Conventional such masking tapes comprise a circular cross-section foam strip with a line of adhesive. Such tapes are described in EP 0356510, Silvestre, and marketed by 3M United Kingdom plc ("3M") and known as"soft edge"tapes, the'soft edge'being a reference to the desire to avoid a hard edge or ridge to the primer, paint or lacquer, the idea being that the foam soaks up any excess. The tape is conventionally applied to the fixed structure of the vehicle-the surround-and the moving member, e. g. the door, is closed on it to form a seal. Unless, however, the tape is very carefully positioned, the closing of the door or other member can displace the foam so as to expose the adhesive by which it is attached, and this can give rise to the formation of a ridge because the adhesive does not absorb the sprayed material. Such a ridge has to be rubbed down, which is a time consuming and costly operation.

3M have recently brought out a new product, called Universal Soft Edge, which is used according to a method disclosed in UK Patent No. 2 327 052, Jevons. This tape is applied to the moving member, and the adhesive is well away from the sprayed area, so that there is no danger of ridge build up. However, that tape contains more foam per unit length than the conventional Soft Edge Tape, and is commensurately more expensive.

In addition, its method of use is quite different from that of the conventional Soft Edge Tape, and many users prefer the tape to which they are accustomed, regardless of the proven advantages of the newer product.

The present invention provides an improved tape, which can be used in the same manner as the 3M Soft Edge Tape, but which is designed to avoid the likelihood of ridge build up; the invention also provides improved tapes which can be used in the manner taught by Jevons, but which are substantially less expensive than the 3M Universal product.

The invention, moreover, provides tapes which are simpler and less expensive to manufacture and pack for shipment and use.

The invention comprises a foam masking tape comprising an elongate flat strip of foam material attached to adhesive strip material so that an elongate section of the adhesive material overhangs the edge of the foam material.

The foam material may be open cell foam.

The adhesive strip material may comprise conventional paper masking tape, which may be inextensible or substantially so under normal tensile forces experienced in manufacture, packing and use, so that there is no risk of stretching it when it is being applied to an aperture to be masked, as can happen with conventional foam tapes, where the elasticity of the foam tends to pull the tape back to length after application, which, in turn, leads to the tape pulling itself free from the surround or the closing member.

In a first embodiment of tape according to the invention, the foam material may be between 10 and 20 mm in width. The adhesive strip material may be 10-12 mm in width, overhanging the foam material be 6-8 mm The adhesive strip material may be double sided adhesive and have two strips of foam material attached at one edge of the adhesive strip. Two strips of foam material may extend inwardly, on the same face of the adhesive strip material, from each edge thereof, so as to leave between them an exposed area of adhesive.

The invention comprises a tape of this first embodiment presented on a roll, which may be presented in a dispensing container.

The invention also comprises a method of masking an opening having a surround and a closing member (such as a door of an automobile during refinishing) using a foam masking tape of the first embodiment, comprising attaching the tape by its overhanging adhesive strip material to the surround of the opening in such manner as to result in the foam tape standing up, around the surround, at an angle from the surface to which the adhesive tape is attached by virtue of the thickness of the foam strip, then closing the closing member on to the upstanding foam.

The invention also comprises a method of masking an opening having a surround and a closing member using a foam masking tape of the first embodiment, comprising attaching the tape by its overhanging adhesive strip material to the (open) closing member in such manner as to result in the foam tape standing up, around the opening member, at an angle less than 90° from the surface to which the adhesive strip is attached by virtue of the thickness of the foam strip, then closing the closing member, so that the foam strip contacts the rim of the surround so that its edge remote from the adhesive strip remains outside the gap between surround and closing member, then repositioning the said edge of the foam strip all round the gap by e. g. finger pressure so as to lie within the gap, but in sealing fashion.

The invention also comprises a method of masking area of panel work by first applying a double sided m asking tape of the first embodiment, then attaching to the exposed adhesive a sheet of plastic film or other masking sheet material.

A second embodiment of masking tape according to the invention comprises an elongate strip of foam material of not completely annular cross section of which the edges are

connected by a strip of adhesive material so that an adhesive face of the adhesive material is exposed between the edges of the foam strip.

