Method for sealing a gap using a sealing strip

Abstract: The sealing strip comprises an elongate sealing portion (7) formed of resiliently compressible material such as foam and an elongate attachment portion (8) extending laterally from the sealing portion (7). The attachment portion is provided with adhesive (2) to affix it to the rear side of a first body panel (9) so that the sealing portion (7) is located in a gap between the panel (9) and an adjacent component (10) so as to seal or mask the gap therebetween. The sealing portion and attachment portion are preferably integrally formed by an extrusion process. The sealing strip has particular application to the sealing of the "B" post gap of a motor vehicle.

Description: Field of the Invention This invention relates to a method of sealing a gap using a sealing strip. A particular application of the invention is to the sealing of gaps around body panels of a vehicle which is being sprayed to prevent overspray from entering the sealed gaps. Background Art US Patents nos. 5128176 and 5260097 describe sealing strips which can be used for sealing or masking gaps between vehicle bodies and the edges of vehicle body panels, such as doors, bonnets or boot lids. Among the sealing strips described in these patents are sealing strips that comprise a length of polymeric foam having a circular or oval cross section and a layer of pressure sensitive adhesive along at least one side surface of the length of foam that can be used to releasably adhere the sealing strip to a vehicle body or body panel in a position along and extending across a gap between adjacent body panels. The sealing strips described in these patents are, however, difficult to affix accurately along some of such gaps and are only capable of providing an effective seal along certain of such gaps on vehicle bodies. WO-A-90/15668 discloses a masking device and, in particular, one with a triangular form of cross-section for use in masking a B-post gap of a motor vehicle body. The device is secured to a fixed panel of the body by means of an adhesive tape attached to the base surface thereof so that the device is deformed as a door is closed thereon in order to seal the gap between the fixed panel and the door. Disclosure of the Invention The present invention aims to provide a method of sealing gaps between vehicle bodies and the edges of vehicle body panels, such as doors, bonnets or boot lids, by means of sealing strips which have novel shapes and constructions that make them easier to apply along certain of such gaps, and which make them able to easily provide seals across certain of such gaps that cannot easily be sealed using the sealing strips described in the prior art referred to above. According to the invention, there is provided a method of sealing, according to claim 1. Other, preferred and optional features of the invention will be apparent from the following description. It should be noted that terms such as "upper" and "lower" used in the following description refer only to directions and the accompanying drawings and are not to be interpreted as restricting the invention to any particular orientation. Brief Description of Drawings The invention will now be further described, merely by way of example, with reference to the accompanying drawings, in which: Figures 1, 2 and 3 are cross-sectional views of three forms of sealing strip used according to the present invention; Figures 4(A) and (B) are cut-away views showing the sealing method using the sealing strip shown in Figure 2; Figures 5(A) to 5(F) are cross-sectional side views of further embodiments of a sealing strip used according to the present invention; and Figure 6 shows a view of a sealing strip provided in roll form. Best Mode of Carrying out the Invention Figure 1 shows a cross-section of a first embodiment of a sealing strip according to the invention. This comprises an elongate sealing portion 5 formed of resilient, compressible, bendable material such as foam with an elongate laterally extending attachment portion in the form of an adhesive strip 6 attached thereto. The sealing portion 5 has a substantially circular or oval cross-section as shown so that it has a convex surface along a first side thereof facing in a first direction (upwards as shown in Figure 1). The adhesive strip 6 has a layer 4 of pressure sensitive adhesive applied thereto so as to present an adhesive surface facing in the same direction, ie upwards in Figure 1. A removable protective liner (not shown) may be provided to cover the adhesive layer when not in use, if required. The elongate sealing portion 5 may be formed of a polymeric foam as used in conventional sealing strips. The adhesive strip 6 may be any suitable form of adhesive tape, whether or paper or plastics, with a layer of adhesive 4 applied to one surface thereof. The strip 6 may be affixed to the sealing portion 5 by means of an adhesive band (not shown) provided on the sealing portion 5, or by means of the layer of adhesive 4 (as shown in Figure 5(A)), or both. Figure 2 shows a cross-section of a second embodiment of a sealing strip. This comprises an elongate sealing portion 7 with a laterally extending