Patent Application
20150107763
This invention relates to a method of applying an adhesive film to a surface of an object such as a printed or colored film applied over a vehicle.
Popular customization of vehicles in some cases involves the application of an adhesive film carrying printed graphics to the exterior surface of the vehicle. Such a film is readily available for example from 3M and is provided in large sheets carrying a pressure sensitive adhesive covered by a release layer allowing the sheet to be printed with the required graphics and applied to the vehicle. The sheet can also be printed with a solid color where portions of the sheet are applied in shaped patterns to provide the required attractive effect.
One issue which remains a difficulty is that of cutting the film at required locations so that the film terminates at the edge of a panel or at any other required location on the surface.
Other issues relate to the cutting of the film to provide butting edges of two adjacent films typically of different colors and to forming narrow stripes of a single color which are popular in the design of graphics of this type.
Reference is made to U.S. Pat. Nos. 8,187,407 and 8,361,615 of the present applicant corresponding to Canadian patent 2700471 which show an arrangement of tape for use in applying a film, the disclosure of which is incorporated herein by reference.
It is one object of the invention to provide a method of applying an adhesive film to a surface using a tape for cutting the film.
According to one aspect of the invention there is provided a method for applying adhesive film to a surface of an object, the method comprising:
providing a tape having a front surface, a rear surface, a first longitudinal side edge and a second longitudinal side edge defining a width therebetween;
the tape having an adhesive on the rear surface for attachment to the surface of the object;
the front surface of the tape being free from adhesive and having a release characteristic relative to the adhesive film such that the adhesive on the film can be contacted onto the front surface of the tape and pulled away without dislodging the tape from the object;
the tape having a first and a second filament attached thereto at spaced positions across the width of the tape defining a constant spacing therebetween;
applying a length of the tape to surface of the object so as to be attached thereto by the adhesive thereon;
positioning the film onto the surface of the object and over the tape such that the film is attached by the adhesive to the surface of the object and so that the film extends to both side edges of the tape;
pulling the first filament from the tape through that part of the film over the tape so as to cut the film and to form a first cut edge of the film;
pulling the second filament from the tape through that part of the film over the tape so as to cut the film and to form a second cut edge of the film;
the cutting of the film by the first and second filaments forming a strip of the film having a width defined by the spacing between the filaments on the tape;
the strip being attached to the object as a visible stripe thereon;
the tape being removed from the surface.
In one preferred arrangement of the method, the tape is severed along its length so as to provide a first portion of the tape along the first side edge of the tape and a second portion of the tape along the second side edge of the tape and in a further step the first portion of the tape is firstly removed while the film remains attached to the surface along the second edge of the tape and in a final step the second portion of the tape is removed while a part of the strip is attached to the surface. In this way the strip is formed by the cutting action of the filaments and is applied to the surface while it remains always attached to the surface at least over a part of its width. Thus it is held in place by is attachment to the surface and is never a free component which can be tangled and misplaced.
Preferably the tape is severed by a third filament carried on the tape between the first and second filaments which is activated first to cut the tape into two sections while the tape is applied onto the surface. However other methods of severing can be used, including supplying the tape as preformed separate section which are held together when applied but can be readily separated for removal.
Preferably therefore for this arrangement there is provided a third filament located between the first and second filaments.
In another method, the strip remains attached to the tape as a layer over the width of the tape and is removed with the tape from the surface and reapplied to the object as a stripe applied onto the surface or onto the film on the surface. Preferably in this arrangement the strip is applied over butting edges of two adjacent films formed by cutting two films with the tape. The strip is then the same color as one of the films and is applied not to provide a distinct color but instead to protect the butting edges while matching the color of one of the films so as to be not visually distinct.
Preferably, as set out in detail in the prior patents identified above, the tape is extensible so as to allow bending to at least one side by extension along the opposite side. However this is not essential to this method.
Preferably the first and second filaments are spaced from both side edges and the tape has a width arranged such that each filament tears through the tape along the length of the tape, when pulled to cut the film, rather than pulling from one side edge of the tape.
