Patent Application
20110162791
One or more embodiments are directed toward a method for preparing a roofing membrane carrying a solid adhesive strip positioned to form a tape selvage edge.
Large, flexible sheets or membranes are often used in the construction industry as roofing material. These sheets are typically delivered to a construction site in a bundled roll, transferred to the roof, and then unrolled and laid flat. The sheets are then affixed to the building structure by employing varying techniques such as mechanical fastening, ballasting, and/or adhering the membrane to the roof deck or insulation layer. In order to achieve the necessary water repellent properties, the sheets are positioned so that the edges of adjoining sheets overlap. These overlapping portions are secured to one another through a number of methods depending upon the membrane materials and exterior conditions. One approach involves providing adhesives between the overlapping portions and applying pressure to the site, thereby creating a water resistant seal.
Adhesives may be applied at the job site in the form of a tape or solid adhesive strip. This method, however, has drawbacks including the need to prime the area where the tape may be applied. Additionally, applying the tape at the job site can be labor intensive and imprecise. Further, construction debris and dirt can contaminate the tape or membrane, leading to flawed or unsatisfactory tape adhesion. To alleviate these problems and provide a more uniform adhesive application, manufacturers provide membrane with a pre-applied tape. In other words, the tape is applied prior to delivery of the membrane to the job site, often within a factory or other controlled environment where priming and cleaning can be performed more effectively, as well as uniform and standard application of the tape.
The ability to pre-apply or factory apply the tape in a uniform, precise manner is particularly advantageous when a tape selvage edge is desired. A tape selvage edge includes the portion of the adhesive tape that overlaps the membrane edge. In other words, the tape selvage edge extends beyond the edge of the membrane and provides additional adhesive to the sealed areas. Particularly, the tape selvage edge improves water resistance and joint stability in areas where more than two membranes converge in areas known as T-joints. This is accomplished because the additional overlapping tape provides a more gradual gradation to the seal and reduces the opening at the T-joints.
Because it has been found that pre-application of the tapes is desirous, it is additionally important to develop efficient methods of applying the tape prior to shipment to a construction site. Particularly, it is preferable to apply tape to more than one membrane at a time, thereby increasing productivity. One such method entails providing a membrane and applying a tape along a central region of the membrane. The membrane and tape is then cut, thus producing two membranes, each of which having a tape on one side. While these construction methods may achieve greater production speeds and efficiency, some drawbacks remain. For example, cutting the membrane and tape after the tape has been applied results in a flush cut edge without a tape selvage. As a result, these methods do not enable a manufacturer to create the more desirable tape selvage edge.
Thus, because the tape selvage edge is desirable, there is a need for a production method that quickly and efficiently applies adhesive tapes to roofing membranes in a manner that can produce a tape selvage edge.
In one or more embodiments, the method of forming a building material according to the concepts of the present invention includes a method of forming a building material with a pre-applied adhesive, the method comprising the steps of manipulating a first membrane and a second membrane to be spaced from one another along parallel adjacent edges to form a gap; securing a single strip of adhesive tape to a top surface of both said first and second membranes adjacent to said adjacent edges so that said adhesive tape extends over said gap; and cutting along the length of said adhesive tape to form a first adhesive tape and a second adhesive tape, said first adhesive tape being secured to the top surface of said first membrane and extending over a portion of said gap, and said second adhesive tape being secured to the top surface of said second membrane and extending over a portion of said gap.
In one or more embodiments, the method of forming a building material according to the concepts of the present invention further includes a method of forming a building material with a pre-applied adhesive, the method comprising the steps of positioning a membrane; removing a strip of said membrane to separate said membrane into first and second membranes having parallel adjacent edges spaced from one another, thereby forming a gap between said adjacent edges; securing an adhesive tape to a top surface of both the first and second membranes so that said adhesive tape extends over said gap; and cutting along the length of the adhesive tape.
In one or more embodiments, the method of forming a building material according to the concepts of the present invention further includes a method of forming a building material with a pre-applied adhesive, the method comprising the steps of creating a gap between parallel adjacent edges of first and second membranes positioned on a cutting grid having a groove; securing an adhesive tape to a top surface of both said first and second membranes using a tape applicator device, the adhesive tape extending over said gap; and cutting said adhesive tape along the length of the adhesive tape with a cutting device having a guide mechanism, thereby forming a first adhesive tape and a second adhesive tape, wherein said gap between said first and second membranes is substantially aligned with said groove in said cutting grid, said guide mechanism engaging said groove to guide said cutting device.
