Core replacement adapter for coreless rolls of film

Abstract

To provide an adapter for the machine unwinding of coreless film rolls (50), an adapter (100) is proposed comprising a first longitudinally extended adapter element (10) and a second longitudinally extended adapter element (30), each having at its free end a projecting head (13, 33) with an adapter ring (11, 31) as a stop for the film roll (50) and a connecting end (17, 37), wherein the two connecting ends (17, 37) have corresponding features to allow them to be connected to each other, and wherein the first adapter element (10) and the second adapter element (30) each have a surface (23) extending between the adapter ring (11, 31) and the connecting end (17, 37).Furthermore, at least two longitudinally extended clamping elements (15, 35) for clamping the adapter element (10, 30) in the roller passage, which are fixed on the cylindrical surface (23) and protrude from the cylindrical surface (23), as well as at least two longitudinally extended grooves (14, 34) are provided, wherein the at least two longitudinally extended clamping elements (15, 35) and the at least two longitudinally extended grooves (14, 34) are maximally spaced apart from each other and are arranged parallel to each other and to the main axis of the first adapter element (10) and the second adapter element (30).

Description

[0001] The invention relates to an adapter for use in unwinding film from coreless film rolls having a roll passage with a first and a second opening at opposite ends of the coreless film roll.

[0002] Stretch films are thin, elastic plastic films used to wrap and secure objects. They are often used in logistics for load securing. Stretch film adheres to the wrapped objects without additional tools due to its inherent adhesiveness (cling) combined with its elasticity and the applied pressure during wrapping.

[0003] In conventional and pre-stretch manufacturing processes, these films are wound onto cardboard or plastic cores, i.e., cardboard or plastic tubes. The stretch films are delivered wound onto the cardboard core by the film manufacturer, ready to be unwound directly from the cardboard core for packaging goods.

[0004] To avoid waste and reduce the weight of the film roll, it is known to produce coreless rolls. Since there is no core, there is no need to dispose of the core after the film is used up. This reduces waste and contributes to sustainability. Coreless film rolls are a special type of stretch film roll that lacks the usual cardboard or plastic core in the center of the roll. Instead, the roll consists only of the stretch film itself, which is wound directly onto the roll using a special wrapping technique. They are available in various thicknesses and sizes and can be used in a variety of industries where stretch film is used for unit load securing.

[0005] Eliminating cardboard cores also results in savings, as these cores account for approximately 5% of the cost of each film roll.

[0006] Coreless film rolls also offer other advantages. They are generally lighter and more compact than conventional rolls, making them easier to transport and store. They are also easier to install on a dispenser, as there is no core to remove or replace. Coreless film rolls offer more film per roll for the same weight.

[0007] Since coreless rolls are not wound on a cardboard or plastic core, an unwinding aid (adapter) is required to unwind the film roll. These adapters are reusable as often as required.

[0008] There are different types of stretch film dispensers, including manual dispensers, where the film is unrolled by hand, and automatic dispensers, where the film is unrolled by a stretch or wrapping machine. Both dispensers allow for even and tight wrapping of the goods to be wrapped. They simplify the wrapping process and ensure efficient and secure packaging. The choice of the appropriate dispenser depends on the individual requirements and the packaging volume.

[0009] Mechanical stretch wrappers are primarily used where large quantities of products need to be packaged. They offer a number of advantages, including faster and more efficient packaging, even and tight wrapping of the film, and the avoidance of physical strain on employees.

[0010] Various adapters for coreless film rolls for manual unwinders are known from the state of the art.

[0011] For example, DE 20 2005 003 248 U1 describes an unwinding device consisting of three parts, with two receptacles that can be inserted into the roller passage on both sides and are connected to each other via a connecting element and mounted so that they can rotate.

[0012] US 2011 / 0041458 A1 describes an adapter that consists of 2 parts, both of which are connected to each other via a thread system and are continuously adjustable in length.

