WO2012121600A1

WO2012121600A1 - Apparatus and method for pressing an adhesive tape on a substrate

Info

Publication number: WO2012121600A1
Application number: PCT/NL2012/050140
Authority: WO
Inventors: Brian RIJNBERGEN
Original assignee: Bostik S.A.
Priority date: 2011-03-08
Filing date: 2012-03-07
Publication date: 2012-09-13
Also published as: NL2006353C2

Abstract

The invention relates to an apparatus (1) and a method for pressing an adhesive tape (2) on a substrate, the apparatus comprising a pressing body (5) with a pressing surface (10) adapted to press the adhesive tape on the substrate and at least a longitudinal tape guide (11, 12) adjacent to the pressing surface for guiding the tape parallel to its longitudinal direction, wherein the pressing surface is continuously convex in the longitudinal direction of the tape guide. The convex face of the pressing surface allows to gradually press the tape onto the substrate while the apparatus is moved over the tape in its longitudinal direction. Preferably the radius of curvature of the pressing surface has a minimal value on a location on the pressing surface and the radius of curvature increases in both directions therefrom. Hence the pressure with which the tape is pressed against the substrate is determined by tilting of the pressure body.

Description

Apparatus and method for pressing an adhesive tape on a substrate.

The present invention relates to the application of an adhesive tape on a substrate. Such tapes may be provided with an adhesive layer on one of its sides, which is usually the case for tapes with a decorative or for a sealing purpose, but it is also possible that the tape is adhesive on both sides. In such cases the tape is often used for the joining of parts of structures, like panels on the frame of a bus. Often the adhering function of these double sided adhesive tapes is temporary, for instance for positioning the panels during the curing of a adhesive layer applied between the parts to be joined.

More in particular the invention relates to an apparatus for pressing an adhesive tape on a substrate, the apparatus comprising a pressing body with a pressing surface adapted to press the adhesive tape on the substrate and at least a first longitudinal tape guide adjacent to the pressing surface adapted to guide the tape parallel to its longitudinal direction.

Such an apparatus is generally known.

It has appeared to the inventors of the present invention that this apparatus often leads to only mediocre results, as the tape often loosens from the substrate as it has not been pressed on to the substrate with the prescribed pressure. When the tape is pressed on the substrate with a pressure which is not sufficiently high, the tape may loosen.

The aim of the invention is to provide an apparatus of the kind referred to above allowing to press the tape onto the substrate with the prescribed pressure.

This aim is reached with an apparatus of the kind referred to above, wherein the pressing surface is continuously convex in the longitudinal direction of the first tape guide.

The convex face of the pressing surface allows to gradually press the tape onto the substrate while the apparatus is moved over the tape in its longitudinal direction. The invention also provides a method for applying a length of adhesive tape on a surface, wherein the tape is positioned on the substrate and is pressed on the substrate by a pressing body with a surface being continuously convex in the longitudinal direction of the tape.

According to a first preferred embodiment the radius of curvature of the pressing surface has a minimal value on a location on the pressing surface and that the radius of curvature increases continuously in both directions from said location. This feature allows to determine the pressure with which the tape is pressed against the substrate by tilting the pressure body.

Another embodiment provides the feature that at the side of the pressing surface opposite the side of the first tape guide, a second tape guide has been located, extending parallel to the first tape guide and of which the profile agrees to the profile of the first tape guide. The tape guide allows to guide the tape during the pressing of the tape against the substrate. Herein it is assumed that the tape has not been adhered to the substrate yet, so that movements in the lateral direction are possible.

The same embodiment provides a method wherein the adhesive tape is pressed on the substrate by a pressing body with a tape guide at either side of the pressing surface and that the thickness of the adhesive tape is larger than the distance between the edges of the tape guide and the highest part of the pressing surface.

To allow use of the apparatus under tilting positions relative to the substrate, it is preferred when the pressing surface is convex in the direction perpendicular to the longitudinal direction of the first tape guide. This embodiment provides a constant pressing force independent on the tilt angle of the apparatus.