A roofing membrane carrying an adhesive may be prepared by applying an adhesive along an edge of the membrane. In one or more embodiments, a solid adhesive may be applied along an edge of the membrane in a manner that produces a tape selvage edge. In these or other embodiments, two adhesive tapes are simultaneously applied to edges of two distinct membranes, respectively. In these or other embodiments, the two adhesive tapes that are simultaneously applied may be carried by a single release liner.
The membranes to which the adhesive is applied may include thermoset and thermoplastic membranes, including those that are conventional in the art. For example, thermoplastic membranes may include those including polyvinylchloride resins or polyolefin resins. Exemplary thermoset membranes include those including ethylene-propylene rubber, ethylene-propylene-diene rubber, or crosslinked derivatives thereof. Several thermoset membranes are known in the art such as those disclosed in U.S. Pat. Nos. 6,502,360, 6,044,604, 5,854,327, 5,735,092, 5,700,538, 5,468,550, 5,130,355, which are incorporated herein by reference. In one or more embodiments, the membranes may be characterized by ASTM-D-4637.
An example of a suitable membrane is shown in
In one or more embodiments, two membranes are positioned within the same planar orientation prior to application of the solid adhesive. In one or more embodiments, this includes positioning an edge of one membrane proximate to or near an edge of a second membrane in a manner that provides a gap between the edges of the membranes. In one or more embodiments, the gap is from about ½ to about 2 inches. In other embodiments, the gap is from about ⅝ to about 1½ inches. In still other embodiments the gap is from about ¾ to about ⅞ inches. In these or other embodiments, the gap between the edges of the membranes does not vary by more than ¼″, and in other embodiments by not more than ⅛″ along the length of the edges that are proximate or near to one another.
The positioning of the membranes may be accomplished by employing several methods. In some embodiments, two separate membranes are positioned in the desired configuration. In other embodiments, a single membrane is cut into two membranes, and the resulting two membranes are separated to create the desired gap therebetween. In yet other embodiments, a single membrane is divided into two membranes by cutting a strip or ribbon from the membrane, thereby resulting in two membranes having the desired gap therebetween. In one or more embodiments, the gap is achieved without moving the membrane
For example, with reference to
In one or more embodiments, the two distinct membranes positioned proximate to each other and within the same planar orientation may be formed by dividing (i.e. cutting) a single membrane. The single membrane may be divided along a cut line to provide two distinct membranes each including a cut edge along the cut line. The gap between the membranes can be achieved by repositioning (e.g. pulling apart or separating the membranes) after dividing them.
In one or more embodiments, the membrane may be divided by using a membrane-cutting grid. These grids include those that are known in the art such as those that exist in the floor of membrane-fabrication facilities or warehouses. For example, as shown in
In one or more embodiments, cutting area 20 may include a plurality of lateral grooves (e.g. 24a), which may be parallel and spaced by a predetermined distance. In one or more embodiments, the cutting area 20 may be provided with a plurality of transverse grooves (e.g. 24b), which can be parallel to one another and spaced by a predetermined distance. The transverse grooves may be disposed at an angle relative to the lateral grooves. In one embodiment, the transverse grooves may be disposed perpendicular to the lateral grooves. In this manner, a grid like array of grooves may be provided on cutting area 20.
Grooves 24 may facilitate cutting of the membrane 10. For example, when membrane 10 is disposed over groove 24, as shown in
Once properly positioned on cutting area 20, membrane 10 may be divided. Referring to
In one or more embodiments, as shown in
In one or more embodiments, it may be desirous to reduce the peripheral dimensions of the membrane 10 prior, during, or after the step of dividing the membrane. In such an instance, the grooves 24 may be positioned so that a pair of lateral grooves and a pair of transverse grooves form the desired peripheral shape. For example,
It should be appreciated that, although it is preferred to position a first and second membrane with a gap therebetween, one may place the membranes in an abutting relationship. This may be accomplished by cutting the membrane with a thin blade, or positioning two membranes next to one another. Thereafter, the tape assembly may be applied in the manner described herein below.
