Laser welded article and method

Abstract

The present invention relates to laser welded articles and methods thereof.SOLUTION: The method includes laminating laser-weldable polymeric film layers including at least one colored film layer and at least first and second uncolored film layers, directing a laser beam of a first wavelength at the laminate, and moving the laser beam along a first welding path. The laser beam impinges on the colored film layer and locally heats and welds the colored film layer and the first uncolored film layer to one another along a first welding path. Next, a laser beam of a second wavelength different from the first wavelength is directed at the laminate and moved along a second welding path offset from the first welding path. The laser beam impinges on the second unpigmented layer to locally heat and weld the second unpigmented layer and the first unpigmented layer together along a second welding path.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to laser weldable articles and methods. [Background technology]

[0002] An automobile seat may include a massage assembly having an inflatable cell or bladder. The bladder is connected to a valve device via an air supply line. A pump supplies air to the valve device, which then delivers the air to the inflated bladder. The bladder can be sequentially inflated and deflated to provide a desired massage effect to the seat occupant. The bladder is made from multiple polymer films that are welded together to form an airtight chamber within the bladder. The construction of the bladder and the welding process used to create it can be labor-intensive. For example, radio frequency (HF) welding has been used to weld polymer films. However, HF welding requires physical access to the welding location for the welding die that creates the weld. For complex configurations, such as bladders with many layers to be welded, physical access often requires folding, pinning, or otherwise holding the unwelded layers out of the way. [Brief explanation of the drawings]

[0003] The various features and advantages of the present disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.

[0004] [Figure 1] 1 shows a seat for an automobile. [Figure 2] Part of the seat system is shown. [Figure 3] 1 shows a cross-sectional view of an inflatable bladder. [Figure 4] 1 illustrates an exemplary method of laser welding. [Figure 5] An example of a laser blocker in a welding process is shown. [Figure 6] 1 shows a cross-sectional view of another inflatable bladder. [Figure 7] 1 shows a view of the layers of an inflatable bladder before they are welded together. DETAILED DESCRIPTION OF THE INVENTION

[0005] Reference will now be made in detail to the embodiments illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the various described embodiments. However, it will be apparent to those skilled in the art that the various described embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, circuits, and networks have not been described in detail so as not to unnecessarily obscure aspects of the embodiments.

[0006] "One or more" includes one function performed by one element, one function performed by more than one element, e.g., in a distributed manner, several functions performed by one element, several functions performed by several elements, or any combination of the above.

[0007] Also, although terms such as "first," "second," etc. are sometimes used herein to describe various elements, it is understood that these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first contact may be referred to as a second contact, and similarly, a second contact may be referred to as a first contact without departing from the scope of the various described embodiments. Although a first contact and a second contact are both contacts, they are not the same contact.

[0008] The terminology used in the description of the various embodiments set forth herein is for the purpose of describing particular embodiments only and is not intended to be limiting. When used in the description of the various described embodiments and in the appended claims, the singular forms "a," "an," and "one" are intended to include the plural forms as well, unless the context clearly dictates otherwise. The term "and / or," as used herein, is also understood to refer to and encompass any and all possible combinations of one or more of the associated listed items. Furthermore, it is also understood that the terms "comprise," "including," "comprises," and / or "comprising," as used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0009] As used herein, the term "if" is optionally interpreted to mean "when" or "upon" or "response to determining" or "response to detecting," depending on the context. Similarly, the phrases "when determined" or "if [described condition or event] is detected" are optionally interpreted to mean "upon determining" or "response to determining" or "upon detecting [described condition or event]" or "response to detecting [described condition or event]," depending on the context.

[0010] 1 shows an example of a seat 20 for an automobile. In this example, the seat 20 includes a seat back 22 and a seat base 24. In the seat back 22, a seat frame 26 supports a cushion 28, which is covered by a trim 30a. In the seat base 24, the frame 26 supports a bottom seat cushion 34, which is covered by a seat trim 30b. While the example seat 20 is for an automobile, it will be understood that these examples are applicable to other types of vehicles, such as, but not limited to, motorcycles, watercraft, aircraft, or locomotives.

[0011] 2 shows selected portions of a seating system 36 that is incorporated into seat 20. Seat system 36 includes a bladder system 38 that includes one or more inflatable bladders 40 and air supply channels 42 in fluid communication with bladders 40 for inflating and deflating bladders 40. Bladders 40 are formed from polymer films (e.g., thermoplastic urethane) welded together to form inflatable cells. Bladders 40 are attached to one or more polymer film carrier substrates 44.