Often a tape has to be applied on a substrate on a predetermined distance from an edge of the substrate. This may be the case if the tape provides a joint between a part of a frame being the substrate and a panel applied thereto, like in coachbuilding. To simplify the application of the tape on such a prescribed distance a specific embodiment provides the feature that the apparatus comprises a first spacer element adapted for engagement behind a first edge of the substrate for maintaining the distance between the first edge of the substrate and the first tape guide. This spacer element provides the required distance.

The same embodiment provides a method wherein during the pressing of the adhesive tape on the substrate the distance between the tape and the edge of the substrate is maintained by a spacer element.

To allow the application of a tape on a prescribed distance from the other edge of the substrate without turning the apparatus around it is preferred if the apparatus comprises a second spacer element arranged at the side of the second tape guide and adapted for engagement behind a second edge of the substrate for maintaining the distance between the second edge of the substrate and the second tape guide.

The preceding embodiment provides two tape guides on the same apparatus wherein both tape guides are adapted to extend under the surface of the substrate onto which the tape has to be applied. This may lead to interference of the two tape guides. To avoid such a situation it is preferred if a tangent line extends in a plane intersecting the pressing surface, which tangent line touches the edge of the first spacer element, the second tape guide and which intersects the pressing surface at the location of the second spacer element. Yet another embodiment provides the feature that the first and the second tape guides and the first and the second spacer elements are arranged symmetrically to a symmetry plane intersecting the pressing surface. This leads to a substantially symmetric structure which can easily be handled by both left and right handed persons. The preceding embodiments related only to the pressing of the adhesive tape onto the substrate. Such a tape has to be provided initially. To allow both provision of the tape and the pressing thereof on a substrate a specific preferred embodiment provides a bearing for holding the core of a roll of adhesive tape to be pressed on the substrate.

The same embodiment provides the feature that preceding the pressing of the adhesive tape on the substrate the tape is wound from a core connected with the pressing body.

To allow provision of the tape and the pressing thereof on the substrate by a single hand, the apparatus according to present invention comprises a handle so that the person handling the apparatus can handle it properly. Further the rolls of tape to be applied may have a substantial diameter. To avoid the gripping of the handle being impaired by the presence of the roll, it is preferred if the bearing is connected to the pressing body by a handle and the bearing has been offset in the direction away from the handle relative to the pressing surface. The tape usually has to be applied in certain lengths. To allow cutting of the tape an embodiment provides a knife moveable by an operating element for cutting off the adhesive tape.

Cutting of the tape is simplified if the knife is adapted to be moveable between an inactive retracted position and an active position protruding from the pressing surface when operated. The tape is then being cut while being in contact with the pressing surface, leading to an adequate cut.

An easy operation of the knife is obtained if the operating element is located at the position of the handle.

Preferably the invention also provides a combination of an apparatus of the kind referred to above and a length of adhesive tape to be applied to the substrate, wherein the thickness of the adhesive tape is larger than the distance between the plane extending through edges of the tape guides and the highest part of the pressing surface. This feature allows to determine the pressing force to the related thickness of the tape. Preferably the adhesive tape is wound on a core and that the core is located on the bearing.

The preceding embodiments relate to the provision of the tape on the substrate. As stated before this may be tape which is adhesive on one side only, like decorative tape, glazing tape or masking tape. However the invention also relates to tape adhesive on both sides. Tapes of this kind may be used for joining parts, like cladding of a building structure. Tapes adhesive on both sides are commonly provided of a release liner to allow the tape being supplied in rolls. According to a preferred embodiment the adhesive tape is adhesive on both sides and that after the pressing of the adhesive on the substrate, a release liner covering accessible adhesive side op the tape is removed before urging a body to be joined on the tape.

