阅读说明：本技术 用于生产复合材料产品的增材制造方法和机器 (Additive manufacturing method and machine for producing composite material products ) 是由 A.T.坎宁安 B.L.怀特 P.J.沃尔科特 A.沙比尔 Z.P.斯特菲斯 于 2020-03-20 设计创作，主要内容包括：本发明公开了用于生产复合材料产品的增材制造方法和机器。一种增材制造方法,其包括：定位复合材料片材；固化所述片材的预定部分；围绕所述预定部分的周界切割所述片材以产生在先加工片材；在所述在先加工片材顶部并与之接触地添加后续的复合材料片材；固化所述后续片材的预定部分,以使所述后续片材和所述在先加工片材的预定部分结合在一起；和围绕所述后续片材的预定部分的周界切割所述后续片材以产生在后加工片材。可以将添加、固化和切割后续片材的步骤重复多个循环以产生三维复合材料产品。(Additive manufacturing methods and machines for producing composite products are disclosed. A method of additive manufacturing, comprising: positioning the composite sheet; curing a predetermined portion of the sheet; cutting the sheet around a perimeter of the predetermined portion to produce a previously processed sheet; adding a subsequent composite sheet on top of and in contact with the previously processed sheet; curing a predetermined portion of the subsequent sheet to bond the subsequent sheet and the predetermined portion of the previously processed sheet together; and cutting the subsequent sheet around a perimeter of the predetermined portion of the subsequent sheet to produce a post-processed sheet. The steps of adding, curing, and cutting subsequent sheets may be repeated for a number of cycles to produce a three-dimensional composite product.)

1. An additive manufacturing method, comprising:

positioning the composite sheet;

curing a predetermined portion of the sheet;

cutting the sheet around a perimeter of the predetermined portion to produce a previously processed sheet;

adding a subsequent composite sheet on top of and in contact with the previously processed sheet;

curing a predetermined portion of the subsequent sheet to bond the subsequent sheet and the predetermined portion of the previously processed sheet together; and

cutting the subsequent sheet around a perimeter of a predetermined portion of the subsequent sheet to produce a post-processed sheet.

2. The method of claim 1, further comprising:

the steps of adding, curing and cutting subsequent sheets are repeated for a number of cycles.

3. The method of claim 1, further comprising, prior to the adding step:

applying an adhesive to a predetermined portion of the previously processed sheet material.

4. The method of claim 3, further comprising, prior to the applying step:

masking at least a portion of the previously processed sheet except for a predetermined portion.

5. The method of claim 1, further comprising, prior to the step of curing the predetermined portion of the subsequent sheet:

masking at least a portion of the subsequent sheet other than the predetermined portion.

6. The method of claim 1, further comprising, prior to the step of curing the predetermined portion of the subsequent sheet:

applying pressure on at least a predetermined portion of the subsequent sheet.

7. The method of claim 1, wherein the composite material comprises an X + Y structural component/resin combination, wherein structural component X is at least one of carbon fiber, aramid, bamboo, and glass fiber, and resin Y is at least one of a thermally reactive material, a photoreactive material, a pressure reactive material, and a chemically reactive material.

8. The method of claim 1, wherein each curing step includes directing at least one of heat, light, pressure, and an activator at the respective predetermined portion.

9. The method of claim 1, wherein each cutting step is accomplished by at least one of a laser, a cutting wheel, a drill bit, a milling tool, a saw, a hot knife, an air jet, and a water jet.

10. The method of claim 1, wherein at least one cutting step further comprises:

cut within the perimeter of the predetermined portion.

Technical Field

The present disclosure relates generally to additive manufacturing and more particularly to additive manufacturing machines and methods for producing composite products.

