Method for producing patterns, molds, and products related thereto

Abstract

To provide a method for producing parts by a lamination technique.SOLUTION: A method for manufacturing parts includes: taking a porous material to form a plurality of individual layer segments from a sheet by using a computer numerical control (CNC) router; forming a plurality of layers with the plurality of individual layer segments; fastening the plurality of layers in a manner to form a part of a shape including a hollow inner part; supplying a thermosetting material adaptable to a porous part of the porous material to a porous material of a part; and removing a porous material on an outer face of a part by using the CNC router so as to form a part having a continuous face and a hollow inner part.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] Aspects of the disclosure of the present invention relate to an apparatus and method for manufacturing components. In some examples, aspects of the disclosure of the present invention relate to a method for manufacturing components (e.g., patterns, molds, and / or similar products) by a technique or process similar to a 3D printing manufacturing process, and such a similar technique or process stacks but uses low-cost filling materials without using a 3D printer.

Background Art

[0002] To create net-shaped or near-net-shaped (NNS) objects, additive (layered) manufacturing techniques and processes involve stacking one or more materials, in contrast to subtractive manufacturing methods. Although "additive manufacturing" is an industrial and standard term (ASTM F2792), additive manufacturing encompasses various manufacturing and prototyping techniques known by various names, including freeform fabrication, 3D printing, rapid prototyping / tooling, etc. Relatively new additive manufacturing techniques use large-scale 3D printers to manufacture very large parts, molds, patterns, etc. These items can be made from fiber-reinforced thermoplastic materials. One way to produce these items is to utilize a polymer extruder that generates beads of molten thermoplastic material that are added to the part to produce one layer at a time. These layers are modified and flattened into wide beads using devices such as a press plate or rollers during the lamination process. Using this method, which is referred to as 3D printing or additive manufacturing, the part is made slightly larger than the desired final part. After the part has cooled and hardened, the part is machined to the final dimensions and shape. After machining, the part may be formed as a shell of a specific thickness having the desired dimensions and shape.

Summary of the Invention

Problems to be Solved by the Invention

[0003] While the above-described process is useful, such a process also introduces the problem of limiting compatibility in certain environments. For example, a thermoplastic material may shrink or contract when it cools from the printing temperature to the ambient or room temperature. This shrinkage is generally not the same in all directions and, in at least some cases, should be taken into account when developing the geometry of the printed part, complicating the design and manufacturing process. Also, the material when printed is soft and subject to the influence of gravity, so there is a limit to the maximum angle at which the walls of the part can be printed. Thus, making a hollow part with a solid vertex may require an internal support structure or other types of additional support structures used during its printing, and such support structures are printed separately and increase the cost. This further complicates the manufacturing operation. Also, the materials and equipment commonly used in this process are expensive and limit the number of suitable applications.

[0004] An exemplary filler material, i.e., a replenishing member, used in a thermoplastic additive manufacturing process is carbon fiber. This filler material added to the base polymer tends to cure and strengthen the underlying polymer and tends to minimize warping that may otherwise occur when the part cools. However, carbon fiber is costly and thus increases the cost of products produced using this process. This increased cost may limit potential use to applications where the value of the piece produced justifies the cost. Low-cost reinforcing materials such as wood fiber may be unsuitable for use with at least some manufacturing equipment. For at least some parts or base materials, there may be a maximum amount of filler material that can be added to the base material (e.g., a thermoplastic material). Exceeding this maximum amount of filler material may adversely affect the ability to process the filled thermoplastic material in an additive manufacturing system such as a 3D printing device. Even if a 3D printing device or other additive manufacturing system can use a high filler material, this equipment may introduce high costs and make the manufacture of such parts unrealistic.

Means for Solving the Problems

[0005] Aspects of the disclosure of the present invention relate, for example, to methods and apparatus for manufacturing components by additive techniques. Each of the aspects disclosed herein includes one or more of the features described in connection with any other aspect disclosed. Some aspects of the disclosure of the present invention are useful in the process of forming patterns, molds, and other articles or products using an additive method. In some aspects, this additive method uses a technical approach that can be used with a relatively low-cost filler material in at least some environments, yet is equivalent to 3D printing or other additive manufacturing methods. Some aspects of the disclosure of the present invention address the above-described and / or other problems in the art.