[0013] There are only a few adapters available for coreless film rolls for mechanical stretch wrapping machines. For example,

[0014] US 10 308 474 B2 describes an adapter that is intended to be used for both hand-stretching and machine-stretching applications. This adapter consists of two interlocking adapter parts with rigid, wedge-shaped elements located along the longitudinal axis of the adapter.

[0015] However, the adapters currently in existence do not guarantee the necessary stability of the film rolls, which is particularly required at the higher unwinding speeds during machine unwinding.

[0016] The object of the invention is to provide an adapter which is suitable for processing coreless film rolls under the higher technical and mechanical conditions of machine unwinding, in which the film roll is unwound evenly and with consistent quality up to the end of the roll, even at high unwinding speeds.

[0017] This object is achieved by adapters having the features of the independent claims. Advantageous embodiments are characterized in the subclaims.

[0018] The invention provides an adapter for use in unwinding film from coreless film rolls having a roll passage. The roll passage has first and second openings at opposite ends of the coreless film roll.

[0019] This adapter comprises a first, elongated adapter element and a second, elongated adapter element, each of which has a projecting head portion with an adapter ring at one end. The adapter ring creates the projection, which serves as a stop for the film roll. This prevents the adapter element from slipping into the first or second opening of the film roll and ensures that the respective adapter element is correctly seated.

[0020] At the other end of each of the first and second adapter elements, a connecting end is provided. These have corresponding recesses for connecting them to one another, preferably in a form-fitting manner or for plugging them together. This can prevent the film roll from bending and ensures correct positioning of the adapter.

[0021] The first adapter element and the second adapter element have a lateral surface that extends between the adapter ring of the head part and the outer edge of the connecting end. The lateral surface only includes the parts of the adapter elements that are visible after the first adapter element and the second adapter element have been joined together. Thus, the protrusions of the first and second adapter elements for the positive connection of both adapter elements are not part of the lateral surface.

[0022] In a first embodiment of the adapter, at least two elongate clamping elements are arranged on the lateral surface of the first and the second adapter element in a fixed or reversible manner for clamping the two adapter elements in the roller passage.

[0023] The at least two clamping elements arch over the lateral surface, preferably in the shape of a circular segment or a shape derived therefrom, such as an ellipse. The at least two clamping elements are spaced apart from each other as far as possible and aligned parallel to each other and to the main axis of the first adapter element and the second adapter element.

[0024] Preferably, 2 to 8, preferably 4, elongated clamping elements are provided on each adapter element.

[0025] The at least two elongated clamping elements preferably have a length of 1 / 5 to 4 / 5, preferably 1 / 2 to 2 / 3, of the length of the outer surface of the adapter elements, so that a relatively large area of ​​the inner surface of the film roll is advantageously acted upon by the clamping elements for a secure hold. In addition to clamping the adapter elements, the clamping elements also advantageously prevent the film roll from twisting on the adapter elements.

[0026] It is also preferred that the at least two elongated clamping elements are arranged centrally with respect to the length of the lateral surface of the adapter elements, so that they are fixed for as long as possible in the event of accidental slipping of the adapter elements, possibly due to improper handling.

[0027] As an alternative to the above-described embodiment, it is provided in a second embodiment that, instead of the clamping elements, at least two longitudinally extending grooves are provided on the lateral surface of the first and the second adapter element, which are spaced apart from one another as far as possible and are arranged parallel to one another and to the main axis of the first adapter element and the second adapter element.

[0028] Preferably, at least 2 grooves, preferably 4 grooves, are provided in the respective lateral surface.

[0029] Preferably, the grooves are provided over the entire length of the lateral surface.

[0030] These grooves are used to use the adapter with special film rolls, in which there are production-related film geometries (protrusions) in the roll passage, corresponding to the grooves, which engage in the grooves.

[0031] According to a third embodiment, the adapter or the first and second adapter elements have both clamping elements and grooves.