The foam may be some 30 mm wide by some 3 mm thick assembled together with a strip of adhesive material some 15 mm wide arranged to adhere to the edges of the foam strip by about 2.3 mm selvedges leaving an exposed adhesive face of some 10 mm width.

However, in a variant of this second embodiment, the foam may be some 45-50 mm wide by some 3 mm thick assembled together with an adhesive strip some 25 mm wide of which the middle 15 mm are exposed for attachment purposes.

It will be seen that this second embodiment is the same as the first embodiment in concept, but the foam has been bent round and attached to the adhesive strip at its other edge to form a tube. This product, appropriately dimensioned, may be used in much the same way as the 3M Soft Edge Tape, or the Universal Soft Edge Tape. On account of its comparatively low foam content, it is, however, less expensive to produce. The use of conventional paper masking tape as the adhesive strip removes a quality control problem from the manufacture of this tape-the quality control over the adhesive properties has already been dealt with in the manufacture of the paper tape. The use of substantially inextensible paper masking tape avoids overstretching the tape on application, so that there is no danger of it falling off due to elastic contraction. And the fact that the adhesive can be recessed with respect to the foam avoids the build up of paint ridges, because the adhesive is always shielded from the spray.

Moreover, the tape is inherently easy to manufacture.

The invention comprises a method of making the second embodiment of masking tape comprising running a foam strip together with an adhesive strip through a fold or gathering device that folds the foam strip around the adhesive strip to adhere the edges

of the foam to the edges of the adhesive strip, adhesion being secured by passing between nip rollers.

The invention also, however, comprises supplying a flat strip of foam with an adhesive strip attached to one edge in that configuration to a dispenser with a folding and pressing device at an aperture and pulling the strip through the folding and pressing device to contact and adhere the free edges of the foam and adhesive strips. A user package of masking tape according to the invention may therefore comprise a package of tape according to the first embodiment which has an optional use folding and pressing device to convert the tape into a tape according to the second embodiment, giving the end user a choice of tape configurations.

Even, however, if packed as second embodiment tape, the packaging requirement is significantly reduced as compared to either Soft Edge Tape or Universal Soft Edge Tape, inasmuch as the tubular construction will pack down into a flat configuration. If the adhesive surface is recessed with respect to the edges of the foam strip, it will not, in a roll of the tape, contact anything, and the tape will be easy to unwind.

The invention comprises, also, then, a method of masking an opening having a surround and a closing member using a foam masking tape according to the second embodiment, comprising attaching the tape by its exposed adhesive to the surround of the opening and closing the closing member.

The invention also comprises a method of masking an opening having a surround and a closing member using a foam masking tape according to the variant of the second embodiment, comprising attaching the tape by its exposed adhesive to the (open) closing member and closing the closing member to trap the foam in the gap between the closing member and the surround. The tape may then be adjusted by e. g. finger pressure applied around the opening to lie flush with the surround and closing member surfaces or to lie

at a small distance beneath such surfaces for wet-on-wet or normal second coat application.

Embodiments of foam masking tapes, methods of making them and methods of using them according to the invention will n ow be described with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a short section of a first embodiment of masking tape; Figure 2 shows how the tape of Figure 1 may be manufactured; Figure 3 is a cross section through a door surround of an automobile showing how the tape of Figure 1 is applied; Figure 4 is a cross section like Figure 3, showing the closing member closed on the tape; Figure 5 is a cross section like Figure 3, showing a first embodiment tape applied to the moving member; Figure 6 is a cross section like Figure 5, showing the moving member closed; Figure 7 is a cross section like Figure 6, showing the tape adjusted in the gap between moving member and surround; Figure 8 is a diagram showing another usage; Figure 9 is a cross section through a variant of the first embodiment of tape;