[0006] In one aspect, a stereolithography method includes removing a material for forming a plurality of segments of an individual layer from a sheet, arranging at least two segments of a first layer that constitutes a first portion of an outer surface of a component adjacent to each other at the same height so as to form a first layer having a hollow interior, and arranging at least one segment of a second layer that constitutes a second portion of the outer surface of the component on at least two segments of the first layer so as to form a second layer having a hollow interior. The stereolithography method may include attaching the first layer to the second layer and removing a portion of the material from the first layer and the second layer so as to form a component having a continuous surface extending along the first layer and the second layer.

[0007] In another aspect, a method of manufacturing a component includes removing a porous material for forming a plurality of segments of an individual layer from a sheet using a CNC router, forming a plurality of layers using the plurality of segments of the individual layer, and bonding the plurality of layers to each other so as to form a component having a shape with a hollow interior. Such a method may include injecting a thermosetting material (crosslinked by a catalyst or the like) into the porous material of the component and removing a portion of the material from the outer surface of the component using a CNC router so as to form a component having a continuous surface and a hollow interior, and the thermosetting material can be adapted to the pores of the porous material by using a vacuum pump, applying pressure, immersing the component in the thermosetting material, or spraying the thermosetting material onto the component.

[0008] In some aspects, there is a concern that a component is manufactured using a lamination process that facilitates the production of polymer-based products, and such products have a greater amount of low-cost filler material compared to the polymer content of the product in particular. This process also includes using equipment that is lower in cost compared to an extrusion-based thermoplastic stereolithography process in particular.

[0009] In some aspects, the processes and apparatus described herein may employ a filler material to produce a component structure. A polymer material is added to the filler material (or filler materials) that forms the majority (e.g., more than 75 volume % and / or weight %) of the finished part, which is the opposite of the process of adding a filler material to the polymer that forms the majority of the finished part. For example, this process may include producing the component structure from the filler material itself and, if necessary, further include trimming the filler material. Subsequently, a thermosetting polymer in liquid form is supplied to the filler material to inject the thermosetting polymer into the filler material. The thermosetting polymer or other suitable material may preferably cure after being supplied in liquid form. The cured filled polymer mixture may preferably impart improved physical properties to the part.

[0010] The accompanying drawings of this specification in which the parts are incorporated or which constitute parts of the specification illustrate exemplary aspects of the disclosure of the present invention and serve to explain the principles of the disclosure of the invention in conjunction with the detailed description of the invention.

Brief Description of the Drawings

[0011]

Figure 1

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Figure 8

[0012] The disclosure of the present invention is directed, among other things, to methods and apparatuses for manufacturing components by layer formation techniques. In particular, the methods and apparatuses described herein are directed to processes for forming patterns, molds, and other parts or products using layer formation methods.

[0013] As shown in FIG. 1, the manufacturing machine is, for example, a CNC router 11, which is configured to remove material from a workpiece in a controllable manner. The CNC router 11 is part of a manufacturing system that includes a control unit, i.e., a controller 100, which is configured to generate commands to operate a plurality of servo motors and position the tool of the CNC router 11, for example. The CNC router 11 is operable to remove material from a variety of different materials. For example, the CNC router 11 is configured to position and operate a cutting tool in response to events generated by the controller 100. The CNC router 11 is any suitable machine for removing material with a cutting tool and for modifying the surface of the material, such as, for example, a 3-axis router (e.g., a device configured to position a cutting tool in three degrees of freedom), a 5-axis router (e.g., a device configured to position a cutting tool in five degrees of freedom), or an additive manufacturing device having a printing head in addition to a machining head.

[0014] Exemplary parts manufactured by the processes described herein are formed, at least in part, of a porous material. Suitable exemplary porous materials include medium density fiberboard (MDF). The plurality of individual parts for the part may, instead of or in addition to MDF, include Plexiglas®, ultra-high molecular weight (UHMW) plastic (e.g., UHMW polyethylene), polyvinyl chloride (PVC), plastic, plywood, drywall, aluminum.

