COVERING TAPE AND A METHOD FOR ITS MANUFACTURE

Description

[0001] The invention relates to a masking tape with an adhesive tape having at least one adhesive side for sticking to a work surface and an edge section and a masking film edge laminated onto the edge section, the masking film having a free gripping edge opposite the laminated masking film edge along a width of the masking film, and the masking film is folded towards the edge section and forms a stack of film.

[0002] The invention also relates to a method for producing a folded masking tape, in which a masking film edge of a masking film is laminated onto an edge section of an adhesive tape, the masking film is folded towards the edge section and forms a stack of films.

[0003] Masking tapes are of course well known in the state of the art.

[0004] From EP 1 149 883 B1, a masking tape is known, comprising an adhesive tape with a paper backing containing a self-adhesive layer. In the edge region of the self-adhesive layer, a masking material with good paint adhesion is laminated, and in the same edge region of the self-adhesive layer, a masking film is laminated, completely covering and backing the masking material. The masking tape exhibits good adhesion for paint, which therefore does not flake off even after oven drying. The masking tape is particularly suitable for masking areas not to be painted during automotive refinishing.

[0005] EP 1 149 634 B1 discloses a masking tape made of a temperature-resistant adhesive tape with a flexible film carrier and a self-adhesive backing. A masking material exhibiting good paint adhesion and absorbency is laminated to the edge of the self-adhesive backing. A masking film laminated to the same paint edge area also backs the masking material when applied. In contrast to the first-mentioned publication, this one discloses a masking material with good paint adhesion and absorbency in general. This masking tape is also suitable for marking areas to be left unpainted during the painting of automobiles.

[0006] EP 0 841 384 A2 discloses a masking membrane for painting and varnishing work. This multi-layered, folded plastic film masking membrane is suitable for painting, plastering, and varnishing. An overhanging longitudinal edge strip carries an adhesive tape that extends laterally and is covered with a top strip. The combination of adhesive tape and top strip allows for flexible material selection for various applications.

[0007] EP 0 548 576 A1 describes a protective film that is folded in a leporello-like fashion and serves to protect adjacent surfaces during processing. A single-layer edge area contains a reinforcing strip with adhesive on the outside. The thickness of the reinforcing strip corresponds to the thickness of the folded film to prevent wrapping problems.

[0008] The protective film is typically very wide and is therefore folded and stacked next to the adhesive tape. The masking tape is usually supplied on rolls. A disadvantage has been found to be the difficulty in unfolding the protective film, as one of the handles disappears into the stack and is covered by the masking material. Furthermore, automatic gripping devices cannot, or can only with great difficulty, grasp these handles, making reliable automatic unfolding of the film impossible.

[0009] Therefore, in a first aspect, the object of the present invention is to provide a cover tape that is easier to unfold.

[0010] In a second aspect, the object of the invention is to provide a method for producing a more easily deployable cover tape.

[0011] The first aspect of the task is fulfilled by a cover tape with the features of claim 1.

[0012] The stack of cover sheets present in the cover sheet according to the invention comprises, or in particular consists of, a cover sheet having a width and a length, and the cover sheet is folded into a double layer along a fold line extending along its length, wherein two free longitudinal edges of the double-folded cover sheet run side by side and the double-layered cover sheet is folded into a stack. One of the free longitudinal edges rests freely accessible on the stack of cover sheets.

[0013] The protective sheet typically has a rectangular outer circumference with a length many times greater than its width, and a width many times greater than the thickness of the sheet. The length of the protective sheet can, in principle, be infinite, or at least several meters; the width, however, can range from a few centimeters or decimeters to several meters. To make such protective sheets manageable, they are folded into a stack. This stack utilizes the principle of first folding the protective sheet in two layers and then folding it again so that the two longitudinal edges lie side by side. They can be exactly on top of each other or offset from one another; preferably, they rest on top of the stack. This creates an outer and an inner longitudinal edge. The outer longitudinal edge is easily accessible and can be grasped with the fingers.

[0014] The inner longitudinal edge, located between the stack of protective films and the outer longitudinal edge, is either covered by the outer longitudinal edge or protrudes slightly below it, so that it too is freely accessible, for example, by being grasped with the fingers or by machine and fed into further use. In particular, the lower free longitudinal edge can be machine-grasped and connected with adhesive tape, which is fed to the stack of protective films manually or by machine.