The solid adhesive, which may also be referred to as a solid adhesive strip or an adhesive tape, may include those that are conventional in the art. These may include those that include EPDM and/or butyl rubber. Useful adhesive tapes are disclosed in U.S. Pat. Nos. 6,120,869, 5,888,602, 5,859,114, 5,733,621, 5,612,141, 5,563,217, 5,545,685, 5,504,136, 4,932,171, 4,849,268, and 4,657,958, which are incorporated herein by reference. Useful tapes are commercially available including those available under the tradenames PLIOSEAL™ (Ashland) or 510™ (Adco) or 505™ (Adco).
In one or more embodiments, the solid adhesive strip may be carried by a release liner. The release liner may include a thin film to which the adhesive strip may form a temporary bond with, but which bond can be readily broken by applying minimal tension. In one or more embodiments, the release liner may include a paper or cellulosic structure coated with a polymeric coating. In other embodiments, the release liner may include a homogeneous polymeric structure; for example, the release liner may include a polyester or polyolefin (e.g. polypropylene) film. The release liner may have different adhesion characteristics on each side, known as a differential release, which may be achieved by applying a different coating to each side. The differential release causes the adhesive tape to release from one side of the release liner before the other, which facilitates unrolling of the tape. The release liner may advantageously provide protection to the tape during storage or shipment, and remains in place until the actual mating of the tape to the adjacent membrane in the field.
In one or more embodiments, a tape assembly, generally indicated by the numeral 50, is provided. As shown in
In one or more embodiments, a gap 59 exists between adhesive tape 54a and 54b. Specifically, gap 59 exists between adjacent edge 57a of tape 54a and adjacent edge 57b of tape 54b. The distance d between adjacent edge 57a and adjacent edge 57b may be from about ¼ to about 1¾ inches, in other embodiments from about ⅜ to about 1¼ inches, and in other embodiments from about ½ to about ⅝ inches.
In one or more embodiments, the pair of adhesive tapes 54a and 54b may be disposed on the bottom surface 56 of release liner 52. The release liner 52 carries the adhesive tapes 54, thus providing structural integrity while simultaneously protecting the adhesive tapes 54 from contaminants and unwanted adhesion prior to installation. The release liner additionally allows the tape to be rolled for storage and shipment. Further, adhesive tapes 54 may generally be described as elongated strips of adhesive material. The adhesive tapes 54 may be disposed along substantially the entire elongated length of release liner 52 in an orientation generally parallel with liner edges 58 and centerline 60. The adhesive tapes 54 are further disposed in a spaced relation to one another by a predetermined distance d. In one or more embodiments, the adhesive tapes 54a and 54b are disposed on opposed sides of centerline 60 and equidistant therefrom.
In an alternate tape embodiment, shown in
In one or more embodiments tape assemblies 50 or 50′ may include a line of perforations 62 that enable easy tearing along that line. Perforations 62 may extend through the entire tape assembly 50/50′ or only through release liner 52/52′ or adhesive tape 54/54′. In one or more embodiments perforations 62 are located substantially along centerline 60.
In one or more embodiments, a primer 66 may be applied to the membrane 10 prior to application of the tape. Primer 66 may clean the surface and generally promotes a strong adhesive bond. Primer 66 may be applied to the top surface 12 of membrane 10 prior to tape application in any areas that will contact the adhesive tape 54. In one or more embodiments, the primer may be applied prior to dividing or cutting the membrane. In yet another embodiment, the primer may be applied after the membrane has been cut.
Once a pair of membrane portions have been positioned as discussed above, the adhesive tape may then be applied thereto. A shown in
In one embodiment, the centerline 60 of release liner 52 may be positioned substantially equidistant from first and second cut edges 34 and 36. The space d between the adhesive tapes 54 may be relatively smaller than the width D of gap 38. Thus, when applied correctly, an overhanging portion 68a and 68b or tape selvage edge of each adhesive strip 54 extends into gap 38. In one or more embodiments, the overhanging portion is from about 1/16″ to about 5/16″, and in other embodiments from about 3/16″ to about ⅛″. Thus, in this manner adhesive tape may be applied to each membrane portion simultaneously while also creating a tape selvage edge.