attachment portion in the form of an adhesive strip 8 integrally formed therewith. The sealing portion 7 and adhesive strip 8 are integrally formed of a resilient compressible material such as foam and may, for example, be produced by an extrusion process. The sealing portion 7 is of generally circular or oval shape so that is presents a convex face in a first direction (upwards as shown in Figure 2). The adhesive strip 8 comprises a thin strip 3 of foam extending laterally from the sealing portion 7 with a layer of adhesive 2 applied to one surface thereof facing in the same direction, ie upwards in Figure 2. Figure 2 illustrates the adhesive strip 8 extending substantially tangentially from the sealing portion 7. In another arrangement, the adhesive strip 8 may extend substantially radially from the sealing portion 7 as shown in Figure 3. It will be seen that the adhesive strip 8 has a substantially uniform thickness in a direction normal to the adhesive surface thereof and that the sealing portion 7 has a larger major thickness in the same direction compared to the adhesive strip 8. Figures 5(B), 5(C) and 5(D) show further embodiments of a sealing strip. The embodiment shown in Figure 5(B) is similar to that shown in Figure 2 with the sealing portion 7 and attachment portion 8 formed integrally with each other but in this case the attachment portion has a more substantial thickness in a direction normal to the adhesive surface 2. However, it should be noted that, as in the embodiments shown in Figures 1 to 3, the sealing portion 7 still has a thickness greater than that of the attachment portion 8 (for reasons discussed further below. Figures 5(C) and 5(D) illustrate further embodiments of the sealing strip. In Figure 5(C), the sealing portion 7 has a more oval rather than circular cross-section. Also, a layer of adhesive 2 is provided on the lower surface of the sealing portion 3. In Figures 5(D), both the sealing portion 7 and then attachment portion 8 are more rectangular in cross-section. Also, a layer of adhesive 2 is provided on the upper surface of the sealing portion 7. Figure 5(E) shows yet another embodiment of a sealing strip. This comprises a sealing portion 23 and an attachment portion 24 which are formed separately and then joined together side by side. Both the sealing portion 23 and the attachment portion 24 have a substantially circular or oval cross-section but the sealing portion has a greater thickness (in the upward direction as shown in the Figures) than the attachment portion 24. The two portions are secured together by adhesive (not shown) or by any other suitable means. The two portions of this form of sealing strip may be co-extruded either with a cross-section as shown or as separate portions which bond together as they emerge from the extrusion die. A layer of adhesive 2 is provided on the attachment portion 24 as in other embodiments. Figure 5(F) shows an embodiment similar to that of Figure 3 but with an attachment portion 8 of more substantial thickness. A layer of adhesive 2 is also provided on both sides of the attachment portion 8 so the sealing strip is symmetrical and can be used either way round. The attachment portion 8 is bendable longitudinally adjacent to the sealing portion 7 so that the sealing portion 7 and attachment portion 8 can be folded back to back as will be described further below in relation to Figure 4A, 4B. Figures 6 (A) and (B) illustrate the application of the sealing strip according to the method of the invention. The gap to be sealed is between two fixed components such as a vehicle bumper 20 and a front (or rear) body panel 21. The sealing strip is first attached to one component, eg the bumper 20, by means of the adhesive strip 8 with the sealing member 7 outermost and facing away from the gap to be sealed as shown in Figure 4(A). The adhesive strip 8 is then folded longitudinally so that the sealing portion 7 is folded back and can be pushed into the gap to be sealed as shown in Figure 4(B). Conventional masking can then be attached to the sealing strip in a known manner. It will be appreciated that such a gap is difficult to seal with a conventional sealing strip as it would be necessary to push the sealing strip into position before it adheres to one of the components, whereas, in practice, the strip will tend to stick to a component as soon as the adhesive comes into contact with the component. In the application described above, the sealing strip is removed from the body panel after the paint or other surface treatment has dried sufficiently. Figures 4A, 4B illustrate the application of the sealing strip shown in Figure 2. If will be appreciated that the sealing strips shown in Figure 1, Figure 3 and in Figures 5(A) and 5(F) may also be used in this application. The sealing strip described herein may be made in a variety of sizes and materials depending upon the application. For sealing gaps in a vehicle body prior to painting, it has been found that the sealing portion 7 conveniently has a width (in the direction in which the attachment portion extends laterally therefrom) in the range 5 to 50mm and the attachment portion 8 a width in the range 10 