[0015] The structure of the part may be formed by assembling a plurality of layers. Each layer may include one or more segments 13. For example, the plurality of layers are stacked one on top of the other as described below to form a desired shape. In the exemplary forms shown in FIGS. 2-8, when the part is assembled, the part is in the shape of a hollow cone. The actual geometric shape of typical parts that can be manufactured using this process can vary widely in both shape and dimensions. For clarity, the conical shape is described herein. However, it is expected that parts produced using the methods described herein will be significantly more complex than a simple cone. In this example, each layer includes or consists of segments (beads) of a particular desired thickness and width, such that the final structure is similar to structures commonly produced using current thermoplastic lamination manufacturing techniques.

[0016] The process of manufacturing the component includes producing a plurality of individual pieces, i.e., segments 13, and subsequently assembling the segments 13 together. For example, each layer including segments (beads) of a predetermined or known width is formed from segments 13 cut from a sheet 12 of a suitable material such as medium density fiberboard (MDF), low density fiberboard (LDF), or synthetic plastic foam. As shown in FIG. 1, initially, a plurality of segments 13 for a single component are formed in a plurality of sheets 12. As shown in FIG. 1, the cutting or machining of the sheet 12 is performed with a suitable machine such as a CNC router 11. The CNC router 11 cuts or separates a plurality of individual segments 13 belonging to the same layer from each other. In the example shown in FIG. 1, each segment 13 forms an open (e.g., semi-circular or arcuate) structure. In addition or alternatively, one or more than one segment 13 may be dimensioned and shaped for use in forming the entire layer, and thus may form a single closed loop structure (e.g., a closed circle, oval, square, rectangle, irregular shape). Additionally, when forming a final component having a hollow interior as described later, as shown in FIG. 1, one or more than one of the plurality of segments 13 may be nested (e.g., positioned inside the arc). Nesting a plurality of segments 13 within a single sheet 12 of material improves the utilization rate of the material and reduces costs.

[0017] As shown in FIG. 2, a plurality of individual segments (pieces) 13 formed by taking out a plurality of materials from the sheet 12 are fixed to each other so as to form one layer of a part, for example, a part of a cone. A seam or joint 14 is formed at the interface between a pair of opposing individual segments 13. In the exemplary assembly shown in FIG. 2, the upper layer, i.e., the second layer 15, including one segment (piece) 13, is continuous with and supported on the top surface of the plurality of pieces 13 of the lower layer, i.e., the first layer 16. On some sides, the joint 14 is formed by an interface where individual segments (beads) of a single layer are in contact with each other. On some sides, each joint 14 may be offset from the joints 14 formed in the adjacent layers (the layer immediately above and / or the layer immediately below). This offset, for example, an alternating arrangement, improves the strength of the part.

[0018] In the exemplary form shown in FIG. 2, since two arc-shaped segments 13 are assembled together, the joints 14 of the plurality of the first layer 16 are spaced 180 degrees apart in the circumferential direction. However, depending on the number and shape of the segments 13, intervals of 120 degrees, 90 degrees, or irregular intervals may be adopted. Each joint 14 of the first layer (for example, layer 16) may be offset from each joint 14 of the second layer (for example, layer 15), whereby the joints 14 of a given layer do not overlap any joints 14 formed by the adjacent layers. In the example shown in FIG. 2, the joint 14 is formed by a contact joint between the segments 13. Each contact joint 14 of the first layer 16 is offset 90 degrees from one or more contact joints 14 of the second layer 15 (the positions of the contact joints 14 formed in the second layer 15 are fully shown in FIG. 2).

[0019] It is often advisable to employ a plurality of segments 13 to manufacture a relatively large structure, such that the finished part, to be described later, is larger than the CNC router 11. Since the formation of a large structure involves the production of a number of components (e.g., segments 13), it is preferable to facilitate the identification and assembly of these segments 13. For example, the CNC router 11 or other suitable machining systems may preferably engrave or otherwise form marks 17 on the surface of each segment 13. Each mark 17 may preferably indicate the layer number (e.g., 1, 2, 3, 4) of the segment 13 and / or the position within a particular layer (e.g., A, B, C, left, right, top, bottom), as shown in FIG. 3. In some aspects, it is possible to identify the segment 13 by removing a portion of the material from each segment 13 to form the mark 17, eliminating the need to attach and then remove a label that may interfere with the assembly.

