Method of splicing a multi-layer laminate, spliced multi-layer laminate and device for splicing a multi-layer laminate

Abstract

The invention relates to a method for splicing upstream and downstream sections of a multi-layered laminated sheet material, wherein each section of material comprises at least three layers, each layer having a first surface and a second surface, and wherein the at least three layers comprise a first outer layer and a second outer layer and at least one inner layer located between the first outer layer and the second outer layer, the method comprising the steps of: a) splicing together the upstream and downstream sections of both the first outer layer and the second outer layer with a splicing material; b) removing the first outer layer from the multi-layered laminated sheet material to expose a surface of the inner layer; c) splicing together the upstream and downstream sections of the exposed inner layer with a splicing material; and d) applying a replacement first outer layer to the exposed surface of the inner layer. Also provided is a spliced multi-layered laminated sheet material produced according to the method. Also provided is an apparatus for splicing two sections of a multi-layered laminated sheet material, wherein each section of material comprises at least three layers, each layer having a first surface and a second surface, and wherein the at least three layers comprise two outer layers and at least one inner layer located between the two outer layers, the apparatus comprising: a first splicer configured to apply a splicing material to both outer layers of the multi-layered laminated sheet material; a delayerer configured to remove the first outer layer; a second splicer located downstream of the delayerer, the second splicer configured to apply a splicing material to the exposed inner layer; and an applicator located downstream of the second splicer, the applicator configured to reapply an outer layer to the exposed inner layer.

Description

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to a method for splicing a multi-layered laminate, its use in a wound dressing and a device used in the method for splicing a multi-layered laminate. BACKGROUND

[0002] Components for wound dressings are often multi-layered laminates. The material is supplied to the manufacturing process in the form of slit logs. Due to the nature of the material, existing automatic splicing systems are not suitable as they only join the outer surface. In order to join the multi-layered log of raw material, a laborious manual splicing of each layer of the laminate must be performed.

[0003] At the junction of the new and old logs, the individual layers must be separated in order to allow for downstream delamination and removal of the outer layers, and thus each individual layer must be joined to each other and separated from the other layers. Manual splicing requires the new and old logs to be stationary for a period of time to allow the operator to separate / delaminate the layers and apply the laminate on their respective junctions.

[0004] Stationary of the logs during this lengthy manual splicing process requires the entire process to be stationary. An alternative (to allow the entire process to continue through the splicing process) is to create a material buffer downstream of the splicing location. This buffer is called a "festoon" and its purpose is to allow the downstream process to remain in motion by feeding out the stored material while the manual splicing upstream is performed. For high speeds, a large capacity festoon is required. However, due to the limited length of the logs, at high speeds (with or without a festoon), the operator performing the splicing will be fully occupied with this task and will have little to no time (if any) to perform other roles. The higher the speed, the more frequently the need to perform the splicing. This can result in low process efficiency. Splicing failures result in costly losses of operational efficiency and material waste.

[0005] After the intra-layer splicing process step(s), the original outer layers need to be relaminated in order to recreate the original raw material structure. Then, these outer layers need to be removed again at a subsequent delamination location before the lamination of the final outer layers. This requires additional, expensive equipment and a more complex production process, both of which result in an increased risk of process waste.

[0006] Therefore, it is desirable to improve the efficiency of the existing process and to facilitate in the future a new, high-speed, high-efficiency process. SUMMARY

[0007] The embodiments disclosed herein relate to a method for splicing upstream and downstream sections of a multi-layered laminated sheet material, wherein each section of material comprises at least three layers, each layer having a first surface and a second surface, and wherein the at least three layers comprise a first outer layer and a second outer layer and at least one inner layer located between the first outer layer and the second outer layer, the method comprising the steps of: a) splicing together the upstream and downstream sections of both the first outer layer and the second outer layer with a splicing material, b) removing the first outer layer from the multi-layered laminated sheet material to expose a surface of the inner layer, c) splicing the upstream and downstream sections of the exposed inner layer with a splicing material, d) applying a replacement first outer layer to the exposed surface of the inner layer.

[0008] Steps b) and c) can be repeated to splice a multi-layered laminated sheet material having more than three layers, wherein by removing the first outer layer and splicing the exposed inner layer, the spliced inner layer becomes an outer layer and can be removed in step b). Step d) is also repeated for each repetition of steps b) and c).