[0032] At least two elongate clamping elements are provided for clamping the first adapter element and the second adapter element in the roller passage, which are fixed on the respective lateral surface, protrude from the lateral surface, and at least two elongate grooves are provided, wherein the at least two elongate clamping elements and the at least two elongate grooves are spaced apart from one another as far as possible and are arranged parallel to one another and to the main axis of the first adapter element and the second adapter element.

[0033] This design with four elongated clamping elements and four grooves is the most preferred, as it provides optimal support and anti-twist protection during mechanical unwinding. The grooves are preferably located centrally between the elongated clamping elements to ensure optimal effectiveness and trouble-free production of the adapter elements.

[0034] The above statements regarding the clamping elements and the grooves for the first and second embodiments apply equally to the third embodiment.

[0035] In the simplest case, the base body of the adapter elements can be conical, tapering from the head portion to the connecting end to facilitate insertion of the adapter elements into the roller passage. The conical shape can also be achieved in stages, with sections of the outer surface having a different basic geometric shape, such as a cylindrical shape.

[0036] In the areas of the adapter elements in which the at least two clamping elements are arranged, these are preferably at least partially cylindrical in the direction of the longitudinal axis, so that the clamping elements have a greater effect because they protrude further from the lateral surface. This also applies to the embodiment in which the conical or cylindrical area in the area of ​​the elongated clamping elements is preferably flattened, with a groove preferably extending between each of the flattened areas.

[0037] Preferably, the at least two clamping elements are made of plastic or a metal wire, preferably spring steel, to achieve the most stable design possible for the clamping elements. Curved spiral springs are preferably used as the clamping elements.

[0038] The clamping elements are preferably each inserted with their free ends into openings in the shell surface, whereby the clamping elements can be secured or clamped by a screw which is arranged inside the adapter element in such a way that the head of the screw is free for actuation and the tip of the screw contacts one end of the clamping element.

[0039] The at least two clamping elements can merge into the outer surface in a flattened manner toward the head section, whereby tensioning / fixing can be achieved via a screw inside the adapter element. The flattened end of the clamping elements allows them to protrude more or less into the corresponding opening in the outer surface, depending on the screw. The area for receiving the clamping element near the head section also preferably merges into the latter.

[0040] Flattened means that at least the head end of the clamping elements is inserted into the surface at an acute angle. The flattened part of the respective clamping element has a linear or nearly linear shape, in contrast to the otherwise curved shape of the clamping element.

[0041] For a preferably positive connection of the two adapter elements, the connecting ends of the adapter elements can be designed with a corresponding recess and an extension. The extension can have a round, elliptical, or angular cross-section, preferably a round cross-section, whereby the recess must be designed accordingly.

[0042] The two adapter elements preferably have a cylindrical recess in the head part coaxial with the main or longitudinal axis, which serves to precisely accommodate a cone of a stretch wrapping machine.

[0043] According to an advantageous embodiment of the adapter elements or the adapter, groove holes can be located at the end of the grooves in the respective head section of the adapter elements. The groove holes at the end of the grooves are created by the projecting head section. In the embodiment with the cylindrical recess in the head section, the groove holes open within the recess. Due to the natural design of the groove, the groove holes are also accessible from the outer surface.

[0044] These grooved holes allow the air to escape, which must be displaced between the two adapter elements and the film roll when joining them. They also allow for easy removal of the adapter elements from the film roll, as a tool can be inserted and secured into these grooved holes, which can serve as a handle for pulling.

[0045] Furthermore, the adapter ring of the projecting head part preferably has at least two fixing holes and / or a circular notch or milling for improved / simplified precise reception of screw heads of certain winder types.

[0046] The adapter, or rather the first and second adapter elements, is / are preferably made of plastic; only the clamping elements are preferably made of spring steel. The plastics used are preferably polyethylene, polypropylene, polyoxymethylene, or PVC, with polyethylene being particularly preferred.

[0047] The body of the first and second adapter element comprises a single, one-piece, uniform structure, which can preferably be manufactured by machining processes such as turning, milling and drilling or also by injection molding and 3D printing.