[0020] As shown in FIGS. 3, 4A, and 4B, one or more segments 13 include features configured to facilitate the assembly of a plurality of segments 13 into a near-net shape part. For example, a plurality of dowel holes 18 are machined or otherwise formed in each layer (e.g., one or more segments 13 of each layer) to facilitate aligning these layers (segments) with each other. As shown in FIGS. 4A and 4B, each dowel hole 18 penetrates the upper and lower surfaces of a particular segment 13. The plurality of dowel holes 18 are used to align each layer with the layer above and / or below it. As shown in FIG. 4B, mechanical fasteners such as a plurality of dowel pins 19 are inserted into two or more aligned dowel holes 18. The dowel pins 19 and dowel holes 18 are configured to facilitate the permanent assembly or attachment of a plurality of layers, each layer including one or more segments 13. After being assembled, each layer is permanently attached to one or more other layers using an adhesive, binder, mechanical fastener, or a combination thereof. When using mechanical fasteners, the plurality of layers do not need to be compatible with adhesive bonding techniques. Thus, when using mechanical fasteners, the entire part may not use an adhesive.

[0021] Figures 5A and 5B show a near-net shape part or object 20 when each of a plurality of layers is assembled and attached to each other. When assembling the object 20, the object 20 has a hollow interior formed by the inner diameter side surfaces of a plurality of arch-shaped segments 13 (FIGS. 1-4A). When assembling the object 20, the outer surface of the object 20 has a stepped shape. As a whole, the object 20 forms a conical shape or a frustum of a cone shape.

[0022] Figures 6A and 6B show an exemplary part or conical mold 21 formed by processing the near-net shape object 20. The conical mold 21 may be formed by machining the outer surface of the part or object 20 to a desired final dimension and shape, for example, the conical mold 21. In some aspects, this machining may be performed by a CNC machine, such as a CNC router 11. The router 11 removes portions of the material from the outer surface of the object 20 to form a continuous surface 30 that extends along at least the first layer 16 and the second layer 15 in response to instructions generated by the controller 100. As shown in FIGS. 6A and 6B, the machined continuous surface 30 may extend from the bottom end of the mold 21 to the top end of the conical mold 21. Also as shown in FIGS. 6A and 6B, the interior of the conical mold 21 that is not machined to form a smooth surface remains a stepped surface formed by a plurality of segments 13 of each layer including the first layer 16 and the second layer 15. The conical mold 21 (or any other part formed by the process described herein) may be larger than the CNC router 11. For example, the mold 21 may have a height greater than the height of the CNC router 11, or a length greater than the length of the CNC router 11, or a width greater than the width of the CNC router 11, or any combination thereof. By forming such a large part with a hollow interior, it is possible to significantly reduce the amount of material required to make such a part.

[0023] Referring to FIG. 7, a process for manufacturing a part, e.g., a conical mold 21 or other mold, includes generating and enclosing a support structure such as a support 22. The support 22 has a shape that at least partially conforms to the shape of the conical mold 21 and the shape inside. The support 22 has, for example, a stepped outer surface shape that conforms to the stepped shape inside the hollow interior of the conical mold 21. Each stepped portion conforms to each layer of the mold 21, e.g., the first layer 16 and the second layer 15.

[0024] To configure a mechanical support for the structure of the conical mold 21, one or more internal supports 22 are added inside the conical mold 21. This mechanical support is advantageous while the mold 21 is being used during the molding process. However, if desired, the support 22 may be placed inside the mold 21 before machining of the continuous surface 30. The support 22 is formed of a suitable material such as wood. The support 22 may be temporarily or permanently attached to the mold 21 using an adhesive, binder, mechanical fastener, or a combination thereof. Although a single support 22 is fixed inside the mold 21, multiple supports 22 may be manufactured and attached to the mold 21.