[0009] The method is preferably performed by a machine.

[0010] Automated splicing machines are known in the art and any suitable splicing machine can be used. Automated splicing systems can require the laminated sheet material to be temporarily stopped at the splicing point, meaning that a suitable capacity of suspension will be required to ensure that the downstream process does not have to be stopped. Both steps a) and c) can be performed by an automated splicing machine. Alternatively, one or more of the steps can be performed manually. In particular, one or more of the splicing steps can be performed manually. Even if a manual splicing process is used, the method can be performed faster than by conventional means, allowing the process to be performed more efficiently and with less manpower. The method is preferably automated. Automation is intended to mean that the process is operated by a largely automated apparatus, i.e. the process can be carried out with minimal or no human intervention.

[0011] Any suitable splicing material can be used to splice the multi-layered laminated sheet material. Preferably, the splicing material is an adhesive tape, preferably a self-adhesive tape. Suitable splicing materials are known to the person skilled in the art and will vary depending on the material to be spliced.

[0012] The outer layers can be spliced simultaneously in step a), or the splicing can be applied first to one side and then to the other side in turn.

[0013] After step a) and / or after step c), the multi-layered laminated sheet material can be pressed to ensure a strong bond across the splice. This can be achieved by any suitable means, for example by passing the multi-layered laminated sheet material through a pair of laminating rollers.

[0014] Preferably, the method is a continuous process. Continuous means that the manufacturing process does not have to be paused substantially to perform one or more steps. The process can be slowed down to allow certain steps to be performed manually. Hangovers can be used to allow the downstream process to continue whilst manual steps are performed. If any of the splicing steps are performed manually, the process can be paused at one or both of steps a) and c). Hangovers can be used at either step or at both steps.

[0015] The multi-layered laminated sheet material preferably travels along a predetermined path through each step of the method. The path can be predetermined by any suitable means, for example by means of rollers, conveyor belts, vacuum devices, etc. The multi-layered laminated sheet material can be under tension throughout the manufacturing process. The multi-layered laminated sheet material typically travels through the process defined by the steps of the method at a speed of 1 m / min to 50 m / min.

[0016] In step b), the first outer layer can preferably continue on the first trajectory and the second outer layer and the inner layer(s) can be removed in an arcuate path away from the first trajectory. Without wishing to be bound by theory, by keeping the first outer layer and removing the inner layer(s) and the second outer layer on an arcuate path, removal of the first outer layer is less likely to cause delamination of the inner layer(s) and the second outer layer. Preferably, the first outer layer continues in a straight line from the delamination point. Preferably, the second outer layer and the inner layer(s) at least partially fold back on themselves when following the arcuate path, i.e. the angle between the first trajectory and the trajectory of the inner layer(s) and the second outer layer after they are removed is less than 90°, preferably the angle is 0-45°, more preferably 0-30°, 0-20° or 0-10°, most preferably 0-5°. Preferably, the second outer layer and the inner layer fold back on themselves almost completely, i.e. the downstream trajectory of the second outer layer and the inner layer(s) is substantially parallel to and opposite the first trajectory. Without wishing to be bound by theory, it is believed that minimising the angle between the first trajectory and the downstream trajectory of the second outer layer and the inner layer(s) reduces the potential risk of a delamination step failing. The inner layer(s) and the second outer layer can be removed in a free loop, i.e. without a physical pivot. The free loop can be controlled by any suitable means, for example by varying the upstream and / or downstream speed at which the multi-layered laminated sheet is fed through the system. Alternatively, the inner layer(s) and the second outer layer can be removed at a specific point defined by a fixed or floating device. The fixed or floating device can be a roller or a blade or any other suitable device.

[0017] The first outer layer can be held by physical means whilst the inner layer and second outer layer are removed. The physical means can be any suitable means. For example, the first outer layer can be held by a roller or by a vacuum applied to the surface on which the first outer layer lies.

[0018] After step d), if the second outer layer is not required in the final product, it can be removed in a similar process to the removal of the first outer layer. The second outer layer can preferably continue on a second trajectory and the replacement outer layer and inner layer(s) can be removed in an arcuate path away from the second trajectory.