[0015] Preferably, the cover film is folded in an accordion fold, and an outer double layer is placed around the accordion stack in at least a U-shape. The U-shaped enclosure of the accordion stack by the outer double layer keeps the cover film stack closed and makes it easier to use.

[0016] In another embodiment of the invention, the double layer is folded in a spiral fold. Here, too, an outer cover layer preferably comprises the stack of cover films in a U-shape. Combinations of accordion folding and spiral folding are also conceivable.

[0017] The outer longitudinal edge rests on the outside of the stack of protective sheets and is easily accessible. It preferably forms a gripping edge. A user can easily grasp the outer longitudinal edge with their fingers and thus pull the protective sheet apart along its width. Advantageously, the gripping edge, as well as the longitudinal edges in general, extend over the entire length of the protective sheets and the stack of protective sheets. The stack of protective sheets has a length corresponding to the length of the protective sheet, while its width is significantly smaller than the width of the protective sheet itself. Advantageously, the stack of protective sheets can thus be rolled up and stored.

[0018] In a further development of the invention, the outer longitudinal edge of the outer cover film layer is folded back. This makes the outer longitudinal edge particularly accessible and easy to grasp with the fingers.

[0019] The gripping edge can also be marked with color or texture, making it easily recognizable and graspable with the fingers.

[0020] The cover film is preferably made of PE, PP, PA, PBT, or PET film, but can also be paper or a metal foil (for example, aluminum foil). Furthermore, composite films made of the above-mentioned materials are particularly advantageous. However, other materials are also conceivable.

[0021] According to the invention, the cover film has a gripping edge which is arranged to lie freely on the stack of films.

[0022] Here, a tape is generally understood to be a physical entity with a length, a width, and a thickness, where the length is a multiple of the width and the width is a multiple of the thickness. The tape can have a constant width along its entire length and a thickness that varies along its width. Alternatively, the thickness can remain constant along its width.

[0023] The masking tape according to the invention comprises an adhesive tape and a release liner. The adhesive tape advantageously has a backing layer and an adhesive layer. The backing layer can be made of common plastics such as polyethylene, polypropylene, or other plastics described below. The backing layer can also be made of paper or metal foils (for example, aluminum foil). The adhesive layer can be a pressure-sensitive adhesive made of various materials, for example, non-polar elastomers. It can also be made of, for example, acrylates. These are also listed below.

[0024] The adhesive tape of the masking tape preferably has a uniform width and thickness along its entire length. The masking film also preferably has a uniform thickness along its length and width.

[0025] The release liner comprises a protective film edge that is laminated onto a section of the adhesive tape. The release liner can be fixed to the side of the adhesive tape opposite the adhesive side, or it can be laminated to the adhesive side. Fixing preferably refers to lamination, but the release liner can also be welded, heat-sealed, glued, or otherwise attached. The release liner can also be created locally using a tool, which locally fixes a separate adhesive tape onto the folded release liner.

[0026] The cover film is preferably also in a ribbon shape. It has a free gripping edge opposite the laminated cover film edge along the length of the cover film. The gripping edge is the cover film edge opposite the fixed cover film edge, the outermost end of which forms the gripping edge.

[0027] The masking tape is typically supplied for sale and storage with a folded protective film. The protective film is folded towards the edge, forming a stack of film. The folded protective film is then wound into a roll.

[0028] When the protective film is folded, the masking tape can be easily rolled up. The resulting stack of film is significantly narrower than the width of the protective film. This stack can be created by folding the protective film 3, 5, 7, 9, 12, or even more times.

[0029] The stack of protective film is characterized by the fact that the gripping edge rests on the side of the film stack opposite the adhesive side of the tape. After unwinding the tape from the roll, the gripping edge can be easily grasped with the fingers, and the protective film can then be unrolled without difficulty. Unlike previous methods, it is no longer necessary to "fish" for the gripping edge between the film stack and the covering material, or to laboriously feel for and pull it out from within a stack of film. Furthermore, it is possible to automatically detect and grip the gripping edge.