[0025] The machined mold 21, with or without a support 22, is suitable for various applications. For example, the mold 21 or other structures manufactured according to aspects of the present disclosure are used as molds for forming components containing glass fibers. The mold 21 is also useful as a component for a CNC router, and such a component is a fixture for fixing a plastic-molded component when machining it with a CNC router 11. Various porous materials (sheets) 12 such as MDF are suitable for this method, although they are inferior in strength, durability, and wear resistance compared to conventional materials. To use the mold 21 in one or more of the above-described applications, it is desirable to improve the physical properties of the mold 21. For example, if most (e.g., greater than 50%, or greater than 75%, or greater than 90% by volume and / or weight) of the material of the mold 21 is a porous material (sheet) 12 such as MDF, the inherent porosity of the material can be utilized to improve the physical properties of the final product.

[0026] For example, it is desirable to attach a reinforcing material to the mold 21. The process of manufacturing the mold 21 preferably includes performing one or more steps of reinforcing the mold 21, and such steps include applying a vacuum inside the component using a vacuum pump 24, as shown in FIG. 8. Other methods of reinforcing the mold 21 include applying pressure to push a reinforcing material (e.g., a thermosetting material) into the mold 21, immersing the mold 21 in a thermosetting material, or spraying a thermosetting material onto the mold 21. If the thickness of the outer wall of the component is sufficiently thin, when the pump 24 is applied to the mold 21 or other component in this way, air enters the component over the entire surface of the component (e.g., depending on the width of the segment (bead) or layer used in this process).

[0027] To effectively apply a reinforcing material such as by vacuum 24 to reinforce parts such as mold 21, it is advisable to seal the base surface or bottom surface 23 of the part at the narrow part of mold 21, i.e., the side opposite the end, and connect a high-flow vacuum pump 24 to the part 21 through the bottom surface 23. As shown in Figure 8, the vacuum pump 24 is attached to the part 21 and used to exhaust air from the inside of the sealed part 21. In at least some applications, the volume of air exhausted by the vacuum pump 24 is more than the volume of air flowing from the surface of the shaped part, so that the vacuum level and the resulting air flow from the surface of the part are maintained regardless of the intrusion of air from the surface.

[0028] Operate the vacuum pump 24 attached in this way to actively exhaust air from the inside of the mold 21, and as shown in Figure 8, supply a resin 25 such as a thin and low-viscosity epoxy to the surface of the part, for example, the continuous surface 30. The air flow generated by the vacuum applied inside the part flows through the part (e.g., from the outside of the part through the continuous surface 30 into the inside of the part), and by such vacuum and air flow, the liquid resin 25 is drawn into the structure of the material. When the resin 25 is drawn into the pores of the material, the air flow in the region where the resin 25 is injected into all or almost all thicknesses gradually decreases. This has the effect of increasing the air flow in the region where the resin is not completely injected into the part. By supplying resin to such a region, ultimately, the entire part 21 is injected with the resin 25. Once the entire part 21 is injected with the resin 25, stop the operation of the vacuum pump 24 and completely cure and harden the resin 25. As a result, the strength and physical properties of the part 21 are improved.

[0029] In the process of the modification example, to form a near-net shape, a plurality of layers of the component 21 are temporarily fastened by the dabo pins 19 or another suitable method. Next, a seal is formed on the bottom surface 23 of the component 21. Then, when a vacuum is applied to the component 21 by the vacuum pump 24, an air flow is generated through the component from the outside to the inside of the component 21. Next, a layer of the resin 25 is supplied to the component 21. When pulling the resin 25 into the component 21, the resin 25 gradually seals these regions, increases the vacuum in other regions of the component 21, and pulls the resin 25 into these unsealed regions. Once the component 21 is completely injected into the resin 25 and the resin 25 is completely cured, the resin 25 forms joints that permanently hold the plurality of layers together. This injection of the resin 25 is preferably performed before machining, for example, when the object 20 has a shape corresponding to FIGS. 5A and 5B. Once the object 20 injected with the resin 25 is machined to the desired final dimensions and shape, it can be used in a wide range of application examples. One exemplary application example for the mold 21 formed in this way is for use in an autoclave. Since all layers of the mold 21 are permanently bonded to each other by the resin 25, it is suitable for use in an autoclave.