[0019] In the multi-layered laminated sheet material, the second surface of the first outer layer is preferably in contact with a surface of the inner layer and the first surface of the second outer layer is in contact with the second surface of the inner layer. Each of the layers of the multi-layered laminated sheet material can be removed as a single, complete layer, however it will be appreciated that each layer of the multi-layered laminated sheet material can itself comprise a plurality of layers and comprise more than one different material.

[0020] The at least one inner layer can have an adhesive layer applied to one or more surfaces of the inner layer. Preferably, the at least one inner layer has an adhesive layer present on both surfaces of the inner layer.

[0021] In certain embodiments, different adhesive layers are present on each surface of the at least one inner layer. The different adhesive layers can have different peel loads. The peel load can be measured by taking a sample of the adhesive sheet and delaminating a portion of the layer present on the relevant adhesive layer. The delaminated layer is placed in the upper jaw of a tensile testing machine and the adhesive layer is placed in the lower jaw of the tensile testing machine. The upper and lower jaws of the tensile testing machine are oriented 180° to each other with the laminated portion of the sample between the jaws and supported at a 90° angle to both jaws. The sample is peeled at a rate of 300mm / minute with the force required being measured by the tensile testing machine. The result is expressed as the average peel force per unit width. The peel load can be defined as the average load per unit width of the bond line required to gradually separate one layer from another at a separation angle of (approximately) 180° and a separation rate of 300mm / minute. This is expressed as grams force / cm width.

[0022] Preferably, the first outer layer corresponds to the outer layer applied to the surface of the at least one inner layer comprising an adhesive having the lowest peel load.

[0023] The adhesive(s) can be any adhesive(s) suitable for the end use of the multi-layered laminated sheet material. Where the multi-layered laminated sheet material is for use in a wound dressing, preferably one or more of the adhesive layers can be a pressure sensitive adhesive. Suitably, the pressure sensitive adhesive layer can be formed from a biocompatible adhesive. Suitable adhesives include silicone, hot melt, hydrocolloid or acrylic based adhesives.

[0024] Preferably, one or more of the adhesive layers can be a wound contact adhesive. The wound contact adhesive can be a silicone or an acrylic adhesive, typically a silicone adhesive. In particularly preferred embodiments, one adhesive can be a pressure sensitive adhesive and one adhesive can be a silicone wound contact adhesive. In such cases, the silicone wound contact adhesive will typically have a lower peel load than the pressure sensitive adhesive.

[0025] Preferably, the outer layer is a release liner for the adhesive layer(s) applied to the inner layer(s). The release liner can be any suitable material, typically a polymeric film, such as a polypropylene film or a coated paper. Preferably, the release liner is a silicone coated release liner. Preferably, the outer layer has a thickness of 50-200 microns.

[0026] When the first outer layer is reapplied in step d), the reapplied first outer layer can be a different outer layer to the original first outer layer that was removed. The reapplied first outer layer can advantageously be the outer layer used in the final product. For example, in a wound dressing, the reapplied outer layer can be a release liner useful in the final use of the wound dressing, such as a release liner with an adhesive free handle. Advantageously, this allows for the earliest opportunity to apply the final outer layer after completion of the internal layer(s) splicing. The reapplied first outer layer can then be used to provide support during further downstream layering processes on the opposite side of the laminated sheet material. The present invention thus avoids the need to reapply an undesirable outer layer after completion of the internal splicing. Advantageously, the present invention seeks to maximise process efficiency by minimising machine complexity and raw material wastage.

[0027] In certain embodiments, steps c) and d) can be combined by applying the splicing material to the exposed inner layer simultaneously with the replacement first outer layer. For example, the splicing material in step c) can be a splicing material capable of adhering to both the exposed inner layer and the replacement first outer layer. The splicing material can be applied first to the replacement first outer layer. For example, the splicing material can be a double sided splicing material.

[0028] Preferably, at least one inner layer comprises a polymeric film, preferably a polyurethane film.

[0029] Preferably, the multi-layer laminated sheet material comprises three layers. Preferably, the multi-layer laminated sheet material comprises three layers, wherein the inner layer has adhesive layers applied to both surfaces of the inner layer, and different adhesives are applied to each surface of the inner layer.