Background

Three-dimensional printing (3 DP) is an Additive Manufacturing (AM) method that builds components layer by layer. 3DP works by depositing a relatively small amount of material at a time, much like a printer deposits a very small amount of ink at a time to create a single layer print on a piece of paper. By using this printing analogy, 3DP can be imagined as a process of adding subsequent "ink" (or any material used) layers on top of each other. The materials used for 3DP are typically thermoplastic materials that are melted (or already in liquid form) and sprayed or deposited onto a substrate or platen in very small quantities at a time as a first layer. The deposited material solidifies, dries or coagulates immediately after deposition, and the small deposits are deposited very closely together, fusing or bonding together to form a continuous layer. That is, when a layer is constructed by depositing thousands of small deposits side-by-side, adjacent deposits merge or bond together to form a continuous layer with no spaces or voids between adjacent deposits. This continuity between deposits occurs not only within each layer, but also between adjacent layers. Thus, when a subsequent layer is deposited onto an earlier/underlying layer, the deposit of the subsequent/top layer will merge or bond with the adjacent deposit of the earlier/underlying layer.

Very complex three-dimensional (3D) structures can be constructed by the 3DP AM method due to the very small deposit size that can be achieved and the ability of adjacent deposits to merge or bond together tightly. However, the typical 3DP method is not well suited for constructing large structural components, which require considerable load bearing or wear resistance capabilities. For this purpose, 3DP has been adapted to deposit small deposits of thermosetting resins containing short bundles of high strength particles or glass fibers, carbon fibers, etc. within each deposit. Although this type of 3DP process using thermosetting resins and structural materials is better for structural, load bearing and wear resistant applications than conventional 3DP using thermoplastic deposits, it still has limitations. For example, the small size of the individual deposits means that the structural material (e.g., chopped glass fibers or carbon fiber particles) is provided only in very small amounts at a time, and thus even if present throughout the entire component, the structural material cannot persist in a continuous, uninterrupted form throughout each layer, thereby limiting the load-bearing capacity of the overall assembly.

It is therefore desirable to provide an improved method of producing components using the 3DP/AM method that avoids or minimizes these and other limitations.

Disclosure of Invention

As an example of the 3DP AM method, the assembly 10 shown in fig. 1 and 2 may be built in a layer-by-layer manner as illustrated in fig. 3. The first layer L1 was deposited on the substrate or platen 12 followed by the second layer L2 on top of the first layer L1 and this process of adding subsequent layers continued until the final layer L12 was completed. Although only twelve layers are shown in fig. 3 for illustrative purposes, a typical assembly 10 constructed by the 3DP method may have tens, hundreds, or thousands of layers.

According to one embodiment, an additive manufacturing method comprises: positioning the composite sheet; curing a predetermined portion of the sheet; cutting the sheet around a perimeter of the predetermined portion to produce a previously processed sheet; adding a subsequent composite sheet on top of and in contact with the previously processed sheet; curing a predetermined portion of the subsequent sheet to bond the subsequent sheet and the predetermined portion of the previously processed sheet together; the subsequent sheet is cut around a perimeter of the predetermined portion of the subsequent sheet to produce a post-processed sheet. The method may further comprise repeating the steps of adding, curing and cutting subsequent sheets for a plurality of cycles.

Prior to the adding step, the method may include applying an adhesive to a predetermined portion of the previously processed sheet material. And prior to the applying step, the method may further comprise masking at least a portion of the previously processed sheet material other than the predetermined portion.

The method may comprise masking at least a portion of the subsequent sheet other than the predetermined portion and/or applying pressure on at least the predetermined portion of the subsequent sheet prior to the step of curing the predetermined portion of the subsequent sheet.

The composite material may have an X + Y structural component/resin construction, where structural component X is carbon fiber, aramid, bamboo, and/or glass fiber, and resin Y is a thermally reactive material, a photo-reactive material, a pressure reactive material, and/or a chemically reactive material.

Each curing step may include directing heat, light, pressure and/or an activator at a respective predetermined portion of the composite sheet. The individual cutting steps can be achieved by using lasers, cutting wheels, drills, milling tools, saws, hot knives, air jets and/or water jets. And at least one of the cutting steps may include cutting within a perimeter of the predetermined portion.