[0030] The gripping edge rests freely on the side of the film stack opposite the adhesive side of the tape. This allows the masking tape to be unrolled first, then the adhesive side of the tape to be applied to the work surface, and finally the masking film to be easily grasped and pulled apart by the gripping edge located on top of the film stack with the applied masking tape.

[0031] In a preferred embodiment, the gripping edge—where "gripping edge" refers not to a logical line but rather a very narrow strip along the outer free edge of the cover film—has an inner side that is in contact with the film stack and an outer side that is not in contact; that is, the outer side has no contact with the film stack, the adhesive tape, or any other contact whatsoever. However, it is also possible for the gripping edge to be crimped or folded. Furthermore, the gripping edge can be visually and / or haptically highlighted by color marking or by the application of contrasting strips.

[0032] The gripping edge, positioned as described, lies freely accessible to the user on top of the film stack, opposite the working surface of the adhesive masking tape on the film stack. This allows the user to grasp the gripping edge with their fingers and peel it off the film stack, thus fully unfolding the protective film. When fully unfolded, the protective film is single-layered and flat.

[0033] Preferably, the stack of films has a double-layered accordion fold. This means that the cover film is first folded once completely or with a slight offset along its width, so that the cover film is double-layered (with one shorter and one longer leg in the case of an offset), and the resulting double layer is then folded accordion-style. The accordion fold is preferably made below, i.e., opposite the handle edge, on the adhesive side of the release tape, so that the handle edge remains freely accessible on top of the film stack, facing away from the adhesive side of the release tape. However, the double layer can also be folded only once.

[0034] Advantageously, the stack of foil has an outer folded layer of the protective film that encloses all other folded layers of the foil stack in a U-shape on one side of the stack facing away from the adhesive side of the tape. This outermost folded layer encompasses the entire foil stack in a U-shape, thus holding the stack together after the protective tape has been unrolled and the adhesive side of the tape has already been applied to the work surface. This prevents the foil stack from unfolding on its own.

[0035] The cover film is advantageously made of PE, PP, PA, PBT, or PET film, but can also be paper or a metal foil (for example, aluminum foil). Furthermore, composite films made of the above-mentioned films or film materials are particularly advantageous. Other plastics are shown in the specific embodiment of the invention, but they can be used for all embodiments of the cover tape.

[0036] The adhesive tape can be designed as masking tape, with PVC-based tapes being particularly advantageous. Alternatively, it can be crepe tape, a particularly cost-effective option. However, in principle, all types of adhesive tape are suitable, including those without a backing material.

[0037] The problem is solved with regard to the method by a method mentioned at the outset with the features of claim 10.

[0038] This manufacturing process is particularly suitable for producing one of the aforementioned masking tapes. Conversely, the aforementioned masking tapes can be more conveniently produced using one of the following methods.

[0039] The process relates to the production of a folded masking tape by fixing an edge section of a masking film to an edge section of an adhesive tape, folding the masking film towards the edge section, and forming a stack of films. For the interpretation of the terms "edge" and "arrangement," reference is made to the above explanations.

[0040] According to the invention, in this method, a free gripping edge opposite the laminated edge of the cover film is arranged to rest freely on the film stack along a length of the cover film. The cover tape can be folded to a significantly smaller width by folding the cover film, which can be as wide as 50 cm, 1 m, 1.5 m, 2 m, 2.5 m or more and is therefore difficult to handle. The width of the folded cover tape is only 20 cm, 40 cm, or 60 cm, with all intermediate dimensions also disclosed. Other widths of the folded cover tape are also conceivable.

[0041] The folding mechanism according to the invention is designed such that the free edge of the release film opposite the adhesive tape remains easily accessible to the user on top of the film stack even after folding. The gripping edge preferably rests along its entire longitudinal dimension on the side of the film stack opposite an adhesive side of the tape on the release film. This allows the user to easily grasp the gripping edge along its entire longitudinal dimension, even after the release film has already been adhered to a work surface with the adhesive tape.

[0042] Ideally, the protective film is laid in two layers and folded accordion-style. This accordion-style folding creates the stack of film. This stack is best positioned on the adhesive side of the tape, so that the handle remains easily accessible at the top of the film stack, opposite the adhesive side.

