Additive manufacturing method of manufacturing a boat

Abstract

The invention relates to an additive manufacturing method of manufacturing a boat (10), the method comprising, for manufacturing at least a part of the boat, the steps of: a) building up the part from a plurality of interconnected layers (2, 3); b) leaving apertures (4) in pre-selected positions of at least a plurality of the layers, the apertures in consecutive layers lining up to create at least one continuous tube (5) in the part; c) running a tendon (6) through each continuous tube (5); d) applying a tension on each tendon (6); and e) fixing each tendon (6) in its respective continuous tube (5) under said tension. The invention also relates to a boat (10) produced by such an additive manufacturing method, having a stack of layers and a cross-layer tube, the boat further including a tensioned tendon (6) extending through each tube (5).

Description

[0001] ADDITIVE MANUFACTURING METHOD OF MANUFACTURING A BOAT

[0002] The present invention relates to an additive manufacturing method of manufacturing a boat. The present invention further relates to a boat manufactured by an additive manufacturing method.

[0003] Conventionally, boats may be manufactured using a glass fibre reinforced plastic, often PET. The glass fibre reinforced plastic is applied to a mould, for instance in the form of some or a combination of fibre cloths, prepregs, or a flowable or sprayable pre-mixed material, and / or pure resin. Building the mould is relatively time and cost intensive. Filling the mould requires skilled labour, and is considered unpleasant even by those equipped to do it. The labour shortage for this traditional boat building technique is therefore particularly urgent, and is also a driver for cost and limitation on building capacity.

[0004] Other boat manufacturing methods also tend to be time intensive and / or costly.

[0005] Therefore, it has been considered to use additive manufacturing for boats, e.g. using forms of 3d printing, which can offer more complex designs, with the added benefit of being able to reduce the weight of the resulting boats. However, currently known methods of 3d printing boats all face challenges. In particular, the problem of limited strength of the 3d printed boat is problematic. Due to the limited strength it is a practically impossible to create a boat of sufficient rigidity, for a high performance boat.

[0006] The present disclosure is aimed at obviating or at least reducing at least some of the aforementioned problems by providing an improved method of additively manufacturing a boat.

[0007] Therefore, the present disclosure provides a method of manufacturing a boat, the method comprising, for manufacturing at least a part of the boat, the steps of:

[0008] a) building up the part from a plurality of interconnected layers;

[0009] b) leaving apertures in pre-selected positions of at least a plurality of the layers, the apertures in consecutive layers lining up to create at least one continuous tube in the part;

[0010] c) running a tendon through each continuous tube;

[0011] d) applying a tension on each tendon; and

[0012] e) fixing each tendon in its respective continuous tube under said tension.

[0013] Said part or parts could for example be hull part(s), which together form a complete hull of said boat. However, it is also possible for the parts to be combined with parts that have been manufactured in a different manner in order to form the complete hull, or the complete boat. By using additive manufacturing with this method, the weight of a boat can be reduced as less bulk material will have to be used by creating the boat parts, as the structural integrity of the hull and boat can be ensured through the use of the tendons. A main advantage of this method, is that due to the tendon inter-layer adhesion can be promoted. Since complex shapes can be made using additive manufacturing, it is possible to provide a tube for the tendon. The tube can run through several layers, allowing the tendon to interconnect these layers. As a result, a boat can be obtained via additive manufacturing that is of high structural rigidity.

[0014] Compared glass fibre production, this method has the significant advantage that no workers are needed to fill the moulds. The claimed production process is much cleaner, and is thus more likely to attract workers.

[0015] When a relatively strong boat is made, less material is needed, so that the boat can additionally be made relatively light, i.e. its weight may be reduced. Reducing the weight of a boat offers several advantages that enhance performance, efficiency, and safety. Firstly, a lighter boat requires less power to propel, which can significantly improve fuel efficiency. Whether powered by an internal combustion engine, electric motor, or human effort, reducing weight decreases drag and resistance in the water, allowing the boat to travel faster and consume less energy. This is particularly beneficial for long-distance cruising or racing, where fuel economy and speed are critical factors.