However as an alternative, the first and second filaments can be arranged respectively at the first and second edges of the tape so as to pull out from the edge of the tape rather than tearing through the tape.
Preferably, as set out in detail in the prior patents identified above, the first and second filaments are carried in or on the adhesive on the rear surface.
Preferably, as set out in detail in the prior patents identified above, the filaments are extensible with the tape and the adhesive acts to hold the filaments in place on the tape during bending of the tape while the tape is applied to the surface.
According to a second aspect of the invention there is provided a method for applying adhesive film to a surface of an object, the method comprising:
providing a tape having a front surface, a rear surface, a first longitudinal side edge and a second longitudinal side edge defining a width therebetween;
the tape having an adhesive on the rear surface for attachment to the surface of the object;
the front surface of the tape being free from adhesive and having a release characteristic relative to the adhesive film such that the adhesive on the film can be contacted onto the front surface of the tape and pulled away without dislodging the tape from the object;
the tape having a first and a second filament attached thereto at spaced positions across the width of the tape defining a constant spacing therebetween so that the first filament is closer to the first edge of the tape and the second filament is closer to the second edge;
applying a length of the tape to surface of the object so as to be attached thereto by the adhesive thereon;
positioning a first film onto the surface of the object and over the tape such that the film is attached by the adhesive to the surface of the object and so that the film extends to both side edges of the tape with a main body of the first film on the first edge side of the tape and a removable edge portion of the first film on the second edge side of the tape;
pulling the second filament from the tape through that part of the first film over the tape so as to cut the first film and to form a first cut edge of the first film so as to separate the main body of the first film from the removable edge portion of the first film;
removing the removable edge portion of the first film from a portion of the surface of the object up to the first cut edge;
positioning a second film so that the second film is located onto the surface of the object at said portion of the surface of the object and is attached by the adhesive to said portion;
the second film extending over the first film on the tape so as to define a removable edge portion of the second film on the first edge side of the tape;
pulling the second filament from the tape through those parts of the first and second films over the tape so as to cut the first and second films film and to form butting cut edges of the first and second films with remaining portions of the first and second films extending beyond said butting cut edges;
removing said remaining portions of the first and second films extending beyond said butting cut edges;
the tape being removed from the surface so that the butting cut edges lie in butting relationship on said surface.
This method therefore provides two accurately abutting edges of the two films no matter what the required shape of the butt.
Preferably a strip of the first film is formed by the first and second filaments having a with equal to the constant spacing between the first and second filaments and wherein the strip is removed with the tape from the surface and reapplied to the object over the butting edges for protection thereof. In this case the strip will be of the same color as one of the films so that it is not intended to be visually distinct.
In some cases a primer is applied to the surface at least underneath the tape for increased attachment of the edge of the film to the surface and the adhesive of the tape preferably has the characteristic that the tape can be pulled from the primer on the surface of the object without leaving a residue of the adhesive and without damaging the primer surface.
Preferably the filament has the following characteristics:
Preferably the filament has a weight per unit length which equates to a calculated diameter of the filament, based on an assumption that the filament is circular in cross-section, of less than 0.005 inch.
The filament may be a monofilament, a twisted multi-filament cord or may be a multi-fiber composite filament for example a twisted multi-fiber filament.
The filament is preferably a polymeric material such as polyester or nylon.
It will be appreciated that such polymeric materials when formed into filaments are typically not circular in cross section so that their cross-section is measured in a weight per unit length measurement of tex which is the mass of the filament in grams per 1000 meters of the filament or denier which is the mass in grams of 9000 meters of the filament.
One can calculate the diameter of a filament (assuming it is circular in cross-section, which is typically not correct) given its weight in denier with the following formula:
where ρ represents the material's density in grams per cubic centimeter and the diameter is in cm.
Or using the following formula based on dTEX (grams per 10,000 meters length)
where ρ represents the material's density in grams per cubic centimeter and the diameter is in cm.
The intention in the present filament is that it has a diameter (assuming it is circular) of less than 0.005 inch (0.127 mm) and preferably less than 0.003 inch (0.0762 mm) and preferably less than 0.002 inch (0.0508 mm) and preferably less than 0.001 inch (0.0254 mm). Depending on the material from which it is formed, the tex or denier of the material can be calculated using the density of the material concerned.