In another embodiment, an additive manufacturing method for producing a composite product may comprise: (i) positioning the composite sheet; (ii) curing a predetermined portion of the sheet; (iii) cutting the sheet around a perimeter of the predetermined portion to produce a previously processed sheet; (iv) adding a subsequent composite sheet on top of and in contact with the previously processed sheet; (v) curing a predetermined portion of the subsequent sheet to bond the subsequent sheet and the predetermined portion of the previously processed sheet together; (vi) cutting the subsequent sheet around a perimeter of the predetermined portion of the subsequent sheet to produce a post-processed sheet; and (vii) repeating the steps of adding, curing, and cutting subsequent sheets for a plurality of cycles.

The additive manufacturing method may further comprise applying an adhesive to a predetermined portion of the previously processed sheet material prior to the adding step. And prior to the applying step, the method may further include masking at least a portion of the previously processed sheet material other than the predetermined portion.

Prior to the step of curing the predetermined portion of the subsequent sheet, the additive manufacturing method may comprise masking at least a portion of the subsequent sheet other than the predetermined portion and/or applying pressure on at least the predetermined portion of the subsequent sheet.

Each curing step of the additive manufacturing method may comprise directing heat, light, pressure and/or an activator at a respective predetermined portion of the composite sheet. The individual cutting steps can be achieved by using lasers, cutting wheels, drills, milling tools, saws, hot knives, air jets and/or water jets. And at least one of the cutting steps may include cutting within a perimeter of the predetermined portion.

In yet another embodiment, an additive manufacturing machine includes a subsystem for positioning a composite material sheet, a subsystem for curing a predetermined portion of the sheet, a subsystem for cutting the sheet around a perimeter of the predetermined portion to produce a processed sheet, and a controller operably connected with the subsystems for positioning, curing, and cutting. The controller has logic to perform the following steps: (i) positioning the composite sheet, (ii) curing a predetermined portion of the sheet, (iii) cutting the sheet around the perimeter of the predetermined portion to produce a previously processed sheet, (iv) adding a subsequent composite sheet on top of and in contact with the previously processed sheet, (v) curing a predetermined portion of the subsequent sheet to bond the subsequent sheet and the predetermined portion of the previously processed sheet together, (vi) cutting the subsequent sheet around the perimeter of the predetermined portion of the subsequent sheet to produce a subsequently processed sheet, and (vii) repeating the steps of adding, curing, and cutting the subsequent sheet for a plurality of cycles.

The subsystem for curing may include a heat source, a light source, a pressure source, and/or an activator source. Subsystems for cutting may include lasers, cutting wheels, drill bits, milling tools, saws, hot knives, air jets, and/or water jets. The machine may further include a subsystem for masking at least a portion of the selected composite sheet material other than the predetermined portion of the sheet material, wherein the controller is operatively connected to the subsystem for masking and has logic for performing the steps of: (viii) (ix) masking at least a portion of the selected composite sheet other than the predetermined portion of the sheet, and (ix) repeating the masking step for a plurality of cycles.

Drawings

Fig. 1 is a top view of a composite product according to an embodiment of the present disclosure.

Fig. 2 is a side view of a composite product according to an embodiment of the present disclosure.

Fig. 3 is a side view of a layer used to construct a composite product according to an embodiment of the present disclosure.

Fig. 4 is a cross-sectional view of a composite sheet according to an embodiment of the present disclosure.

Fig. 5 is a cross-sectional view of another composite sheet according to an embodiment of the present disclosure.

Fig. 6 shows a top view of three different layers of a processed composite sheet according to an embodiment of the present disclosure.

Fig. 7 is a flow diagram of a method of additive manufacturing according to an embodiment of the present disclosure.

Fig. 8 is a flow diagram of a method of additive manufacturing according to an embodiment of the present disclosure.

Fig. 9 is a schematic view of an additive manufacturing machine according to an embodiment of the present disclosure.

Detailed Description

Referring now to the drawings, in which like numerals represent like parts throughout the several views, there is shown and described herein a method 100/200, a machine 300, and a composite product produced by such methods and machines.