Figure 10 is a cross section through another variant; Figure 11 is a cross section through yet another variant; Figure 12 is a cross section through layers of a stack or roll of tape like that of Figure 9; Figure 13 is a cross section through an edge of a panel to be masked showing a tape like that of Figure 9; Figure 14 is a section like that of Figure 13 with a plastic masking sheet attached to the masking tape; Figure 15 is a section like Figure 14, showing the sheet trimmed; Figure 16 is a section through a tape like that of Figure 9, folded lengthwise; Figure 17 is a perspective view of a short section of a second embodiment of tape; Figure 18 is a view like Figure 17 of a first variant; Figure 19 is a view like Figure 17 of a second variant; Figure 20 is a cross section like Figure 5 showing the application of the tape of Figure 19 to a moving member; Figure 21 is a cross section like Figure 20, with the moving member closed; Figure 22 is a cross section like Figure 21, with the tape adjusted in the gap;

Figure 23 is a diagrammatic side elevation of a tape manufacturing arrangement; Figure 24 is a plan view of the arrangement of Figure 23; Figure 25 is a cross section of the line XXV-XXV of Figure 24; Figure 26 is a cross section on the line XXVI-XXVI of Figure 24; Figure 27 is a cross section through a first roll of second embodiment tape; Figure 28 is a cross section through a roll of first or second embodiment tape; and Figure 29 is a view of a"spout"for a box for the roll of tape illustrated in Figure 28.

The drawings illustrate a foam masking tape 11 comprising a strip 12 of flat foam tape having attached at one edge 12a, so as to overhang that edge, a strip 13 of adhesive tape.

The foam tape 12 is open cell foam, so as to absorb primer and lacquer sprayed on to the vehicle in refinishing. A suitable thickness is 3 mm, but this is not critical. A suitable width, for a first embodiment of tape as illustrated in Figures 1 to 7, is 15 mm, but, again, wider or narrower tapes will be appropriate for different applications.

The adhesive strip comprises conventional paper masking tape such as is made in large quantities and hence inexpensively obtained and of known, standard quality, so far as its adhesive properties are concerned. A suitable width is 10-12 mm, of which perhaps 8 mm overhangs the edge 12a.

Manufacture is simply a matter of providing, or cutting, appropriate widths of foam and adhesive tape and running them together, as shown in Figure 2, through nip rollers 21

which press the tapes together causing the adhesive tape 13 to adhere to the foam 12 by virtue of its own adhesive. The composite tape 11 is wound up on a conventional spooling machine, not shown.

Figures 3 and 4 show one method of using the tape 11. A door opening of an automobile has a surround 31 to which the tape 11 is attached by its overhanging adhesive strip 13.

The thickness of the foam causes it to stand out at an angle from the surface of the surround 31. The tape is applied with the door 32 open, as shown in Figure 3. When the door 32 is closed, Figure 4, it contacts the free edge of the foam 12 and bends it back into the gap 33 between the door 32 and surround 31 so as to seal the gap against ingress into the interior of primer or lacquer.

Figures 5 to 7 illustrate the tape being used in the fashion of the 3M Universal tape aforementioned. The tape is attached to the door 32. Again by virtue of the thickness of the foam, it stands up at an angle from the surface to which the adhesive tape is adhered, but in this application it is important it be not too big an angle. The door 32 is, after the tape has been applied all round its periphery, closed. It is then a simple measure to apply finger pressure to the projecting edge of the foam 12 to relocate it inside the gap in sealing relationship therewith.

Somewhat wider tapes will be more appropriate to the method of use as illustrated in Figures 5 to 7 than will suffice for the method of Figures 3 and 4, but a universal (truly) tape may be made having dimensions suitable for either method of application on most if not all automobiles and most if not all gaps on automobiles.

As also mentioned above, tapes, perhaps differently dimensioned, but of the same general description, may find application in other masking operations.

For example, in painting a panel 81, to produce a"feathered"edge near, for instance, a stripe 86, the tape may be deployed as illustrated in Figure 8, with the free edge 1 la raised from the surface of the panel.

Because the free edge 1 la is raised above the level of the panel there is diffusion of the spray around the edge 1 la of the tape 11, or a penumbral effect and a tapering off in the amount of primer/lacquer applied due to the movement of the spray device 83, avoiding a sharp edge to the paintwork.