[0043] Advantageously, the gripping edge is positioned approximately 0 cm to 10 cm from the edge of the adhesive tape, preferably along its entire length, but it can also be located further away from the tape. Most preferably, the gripping edge lies directly against the adhesive tape.

[0044] The invention is described with reference to an exemplary embodiment in three figures. These figures show: Fig. 1 Perspective view of a cover tape according to the invention in the folded and unwound state, Fig. 2 Sectional view along line II. Fig. 1, Fig.3 Sectional view of a further embodiment of the cover tape according to the invention.

[0045] Fig. 1Figure 1 shows a masking tape 1 with an adhesive tape 2 extending in a longitudinal direction L. A tape, i.e., masking tape 1 or adhesive tape 2, is understood to be a band extending essentially very long, in principle endlessly, in the longitudinal direction L, whose length L is many times greater than its extent along a width B. The tape 1, 2 also has an extent along a thickness D. The thickness of the masking tape 1 varies along the width B. Typical dimensions are given below. In this example, the adhesive tape 2 typically has a width B of 15 mm to 30 mm, and the masking tape has a thickness of 100 µm to 250 µm in the section of the adhesive tape 2. The protective film 6 extends from the longitudinal side of the adhesive tape 2. The width B of the masking tape 1 in the section of the protective film 6 is typically 500 mm to 2.500 mm, in the section of the cover film 6, the cover tape 1 typically has a thickness of 10 µm to 50 µm, the thickness referring to a single layer of the cover film and not to the entire cover stack.

[0046] The extent along width B is many times greater than the extent along thickness D. "Many times" here means 100 times to over 10,000 times greater.

[0047] The adhesive tape 2 typically comprises a carrier layer 3 and an adhesive layer 4. The carrier layer 3 consists of a common plastic, paper, and / or metal (for example, aluminum). Examples of plastics, but not limited to, include: polyethylene (PE), polypropylene (PP) – especially oriented polypropylene (OPP) produced by mono- or biaxial stretching, cyclic olefin copolymers (COC), polyvinyl chloride (PVC), polyesters – especially polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT), ethylene vinyl alcohol (EVOH), polyvinylidene chloride (PVDC), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polycarbonate (PC), polyamide (PA), polyethersulfone (PES), polyimide (PI), ethylene vinyl acetate (EVA), as well as copolymers, blends, multilayer films, or composite films made of the aforementioned polymers, which are, for example, glued, welded, or coextruded. Furthermore, the carriers may be present in a treated state, e.g.Paper can be coated, creped, printed, or otherwise pretreated and / or modified by coating with a primer or varnish, corona treatment, and / or etching. The same applies to metal-based substrates.

[0048] The adhesive layer 4 consists of a common pressure-sensitive adhesive, for example acrylates, natural and synthetic rubber compounds, silicones, etc.

[0049] The adhesive layer 4 is preferably applied over the entire surface of one side of the carrier layer 3. However, it can also be arranged along a strip on the carrier layer next to the cover film.

[0050] The adhesive tape 2 has a release liner edge section 7, which can also be part of the adhesive layer 4. A release liner edge 8 of the release liner 6 is fixed to the release liner edge section 7.

[0051] The cover film 6 is preferably, but not exclusively, made of the following materials: paper, metal (e.g., aluminum), polyethylene (PE), polypropylene (PP) – in particular oriented polypropylene (OPP) produced by mono- or biaxial stretching, cyclic olefin copolymers (COC), polyvinyl chloride (PVC), polyester – in particular polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT), ethylene vinyl alcohol (EVOH), polyvinylidene chloride (PVDC), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polycarbonate (PC), polyamide (PA), polyethersulfone (PES), polyimide (PI), ethylene vinyl acetate (EVA), as well as copolymers, blends, multilayer films, or composite films made of the aforementioned polymers, which are, for example, glued, welded, or co-extruded. Furthermore, the substrates may be treated, e.g.,Paper can be coated, creped, printed, or otherwise pretreated and / or modified by coating with a primer or varnish, corona treatment, and / or etching. The same applies to metal-based substrates.

