 13a, taking into consideration the tackiness of the particular adhesive involved and the qualities of the release coating on the upper surface of the tab, such that the tab 12c may, in effect, be slid laterally from the section 13a upon final application of the tape section.

It will be observed that a section 130 of pressure sensitive backed adhesive sheet material is removed from the composite assembly merely by lifting and pulling on the tab 12c. The section 13c can thus be removed without involving any contact of the fingers with the adhesive on the underside of the article 13a or even with the edges thereof. Referring to FIGS. 3 and 4, there are illustrated ends 45 and 46 of a recording tape to be spliced together by application of one of the sections 13a. It will be seen that the section may be brought into parallel alignment with the ends 45 and 46, in position to span the abutting terminal end portions of the tapes and applied by manual pressure on top of the section 13a. The tab 120 can thereafter be pulled laterally in the direction of the arrow 47, in effect sliding the tab out of contact with the underside of the section 13a. Thereafter, as is illustrated in FIG. 4, finger pressure may be applied to deflect the previously unadhered portion of the section 13 a into contact with the tape end 46. Since manual contact with the adhesive on the underside of the tape section 13a has been completely avoided, the integrity of the splice is greatly enhanced. Referring to FIG. 2, note should also be taken of the oblong parallelogram configuration of the tape section 13a, achieved by-vir'tue of the slantwise slitting of the tape. In connection with the use of sheet articles 13a intended for use in splicing sound recording tape and the like this parallelogram configuration is of particular utility both in attaining the proper alignment of the section 13a with the tape ends and, also, in connection with inhibiting mechanical displacement of the section 13a from the splice once it has been finally applied.

In FIGS. 5 and 6 there is illustrated an apparatus adapted for automatically dispensing the tape sections 13a from a roll 35. A housing 50 incorporates a top wall 51 over which a weighted guide plate 52 is superimposed. The top wall 51 and guide plate 52 thus desufficiently to bring the first tab 120 on the carrier strip 10 through the dispensing station, with the corresponding tape section 13a at rest in a position to intercept a ray 62 focused by means (not shown) onto the section 13a, to be reflected as a ray 63 directed into the photoelectric cell 60.

The photoelectric cell 60 comprises a portion of a circuit (not shown) including a relay and adapted to start and stop a motor orthe like drivingly engaged to the wind-up drum 61. Thus, so long as a tape section 13a is in position to reflect light from the source 59 onto the cell 60 the motor drive circuit remains open and the wind-up. drum 61 is deactivated. However, upon the foremost and forwardly projecting tab 120 being grasped and the corresponding tape section 13a being peeled from the first marginal portion 12a, the control circuit is closed, actuating the relay in order to turn the wind-up drum 61 through an arc sufficient to bring the next article 13a into the dispensing position. Thereupon, the light from the source 59 is again reflected from the upper surface of a section 13a into the photoelectric cell 60, deactivating the control system. In this connection, while the control system just described has been successfully employed with a metallic foil faced tape section 13a, it will be appreciated that it may also be employed with sections 13a not incorporating any metallic face. All that is required is a differfine a channel therebetween through which the corn,-

posite is channelled towards a forward wall 53 of the housing. At its rear end, the top plate 52 is formed with an upwardly and rearwardly projecting curved section 54 whereby individual tabs 12c will be deflected downwardly onto the carrier strip '10, into contacting superposition thereon, as the roll 35 turns in the unwinding direction.

' The apparatus has a dispensing station at the junction of the forward wall 53 and the top wall 51 of the housing. This dispensing station includes a roller 54 mounted for rotation on a horizontal axis and over which the carrier strip 10 is turned to be deflected downwardly for passage through a clearance space provided between the front surface of the front wall 53 and a cover plate 55. Also mounted at the dispensing station, on an appropriate bracket 57, is a housing 58 containing a focused light source 59 and photoelectric cell 60.

The roll 53 may be provided with a leader comprising a blank portion of the carrier strip 10 that is initially passed through the guide means just described to have 6 its end connected to a wind-up drum or spool 61. A sufficient length of leader is provided whereby its end may be so connected to the wind-up drum and advanced ence in reflectivity between the upper surface of the particular tape section 13a under consideration and that portion of the underlying first marginal portion 12a normally covered by the section 13a. For example, one of the surfaces may comprise a specular reflector while the other surface may comprise or have the characteristics of a diffuser, or both surfacesmmay be specular or diffuse, or may vary in color or hue, but appropriate filters may be interposed in the line of the reflected ray 63 to discriminate between any differing characteristics of light reflected from two differently optically reflecting surfaces.

Referring to FIG. 5, it will be seen that the guide means for the composite structure, at the dispensing station, is adapted to separate the individual tabs from the normally underlying supporting strip 10. Thus, as the composite tape is fed outwardly of the housing50, since the free end of each tab' precedes the tape section 13a to which it is joined, a sufficient por tion of the length of the tab is supported in the horizontal plane toproject forwardly from the front wall of the housing while that portion of the carrier strip .10 originally disposed immediately thereunder has been turned downwardly into the channel-defined between the forward wall 53 and the cover plate 55. v

Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred fonn has been made by way of example and that numerous changes inthe details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention.

I claim:

I. A process of making aseries of individually dispensible adhesive-backed flexible sheet articles comprising:

longitudinally aligning a carrier strip and a flexible web, leaving a release coated side of said web exposed, in contacting superposition;

securing the strip and the web together longitudinally thereof, leaving a marginal portion of the web unsecured;

severing the unsecured portion of the web longitudinally thereof;

applying a strip of a pressure sensitive adhesivebacked tape material longitudinally of the web, onto the release coated side of the web and over the line of severance of the web, to secure the longitudinally severed portions of the web together 10 while leaving a longitudinally extending edge portion of the marginal portion of the web exposed;

and cutting the tape and web transversely at intervals spaced longitudinally thereof for defining a series of individually dispensible adhesive-backed sec tions of the tape adhesively joined to a series of severed sections of the marginal portion of the web providing tabs by means of which the corresponding sections of tape may be released from adherence to that portion of the web secured to the carrier strip.

2. The process of claim 1 in which the cutting of the web and the tape is along lines other than normal to the longitudinal edges of the web.

3. The process of claim 2 in which the carrier strip, release coated web and the tape are moved linearly in being assembled, said strip being flexible,

and in which the lines along which the tape and web are out are slits at an angle such that each section of the tape linearly precedes the corresponding tab portion of the web whereby to prevent lateral displacement of each tab as the assembled composite .of strip, web and tape is wound on a spool.

4. The process of claim 1 in which the area of mutual contact between the underside of each section of tape and the release coated surface of the corresponding tab is less than the remaining area of the section of tape.

5. The process of claim 1 in which the carrier strip and the web are adhesively secured together by a strip of an adhesive that is laid onto the carrier strip in advance of the strip and the web coming into contacting superposition.

Claims

2. The process of claim 1 in which the cutting of the web and the tape is along lines other than normal to the longitudinal edges of the web.
3. The process of claim 2 in which the carrier strip, release coated web and the tape are moved linearly in being assembled, said strip being flexible, and in which the lines along which the tape and web are cut are slits at an angle such that each section of the tape linearly precedes the corresponding tab portion of the web whereby to prevent lateral displacement of each tab as the assembled composite of strip, web and tape is wound on a spool.
4. The process of claim 1 in which the area of mutual contact between the underside of each section of tape and the release coated surface of the corresponding tab is less than the remaining area of the section of tape.
5. The process of claim 1 in which the carrier strip and the web are adhesively secured together by a strip of an adhesive that is laid onto the carrier strip in advance of the strip and the web coming into contacting superposition.