[0048] The adapter is otherwise adapted to the internal geometry of the film roll and features tensioning elements for centering, stabilizing, and securing the film. Another function of the tensioning elements is to prevent damage to the roll due to slippage and to secure the adapters to each other. With the help of the adapter described, coreless stretch films can be used in machine stretch applications that must meet higher requirements (e.g., unwinding speed).

[0049] The invention also claims the use of the adapter described above for unwinding coreless film rolls, in particular in machine stretch applications.

[0050] The invention is explained in more detail below with reference to figures. Figure 1a shows a perspective view of the two separate adapter elements of the adapter according to the invention. Figure 1b shows a perspective view of the two interconnected adapter elements of the adapter according to the invention. Figure 2 shows a sectional view of the two separate adapter elements of the adapter according to the invention. Figure 3 shows a perspective view of the two interconnected adapter elements of the adapter according to the invention arranged in a film roll. Figure 4 shows a side view of a first adapter element and a sectional view of the same adapter element arranged in a film roll. Figure 5 shows a side view of a second adapter element and a sectional view of the same adapter element arranged in a film roll. Figure 6a shows a top view of the connecting end of the first adapter element. Figure 6b shows a top view of the head part of the first adapter element.Figure 7a is a plan view of the connecting end of the second adapter element, and Figure 7b is a plan view of the head part of the second adapter element.

[0051] The adapter 100 according to the invention consists of two nestable adapter elements 10, 30, each of which is inserted into the film roll 50 from the outside through openings in a coreless film roll 50. A cylindrical extension is arranged at the connecting end 17 of the first adapter element 10, which engages in a corresponding cylindrical recess in the second adapter element 30. The base body of the two adapter elements 10, 30 is conically shaped and tapers towards the connecting end 17, 37. The maximum outer diameter of the adapter elements 10, 30 is slightly smaller than the inner roll diameter of the film roll 50, so that the adapter elements 10, 30 can be inserted into the roll 50 without damaging the inner film layers.

[0052] The first adapter element 10 and the second adapter element 30 have a lateral surface 23 that extends between the adapter ring 11, 31 of the head part 13, 33 and the outer edge of the connecting end 17, 37. The lateral surface 23 comprises only those parts of the adapter elements 10, 30 that are visible after the first adapter element 10 and the second adapter element 30 have been joined together. Thus, the formations of the first and second adapter elements 10, 30 for the positive connection of both adapter elements 10, 30 are not part of the lateral surface 23.

[0053] On the outer longitudinal sides of the adapter elements 10, 30 there are tensioning elements 15, 35 which are attached along the longitudinal axis of the adapter elements 10, 30. These tensioning elements 15, 35 are made of a flexible material that can be reversibly deformed under external pressure. Various materials and geometries are suitable for this purpose, e.g. metallic elements or fiber-reinforced plastics in the form of wires or strips. These tensioning elements 15, 35 serve to fix the two adapter elements 10, 30 inside the film roll 50. This prevents the adapter elements 10, 30 from slipping out. In addition, the film roll 50 is held under tension from the inside, which leads to a stabilization of the film roll 50. This prevents deformation, e.g. due to twisting of the film, especially when unwinding the last meters of film on the roll 50. The number of tensioning elements 15, 35 is at least two.

[0054] According to a preferred embodiment, grooves 14, 34 are located along the longitudinal axis of the adapter elements 10, 30, which are each located between the clamping elements 15, 35.

[0055] These grooves 14, 34 are used to accommodate coreless film rolls 50 with a non-spherical inner diameter. Various winding shafts are available on the market for the production of coreless film rolls 50. Some of these winding shafts have an internal roll geometry with notches and raised portions due to hydraulic clamping segments. To accommodate these raised portions and ensure a precise fixation of the adapter 100 in the roll 50, grooves 14, 34 are provided on the adapter 100. These raised portions accommodate these raised portions. This provides additional fixation of the film roll 50 for the corresponding film rolls 50.

