System and method for sealing open ends of multi-wall sheets

Abstract

A device and a method allow for adhering sealing tape to open end of a multilayer sheet, usable at the production line and at the installation site. The device comprise means for applying pressure and heat onto the sealing tape and cutting blades for removing protruding edges of the sealing tape after it was adhered. The method comprise providing of a sealing tape, attaching and adhering the sealing tape to an open end of a multi-wall sheet by means of heat and/or pressure and adhesive and removal of protruding edges using cutting blades.

Claims

1. A method for sealing an open end of a multi-layer sheet comprising: providing a multi-layer sheet; providing a sealing tape, the width of said sealing tape is equal to or larger than the thickness of said multi-layer sheet, wherein the sealing tape is made from a thermo-plastic material; thermo-plastically adhering said sealing tape into said open end of said multi-layer sheet by at least heating said sealing tape to a temperature above the Glass transition temperature of the sealing tape's material, so as to submerge said sealing tape into said open end of sub-spaces in said multi-wall sheet, wherein thermo-plastically adhering said sealing tape into said open end results in sealing of said open end; and removing protruding edges of said sealing tape when said edges are protruding from said open end.

2. The method of claim 1, further comprising providing pressure to said sealing tape using one from a list including a pressure plate and a pressure roller.

3. The method of claim 1 wherein said heating is to be provided using heat applying means selectable from a list including hot air means for heating by means of hot air and heating filament means for heating by way of radiation.

4. The method of claim 1 wherein said removing of protruding edges is achievable using at least one cutting blade.

5. The method of claim 4 further comprising adjusting the location of said at least one cutting blade to remove said protruding edges of said sealing tape adjacent to an outer wall of said multi-wall sheet.

6. The method of claim 1, wherein adhering said sealing tape and removing protruding edges are performed by a single hand.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:

(2) FIGS. 1A and 1B depict prior art multi-wall sheets;

(3) FIGS. 2A and 2B are samples depicting dirt, fungus and moss created at the end of a prior-art multi-wall sheet due to accumulation of moisture and dirt;

(4) FIGS. 3A and 3B depict a prior-art non-durable method of multi-wall end sealing;

(5) FIGS. 4A-4D depict a prior art method of multi-wall sealing involving change of the sheet profile;

(6) FIGS. 5A, 5B and 5C depict method of sealing open ends of sub-spaces of a multi-wall sheet, according to some embodiments of the present invention;

(7) FIGS. 6A-6E depict steps of preparing sealing end at the open end of a multi-wall sheet using proper machinery, according to some embodiments of the present invention;

(8) FIG. 6F depicts applying of a sealing tape to an open end of a multi-wall sheet manually, according to some embodiments of the present invention;

(9) FIGS. 6G-6H schematically present a manual device for applying, on-site, pressure and heat to a sealing tape, according to some embodiments of the present invention;

(10) FIGS. 7A, 7B and 7C depict various views of edges of a multi-wall sheet sealed with a sealing tape according to some embodiments of the present invention; and

(11) FIG. 8 describes schematically a method of sealing open ends of a multi-wall sheet, according to some embodiments of the present invention.

(12) It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

(13) In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.

(14) Reference is made now to FIGS. 5A, 5B and 5C which depict a method of sealing open ends of sub-spaces 500B of a multi-wall sheet 500A, according to some embodiments of the present invention. As seen in FIG. 5A, at least one open end of sub-spaces 500B of a multi-wall sheet 500A may be covered with tape 510, herein after called sealing tape 510. Sealing tape 510 may be longer than the length of the sheet end that needs to be covered and wider than its width. Sealing tape 510 may be made of materials such as EMA (Ethylene Methyl Acrylate), EVA (Ethylene Vinyl Acetate) and other materials that demonstrate high adhesion to Polycarbonate (PC). The sealing material may have adhesive layered on one of its faces for directly adhering to the multi-wall sheet. In a different embodiment, the sealing material may contain chemical groups in various concentrations with adhering properties to the multi-wall sheet. This adhesion can be encouraged by applying heat or by the suitable selection of the concentration of the side groups (MA in EMA or VA in EVA) in the PC, where side groups here refer to chemical groups which chemically connected to the backbone chain (main chain) of the polymer. A tape of material with adhesion to the multi-wall sheet can be used itself as the sealing tape or as an adhesive layer between the ends of the multi-wall sheet and the sealing tape, which may be made of another material/polymer. According to some embodiments of the present invention, sealing tape 510 may be made to be adjoined, be joined, be weld or otherwise adhered to the open ends of multi-wall sheet 500A.