Figures 9 to 13 illustrate masking tapes 11 using double sided adhesive tape 13, which, as before, comprises conventional paper masking tape, but with adhesive on each face, 13a, 13b.

These tapes, as seen in Figure 9, have two strips of foam 12, one attached at each edge of the adhesive tape 13. The two strips of foam 12 extend inwardly from each edge of the adhesive tape 13, on the same face, 13a, thereof, so as to leave, between them, an exposed area of adhesive.

Figure 10 shows a tape 11 of which the adhesive tape 13 projects beyond the outer edges 12e, 12f of the foam strips.

Figure 11 shows a tape like that of Figure 10, but one which has foam strips 12 which have been cut from sheet foam by blunt rotary blades, after the fashion of EP 0384626, so as to yield rounded edges 12g.

Figure 12 is a cross section through layers of a stack or roll of masking tape 11 like that of Figure 9. It will be evident that because the exposed adhesive face 13a is recessed between the foam strips 12, it does not, in the stack or on the roll come into contact with

the adhesive of the face 13b, which merely contacts the foam 12 and is therefore easily unstacked or unrolled.

Figures 13 to 15 illustrate how masking tapes according to Figures 9 to 12 can be used for masking panels 131 of an automobile (or any other paint job) when as a adjacent area 132 is to be painted. The first step, shown in Figure 12, is to apply the masking tape 11 at the edge of the area 131 to be protected, to which it adheres by virtue of the adhesive on face 13b of the tape. A plastic film sheet 133 is then applied over the area 131 and adhered, roughly, to the exposed adhesive face 13a of the tape, this being shown in Figures 13 and 14.

Figure 15 shows the sheet 133 having been trimmed by a blade or an envelope opener, not shown.

Tapes as illustrated in Figures 9 to 12 can also, of course, be used in like manner to the tapes with only one foam strip, as illustrated in Figure 1, by simply folding the tape lengthwise and adhering the two halves of face 13b together, as seen in Figure 16. This may still be used to attach a plastic film sheet for masking a panel or other large area, as there is adhesive on both faces of the edge of adhesive film that projects from the foam.

Figures 17,18 and 19 illustrate a foam masking tape 11 comprising an elongate strip of foam material 12 of which the edges 12a, 12b are connected by a strip 13 of adhesive material so that an adhesive face of the adhesive material 13 is exposed for attachment of the tape to a part of an automobile.

This is, essentially, the tape of Figure 1 bent around lengthwise and the free edge of the foam adhered to the free edge of the adhesive tape.

The tape 11 is of such cross sectional size that it can be attached to the moving member 14 of a door or other aperture 15 and shaped so as to project beyond the edge 14a thereof, so that, when the moving member is closed into its surround 16, the projecting edge thereof 11 a is lightly trapped between the surround and the edge 14a of the moving member 14 but free to be adjusted by finger pressure to lie flush with the outer face 14b of the moving member, whereby it fills the gap 17 between them.

The foam tape 12 is typically some 45-50 mm wide by 3 mm thick, and may be supplied for use in that configuration, or may, as part of the manufacturing process, be slit from foam sheet, for example, by sharp or blunt cutting wheels, the latter giving rounded, cold-welded edges as taught in EP 0384626. The foam 12 is assembled together with an adhesive strip 13,25 mm wide, overlapping the adhesive strip 13 by 5 mm at each edge 12a, 12b so that the middle 15 mm of the adhesive strip 13 are exposed for purposes of attachment to the moving member 14.

The adhesive strip, as before, comprises conventional paper masking tape, which adheres to the edges 12a, 12b of the foam strip by its own adhesive, so that no additional adhesive application step, usually involving an expensive hot melt unit, is required, although additional adhesive could be applied if the adhesive system of the adhesive tape required reinforcement to make it stick preferentially to the foam rather than to the surface of the moving member 14 so that it may be stripped from a finished job without separating into its component parts. As before, using a material such as conventional paper masking tape, which is inextensible under forces normally encountered in use, has an additional advantage in that the tape 11 as a whole cannot be stretched during application to the moving member 14, reducing the risk that the tape, trying to get back to its original length, unsticks from the surface to which it has been applied, requiring time-consuming reattachment.