[0056] According to an advantageous embodiment of the invention, groove holes 12, 32 can be located at the end of the grooves 14, 34 in the head portion 13, 33 of the adapter element 10, 30. These holes allow the air to escape, which must be displaced between the two adapter elements 10, 30 and the film roll 50 when they are brought together. They also allow for easy removal of the adapter elements 10, 30 from the film roll 50.

[0057] In the area of ​​the clamping elements 15, 35, there may be a flattened surface below them, which is referred to as the clamping element receiving area 16, 36. This area serves to provide space for the film in the case of a non-circular roll geometry as described above. It is advantageous if the end of the clamping element receiving area 16, 36 tapers into the head part 13, 33 to ensure a more even pressure distribution. At the two outer ends of this clamping element receiving area 16, 36, there are bores 23, 43 in the adapter 100, which run horizontally along the longitudinal axis of the adapter element 10, 30. The clamping element 15, 35 is fixed in these bores.

[0058] Located inside the head section 13, 33 of the adapter 100 is the cone mount 21, 41. This is the area where the cone of the unwinder's winder is secured to the adapter 100. This fixation is achieved by the precise design of the cone mount 21, 41. Since some winders have special technical features, such as screw heads, in the cone area, fixing holes 19, 39 can be provided to accommodate these elements. This also provides additional fixation between the adapter 100 and the stretch wrap machine.

[0059] The adapter ring 11, 31 represents the outer boundary at the head of the adapter 100. The film roll 50 ends with its outer edges at the lower edge of the adapter ring 11, 31, so that the film roll 50 is located between these two adapter rings 11, 31. This ensures that the end face of the film roll 51, 52 is protected during processing and transport, as well as when inserted into the stretch machine.

[0060] The inner adapter ring 22, 42 may be provided with holes that can be closed with grub screws. These holes are referred to as insertion holes 20, 40 for the clamping element 15, 35. Using a grub screw, the clamping element 15, 35 can be adjusted to the desired tension by screwing it in from the head side of the adapter 100 through the hole 20, 40 and bringing it into contact with the clamping element 15, 35. List of reference symbols

[0061] 100Adapter 10First adapter element 11Adapter ring 12Groove holes 13Head section 14Groove 15Clamping element 16Clamping element receiving area 17Connecting end 18Adapter opening 19Fixing hole 20Insertion hole with grub screw 21Cone receptacle / cylindrical recess 22Inner adapter ring 23Shell surface 30Second adapter element 31Adapter ring 32Groove holes 33Head section 34Groove 35Clamping element 36Clamping element receiving area 37Connecting end 38Adapter opening 39Fixing hole 40Insertion hole with grub screw 41Cone receptacle / cylindrical recess 42Inner adapter ring 50Foil 51End of the foil 52End of the foil

Claims

1. An adapter (100) for use in unwinding film from coreless film rolls (50), having a roll passage with a first and a second opening at opposite ends of the coreless film roll (50), the adapter (100) comprising: a first, elongated adapter element (10) and a second, elongated adapter element (30), the first adapter element (10) and the second adapter element (30) each having, at the free ends of the first adapter element (10) and the second adapter element (30), a projecting head part (13, 33) with an adapter ring (11, 31) as a stop for the film roll (50) and a connecting end (17, 37), the two connecting ends (17, 37) having corresponding formations in order to be connectable to one another, and the first adapter element (10) and the second adapter element (30), each on the outer surface (23) which is located between the adapter ring (11,31) and the connecting end (17, 37), at least two elongated clamping elements (15, 35) for clamping the first adapter element (10) and the second adapter element (30) in the roller passage, which are fixed on the lateral surface (23), bulge out from the lateral surface (23) and are maximally spaced from one another and are arranged parallel to one another and to the main axis of the first adapter element (10) and the second adapter element (30).