[0016] Moreover, a lighter boat enhances manoeuvrability and handling. With reduced mass, the vessel becomes more responsive to steering inputs, making it easier to navigate through tight spaces, avoid obstacles, and adapt to changing water conditions. This increased agility is especially advantageous for recreational boats, racing yachts, or rescue operations, where quick, precise movements can make a substantial difference in performance and safety outcomes.

[0017] Another important benefit is improved buoyancy and stability. By reducing weight, a boat sits higher in the water, decreasing the likelihood of hull submersion in rough conditions. This can lead to a drier, more comfortable ride and reduce the risk of capsizing. Additionally, lighter boats are easier to transport and launch, making them more accessible for recreational users and reducing strain on trailers and docking equipment. Overall, optimizing boat weight not only enhances performance but also promotes a safer experience on the water.

[0018] Preferably, step c) takes place after step a) has been completed. This way, the tendons will not interfere with e.g. the nozzle of the printer used during additive manufacturing. Furthermore, it will also not interfere with any of the printed materials. This can reduce the complexity of the printer, as well as reducing occurrence of damaged parts.

[0019] In order to produce a substantial part of or a complete a boat, it is preferable to make multiple parts, and interconnecting the parts. This way, a smaller printer for the additive manufacturing method can be used, and thus a lower investment cost has to be made in order to start performing the method. As will be explained below, a single tendon could join multiple parts. It is possible for the multiple parts to be processed further after being additively manufactured but before being interconnected, by e.g. milling, polishing or other types of machining. This way, surfaces can be smoothed and edges can be reduced, which can in turn increase the connectability of said multiple parts. Additionally or alternatively, they can also be processed after the interconnection has been provided, for example to reduce surface roughness and / or to create a more aerodynamic boat. In particular, the post-processing may include post¬ processing the tendon’s ends, preferably to be flush with the exterior of the part.

[0020] Preferably, the interconnecting of said multiple parts takes place before steps c) - e), so that a complete tube layout is created before arranging tendons through said tubes, of course in case the tubes run through multiple parts. It is noted however that in some particular cases it might be advantageous to place the tendons in tandem with connecting the parts.

[0021] In particular a tube of one part can align with a tube of another part, so that the partial tubes form one continuous tube before tendons are arranged through said continuous tube. In such a case, it is advantageous if a single tendon is ran through both said tubes. This way, it is not necessary to connect multiple tendons, and a better force distribution can be achieved, rather than creating weak spots at such connections. Additionally, the tendon may serve as a way to connect the parts together in addition to connect the layers of the additively manufactured part.

[0022] It can be advantageous if during step e), the at least one continuous tube is filled with a curable material. This way, the tendons can be surrounded, preferably completely surrounded, by curable material, which after curing and optionally solidifying will keep the tendons in place. This way, the tendons are unable to move around, and therefore will act to ensure all parts and layers will stay connected through this connection between the tendon and the parts. The curable material may also ensure the tubes cannot flood with water when the boat is in use.

[0023] It is of course also possible to anchor the tendons at several discrete locations, in addition to or as an alternative to using the curable material.

[0024] In particular, said curable material can be epoxy or polyester. Epoxy and polyester resins can offer significant advantages for 3D-printed, lightweight parts due to their distinct material properties. Epoxy resins are known for their high strength, durability, and chemical resistance, making them ideal for parts that require high structural integrity and need to withstand mechanical stress or environmental exposure, which both are prevalent for boats. Their low shrinkage during curing ensures dimensional accuracy and stability. Polyester resins, on the other hand, are more cost-effective and provide good resistance to UV light and weathering, making them suitable for lightweight applications that do not demand extreme mechanical performance. Additionally, both materials can be reinforced with fibres (like carbon or glass) to enhance strength-to-weight ratios further. Further, both materials may be selected based on their compatibility and adherence to the tendon and / or the bulk material of the part. In one embodiment, step e) comprises anchoring the tendon corresponding to a part to another part. It is important that the interconnected parts stay connected during use of the boat, to ensure no leaks can occur. One option of providing this continued connection is by anchoring the tendons running through one part to another part.