(15) Sealing tape 510 may have features such as elasticity, thermo-plasticity, compatibility with thermo-plasticity of the multi-wall and good adhesion to the multi-wall sheet, low Tg (Glass transition temperature) compared to that of the sealed multi-wall sheet, and high thermal stability. According to some embodiments of the present invention, sealing tape 510 may have a flexibility figure of less than 90 in the Shore A hardness scale and may have an adhering strength to the multi-wall sheet of no less than 0.5 N/cm. Sealing tape 510 may be made of a single or multi-layer of polymeric material. According to some embodiments, sealing tape 510 may be made of two layers, first layer of an elastic polymer having a thickness of no less than 100 micron, and a second layer with less flexibility than the first layer and a thickness smaller than the thickness of the first layer by at least 20 percent. Sealing tape 510 may be applied onto open ends of sub-spaces 500B using adhesive and/or heat to urge thermoplastic adhering and/or pressure to firmly adhere sealing tape 510 onto open ends of sub-spaces 500B. According to some embodiments, sealing tape 510 may be submerged, partially or fully, into the open ends of sub-spaces 500B of multi-wall sheet 510A.

(16) Once the adhering of sealing tape 510 onto the open ends 500B of sub-spaces of multi-wall sheet 510A has been completed, as seen in FIG. 5B, the residual margins of sealing tape 510 may be removed, leaving the ends of sub-spaces of sheet 500A firmly and smoothly sealed, without changing the form of the respective end of sheet 500A, as depicted in FIG. 5C. In some embodiments, adhering of sealing tape 510 onto the side of a multi-wall may be done using an intermediate tape, having adhesive material layered on both sides of the tape, or at least on one of its faces. The intermediate layer may have high adhering features as well as flexibility, transparency, elasticity and the like, as is required from the respective sealing tape.

(17) According to some embodiments of the present invention, application of a sealing tape onto the open end of a multi-wall sheet may be performed using machinery, for cutting the sheet to the required size and form, for attaching the sealing tape onto the open ends of the multi-layer sheet and for adhering it to the sheet and removing protruding ends of the tape. Reference is made now to FIGS. 6A-6E, which depict steps of preparing sealing end at the open end of multi-wall sheet 602 using proper machinery, according to some embodiments of the present invention. Multi-wall sheet 602 may be placed in a suitable machine 650, equipped with work plane 652 and at least one pressing plane 660 adapted to press onto and/or to provide heat to a sealing tape in order to adhere it to an open end of multi-wall sheet 602 as seen in FIG. 6A. A sealing tape 610 may be located along a certain open end 602A of sheet 602 (FIG. 6B), and machine 650 may be operated to apply pressure, and optionally heat, onto sealing tape 610, even if the sealed end is cut in an angle other than right angle with respect to other edges of sheet 602, as seen in FIG. 6C. As a result of the pressure, and optionally heat, that are applied to sealing tape 610, sealing tape 610 is firmly adhered onto the open end of sheet 602, as seen in FIG. 6D. All that is left to do now is the removal of the protruding ends 602D of tape 610 beyond the edges of sheet 602, as seen in FIG. 6E. As described above, this method is suitable for preparation of sealing to open ends of multi-wall sheet that are cut to a measure in the factory. In several cases multi-wall sheet are cut to measure on-site, where machine such as machine 650 are not available.