2. Adapter (100) for use in unwinding film from coreless film rolls (50), which has a roll passage with a first and a second opening at opposite ends of the coreless film roll (50), wherein the adapter (100) comprises: a first, elongated adapter element (10) and a second, elongated adapter element (30), wherein the first adapter element (10) and the second adapter element (30), each at the free ends of the first adapter element (10) and the second adapter element (30), a projecting head part (13, 33) with an adapter ring (11, 31) as a stop for the film roll (50) and a connecting end (17, 37), wherein the two connecting ends (17, 37) have corresponding formations in order to be connectable to one another, and wherein the first adapter element (10) and the second adapter element (30), each on the outer surface (23), which is located between the adapter ring (11,31) and the connecting end (17, 37), at least two longitudinally extending grooves (14, 34) are arranged, which are maximally spaced from each other and are arranged parallel to each other and to the main axis of the first adapter element (10) and the second adapter element (30).

3. An adapter (100) for use in unwinding film from coreless film rolls (50), having a roll passage with a first and a second opening at opposite ends of the coreless film roll (50), the adapter (100) comprising: a first, elongated adapter element (10) and a second, elongated adapter element (30), the first adapter element (10) and the second adapter element (30) each having, at the free ends of the first adapter element (10) and the second adapter element (30), a projecting head part (13, 33) with an adapter ring (11, 31) as a stop for the film roll (50) and a connecting end (17, 37), the two connecting ends (17, 37) having corresponding formations in order to be connectable to one another, and the first adapter element (10) and the second adapter element (30), each on the outer surface (23) which is located between the adapter ring (11,31) and the connecting end (17, 37), at least two elongate clamping elements (15, 35) for clamping the first adapter element (10) and the second adapter element (30) in the roller passage, which are fixed on the lateral surface (23), bulge out from the lateral surface (23), and at least two elongate grooves (14, 34) are arranged, wherein the at least two elongate clamping elements (15, 35) and the at least two elongate grooves (14, 34) are spaced apart from one another as far as possible and are arranged parallel to one another and to the main axis of the first adapter element (10) and the second adapter element (30).

4. Adapter (100) according to claim 1 or 3, characterized in that 2 to 8, preferably 4 elongated clamping elements (15, 35) are provided.

5. Adapter (100) according to one of claims 2 to 4, characterized in thatat least 2 grooves (14, 34), preferably 4 grooves (14, 34), extend over the entire length of the lateral surface (23) of the first adapter element (10) and the second adapter element (30), which are arranged at a maximum distance from one another and parallel to one another and to the main axis of the first adapter element (10) and the second adapter element (30).

6. Adapter (100) according to one of the preceding claims, characterized in that the first and second adapter elements (10, 30) are substantially conical in shape and taper from the head part (13, 33) to the connecting end (17, 37).

7. Adapter (100) according to one of the preceding claims 1, 3 to 6, characterized in that the first and second adapter elements (10, 30) are cylindrically shaped in the region of the elongated clamping elements (15, 35).

8. Adapter (100) according to one of the preceding claims 3 to 7, characterized in thatthe first and second adapter elements (10, 30) are flattened in the region of the elongated clamping elements (15, 35), wherein the grooves (14, 34) run between the flattened regions.

9. Adapter (100) according to one of the preceding claims 1, 3 to 8, characterized in that the at least two clamping elements (15, 35) merge into the lateral surface (23) in a flattened manner in the direction of the head part (13, 33).

10. Adapter (100) according to one of the preceding claims, characterized in that the first adapter element (10) on the head part (13) has a cylindrical recess (21) and the second adapter element (30) on the head part (33) has a cylindrical recess (41), which serve to precisely accommodate a cone of a stretch wrapping machine.

11. Adapter (100) according to one of the preceding claims 2 to 10, characterized in that at the end of the grooves (14, 34) in the head part (13, 33) of the adapter elements (10, 30) there are groove holes (12, 32).

12. Use of an adapter (100) according to one of the preceding claims for unwinding coreless film rolls (50), in particular for use in machine stretch applications.

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