[0012] Channel 42 is attached to connector 46, which is in fluid communication with valve bank 48. Valve bank 48 is fluidly connected to one or more pumps 50. Processor 52 is connected to pumps 50 and controls their operation. Processor 52 is also connected to valve bank 48 and can open and close valves in bank 48 to selectively supply air to bladder 40 via channel 42. Connector 46 serves to provide an airtight connection between channel 42 and valve bank 48.

[0013] FIG. 3 shows a cross-sectional view of a representative one of the bladders 40. Each bladder 40 is composed of multiple laser-weldable polymer film layers 54 that form expandable cells 56. The layers 54 are joined together at welds 58. For example, a "weld" is an area where two adjacent layers 54 are melt-joined, for example, by a laser welding process, to form an airtight weld seam. The term "laser-weldable" refers to polymer film layers that can be welded together by laser welding to form an airtight weld seam. Exemplary laser-weldable films include, but are not limited to, thermoplastic urethane, polystyrene, polyamide, polybutylene terephthalate, or other thermoplastics that generate heat and absorb a laser to melt and bond, but without substantial thermal degradation.

[0014] FIG. 4 illustrates an exemplary laser welding method that can be used to form the bladder 40. The method involves stacking layers 54 one on top of the other. At least one of the layers 54 is a colored film layer, designated 54a, and there are at least first and second uncolored film layers 54b / 54c. It should be understood that additional colored and / or uncolored layers may be used. A "colored" film layer is one that contains an additive that makes the layer opaque and therefore absorbent to the laser wavelength used for welding. The additive may be dispersed throughout the polymer of the film or applied as a surface coating on the film. Exemplary additives include, but are not limited to, carbon black. An "uncolored" film layer does not contain any additives that make the layer opaque, such that the layer is transparent and therefore non-absorbing to the laser wavelength used for welding. An uncolored layer does not need to be completely transparent to the laser, as long as the nominal laser absorption does not generate enough heat to melt and bond the layer (the laser is sufficient to weld other layers). As an example, a transmittance of 85% or greater is considered transparent for purposes of this disclosure, while less than 85% is considered opaque.

[0015] As an example, the uncolored layers 54b / 54c are transparent to a first wavelength laser L1, while the colored layer 54a is opaque (absorbent) to the laser L1. That is, a laser L1 directed at the stack of layers 54 passes through the uncolored layers 54b / 54c and strikes the colored layer 54a. The colored layer 54a absorbs the laser L1, thereby generating heat. The temperature at the interface between the colored layer 54a and the adjacent uncolored layer 54b rises rapidly, causing localized melting of the layers 44a / 44b, which, upon solidification, joins the layers 54a / 54b to one another in an airtight weld. The laser L1 is moved along a welding path to form an airtight seam between the layers 54a / 54b. Appropriate laser power, pulse frequency, and welding speed may be determined by one of ordinary skill in the art with the benefit of this disclosure.

[0016] The unpigmented layers 54b / 54c are opaque (absorbent) to the laser L2 of a second wavelength (different from the first wavelength). That is, the laser L2 directed at the stack of layers 44 is substantially absorbed by the layers 54b / 54c, but some of the laser L2 passes through. The absorption generates heat at the interface between the layers 54b / 54c, causing localized melting of the layers 54b / 54c, which, upon solidification, bonds the layers 54b / 54c to each other at the weld. The laser L2 can be moved along a welding path to form an airtight seam between the layers 54b / 54c. The wavelengths of the lasers L1 and L2 can vary depending on the type of polymer from which the layers 54 are made and the type of additives. By way of example, the lasers L1 and L2 each have a wavelength between 1000 nm and 2000 nm.

[0017] Figure 5 demonstrates the use of laser blockers in the welding process. Two types of laser blockers, designated 60a and 60b, exist. Laser blocker 60a blocks the laser by being constructed from a tape or film that is opaque to the laser. Because the uncolored layer does not completely absorb the laser L2, laser blocker 60a is placed under the uncolored layer to block any portion of the laser L2 that passes through the uncolored layer, thus preventing undesired welding of the film layer underneath. Laser blocker 60b is constructed from an uncolored tape or film that is transparent to the laser L1. If localized heating at the weld does not dissipate quickly, the heat can be transferred to adjacent layers, causing undesired sticking or welding of the adjacent layers. That is, laser blocker 60b is placed between the primary weld location and the adjacent layer, providing a physical thermal barrier that prevents undesired welding of the adjacent layers.