(18) Reference is made now to FIG. 6F, which depicts applying of sealing tape 610 to an open end of multi-wall sheet 602 on-site where the multi-wall sheet is to be installed, according to some embodiments of the present invention. As seen in FIG. 6F, sealing tape 610 is first placed against the respective open end 602A of multi-wall sheet 602, and then sealing tape 610 is heated by heater 640 (in cases where the adhering is heating dependent) and pressure may also be applied onto sealing tape 610 (in cases where the adjoining or adhering is pressure-dependent) using pressure-applying device, such as manual pressure roller 645. By this method, sealing tape 610 may be adhered, welded, adjoined and the like, along any desired end of plate 602. The advantage of this method for on-site sealing is evident. The heating can be applied on both sides of the sealing tape (top and bottom). It will be apparent to one skilled in the art that the method of joining, adhering, adjoining or adhering of a sealing tape on-site according to some embodiments of the present invention may also be carried out using on-site compatible light machinery that may assist in, or perform instead of a worker, some or all of the steps described above.

(19) Reference is made now to FIGS. 6G and 6H schematically presenting, in front view and partial side view respectively, manual device 680 for applying by a single hand, on-site of the place where the multi-layer is to be installed, pressure and heat to a sealing tape, according to some embodiments of the present invention, in order to adhere that sealing tape onto an open end of a multi-wall sheet as described above with regard to FIG. 6F. Manual device 680 may comprise pressure roller 680A, air heater unit 680B, hot air duct 680C, one or two edge removing cutting blades 680E and manual handle 680D, all connected together to allow an operator of device 680 to conveniently apply pressure and heat to a sealing tape such as sealing tape 610 so as to adhere said sealing tape onto an open-end of multilayer sheet such as sheet 602 and to remove protruding edges. The distance d.sub.cut between the two cutting blades 680E may be adjustable so as to adapt to the width of multi-wall sheet 602. Each one of cutting blades 680E may be moved left or right (as seen in the side view of FIG. 611) by d.sub.adjust amount of movement to enable convenient setting of the location of the cutting blades with respect to an imaginary longitudinal central axis 680F located substantially in the middle of the side view seen in FIG. 6H. According to some embodiments of the present invention, setting of the desired magnitude of d.sub.cut may be done by separate setting of the d.sub.adjust of the location of each of cutting blades 680E.

(20) Reference is made now to FIGS. 7A-7C, which depict various views of edges of multi-wall sheet 702 sealed with sealing tape 710 according to some embodiments of the present invention.

(21) Sealing tape according to some embodiments of the present invention, such as sealing tapes 610, 710, may be made of flexible tape having width and thickness as may be required and in lengths as required. The tape may be transparent, semi-transparent or opaque, with natural color or in any other coloras may be desired. The material of which the sealing tape is made may be, for example, EVA (Ethylene Vinyl Acetate) with various concentrations of VA (Vinyl Acetate). The sealing tape may, for example, have adhesive features that will enable good adhering to the open ends of a multi-wall sheet, depending, for example, on the material of which the multi-wall sheet is made. For example, a multi-wall sheet made of polycarbonate may require that its sealing tape will be compatible and with good adhesion to PC, thermoplastic and elastic. The sealing tape may have other features and may be made of other materials, such as EMA (Ethylene Methyl Acrylate), with various concentrations of MA (Methyl Acrylate) and TPU (Thermoplastic Polyurethane).

(22) Reference is made now to FIG. 8, which describes schematically a method of sealing open ends of a multi-wall sheet, according to some embodiments of the present invention. A multi-wall sheet is cut to a desired measure and form, either at the factory or on-site where it will be used (block 802). A sealing tape is attached to the open ends of the multi-wall sheet (block 804). The attached sealing tape is pressed into the open ends of the multi-wall sheet and adhered/welded/glued/adjoined and the like, whether with a stationery machine (off-site) or with a manual/on-site compatible tool (on-site) (block 806). The process can be done in hot or cold method. After the sealing tape was pressed and adhered the tape edges protruding are removed (block 808).

(23) While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.