[0030] The multi-layer laminated sheet material can be perforated. Preferably, each layer of the multi-layer laminated sheet material is perforated, preferably the perforations in each layer are uniform.

[0031] The multi-layered laminated sheet material is preferably a component of a wound dressing. More preferably it is a wound contact layer.

[0032] According to a second embodiment, there is provided a spliced multi-layered laminated sheet material produced according to the method of any preceding embodiment. According to a further embodiment, there is provided a wound dressing comprising the material according to the second embodiment.

[0033] Further preferred features of the spliced multi-layered laminated sheet material of the second aspect are defined above in relation to the first aspect and can be combined in any combination.

[0034] According to a third embodiment, there is provided an apparatus for splicing two sections of a multi-layered laminated sheet material, wherein each section of material comprises at least three layers, each layer having a first surface and a second surface, and wherein the at least three layers comprise two outer layers and at least one inner layer located between the two outer layers, the apparatus comprising: a first splicer configured to apply a splicing material to the two outer layers of the multi-layered laminated sheet material; a delaminator configured to remove the first outer layer; a second splicer located downstream of the delaminator, the second splicer configured to apply a splicing material to the exposed inner layer; and an applicator located downstream of the second splicer, the applicator configured to reapply an outer layer to the exposed inner layer. Preferably, the apparatus is suitable for use in a continuous process.

[0035] Preferably, the first splicer and / or the second splicer is an automated splicer. Suitable automated splicers are known to the person skilled in the art.

[0036] Preferably, the delaminator comprises a means for holding the first outer layer. Suitable means are known to the person skilled in the art, but include a vacuum or one or more rollers applied from below the surface on which the first outer layer is located.

[0037] The delaminator can further comprise means for removing the inner layer(s) and the second outer layer in an arcuate path away from the first outer layer. Suitable means include rollers and blades. The means can be located distally of the point at which delamination occurs to enable the inner layer(s) and the second outer layer to be removed in a free loop. Alternatively, the delamination point can be determined by a floating or fixed roller or blade or other suitable means located at the delamination point. Preferably, the means are arranged such that the second outer layer and the inner layer(s) at least partially fold back on themselves as they follow the arcuate path, i.e. the angle between the trajectory of the multi-layered laminated sheet material into the delaminator and the trajectory of the inner layer(s) and the second outer layer as they exit the delaminator, i.e. after they have been removed from the first outer layer, is less than 90°, preferably the angle is 0-45°, more preferably 0-30°, 0-20° or 0-10°, most preferably 0-5°. Preferably, the second outer layer and the inner layer(s) fold back on themselves almost completely, i.e. the downstream trajectory of the second outer layer and the inner layer(s) is substantially parallel to and opposite the first trajectory.

[0038] Preferably, the means further comprise means for ensuring that the spliced material forms a strong splice downstream of the one or more splicers. Suitable means include rollers.

[0039] Preferably, the means further comprise means for ensuring that the multi-layered laminated sheet material follows a predetermined path through the means. Suitable means will be known to the person skilled in the art but include rollers, blades and conveyor belts.

[0040] The means can comprise a processor and a memory, the memory storing instructions which, when executed by the processor, cause the means to perform any of the methods disclosed herein.

[0041] Further preferred features of components required in the means of the third aspect are defined above in relation to the first and second aspects and can be combined in any combination.

[0042] According to a further aspect of the application, there is provided a computer- readable storage medium comprising instructions which, when executed, cause the means defined in the third aspect to perform any of the methods defined herein. The computer- readable storage medium can be non-transitory. BRIEF DESCRIPTION OF DRAWINGS

[0043] Embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings in which:

[0044] Figure 1 A multi-layered laminated sheet material according to some embodiments is shown.

[0045] Figure 2is a schematic block diagram of an exemplary device according to some embodiments and suitable for use in a method according to some embodiments;

[0046] Figure 3 shows a device according to some embodiments and suitable for use in a method according to some embodiments;

[0047] Figure 4 is a flow chart showing steps of a method according to some embodiments.