[0030] As a modification example of using a vacuum to inject resin into an assembled structure, a liquid thermosetting material may be used. The concentration of a suitable liquid thermosetting material should be thin enough to penetrate through capillary action into the open pores of the material forming the structure of the mold 21. In this case, the liquid thermosetting material penetrates into the structure of the mold 21. This capillary action should be sufficient to inject the resin without the need for additional forces such as vacuum or pressure.

[0031] As a modification example of using a vacuum to inject resin into an assembled structure, it is also possible to use a liquid thermosetting material with a concentration thin enough to penetrate into the open pores of a specific structural material utilized through natural capillary action. In this case, the liquid material penetrates sufficiently into the structure without the need for additional external forces such as vacuum or pressure.

[0032] To achieve the desired properties, different resin formulations and different substrates (e.g., the material of sheet 12) may be combined. When forming an object according to one of the above-described embodiments, in order to achieve the desired physical properties useful for one or more specific applications of the finished part formed by assembling and modifying this object, it is possible to select a specific resin formulation and / or the material of the substrate. The finished part 21 is a low-cost and high-fill polymer part having many desired properties.

[0033] From the above detailed description, it is clear that there are numerous variations, adaptations, and modifications of the disclosure of the present invention within the scope of those skilled in the art related to the above-described disclosure. However, all such variations that do not depart from the spirit of the disclosure of the present invention are intended to be considered within the scope of the present invention when they are included in the claims.

Claims

1. A method of manufacturing a component, comprising: removing a porous material forming a plurality of individual layer segments from a sheet using a computer numerical control (CNC) router; forming a plurality of layers with the plurality of individual layer segments; adhering the plurality of layers to one another to form a component having a shape with a hollow interior; sealing a first open end of the hollow interior to form a closed end; injecting a thermosetting material adaptable to the porous portion of the porous material into the porous material of the component while sealing the first open end of the hollow interior; removing the porous material on the outer surface of the component using a CNC router to form a component having a continuous surface and the hollow interior.

2. The method according to claim 1, wherein the plurality of layers are permanently attached to one another by a thermosetting material.

3. The method according to claim 1 or 2, further comprising removing, using a CNC router, at least one porous material of the plurality of individual layer segments to form a mark indicating the layer number, position, or both.

4. The first and second layers include aligned dimples such that the dimple extends at least partially through the first and second layers, and at least one of the aligned dimples of the second layer is configured to receive a fastener at a radially inward position of the first layer. The method according to claim 1.

5. The method according to claim 1, wherein the hollow interior includes a stepped surface.

6. The hollow interior extends from a second open end to the closed end, and further comprising, after adhering the plurality of layers to one another and before injecting the thermoplastic material into the porous material, disposing a physical support extending from the closed end to the second open end into the hollow interior. The method according to claim 1.

7. The method according to claim 6, wherein the thermosetting material is supplied after removing the porous material on the outer surface of the component.

8. The method according to claim 1, wherein the component is a mold.

9. The method according to claim 1, wherein the plurality of individual layer segments are arc-shaped segments forming a plurality of joints.

10. The method according to claim 1, wherein the component is larger than the CNC router.

11. ​ The method according to claim 1, wherein adhering a plurality of layers to one another to form a component having a shape with the hollow interior includes forming a component in the shape of a cone.

12. The method according to claim 1, wherein removing the porous material from the outer surface of the component includes removing the porous material of two or more of the plurality of layers.

13. The method according to claim 1, wherein the thermosetting material is a resin.

14. The method according to claim 1, wherein supplying the thermosetting material to the component is performed by using a vacuum pump, or by applying pressure to the component, or by immersing the component in the thermosetting material, or by spraying the thermosetting material onto the component.

15. Injecting the thermosetting material into the porous material of the component includes connecting a vacuum pump to the hollow interior after sealing the first open end, and supplying the thermosetting material to the outer surface of the component while operating the vacuum pump to draw the thermosetting material into the porous material. The method according to claim 1.

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