[0018] In the example of FIG. 5, there are four welds, designated W1, W2, W3, and W4. Weld W1 is made using laser L1 between uncolored layer 62 and colored layer 64. Laser blocker 60b is positioned above weld W1, between weld W1 and uncolored layer 66. Laser blocker 60b prevents uncolored layer 66 above weld W1 from being undesirably welded. Weld W2 is made using laser L2 between uncolored layer 66 and uncolored layer 62. Laser blocker 60a is positioned below weld W2 to prevent the portion of laser L2 passing through layers 62 and 66 from impinging on layer 64 below. Weld W3 is made using laser L1 between uncolored layer 68 and colored layer 64. A laser blocker is not required for weld W3 because colored layer 64 blocks laser L1 and prevents it from passing through. If undesirable sticking or welding of layer 66 is found, laser blocker 60b may be used above weld W3, between weld W3 and uncolored layer 66. No laser blocker is used for weld W4, as there are no layers above or below it.

[0019] FIG. 6 shows a cross-sectional view of another example bladder 140 for use in the bladder system 38 described above. The bladder 140 is constructed from a stack of laser-weldable polymer film layers 154 forming expandable cells 156. The layers 154 include first and second substrate layers 154a / 154b. The first and second substrate layers 154a / 154b are joined together at welds 158a so that channels 42 are defined between the layers 154a / 154b. The second substrate layer 154b has a first port 170a (e.g., a circular opening) in fluid communication with the air supply channel 42. There is a colored film layer 154c that includes a second port 170b aligned with the first port 170a. For example, the ports 170a / 170b are aligned when the centers of the ports 170a / 170b are aligned. The colored film layer 154c is joined to the second substrate layer 154b by a first ring weld 158b. For example, the ring weld is a closed-loop weld path, such as a circular path surrounding the ports 170a / 170b. The first and second pleated layers 154d / 154e each include first and second pleated layer orifices 170c / 170d that are aligned with each other. The pleated layers 154d / 154e are joined to each other by a second ring weld 158c that surrounds the first and second pleated layer orifices 170c / 170d. The first pleated layer 154d is also joined to the colored film layer 154c by a first peripheral ring weld 158d that extends around the periphery of the colored film layer 154c and the periphery of the first pleated layer 154d. End layer 154f is joined to second pleat layer 154e by second peripheral ring weld 158e around the periphery of end layer 154f. Second substrate layer 165b, color layer 154c, first and second pleat layers 154d / 154e, and end layer 154f define therebetween cells 156 that are inflatable with air supplied through air supply channels 42. First ring weld 158b, second ring weld 158c, first peripheral ring weld 158d, and second peripheral ring weld 158e are each endless loops. Layers 154c / 154d / 154e / 154f are also individually shown in plan view in FIG. 7.

[0020] 6 are not necessarily to scale, all welds 158a / 158b / 158c / 158d / 158e are offset so that they do not intersect with one another. That is, the weld path of each weld 158a / 158b / 158c / 158d / 158e does not intersect with the weld path of any other weld 158a / 158b / 158c / 158d / 158e. As an example, bladder 140 is arranged about a central axis A that intersects the center of each of ports 170a / 170b / 170c / 170d, and has a radial proximity P to axis A. 溶着部 (e.g., in millimeters) 第2リング溶着部 <P 第1リング溶着部 <P 第2周縁リング溶着部 <P 第1周縁リング溶着部 That is, the radial proximity of second ring weld 158c is less than the radial proximity of first ring weld 158b, which is less than the radial proximity of second peripheral ring weld 158e, which is less than the radial proximity of first ring weld 158a.

[0021] Such an offset allows all of the welds 158a / 158b / 158c / 158d / 158e to be made on the stack of layers 154 without having to sequentially add layers to the stack after each or any weld. For example, all of the layers 154 are initially placed in the stack with the ports 170a / 170b aligned and the orifices 170c / 170d aligned. Weld 158a can then be made from above or below the stack. Welding from above means that the laser is above the stack, i.e., at the top in FIG. 6. Welding from below means that the laser is below the stack, i.e., at the bottom in FIG. 6. Weld 158b can be made from above the stack, weld 158c can be made from below the stack, and welds 158d / 158e can be made from below the stack. Thus, each weld can be made without having to move or fold any of the layers 154 out of the way, or without having to make one weld and then add the next layer or layers before making the next weld, thereby reducing the labor involved in the welding process. In other words, each weld has a weldable line of sight in the initial stack of layers, and the weld location is accessible by a laser without necessarily having to move other layers 154 out of the way. This further allows the welds to be made in any order. As explained above, weld blockers 60a / 60b may also be used.