[0025] As the tendon may carry a relatively large part of the load, it is of importance to ensure that it has sufficient properties to withstand said load. One method of ensuring a sufficiently strong tendon is by having using a fibrous material. In particular, said tendon comprises at least one carbon fibre, as carbon fibres have a high strength-to-weight ratio and thus can help in reducing the weight of the part and thus the boat. Additionally or alternatively, the tendon comprises at least one ultra-high-molecular-weight fibre, such as Dyneema, to help achieve a boat that is as lightweight as possible while still retaining the desired strength to withstand any load the boat is subjected to.

[0026] In particular, it is advantageous if the tendon is a woven tendon. Woven tendons can offer even higher tensile strength, along with a better load distribution. Furthermore, woven tendons have an increased resilience and durability. During operation, the hull of a boat will deform slightly e.g. as the boat hits waves and through torsion induced by turning the boat. Therefore, the tendons will also slightly deform, which repetitive motions are better absorbed by woven tendons.

[0027] Step d), the tensioning of the tendon, is preferably performed using a hydraulic press, as said press has the ability to apply precise, controlled force at relatively high loads. Hydraulic presses offer consistent pressure regulation, which is crucial in ensuring that tendons (such as those in prestressed concrete structures) are uniformly tensioned to the required specifications. This control can help prevent over- or under-tensioning, reducing the risk of structural failure or performance issues. Additionally, hydraulic systems can handle high forces efficiently, making them ideal for such heavy-duty tensioning tasks where accuracy and safety are paramount.

[0028] Preferably, the method further includes finishing ends of the tendon after step e). As the tendons are put through the tubes, it is likely they will stick out of the apertures at the first and at the final layer of the tube. Finishing ends of the tendon can help reduce the surface roughness of the part, and can help create a more aerodynamical part and thus boat. Furthermore, finishing ends of the tendon can help create a more visually pleasing design of said part and boat.

[0029] In one embodiment of the invention, the at least one continuous tube comprises at least a tube running alongships. Additionally or alternatively, the at least one continuous tube comprises at least a tube running athwartships. This could encompass a tube that runs alongships, and then makes a turn, continuing to run athwartships, but could also encompass a plurality of tubes running in multiple directions. Depending on the specific layout of the ship, there will be higher forces in different directions. By comprising tubes, and thus tendons, that are placed in said directions, said forces can be withstood. As the tendons have a high tensile strength in lengthwise direction, but a lower strength in transverse directions, it is thus preferred to ensure there are tendons and accordingly tubes in both cardinal directions.

[0030] In any case, it may be advantageous if the tubes run substantially in the stacking direction of layers. The tubes may open to the exterior of the part on both ends to facilitate introduction and fixing of the tendon.

[0031] A particularly suitable method of additive manufacturing is an FDM (fused deposition modelling) method. FDM offers significant advantages when printing parts, e.g. with epoxy or polyester resins, as it is a layer-by-layer additive process that allows precise control over the geometry and density of structures, enabling the creation of complex, hollow, or lattice designs that maximize strength while minimizing material usage and weight. Thus, the tubes can be incorporated into the parts easily, and complex tube layouts are possible.

[0032] Additionally, FDM's compatibility with fibre-reinforced materials allows for the incorporation of fibres into epoxy or polyester matrices, further enhancing mechanical properties without adding excess weight. The process also reduces material waste and allows customization of internal structures to optimize performance, making it ideal for aerospace, automotive, and other applications where lightweight, high-strength parts are essential.

[0033] It is noted that while the additive manufacturing method as described in the previous paragraphs is particularly suitable for the production of boats, it could also be used for the manufacturing of any object. Particularly, any light-weight objects can be produced by said method, e.g. (high-end) cars, aircrafts, helicopters or flotation devices. The invention is therefore not limited to the production of only boats.

[0034] The invention also relates to a boat produced by an additive manufacturing method, the boat including, due to its additive manufacturing process, a stack of interconnected layers, at least some layers defining therein apertures, which in consecutive layers line up to form at least one cross-layer tube, the boat further including a tensioned tendon extending through each tube.