Often cladding panels are joined to building structures through adhesive. As this adhesive requires some time to cure, the adhesive forces of this adhesive develop only after some time, requiring temporal fixation of these panels during the curing of the adhesive. Adhesive tape has excellent properties to provide this temporal fixation. This implies that before the cladding panels are brought into their positions both the tape and an adhesive bead has to be provided. Hence a preferred embodiment provides the feature that after the application of the tape an adhesive bead is applied between the edge of the substrate and the adhesive tape applied thereon. Although the release liner from the adhesive tape may be removed before the application of the adhesive, it is preferred that initially the adhesive is applied and only then the release liner is removed. The positioning of both the tape and the adhesive bead is important as covering of the adhesive tape by adhesive will both lead to impairment of the adhesive properties of the adhesive layer of the tape and to a reduction of the amount of adhesive available for the permanent fixation of the cured adhesive. Preferably the adhesive bead is applied from an applicator comprising an spacer element for maintaining a constant distance between the adhesive tape and the adhesive bead. Often the cladding panels have to be adhered to substrate having a certain unevenness, like wooden battens. Further the thermal expansion coefficients of the panels and the substrate may be different. Also varying moisture content may lead to different expansion of the panels and the substrate. To allow for the mutual movement caused by these effects it is preferred that the adhesive layer not only has a certain flexibility in its cured state, but also that the adhesive layer has a certain thickness. These considerations refer to the cured adhesive bead. To obtain such cured adhesive layer with the thickness sufficient for the above configurations the adhesive bead must have a larger thickness (in the direction perpendicular to the surface of the substrate) as during the pressing of the cladding panel onto the substrate the thickness will be reduced. When the panel is applied, the movement of the panel towards the substrate will be stopped by tape. Hence the thickness of the tape determines for an important part the thickness of the adhesive layer. To avoid air enclosure the adhesive bead is preferably triangularly shaped. When during application of the cladding panel the panel is moved towards the substrate, the panel will initially contact the adhesive layer as this has a larger thickness than the tape. The contact with this adhesive layer limits the movement of the panel in the direction of the plane of the substrate, still allowing a proper positioning of the panel. When the correct position has been reached, the panel is pressed towards the substrate until it contacts the adhesive tape. Hence a preferred embodiment provides the feature that the applied bead of adhesive has a larger thickness than the adhesive tape, that a panel is located on the substrate, wherein initially the panel brought into contact to the bead of adhesive, the panel is positioned and subsequently the panel is pressed into contact with the adhesive tape. Although not explicitly discussed beforehand it is attractive to use tape having a foam carrier. This foam carrier allows the relative movements of the panel and the substrate.

Subsequently the present invention will elucidated with the help of the following drawings wherein show:

Figure 1 : a perspective view of a preferred embodiment of the invention;

Figure 2: a schematic upper view of the embodiment depicted in figure 1; Figure 3 : a cross-sectional view of an adhesive tape to be used together with the embodiment depicted in figures 1 and 2;

Figure 4: a cross-sectional view of a frame member of a bus and coach panels adhered to the frame member by tape;

Figures 5a, 5b and 5c: cross-sectional views of different stages of the application of cladding panels to a batten; and

Figure 6: a perspective view of a batten onto which an adhesive bead is applied.

Figures 1 and 2 show an applicator, in its whole designated by 1, for applying and pressing of adhesive tape 2 to a substrate. The applicator 1 is made of a suitable plastic and it comprises three main parts, i.e. a core holder 4, a pressing body 5 and a handle 6 connecting the core holder 4 and the pressing body 5.

Tape 2 is commonly supplied on a core 7. The core 7 has an inner diameter only slightly larger than the outer diameter of the core holder 4 to allow rotation of the core 7 around the core holder 4. The core holder 4 further comprises a fixed notch 8 to limit the axial movement of the core 7 and two moveable notches 9, for the same reason in the opposite direction. The moveable notches 9 are moveable in the radial direction to allow the core 7 with the tape 2 wound on it to move onto the core holder 4.

The pressing body 5 comprises a pressure surface 10 having a convex cross-section both in the direction parallel to the longitudinal direction of the pressing body as appears from figure 2 and in the direction perpendicular thereto. On both sides of the pressing surface 10 an inner ridge 11, 12 respectively is provided. These inner ridges 11, 12 serve to guide the tape 2 in the lateral direction during the pressing of the tape 2 on the substrate. On both edges of the pressing body 5 second outer ridges 13, 14 have been provided. These outer ridges 13, 14 serve as guides during the application and pressing of the tape 2 to apply the tape on the substrate on a predetermined distance from the edge of the substrate. The presence of two outer ridges 13, 14 allows the use of the apparatus on a predetermined distance from edges on either side of the substrate, without turning the applicator 1 over. The geometry of the ridges is chosen such that the outer ridge 13, 14 not in use does not interfere with the inner ridges 11, 12 so that the apparatus 2 may be used at either side. This is indicated by the dotted lines 15, 16 in figure 2, which represent the surface of the substrate in both positions of the applicator 1.