The filament is selected from one of these materials such that it has the minimum diameter to meet the strength requirements for the cutting action set forth above.
Such characteristics of the filament cannot be met by filaments of metal (typically steel), Kevlar or UHMW polyethylene which have a high elastic modulus and cannot be elongated along their length. These materials have very high strength and are typically selected for this purpose on the ground that high strength is required. The present inventors have realized that strength is of secondary importance provided there is sufficient strength to actually cut through the film, and the tape if the filament cuts the tape simultaneously. Thus the strength should be the minimum which can be acceptable and instead the diameter of the filament should be minimized while providing the required strength.
Thus the strength of the filament must be greater than 1.0 pound force to break, so that the action of cutting can be carried out. Where the strength is only slightly greater than 1.0 pounds force it can be maintained less than 3.0 pounds which allows the tape and filament to be both broken by hand.
Thus the filament itself has a strength to break in the range 1 to 3 pounds force. That is a filament having a strength to break greater than 3 pounds and up to 5 pounds is less desirable to use because the strength is unnecessary so that the filament is better to be finer than stronger. It has been established that the pull strength of the order of 1 pound is sufficient to allow the filament to tear through multiple layers simultaneously of the vinyl material provided by 3M which is the preferred film used in the industry. Provided this can be achieved, any additional strength is unnecessary.
Thus the combination of the tape and the filament has a strength to break of less than 3.5 pounds force which reasonable allows the tape and filament to be snapped by hand by the installer as he reaches the end of the tape strip to be applied. This is of significant advantage in the time required for installation. This ability to hand break the tape and filament is a consequence of the realization that the high strength required in previous proposals is not required.
With regard to extensibility, the tape itself is highly extensible having an extension under a load of 8 to 12 pounds force per inch width of the order of 300 to 830%. In many cases the tape is formed of polyethylene or a polyethylene/polyester multi polymer film mix, which provides the high extensibility.
Such a high extension under load allows the tape to bend left to right in its plane to follow curvatures of less than 0.5 inches as set forth above. To achieve such curvatures in a tape of the order of 0.125 inches in width and wider, one side must extend significantly relative to the other side creating an extension gradient across the tape. Previous filaments in order to achieve the high strength believed to be required have been basically inextensible under the loads involved.
The filament has been determined to preferably provide an extension greater than 15% under a load of 1.0 pounds force. This extension of the filament allows it to extend during the side to side bending of the tape. This extension of the filament allows it to extend during the application of the tape to the surface. That is the filament extends with the tape as the tape is pulled by the installer with a significantly reduced tendency of the filament to break out of the tape. It has been found that inextensible filaments of the type previously used and proposed, due to the differential in extension from the tape, tend to break out of the adhesive leaving the filament and tape as separate components so that the installer must try to apply the tape while re-inserting the filament into the tape as it is applied. This pulling action on the tape can occur as it is pulled off the supply roll or as it is applied onto the surface. In both cases the separation of filament and tape is highly problematic.
The above stated extension of 15% under a load of 1.0 pounds force has been found to be sufficient to allow the tape and filament to remain connected during the level of stretching of the tape which occurs in practice. The reduction in differential forces tending to separate the filament from the tape also reduces the requirement to have a high bond between the filament and the adhesive on the tape so that filaments which are inherently less able to bond to the adhesive can be used.
Thus the tape with the filament attached should turn through a radius of curvature in both directions (in the plane of the tape) which is less than 3 inches and more preferably less than 1.0 m inch or even 0.5 inch without the filament pulling away from the underneath the tape. That is the adhesion of the filament underneath the tape and the ability of the tape and filament to generate the differential stretch must be necessary to make these turns.
The above reduction in required strength which leads to a reduction in diameter (or denier) of the filament also allows a further significant advantage in that the necessity to bond the filament to the adhesive on the tape or bond the adhesive to the surface is much reduced. A high diameter of the filament of greater than 0.005 inch lifts the tape at the location of the filament away from the surface in a “tenting” effect which necessarily reduces the contact width of the adhesive on the surface. A filament of smaller diameter allow a greater width of the tape to be applied to the surface thus increasing the bond of the tape to the surface and reducing the possibility that the filament can escape from the highly bonded tape.
