Method for manufacturing large-width polymer film coverings
The method addresses the challenge of producing wide polymer film coatings by pre-folding material for optimal heating element access, achieving high-quality, continuous seams and mechanical properties comparable to the original material.
Patent Information
- Application Number
- PCT/RU2024/000170
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-05-16
- Filing Date
- 2024-05-23
- Publication Date
- 2025-11-20
AI Technical Summary
Existing methods for producing wide polymer film coatings face limitations in creating longitudinal seams of required widths and maintaining high-quality welds along the entire length of the material, particularly due to the positioning of heating elements and the need for constant orientation of welding devices.
A method involving pre-folding of rolled material to ensure free access of heating elements to the welding zone, allowing for a high-quality, continuous longitudinal seam by aligning outer edges symmetrically and using multiple heating elements if necessary, with adjustable tension control for the finished product.
Enables the production of film coatings up to 36 meters wide with a high-quality, even seam along the entire length, eliminating the need for constant device reorientation and ensuring mechanical properties similar to the original material.
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Abstract
Description
[0001] METHOD FOR PRODUCING LARGE-WIDTH POLYMER FILM COATINGS
[0002] The present invention relates to methods for joining polymer films made of thermoplastic materials (including foil-laminated and metallized ones), and allows joining bodies by means of fusion welding.
[0003] Film coverings up to 36 meters wide are often required for applications in agriculture (silage films), road construction, airfield construction, sludge pit construction, and artificial reservoir foundations as waterproofing, as well as for temporary roofing and windbreaks for off-season work on building facades. The proposed method allows for the production of a film covering of the required width by joining rolls, including multiple rolls, of standard width (4 to 6 meters) into a single sheet (film covering) of greater width (up to 36 meters).
[0004] Thermoplastic polymeric materials can be joined together mechanically using bolts, rivets and other fasteners, by gluing using various adhesives, or by welding.
[0005] Of all the listed methods, only welding eliminates the need to introduce foreign materials into the joint zone and makes it possible to obtain bonds and supramolecular formations characteristic of the original material in this zone, consequently, to bring the joint as close as possible to the original material in mechanical properties, gas permeability, dielectric characteristics and other properties. Therefore, in cases where high demands are placed on joints in structures with regard to strength, tightness and other properties, it is preferable to assemble the structures by welding. (Welding of polymeric materials. Handbook. Zaitsev K. I. et al. 1988) In most cases, sheet and roll polyethylene is welded using: hot air (hair dryer); hand extruder; heating element (butt joint).
[0006] (https: / / www.weldi.ru / blog / svarka polietilena / )
[0007] A method for producing bags and sleeves is known, characterized by the fact that when flexible belts move through a former, a certain amount of excess material is formed, folded into folds, and when two belts move between the shafts of the shaft assembly, it is finally formed into a flat structure (Russian Federation patent for invention RU 2299841, C2, published 05 / 27 / 2007)
[0008] The disadvantage of this method is that the heating elements are located inside spring-loaded shafts, located transversely to the direction of movement of the tapes and cannot provide the ability to produce a longitudinal continuous seam, nor limit the welding zone in width.
[0009] A portable device for welding polymeric materials is known, comprising a housing with a handle, made in the form of two identical rectangular cheeks, each of which has two shaped cutouts that form a socket for a heater and a handle, respectively, on which an electric heater with a working skid is mounted, two guide rollers installed on opposite sides of the heater at the corners of the housing at the level of the working skid, and an endless closed gasket tape made of an anti-adhesive material, covering the rollers and the heater in the plane of rotation of the rollers, (Russian Federation patent for invention RU 2019413, C1, published 09.15.1994)
[0010] The disadvantage of this device is the need to constantly orient the portable device relative to the base-substrate to obtain a high-quality weld, as well as the inconvenience of use when welding along the entire length of the rolled material (up to 100 linear meters).
[0011] A method is known for continuous longitudinal welding of plastic film material, characterized in that it consists of the continuous formation and circulation of a double layer (1 1) of said material and subjecting part of said double layer to thermal radiation from a fixed heat source (12) until local melting of said material (patent for invention FR2537914, A1, published 06 / 22 / 1984)
[0012] The disadvantage of this method is the inability to produce a film coating of the required width.
[0013] The task set in the creation of the proposed method was to eliminate the above-mentioned shortcomings and ensure the possibility of producing a film coating of large width.
[0014] To solve the problem, a method is proposed that consists of pre-folding the rolled material in such a way as to ensure free access of the heating element to the welding zone of the outer edges located at a distance from the central axis of the cross-section, without touching or thermally influencing the folded layers of the film coating.
[0015] The method for producing wide polymer film coatings is illustrated by the following drawings:
[0016] Fig. 1 shows a diagram of a device for producing a wide polymer film coating, side view.
[0017] Fig. 2 shows a diagram of a device for producing a wide polymer film coating, top view.
[0018] Fig. 3 shows an example of welding rolls of polymer film coating.
[0019] The method is carried out in the following way.
[0020] Standard rolls 2 are placed on the receiving unwinding terminal module in the required quantity. Then, on the preparation line (not shown), the film covering 1 of each roll is folded in a manner required for welding. The film covering 1 of each roll 2 is folded such that the number of layers in the cross-section can range from 8 to 16, and the outer edge intended for welding is located at a distance from the central axis of the cross-section. The folding of the film covering 1 must also ensure free access of the heating element 5 to the welding zone without touching or thermally influencing the folded layers of the film covering 1. In the case where the film covering 1 is a continuation of the web to be welded in the transverse direction, the outer edges are made at a distance symmetrically on each side.The folded film coverings 1 are then fed to table 3, where the outer edges of the adjacent rolls of film covering 1 are aligned for subsequent splicing. Welding is accomplished by lowering welding device 4 into the area of the aligned edges of film covering 1, where heating element 5 presses the aligned edges against table 3 and, by transferring thermal energy, the two blanks are joined with a single seam along the entire length of the product. In another embodiment, to create stronger joints, two or more heating elements 5 may be installed in welding device 4. The finished product is then fed to the winding area, where it is wound into a roll on receiving spool 10 by winding device 8, having first passed through tension device 6.To prevent internal creases and increase the density of the finished roll 7, the winding device 8 has an additional adjustable drive 9, which regulates the rotation speed of the take-up spool 10 depending on the diameter of the finished roll 7 and the degree of tension of the finished product at any given time. The process may include several operating cycles, depending on the required width of the finished product and the number of seams. The finished roll 7 is then fed into the packaging area.
[0021] The proposed method for producing wide polymer film coverings allows for finished products up to 36 meters wide, depending on requirements. It also ensures a high-quality, even longitudinal seam along the entire length of the rolled material (up to 100 linear meters).
Claims
Invention formula A method for producing polymer film coatings of large width, consisting of forming a double layer of material and subjecting a portion of said double layer to thermal radiation from a fixed heat source until said material is locally melted, characterized in that the roll material is first folded in such a way as to ensure free access of the heating element to the welding zone of the outer edges located at a distance from the central axis of the cross-section, without touching or thermally influencing the folded layers of the film coating.