[0035] In particular, the at least one continuous tube of said boat is filled with a cured material, such as epoxy or polyester, as they are suitable to use in a product like a boat for the reasons explained in previous paragraphs.

[0036] The invention will be further elucidated with reference to the attached drawings, in which: Figures la and lb show schematically an additively manufactured part according to the method of the invention;

[0037] Figures 2a and 2b show schematically a top-down view’ and a cross sectional view of a boat manufactured by an additive manufacturing method;

[0038] Figure 3 shows schematically a cross-section of an additively manufactured hull for a boat; and

[0039] Figure 4 shows a flow chart of the additive manufacturing method of manufacturing a boat. Figure la shows a closeup of an example of a 3d printed part 1, for example printed by an FDM method, which comprises a first layer 2 and a second layer 3, Both the first and seconds layers 2,3 comprise two apertures 4. Said apertures 4 have been positioned in the printed layers in such a way that they align, so that together the apertures 4 form two tubes 5. In practice, a part 1 might comprise a large number of layers, such as more than 100, wherein such tubes 5 could span through a subset of layers, or through the entire part 1. It is noted that while the tubes 5 depicted herein are perpendicular to the layers, the apertures 4 could also be placed at positions in continuous layers such that the corresponding tube 5 is placed at an angle with respect to the part 1.

[0040] Figures lb shows the 3d printed part 1 of figure la. A tendon 6, in this case a woven carbon-fibre tendon, has been run through the tubes 5 present in the part 1. A tension has been applied to the tendons 6 by a hydraulic press (not shown in the figure), after which they have been fixed to their respective continuous tubes 5 by filling the tubes 5 with a curable material, such as epoxy or polyester, and letting it cure. As can be seen, the ends 7 of the tendons 6 stick out slightly from the tubes 5. Said ends 7 can be anchored to another part 1, or could be finished, for example by milling, cutting, or polishing.

[0041] Figure 2a shows the top view of a boat 10, manufactured by the additive manufacturing method as described in the paragraphs hereabove. An example is shown of how tendons 6, drawn as dashed lines, stretch out, following the curvature of the hull 11 of said boat. The tendons 6 generally follow an alongships direction, but as curvature of the hull 11 changes also comprise an athwartships directional component. The hull 11 of the boat 10 comprises three parts 12,13,14, interconnected at their surfaces. Said tendons 6 run through all three parts 12,13,14.

[0042] Figure 2b shows the side view of the boat 10 of figure 2a. The same tendons 6, again depicted by dashed lines, can be seen spanning the alongships direction, but also varying in height along the hull 11. All tendons 6 have had their ends finished, so that no visual imperfections remain on the outer surface of the hull 11.

[0043] Figure 3 shows the a cross-section in back view of a hull 11 for a boat that is being printed. In order to reduce the necessary support material, the hull 11 is printed upside-down. Two tubes have been printed into the left and right half of the hull 11 respectively, in which two corresponding tendons 6 have been arranged. It is noted that in order to apply tension to the tendons 6, there are tendon ends 6b extending from the hull 11. After the hull 11 has been manufactured, and the curable material that will be poured into the tubes has cured and settled, said tendons end 6b will be removed, so that the surface of the hull 11 is flush. The tube corresponding with the tendon 6 on the left side of the boat has been printed such that tendon 6 runs through the entire wall and bottom of the hull 11, whereas the tendon 6 on the right side runs just through the side wall of the hull 11. It is noted that, depending on the specific requirements of a boat, many different tube and tendon lay-outs are possible, which can, but do no necessarily have to, be symmetrical.

[0044] Figure 4 shows method 100, comprising a first step of building up 101 a part from a plurality of interconnected layers. During this building of the part, apertures are left 102 at preselected positions of at least a plurality of the layers. Herein the apertures are placed at specific positions in each layer, such that the apertures of consecutive layers together form at least one continuous tube in the part.