to 50mm. The sealing portion preferably has a thickness (in a direction normal to the adhesive surface 2) in the range 5 to 50mm and the attachment portion preferably has a thickness in the range 0.1 to 30mm. The combined width of the sealing portion and attachment portion is preferably in the range 20 to 90mm (so as to be wide enough to attach to a body panel and extend into a gap adjacent thereto which is to be sealed) and, as previously indicated, the sealing portion is of greater thickness than the attachment portion. This is important for several reasons. Firstly, if the sealing portion and attachment portion are of different thickness, the sealing strip can be easily attached in the correct position around the edge of a panel by locating the edge of the panel in the step between the sealing portion and the attachment portion. Furthermore, the greater thickness of the sealing portion causes it to project beyond the edge of the panel into the space which is to be sealed. The change in thickness between the sealing portion and the attachment portion also provides a natural longitudinal hinge to assist in folding the sealing portion back over the attachment portion in applications such as that described above in relation to Figure 4A, 4B. In further embodiments of the invention (not shown), at least the sealing portion of the sealing strip may be hollow. The sealing strip has substantially the same cross-section over its whole length and may be provided in any convenient length. Typically it may be provided in lengths of several metres in roll form (as illustrated in Figure 8). The sealing portion 7 can be formed of any material having sufficient resilience to be able to conform to the shape of a gap in which it is installed and to press against and thus seal the sides of the gap. Possible materials include: polymeric foam, synthetic sponge and rubber. The sealing strip may conveniently be manufactured by an extrusion process. If the sealing strip is to be used to seal gaps adjacent to a panel being sprayed, as described above, it also needs to be made of a material which will not be affected by the paint (or other material being sprayed), although it may absorb the paint, and should preferably be useable in and withstand temperatures in the range 0° to 80°C. The material should also be lint free so that it does not spread any dust or particles on the paint surface even when compressed air, eg at up to 150 psi (1000 KN/m 2 ), is passed over it and the adhesive should be strong enough to withstand this pressure without the sealing strip lifting off the component. The sealing strip should also be sufficiently flexible to be able to follow the contours of the component to which it is fitted. The attachment portion and the sealing portion may also be formed of a tacky material in which case it would not be necessary to provide a layer or strip of adhesive to provide the required adhesive surface(s). As indicated above, in some applications, it may be found advantageous to provide one or more bands of adhesive along the sealing strip in addition to that provided on the laterally extending attachment portion. A further band of adhesive may, for example, be provided on the convex surface of the sealing portion which faces in the same direction as the adhesive layer on the laterally extending strip (as shown in Figure 5(D)) or on the opposite surface of the sealing portion. An adhesive layer may also be provided on both faces of an attachment portion as shown in Figure 5(F) which extends radially from the sealing member so that the sealing strip may be used either way round. The sealing strip described above thus makes it easier to seal certain gaps, such as the "B" post gap, on a vehicle body and thus saves a considerable amount of time in the process of masking a vehicle body in preparation for spraying. Industrial Applicability The sealing strip and method of sealing described above can be used in the sealing or masking of vehicle body panels during paint spraying or other spraying treatments and in a wide range of other applications.

Claims: A method of sealing a gap between adjacent surfaces of first and second components (20, 21) of a structure to be sprayed, which method uses a sealing strip provided in the form of an elongate sealing portion (5, 7) formed of resiliently compressible material and an elongate attachment portion (6, 8) extending laterally from the sealing portion (5, 7), wherein the sealing portion (5,7) has a thickness greater than that of the attachment portion (6, 8), the method comprising the steps of: adhering the adhesive surface (2,4) of the attachment portion (6, 8) of the sealing strip to a surface of the first component (20) with the sealing portion (5, 7) projecting therefrom, and longitudinally bending the attachment portion (6,8) adjacent the sealing portion (5,7) and pushing the seating portion (5, 7) into the gap so that the sealing portion (5,7) seals the gap between the first and second components (20,21).

Inventors: HILLS ROBIN WILLIAM, HILLS, ROBIN WILLIAM
Applicants: SPEEDARRIVE PROJECTS LTD, SPEEDARRIVE PROJECTS LTD.
Application year: 1995
Main classification: B05B15
IPC codes: B05B15