Although the applicator according to the present invention may be used to apply tapes of any kind on substrates, a major field is the application of double sided adhesive tapes. Figure 3 shows a cross section of such a tape. The tape 20 comprises a carrier 21, which may be formed by foam. Other carriers are not excluded. On either side of this carrier 21 an adhesive layer 22, 23 has been provided. A release liner 24, preferably made of siliconised paper or a plastic film is applied on the upper adhesive layer 23, to avoid the adherence of the tape 20 to itself when wound on a core.

Figure 4 shows a part of the coachwork of a bus, comprising a frame, preferably made of aluminium of which a strip 30 is shown. On one side of the strip 30 two lengths of double sided adhesive tape 31 has been applied by the applicator according to the invention. Herein the applicator serves for guiding the tape 31 during the application thereof on the strip 30 on a predetermined distance from the edge of the strip 30. Further the convex surface of the applicator ensures a proper pressing of the adhesive tape 31 to the strip 30. It is noted that the quality of the bond between the tape 31 and the strip 30 is for a substantial part determined by the pressure used press the tape 31 onto the strip 30. Another function of the applicator is the exact positioning of the tape 31, to make sure that the complete surface of the tape 31 is in contact with the strip 30. After the tapes 31 have been applied on the strips 30, the release liner is removed from the strip to expose the second adhesive layer of the tape 31. Then bodywork panels 32 are pressed onto the proper locations on the strip 30 and on the adhesive tapes 31 to obtain a proper bond.

Figure 5 shows another major field of application of the invention, that is the provision of cladding panels on building structures. Initially a pair of double sided adhesive lengths of tape 41 is applied on a vertical lath 40 of a building structure. The tape 41 is of the foam type to allow movement and expansion between the laths 40 and the cladding panels 42. Herein the applicator according to the invention is used to apply the tape 41 to a predetermined position as depicted in figure 5 A. The position of the tape 41 is chosen such that room is left for the application of two adhesive beads 43, which are both required to fix a cladding panel 42. Care should be taken during the application of the adhesive beads 43 such that the adhesive does not cover the adhesive tape 41 and that the adhesive beads 43 are higher than the tape 41. Then the situation depicted in figure 5B is obtained. Finally, after the release liners have been removed from the tapes the panels 42 are brought into contact with the adhesive beads 43. The adherence between the adhesive and the panels 42 allow the panels to be carefully positioned in the direction of the main plane of the panels 42. When the correct positions of the panels have been reached, the panels are urged towards the laths 40 until the panels 42 come into contact with the tapes 41. Then the adhesive layer on the tape 41 tacks the panels 42 and inhibits further movement thereof. During the movement of the panels 42 towards the lath 40, the adhesive bead comes intimately into contact with the panels 42, allowing to make a proper bond. During the setting or curing of the adhesive the tape 41 provides for fixation of the panel 42, and subsequently the adhesive 43 takes over the bonding of the panel to the lath, so that a permanent bond is obtained.

Finally figure 6 show the application of the adhesive bead 43 on the lath 40. The two lengths of tape 41 have already been provided on the lath 40 and the application of the adhesive beads 43 has to be performed such that a certain distance to the tape 41 is maintained. Therefore the applicator for the adhesive which itself is not depicted has a spout 45, provided with a spacer element 46. As the tape 41 has already been provided on a predetermined distance from the edge of the lath 40, the adhesive bead 43 is also applied on a distance from the edge of the lath 40, so that the full amount of adhesive is available for forming the bond between the panel and the lath.

It will be clear that numerous variations to the above embodiments are possible and that features of different embodiments may be combined as the scope of the invention is determined by the claims.

Claims

1. Apparatus for pressing an adhesive tape on a substrate, the apparatus comprising a pressing body with a pressing surface adapted to press the adhesive tape on the substrate and at least a first longitudinal tape guide adjacent to the pressing surface adapted to guide the tape parallel to its longitudinal direction, characterized in that the pressing surface is continuously convex in the longitudinal direction of the first tape guide.