[0045] After this, a tendon is placed 103 in each of the at least one continuous tubes, after which a tension is applied 104 to each of the tendons, for example by a hydraulic press. Finally, the tendons are fixed 105 in their respective tubes by pouring a curable material such as epoxy or polyester in the tubes. After the material has cured an solidified, the tendons are fixed with respect to the layers and parts.

[0046] It is noted that terms like “preferably”, “generally” and “typically” are not utilized herein to limit the scope of the claims or to imply that certain features are critical, essential, or even important to the structure or function of the claims. Rather, these terms are merely intended to highlight alternative or additional features that may or may not be utilized in a particular embodiment of the present disclosure. Likewise, for the purposes of describing and defining the present disclosure, it is noted that the terms “substantially” and “approximately” and their variants are utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement or other representation, as well as to represent the degree by which a quantitative representation may vary without resulting in a change in the basic function of the subject matter at issue.

[0047] While certain representative embodiments and details have been shown for purposes of illustrating the present disclosure, it will be apparent to those skilled in the art that various changes may be made without departing from the scope of the disclosure, which is defined in the appended claims.

[0048] Furthermore, it is noted that the steps of the method as listed herein can theoretically be performed in any suitable order. However, the preferred order is the same order as in which the steps are introduced. Any other steps, which have not been discussed throughout this document, can be interjected between other steps in order to further increase the efficiency of the method.

[0049] Although the invention has been described herein with reference to specific examples and embodiments, even specific figures, the invention is not limited necessarily thereto. In fact, the invention is described by the claims, which now follow.

Claims

Claims1. Additive manufacturing method of manufacturing a boat, the method comprising, for manufacturing at least a part of the boat, the steps of:a) building up the part from a plurality of interconnected layers;b) leaving apertures in pre-selected positions of at least a plurality of the layers, the apertures in consecutive layers lining up to create at least one continuous tube in the part;c) running a tendon through each continuous tube;d) applying a tension on each tendon; ande) fixing each tendon in its respective continuous tube under said tension.

2. Additive manufacturing method according to the previous claim, wherein step c) takes place after step a) has been completed.

3. Additive manufacturing method according to any of the preceding claims, comprising making multiple parts, and interconnecting the parts.

4. Additive manufacturing method according to the previous claim, wherein the multiple parts are processed further after being additively manufactured but before being interconnected, by e.g. milling or polishing.

5. Additive manufacturing method according to any of claims 3 - 4, wherein interconnecting takes place before steps c) - e).

6. Additive manufacturing method according to the previous claim, wherein a tube of one part aligns with a tube of another part, and a single tendon is ran through both said tubes.

7. Additive manufacturing method according to any of the preceding claims, wherein step e) comprises filling the at least one continuous tube with a curable material.

8. Additive manufacturing method according to the previous claim, wherein the curable material is epoxy or polyester.

9. Additive manufacturing method according to any of the claims 3 - 8, wherein step e) comprises anchoring the tendon corresponding of a part to another part.

10. Additive manufacturing method according to any of the preceding claims, wherein one or more of the following:- the tendon is a woven tendon;- the tendon comprises at least one carbon fibre;- the tendon comprises at least one ultra-high-molecular- weight fibre.

11. Additive manufacturing method according to any of the preceding claims, wherein step d) is performed using a hydraulic press.

12. Additive manufacturing method according to any of the preceding claims, further including finishing ends of the tendon after step e).

13. Additive manufacturing method according to any of the preceding claims, wherein the at least one continuous tube comprises at least a tube running alongships.

14. Additive manufacturing method according to any of the preceding claims, wherein the at least one continuous tube comprises at least a tube running athwartships.

15. Additive manufacturing method according to any of the preceding claims, wherein the additive manufacturing method is an FDM method.

16. Additive manufacturing method according to any of the preceding claims, of manufacturing any object.

17. Boat produced by an additive manufacturing method, the boat including, due to its additive manufacturing process, a stack of interconnected layers, at least some layers defining therein apertures, which in consecutive layers line up to form at least one cross-layer tube, the boat further including a tensioned tendon extending through each tube.

18. Boat according to the previous claim, wherein the at least one continuous tube is filled with a cured material, such as epoxy or polyester.

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