[0048] In the drawings, like reference numerals refer to like elements throughout. The skilled person will appreciate that elements in the drawings are shown for simplicity and clarity and that actual positions and other details may differ somewhat from those shown in the Figures. For example, the dimensions of some of the elements in the Figures can be exaggerated relative to other elements for increased legibility and understanding. Furthermore, elements shown in the Figures are generally not drawn to scale unless so specified. DETAILED DESCRIPTION

[0049] Examples of multi-layer laminated sheet materials are shown in Figure 1 where the outer layers (1, 2) are silicone-coated release liners, the inner layer (3) is a polyurethane film coated with a silicone adhesive on a first surface (4) and with a pressure sensitive adhesive on a second surface (5). The first outer layer (1) comprises two sections and forms a non-adhesive handle to facilitate removal in use. The first surface of the inner layer is the wound contact layer.

[0050] The methods can be performed using a device as shown in Figure 2 and 3 The methods can be performed using a device as shown in Figure 2 is a schematic diagram of a device 200 for splicing a multi-layer laminated sheet material 100. The device 200 comprises a first splicer 210, a delaminator 220, a second splicer 230 and an applicator 240. The device can take the form of a machine or combination or series of machines arranged in a production line and suitable for mass production. The multi-layer laminated sheet material comprising an upstream section and a downstream section is fed into the first splicer where a splice material is applied to the outer layer of the laminate, thereby joining the upstream section and the downstream section of the two layers. The splice material is then fed into the delaminator where the first outer layer is removed for disposal, thereby exposing the inner layer. The remaining layers of the multi-layer laminated material are then fed into the second splicer where a splice material is applied to the exposed inner layer of the laminate, thereby joining the upstream section and the downstream section of the exposed inner layer. The spliced laminate is then fed into the applicator where an outer layer is applied to the exposed surface of the spliced inner layer, thereby replacing the first outer layer removed by the delaminator. Figure 3The process is shown in more detail. A multi-layered laminated sheet material (6) is unwound onto a roller (7). The outer layers are spliced with a splice tape (9) at a first splice point (8) using a first splicer. The spliced laminate travels through a suspension (15) to a delaminator comprising a vacuum conveyor (10) holding a first outer layer (11) in operation to be discarded. The inner layer and second outer layer are removed in an arcuate path at a second splice point (12) to a second splicer where a splice tape is applied to the exposed inner layer. A replacement outer layer (13) is unwound by an applicator onto the exposed surface of the inner layer and a nip roller (14) ensures the splice forms a strong bond.

[0051] Figure 4 An exemplary method for splicing upstream and downstream sections of a multi-layered laminated sheet material is shown, wherein each section of material comprises at least three layers, each layer having a first surface and a second surface, and wherein the at least three layers comprise a first outer layer and a second outer layer and at least one inner layer positioned between the first outer layer and the second outer layer. The method comprises: step S1 comprising splicing together the upstream and downstream sections of both the first outer layer and the second outer layer with a splicing material; step S2 comprising removing the first outer layer from the multi-layered laminated sheet material to expose a surface of the inner layer; step S3 comprising splicing together the upstream and downstream sections of the exposed inner layer with a splicing material; and step S4 comprising applying a replacement first outer layer to the exposed surface of the inner layer.

[0052] While this disclosure includes certain embodiments, examples, and applications, it will be appreciated that the present disclosure is not limited to the specific embodiments described, and that the scope of the disclosure extends to other alternative embodiments or uses and obvious modifications and equivalents thereof not provided herein. Accordingly, the scope of the disclosure is not intended to be limited to the particular preferred embodiments described herein, and the scope of the disclosure is defined by the claims set forth herein or claims to be hereafter presented.

[0053] Conditional language, such as "can," "could," "might," or "may," unless specifically stated otherwise, or otherwise understood within the context as used, generally contemplated the inclusion of one or more embodiments of the feature, element, or step that the conditional language is used in, whether or not the conditional language is in its positive or negative form. Thus, such conditional language generally contemplated that the feature, element, or step would be included in some embodiments. The term "consisting of' is synonymous with "consisting only of' and is open-ended, allowing for the inclusion of additional elements, features, acts, operations, etc. that do not detract from the core or essential characteristics of the technology. The term "comprising" is also synonymous with "including" and "having" in an open sense and does not exclude additional elements, features, acts, operations, etc. Additionally, the term "or" is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, in a list of elements, the term "or" means one, some, or all of the elements in the list. Further, the term "each," as used herein, can mean any subset of a set of elements to which the term "each" applies.