Thus a filament useable in the above method preferably has the following characteristics:
A strength to break in the range 1 to 3 pounds force;
An extension of at least 15% under a load of 1.0 pounds force;
A weight per unit length which equates to a calculated diameter of the filament, based on an assumption that the filament is circular in cross-section, of less than 0.005 inch;
the ability to bend, with zero resistance to bending, to a radius of curvature of less than 0.5 inches.
In one example, a polyester multi-fiber filament of 16 tex can be used which provides a strength to break of 2 pounds force, an extension of 15% under a load of 1.0 pounds force.
The 16 tex polyester fiber described herein has a calculated diameter a little less than 0.005 inch.
This filament with a tape formed from polyethylene of 0.125 inch in width has a combined breaking strength of 2.5 pounds force and can bend side to side to a radius of curvature of 0.5 inches without the filament breaking out from the tape.
This filament provides a breaking strength sufficient to cut through 3 layers at a total of 18 mil (0.018 inch) thickness of materials from 3M sold under the designation 480cv3 which has been recently introduced. The filament can also cut four layers at a total of 20 mil (0.020 inch) thickness of conventional vinyl film and provides a cut line which under magnifying glass is a clean line with no jagged edges. It will be appreciated in this regard that the filament is in some cases required to cut through more than one layer of film and up to three or four layers where the films are overlaid to provide a particular graphics effect with the films.
Adhesive films of this type are available with a release layer from suppliers such as 3M and can be printed with the pattern at the place of application using designs supplied by a customer or can be supplied in solid color for application of solid color panels, strips or other shapes to the surface.
The object is typically a vehicle or boat or other transportation device including automobiles, vans, buses, airplanes and the like. In this case the panel is typically a door or trunk lid.
The area to be left uncovered can be any area of a surface of the object such as a door handle, gas filler cap or the like. In this case the whole surface of the vehicle or other object is to be covered but includes such areas which cannot be covered without interfering with the operation.
Embodiments of the invention will now be described in conjunction with the accompanying drawings in which:
In the drawings like characters of reference indicate corresponding parts in the different figures.
Reference is made to the above patents of the present Applicant to which reference may be made for details of the tape and initial method which are not included herein.
As shown in
In
The front surface 13A of the tape is free from adhesive and has a release characteristic relative to the adhesive film so that the adhesive 10A on the film 10 can be contacted onto the front surface 13A of the tape and pulled away without dislodging the tape 13 from the object 12. The tape has a first filament 14 and a second filament 15 attached to the tape at or in the adhesive layer 13F at spaced positions across the width of the tape defining a constant spacing S therebetween. There is also provided a third filament 16 located between the first and second filaments.
All three filaments are located so that the first and second filaments are spaced from both side edges and the tape has a width arranged such that each filament tears through the tape along the length of the tape, when pulled to cut the film, rather than pulling from one side edge of the tape. Thus each of the filaments 14 and 15 is spaced from the respective side edge 13C, 13D by a distance D and preferably he distance is the same so that the tape is symmetrical.
In
In
In
In
With the portion 10X removed as shown in
As shown in
While the preferred arrangement is shown in
Turning now to
The method comprises, as shown in
In
In
In
As shown in
As shown in
The remaining portion 20X of the second film extending beyond said butting cut edge 40B is removed. The tape 23 including all portions thereof on either side of the cut lines is removed and the portion 30 of the film 10 is removed from the surface with the center part of the tape between the filaments 24, 25 so that the butting cut edges 40A, 40B lie in butting relationship directly on the surface 11 and attached thereto by the adhesive thereon.
The strip 30 of the first film 10 is formed by the first and second filaments 24, 25 having a with equal to the constant spacing between the first and second filaments so that the strip 30 is removed with the tape 23 as shown in
This method as in the first method thus generates a strip of the film of constant width but in this case the strip is applied onto the film in a separate step and is not held in place n the surface as set out in the first method.