[0052] The masking tape 1 in Fig. 1The tape 1 is very long, although only a short section L of the tape is shown here. Advantageously, the tape 1 can be wound into a roll. In this wound state, the tape is preferably transported and stored before use. The adhesive layer 4 of the tape 2 is located on the inside of the roll, and the backing layer 3 of the tape 2 is located on the outside. The tape 1 can be wound around a core through which the end of a handle is inserted for application, allowing the tape 1 to be unwound continuously from the roll. The core can be made, for example, of cardboard – even siliconized – or a plastic such as polyethylene (PE).

[0053] The cover sheet 1 is folded into a stack of sheets 9. The fold lines all run parallel to the longitudinal direction L.

[0054] The in Fig. 1The folded masking tape 1 according to the invention is characterized by an exposed and therefore easily graspable gripping edge 11, which is arranged opposite the edge of the release film 8, which is laminated onto the edge section 7 of the adhesive tape 2, on the unfolded release film 6. Easily graspable here means that the gripping edge 11 extends freely over the entire longitudinal dimension of the masking tape 1 and is arranged approximately 0 to 10 cm beside and parallel to the adhesive tape 2, more precisely beside the carrier layer 3 of the adhesive tape 2. After unwinding the masking tape 1, according to Fig. 1The gripping edge 11 is exposed. It is not covered by a covering material or similar, but is visible along its entire longitudinal extent and directly touchable and accessible to the user, and can be explored by semi- or fully automated optics and grasped by semi- or fully automated mechanics when the cover tape 1 is unwound from the roll.

[0055] For particularly easy identification, the handle can be highlighted visually and / or haptically, for example by color, additional folding, gluing and / or by curling.

[0056] Fig. 3 Figure 1 shows a sectional view of a further embodiment of the masking tape 1 according to the invention. This further embodiment of the masking tape 1 also has an adhesive tape 2 to which a stack of masking films 9 is adhered along its entire longitudinal extent. In this further embodiment according to Figure 2, the masking tape 1 is further divided into two parts. Fig. 3An inner longitudinal edge of the cover film 6 is adhered to an adhesive layer 4 of the adhesive tape. Other fastening methods are of course also conceivable.

[0057] The stack of cover sheets 9 of the Fig. 3 The two-layer cover film 6 is stacked in a spiral or snail-like pattern. Here, too, an outer layer of cover film 12 is wrapped around the stack of cover films 9 in an approximately U-shape. The gripping edge 11 of the cover film 6 is folded back. "Back" here means folded away from the adhesive tape 2. This makes the gripping edge 11 particularly easy to grasp. It can be easily grasped, especially with the user's fingers.

[0058] The width B of the unfolded cover film 6 can be between 50 cm and 2.50 m, preferably between 1.4 m and 1.9 m. However, all other intermediate dimensions are also conceivable and are disclosed. The unfolded cover film can also have larger or smaller widths B.

[0059] To produce the masking tape 1 according to the invention, the masking film 6 is first fixed with the masking film edge 8 along its entire longitudinal extent on the edge section 7 of the adhesive tape 2 and then folded in two layers. The masking film is folded over with a slight offset along a fold line extending in the longitudinal direction L and the gripping edge 11 is folded towards the adhesive tape 2, so that the gripping edge 11 is located on the side of the masking film 6 opposite the adhesive layer 4.

[0060] The cover film 6 is then laid in a double layer over essentially its entire extent. It is subsequently folded accordion-style on the side opposite the handle edge 11 towards the film stack 9, forming a double layer. The accordion fold is made from the outside in, i.e., towards the handle edge 11. This creates an outer folded layer 12 of the cover film 6, which surrounds the other folded layers in a U-shape, preferably completely on three sides, on a side of the film stack 9 facing away from the adhesive tape 2.

[0061] Another method for manufacturing the masking tape begins with folding the film into a double layer. The use of an asymmetrically folded film, already wound onto a core, has proven particularly advantageous. This type of film is obtained, for example, from blown film extrusion, where, in double-sided production, the resulting film tube is cut asymmetrically and then wound up after being folded.