[0054] Conjunctive language such as the phrase "at least one of X, Y, and Z," unless specifically stated otherwise, is generally understood to present that an item, term, etc. can be either X, Y, or Z. Thus, such conjunctive language is generally not intended to imply that certain embodiments require at least one of X, at least one of Y, and at least one of Z.

[0055] Degree language such as the terms "about," "approximately," "generally," and "substantially," as used herein, mean to be near or approximately a stated value, amount, or characteristic and within a degree acceptable in the art considering the purpose to which the language is applied and the associated context. For example, the terms "about," "approximately," "generally," and "substantially" can refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of a specified amount. As another example, in certain embodiments, the terms "generally parallel" and "substantially parallel" refer to a value, amount, or characteristic that deviates from being completely parallel by less than or equal to 15 degrees, 10 degrees, 5 degrees, 3 degrees, 1 degree, or 0.1 degrees.

[0056] The terms "laminate" and "laminate sheet material" are used interchangeably.

[0057] The scope of the disclosure is not intended to be limited to the specific embodiments of the preferred embodiments in this section or elsewhere in this specification and is instead defined by the claims following this section or elsewhere in this specification. The language of the claims will be interpreted broadly based on the language employed in the claims and not limited to a narrow interpretation based on the examples in the specification or examples described during prosecution of the application.

Claims

1. A method for splicing upstream and downstream segments of a multilayer laminated sheet material, wherein each segment of the material comprises at least three layers, each layer having a first surface and a second surface, and wherein the at least three layers comprise a first outer layer, a second outer layer, and at least one inner layer located between the first outer layer and the second outer layer, the method comprising the following steps: a. Use splicing material to splice the upstream and downstream sections of the first outer layer and the second outer layer together; b. Remove the first outer layer from the multilayer laminated sheet material to expose the surface of the inner layer; c. Use splicing material to splice together the upstream and downstream sections of the exposed inner layer; as well as d. Apply the replacement first outer layer to the exposed surface of the inner layer.

2. The method of claim 1, wherein the process is performed by a machine.

3. The method according to any of the preceding claims, wherein the second surface of the first outer layer is in contact with the surface of the inner layer, and the first surface of the second outer layer is in contact with the surface of the inner layer.

4. The method according to any of the preceding claims, wherein at least one inner layer has an adhesive layer applied to one or more surfaces of the inner layer.

5. The method according to any of the preceding claims, wherein the method is a continuous process.

6. The method according to any of the preceding claims, wherein in step b, the first outer layer continues on the first trajectory, and the second outer layer and one or more inner layers are removed in an arcuate path away from the first trajectory.

7. The method of claim 4, wherein the at least one inner layer has an adhesive layer applied to both surfaces of the inner layer.

8. The method of claim 7, wherein different adhesive layers are applied to each surface of the inner layer.

9. The method of claim 8, wherein the first outer layer corresponds to the outer layer applied to the surface of the inner layer comprising an adhesive having a minimum peel load.

10. The method according to any of the preceding claims, wherein the multilayer laminated sheet material comprises three layers.

11. The method according to any one of claims 6-10, wherein the first outer layer is held on the surface by an external force.

12. The method of claim 11, wherein the external force is a vacuum.

13. The method according to any of the preceding claims, wherein the multilayer laminated sheet material is a component of a wound dressing.

14. The method of claim 13, wherein the multilayer laminated sheet material is a wound contact layer.

15. A spliced ​​multilayer laminated sheet material produced by the method according to any of the preceding claims.

16. An apparatus for splicing two segments of a multilayer laminated sheet material, wherein each segment of the material comprises at least three layers, each layer having a first surface and a second surface, and wherein the at least three layers comprise two outer layers and at least one inner layer located between the two outer layers, the apparatus comprising: a. A first splicer, configured to apply splicing material to the two outer layers of the multilayer laminated sheet material. b. A layerer configured to remove a first outer layer and expose an inner layer. c. A second splicer located downstream of the layerer, the second splicer being configured to apply splicing material to the exposed inner layer, and d. An applicator located downstream of the second splicer, the applicator being configured to apply the outer layer to the exposed inner layer.

Images