[0022] Although combinations of features are shown in the illustrated examples, not all of them need to be combined to realize the benefits of various embodiments of the present disclosure. In other words, a system designed in accordance with an embodiment of the present disclosure will not necessarily include all of the features shown in any one figure or all of the parts shown schematically in a figure. Furthermore, selected features of one exemplary embodiment may be combined with selected features of other exemplary embodiments.

[0023] The foregoing description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art without necessarily departing from the present disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims.

Claims

1. 1. A method comprising: laminating a plurality of laser-weldable polymeric film layers, the laser-weldable polymeric film layers including at least one colored film layer and at least first and second uncolored film layers; directing a laser beam of a first wavelength at the stack of film layers and moving the laser beam along a first welding path, the laser beam impinging on the at least one colored film layer and locally heating and welding the at least one colored film layer and the first uncolored film layer to one another along the first welding path; directing a laser beam of a second wavelength different from the first wavelength at the stack of film layers and moving the laser beam along a second welding path offset from the first welding path, the laser beam impinging on the second uncolored layer and locally heating and welding the second uncolored layer and the first uncolored layer to one another along the second welding path; A method comprising:

2. 10. The method of claim 1, wherein the laser beam of the first wavelength passes through at least one of the first and second unpigmented film layers before impinging on the pigmented film layer.

3. The method of claim 1 , wherein the first and second wavelengths are between 1000 and 2000 nm.

4. the at least one pigmented film layer comprises a carbon additive; The method of claim 1 , wherein the at least first and second unpigmented film layers are free of carbon additives.

5. The method of claim 1 , wherein the laser-weldable polymeric film layer is TPU.

6. The method of claim 1 , wherein the at least first and second unpigmented film layers are transparent to the laser beam of the first wavelength.

7. The method of claim 1 , wherein the first and second weld paths are endless loops.

8. The method of claim 7 , wherein the endless loops do not cross each other.

9. further comprising providing a laser blocker under the at least first and second unpigmented film layers; The method of claim 1 , wherein the laser blocker prevents the laser beam from impinging on any of the laser-weldable polymeric film layers underlying the at least first and second unpigmented film layers.

10. The method of claim 9 , wherein the laser blocker is colored.

11. further comprising providing a welding blocker on the at least first and second unpigmented film layers; 10. The method of claim 9, wherein the weld blocker prevents the at least first and second unpigmented film layers from welding to any of the laser-weldable polymeric film layers overlying the at least first and second unpigmented film layers.

12. The method of claim 11 , wherein the weld blocker is uncolored.

13. The method of claim 1 , wherein the welding forms a pleated inflatable bladder.

14. The method of claim 1 , wherein at least one of the laser-weldable polymeric film layers includes an air supply channel.

15. An article, a stack of laser-welded polymer film layers; The laminate is first and second substrate layers including a substrate, the substrate defining an air supply channel between the first substrate layer and the second substrate layer, the second substrate layer having a first port in fluid communication with the air supply channel; a colored film including a second port aligned with the first port, the colored film layer being joined to the second substrate layer by a first ring weld that surrounds the first and second ports; first and second pleated layers, each including first and second pleated layer orifices aligned with one another, the first and second pleated layers joined together by a second ring weld surrounding the first and second pleated layer orifices, and the first pleated layer joined to the layer of colored film by a first peripheral ring weld around a periphery of the first pleated layer; End layer and Including, the end layer is joined to the second pleated layer by a second peripheral ring weld around the periphery of the end layer; The article, wherein the second substrate layer, the color layer, the first and second pleat layers, and the end layer define therebetween a bladder chamber inflatable with air supplied through the air supply channel.

16. the colored film layer includes a carbon additive; 16. The article of claim 15, wherein the first and second substrate layers, the first and second pleat layers, and the end layers are free of carbon additives.

17. 16. The article of claim 15, wherein the laser welded polymeric film layer is TPU.

18. 16. The article of claim 15, wherein the first ring weld, the second ring weld, the first peripheral ring weld, and the second peripheral ring weld are endless loops.

19. 16. The article of claim 15, wherein the first ring weld, the second ring weld, the first peripheral ring weld, and the second peripheral ring weld all do not intersect with one another.

20. the first and second ports define a central axis; The radial proximity P to the central axis 溶着部 Regarding P 第２のリング溶着部 <P 第１のリング溶着部 <P 第２の周縁リング溶着部 <P 第１の周縁リング溶着部 16. The article of claim 15,

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