[0062] Another method involves a symmetrical cut, resulting in a tube with a slit at the edge. This tube is then precisely folded on top of each other, and a subsequent edge trim creates asymmetrical film sections. The asymmetrically folded film is then folded according to the previously described procedure, producing the finished film stack. Adhesive tape is then applied to the film stack. In principle, the adhesive tape can be applied to the edge of the release film at any point during production.

[0063] The stack of film can also be pre-folded and wound onto a core. The adhesive tape is then locally fixed to the edge of the release film using a tool that can hold and guide both the tape and the wound stack of film, so that the release tape can be produced with the tool.

[0064] Fig. 1This does not show that the masking tape 1 is wound up. Usually, the masking tape 1 is wound around a Fig. 1 The winding axis is arranged below the cover tape 1, so that the adhesive layer 4 is arranged on the inside of the winding and the carrier layer 3 of the adhesive tape 1 is arranged on the outside of the winding.

[0065] Advantages of accordion folding according to Fig. 1 The advantage of the cover film 6 is that the cover film 6 of the masking tape 1, which is adhered to the (not shown) work surface, can be completely unfolded by grasping the gripping edge 11 and pulling. Furthermore, it is advantageous that the adhered but not yet unfolded cover film 6 remains in its position, since the outer folded layer 12 completely encloses the stack of cover films 9. This prevents it from unfolding on its own. Additionally, the folds of the film stack do not need to be at the same height, but can be offset from one another. Reference symbol list

[0066] 1. Masking tape 2. Adhesive tape 3. Carrier layer 4. Adhesive layer 6 Cover film 7 Cover film side edge section 8 Cover film edge 9 Film stack 11Handling edge 12Outer folded layer BWidth DThickness LLongitudinal direction

Claims

1. Masking tape with an adhesive tape (2) having at least one adhesive side for adherence to a working face and having an edge portion (7), and disposed on the edge portion (7), a masking film edge (8) of a masking film (6) which has a free manual engagement edge (11) opposite the masking film edge (8) along a width (B) of the masking film (6), where the masking film (6) is folded toward the edge portion (7) and forms a masking film stack (9) with a masking film (6) which has a width (B) and a length (L), and the masking film (6) is folded along a folding line, running along the length (L), to form a double ply, where two free longitudinal edges of the double-ply-folded masking film (6) run adjacent to one another and the double-ply masking film (6) is folded to form a stack and the two longitudinal edges lie on the masking film stack (9), characterized in that the manual engagement edge (11) is disposed lying freely on the masking film stack (9) and the manual engagement edge (11) lies on a side of the film stack (9) opposite the adhesive side of the adhesive tape (2).

2. Masking tape according to Claim 1, characterized in that the manual engagement edge (11) has an inner side which is disposed under contact on the film stack (9) and has an outer side which has no contact.

3. Masking tape according to either of Claims 1 and 2, characterized in that the manual engagement edge (11) is turned over in the adhesive tape-remote direction.

4. Masking tape according to any of Claims 1 to 3, characterized in that the adhesive tape (2) takes the form of a crepe adhesive tape or PVC-containing adhesive tape.

5. Masking tape according to any of Claims 1 to 4, characterized in that the double ply is folded in a concertina fold and an outer double ply (12) is placed at least in U-shape around a concertina stack.

6. Masking tape according to any of Claims 1 to 4, characterized in that the double ply is folded in a helical fold.

7. Masking tape according to any of Claims 1 to 6, characterized in that the manual engagement edge (11) has coloured or tactile marking.

8. Masking tape according to any of Claims 1 to 7, characterized in that the masking film (6) is a PE, PP, PA, PET or PBT film or is a composite film of PA and PE or PP and PE or is made of paper or is an aluminium foil.

9. Masking tape according to any of Claims 1 to 8, characterized in that the masking film stack is wound on a cardboard or plastic core.

10. Method for producing a folded masking tape (1) according to Claim 1, by disposing a masking film edge (8) of a masking film (6) on an edge portion (7) of an adhesive tape (2), folding the masking film (6) toward the edge portion (7) and forming a masking film stack (9), characterized in that a free manual engagement edge (11) opposite the masking film edge (8) along a width (B) of the masking film (6) is disposed lying freely on the masking film stack (9).

11. Method according to Claim 10, characterized in that the masking film (6) is made into a double ply and folded concertinawise.