Figure 17 shows an arrangement in which the adhesive strip 13 is attached to the inner face 12i pf the foam"tube"12. This is, perhaps, the simplest arrangement.

Figure 18 shows an arrangement in which the adhesive strip 13 is bent over at its edges and adhered to the outer surface 12o of the foam strip 12. Of course, one edge of the adhesive strip 12 could equally well be attached to the outer face 12o, as in Figure 18, while the other edge is attached to the inner face 12i, as shown in Figure 1.

Figure 19 shows an arrangement in which the adhesive strip has been given a crease 13c, the edge thereof adjacent the crease 13c being attached not quite at the edge 12b of the foam strip 12, so that there is a"tail"of foam 12t. This forces the arrangement into something akin to the bullet section disclosed in GB 2 327 052 aforementioned, and makes it abundantly clear, to anyone familiar with the tape, or the £M version of it, how it should be applied. With the embodiments of Figures 17 and 18, it will be necessary to direct manual pressure during application to the moving member in such a way as will properly orientate the foam to assume the appropriate"bullet"section in order to be trapped on closure of the moving member.

Figures 20 to 22 illustrate the process of applying the foam masking tape 11 to a moving member-the door 14. It is simply run around the edge 14a of the door 14, following the"contours"thereof and pressed down by finger pressure, so that the adhesive strip 13 sticks to the door 14 by virtue of its adhesive face 13a. When the tape 11 is applied all around the edge of the door 14, and, if necessary,"brushed"out to project beyond the edge 14a of the door 14, the door is closed, as seen in Figure 21, which will leave a rounded edge for the tape 11 protruding to a greater or lesser extent at different [places around the door 14. Simply, as taught in GB 2 327 052, the tape 11 is then pushed in, all around the gap 17 between the door 14 and surround 16, with light finger pressure, so that it lies flush as seen in Figure 22. The procedure is the same regardless of which variant is being used, the variants of Figures 17 and 18, however, perhaps having to be

"coaxed"by appropriately directed finger pressure into lying towards the outside of the door 14 so as to be trapped as required when the door 14 is closed.

Of course, the embodiment of Figure 17 closely resembles the 3M Soft Edge Tape, and may, indeed, be used after the fashion in which that tape is used, namely by attachment to the door surround, closing the door on it to effect the seal. An important advantage, however, is that, as the adhesive is recessed, it is much less likely to cause a ridge to build up by exposure of the spray to the adhesive rather than the absorbent foam.

It would be possible to make a smaller cross section tape like the one in Figure 17 exclusively for use as conventional Soft Edge Tape, but it seems more sensible to make a standard product that can be used in both ways.

Figures 23 to 26 illustrate one method for making the tape 11 of Figures 17 to 19. A strip of foam 12 is merged together with a strip of adhesive material 13 in a folding condenser 71, which takes the two components at Section line XXV-XXV of Figure 24 and folds the edges of the foam around the adhesive tape 13 as shown in Figure 26. In this configuration, the two tapes are passed together through the nip of a pair of rollers 71, which pressure-set the adhesive between the paper tape 13 and the foam tape 12. The composite tape is then ready to be wound up into a roll.

Rolls of tape are shown in cross section in Figures 27 and 28. In Figure 27 is shown tape 11 in successive layers on a core or former 111, the tape 11 having possibly been made by a process as just described.

However, as Figure 28 shows, the tape 11 may be semi-finished before being wound up for use, inasmuch as only one edge of the adhesive strip 13 need be adhered, initially, to one edge of the foam 12. Clearly, more tape can be wound up on to a wind-up package

of smaller diameter, resulting in cost savings in packing, storage and transportation, at the expense, however, of having to complete the assembly of the tape at the point of use.

Pulling the tape, wound up in this way, for example, through a"spout"or folding die arrangement, Figure 29, on the package in which the tape is supplied can readily achieve this, even without the presence of nip rollers, as it folds round the fee edge of the foam and places it neatly on the edge or edges of the adhesive tape, Of course, the use of the spout can be optional, if users prefer to use the tape as described with reference to Figures 3 to 7.