In one or more embodiments, tape assembly 50 may be provided in the form of a roll, as shown in
In one or more embodiments, the adhesive tapes (e.g. 54a and 54b) may be simultaneously applied from separate release liners. For example, two distinct tape rolls can be positioned on a single tape applicator and applied to the two membranes, respectively, from the single applicator. In one or more embodiments, the respective tapes may be positioned in the same or similar position with respect to the length of the membrane or edge thereof.
After application of the adhesive tapes to first and second portions 30 and 32, the release liner 52 may then be cut, thereby creating a first and second tape assembly portion 70 and 72. In one or more embodiments, the release liner may be cut generally down centerline 60. In other embodiments the release liner may be torn along perforations 62. In any event, the release liner may be cut at a location between adhesive tapes 54a and 54b. In this manner, a pair of membrane portions 30 and 32 may be provided that have a first and second tape assembly portion 70 and 72 disposed respectively along one edge. The membrane portions may then be rolled or otherwise prepared for shipment to a construction site.
To the extent that adhesive strip 54a and 54b include a gap therebetween, by cutting release liner 52 in the area of that gap can result in a release-liner selvage 74 and 76. These release-liner selvages may be advantageous because extra protection is achieved from contaminates, particularly along the edge of tape 54. The release liner also overhangs the opposed sides of adhesive strips 54a and 54b. Again, this overhanging edge provides added protection from contaminates and debris prior to installation.
In an alternative embodiment, shown in
After application of the adhesive tape 54′ to first and second portions 30 and 32, the tape assembly 50′ may then be cut, creating a first and second tape assembly portion 70′ and 72′. In one or more embodiments, tape assembly 50′ may be cut generally down centerline 60. In other embodiments, tape assembly 50′ may be torn along perforations 62. In any event, tape assembly 50′ may be cut so that a portion of tape 54′ overhangs each section 30 and 32. In this manner, a pair of membrane portions 30 and 32 may be provided that have a first and second tape assembly portions 70′ and 72′ disposed respectively along one edge. The assembly portions 70′ and 72′ include overlap portions 68a′ and 68b′.
In one or more embodiments, several of the aforementioned steps may be combined. For example, the step of cutting membrane 10 and the step of applying tape assembly 50 may be combined by using a machine that includes a cutting blade at the front leading edge and a tape applicator at the trailing edge. In yet another embodiment, a single machine may both apply and cut tape assembly 50. For example, the machine may include a tape applicator at the leading edge and a cutting means at the trailing edge. In yet another embodiment a single machine or apparatus may perform the steps of cutting a strip from membrane 10, applying tape assembly 50 and cutting tape assembly 50. In one or more embodiments, this machine may include a guide mechanism that can communicate with a groove within the assembly floor and/or the gap between the membranes. In one or more embodiments, the machine or apparatus may include a roller device that contacts the tape after application and applies pressure thereto so as to secure or set the tape to the membrane.
In one or more embodiments the manufacturing facility may include a laser guidance assembly. The laser guidance assembly may project a laser line onto the membrane surface to allow a worker to properly align the tape assembly. In still other embodiments a tape applying machine may include a contrast sensor adapted to view the dark edge of a tape assembly and a stepper motor to adjust the lateral position of the tape roll to maintain proper alignment during application. This may be necessary because variations may exist in the tape manufacturing process and thus the tape roll dimensions may vary.
Thus a method of quickly and efficiently applying a tape assembly to roofing membranes is disclosed. The methods of this invention improve upon the art because tape may be applied simultaneously to more than one membrane while also creating a tape selvage edge.
Various modifications and alterations that do not depart from the scope and spirit of this invention will become apparent to those skilled in the art. This invention is not to be unduly limited to the illustrative embodiments set forth herein.
This application is a continuation of U.S. Non Provisional application Ser. No. 11/642,200, filed Dec. 20, 2006, which claims the benefit of U.S. Provisional Application 60/753,014, filed Dec. 21, 2005, both of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60753014 | Dec 2005 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11642200 | Dec 2006 | US |
| Child | 13048162 | US |