2. Apparatus as claimed in claim 1, characterized in that the radius of curvature of the pressing surface has a minimal value on a location on the pressing surface and that the radius of curvature increases continuously in both directions from said location.

3. Apparatus as claimed in claim 1 or 2, characterized in that at the side of the pressing surface opposite the side of the first tape guide, a second tape guide has been located, extending parallel to the first tape guide and of which the profile agrees to the profile of the first tape guide.

4. Apparatus as claimed in claim 1, 2 or 3, characterized in that the pressing surface is convex in the direction perpendicular to the longitudinal direction of the first tape guide.

5. Apparatus as claimed in any of the preceding claims, characterized in that the apparatus comprises a first spacer element adapted for engagement behind a first edge of the substrate for maintaining the distance between the first edge of the substrate and the first tape guide.

6. Apparatus as claimed in any of the preceding claims, characterized in that the apparatus comprises a second spacer element arranged at the side of the second tape guide and adapted for engagement behind a second edge of the substrate for maintaining the distance between the second edge of the substrate and the second tape guide.

7. Apparatus as claimed in claim 5 or 6, characterized in that a tangent line extends in a plane intersecting the pressing surface, which tangent line touches the edge of the first spacer element, the second tape guide and which intersects the pressing surface at the location of the second spacer element.

8. Apparatus as claimed in claim 7, characterized in that the first and the second tape guides and the first and the second spacer elements are arranged symmetrically to a symmetry plane intersecting the pressing surface.

9. Apparatus as claimed in any of the preceding claims, characterized by a bearing for holding the core of a roll of adhesive tape to be pressed on the substrate.

10. Apparatus as claimed in claim 9, characterized in that the bearing is connected to the pressing body by a handle and that the bearing has been offset in the direction away from the handle relative to the pressing surface.

11. Apparatus as claimed in any of the preceding claims, characterized by a knife moveable by an operating element for cutting off the adhesive tape.

12. Apparatus as claimed in claim 11, characterized in that the knife is adapted between an inactive retracted position and an active position protruding from the pressing surface when operated.

13. Apparatus as claimed in claim 11 or 12, characterized in that the operating element is located at the position of the handle.

14. Combination of an apparatus as claimed in any of the preceding claims and a length of adhesive tape to be applied to the substrate, characterized in that the thickness of the adhesive tape is larger than the distance between the plane extending through edges of the tape guides and the highest part of the pressing surface.

15. Combination of as claimed in claim 14, characterized in that the adhesive tape is wound on a core and that the core is located on the bearing.

16. Method for applying a length of adhesive tape on a surface, wherein the tape is positioned on the substrate and is pressed on the substrate by a pressing body with a surface being continuously convex in the longitudinal direction of the tape.

17. Method as claimed in claim 16, characterized in that the adhesive tape is pressed on the substrate by a pressing body with a tape guide at either side of the pressing surface and that the thickness of the adhesive tape is larger than the distance between the edges of the tape guide and the highest part of the pressing surface.

18. Method as claimed in claim 17, characterized in that during the pressing of the adhesive tape on the substrate the distance between the tape and the edge of the substrate is maintained by a spacer element.

19. Method as claimed in claim 18, characterized in that preceding the pressing of the adhesive tape on the substrate the tape is wound from a core connected with the pressing body.

20. Method as claimed in any of the claims 16-19, characterized in that the adhesive tape is adhesive on both sides and that after the pressing of the adhesive on the substrate, a release liner covering accessible adhesive side op the tape is removed before urging a body to be joined on the tape.

21. Method as claimed in claim 20, characterized in that after the application of the tape a bead of adhesive is applied between the edge of the substrate and the adhesive tape applied thereon.

22. Method as claimed in claim 21, characterized in that the bead of adhesive is applied from an applicator comprising an spacer element for maintaining a constant distance between the adhesive tape and the bead of adhesive.

23. Method as claimed in claim 21 or 22, characterized in that the applied bead of adhesive has a larger height than the adhesive tape and that a panel is located on the substrate, wherein initially the panel is contacted to the bead of adhesive, the panel is positioned and subsequently the panel is pressed into contact with the adhesive tape.