The inventors of the present disclosure have developed an additive manufacturing method and machine utilizing the method that overcomes the limitations of previous methods and is suitable for producing large and small structural components. One aspect of the inventors' method disclosed herein is the use of a composite sheet 20/30 as shown in fig. 4 and 5. The composite sheet 20 in fig. 4 includes an inner layer 22 sandwiched between a top outer layer 24 and a bottom outer layer 26. The inner layer 22 may be a mat, woven fabric, or an arrangement of structural materials such as carbon fibers, aramid, bamboo, glass fibers, and the like to serve as a structural component. The structural material may be in the form of cloth, batting, fibers, strands or other suitable arrangements.

The outer layer 24/26 may be a resin or other material having adhesive or cohesive properties. Suitable materials for these layers include epoxy, adhesive, polyester, resin, or other similar materials. These materials may coat the upper and lower surfaces or both of the inner layer 22 and may also be impregnated or dispersed within the inner layer 22. One well-known arrangement of such structures is a sheet of "prepreg", which is a sheet of carbon fiber, aramid, bamboo, glass fiber, etc. coated and infused ("impregnated") with a resin. These prepreg sheets are typically "tacky" to the touch due to the exposed resin on both surfaces, so they are provided with a "tear-off" or "peel-off" release/separator sheet (not shown) covering both surfaces 24/26.

Figure 5 shows an alternative version 30 of a composite sheet or prepreg. Here, there is no significant resin coating or layer on the top and bottom surfaces 34/36. Instead, the sheet 30 may contain only structural material (e.g., carbon fiber sheet) and no resin at all, or the sheet 30 may contain structural material with resin that penetrates the interior 32 of the sheet 30. As with the version shown in fig. 4, the sheet 30 may have a release/membrane sheet (not shown) covering the top and bottom surfaces 34/36 to facilitate handling and positioning of the sheet. When using sheet 20 according to fig. 4 or sheet 30 according to fig. 5 containing a resin, the resin in/on sheet 20/30 may comprise a first part or "a" part of a two part "a + B" resin/curing agent system. In such cases, the second part or "B" part (i.e., the hardener, accelerator, or other curing agent used to cure the part "a" resin) may be applied separately as part of the curing step (described below).

Thus, composite sheet 20/30 may include an "X + Y" structural component/resin combination or composition, where structural component X may be carbon fiber, aramid, bamboo, fiberglass, etc., and resin Y may be a heat reactive material, a light reactive material, a pressure reactive material, a chemical reactive material, etc. Such an X + Y combination or composition may take the form of sheet 20/30 as shown in fig. 4 and 5.

It should be noted that the terms "upper," "lower," "top," and "bottom" as used herein are relative (non-fixed) and refer to the orientation of the composite sheet surface when the sheet 20/30 is positioned for use in the disclosed method. Thus, either surface of the sheet may be a top/upper surface or a bottom/lower surface, depending on how the sheet is oriented. Likewise, the words "prior," "subsequent," and "after" are used herein to denote a relative order or sequence in which the sheets are presented or used relative to other sheets used earlier or later in the additive manufacturing method 100/200 according to the present disclosure.

Fig. 6 shows a top view of three different layers of a composite sheet 40/50/60 according to an embodiment of the disclosure, and fig. 7 shows a flow chart of a method of additive manufacturing 100 according to an embodiment of the disclosure. In step 110, the composite sheet 40 is positioned (e.g., on platen 12 of the table) as a first layer L1 for further processing. Step 110 may be performed manually by a human operator or by using automated material handling equipment.

In step 120, a predetermined portion, area or region 41 of the sheet 40 is cured. The predetermined portion 41 has a perimeter 42 that is within an outer perimeter or boundary 43 of the composite sheet 40. As shown in fig. 1-3 and 6, the predetermined portion of each sheet or layer corresponds to a layered "slice" of the desired composite product. The curing step 120 may be accomplished by selectively directing heat, light, pressure, and/or an activator at the predetermined portion 41 of the composite sheet 40. Depending on the type of resin used in or on the surface of the sheet, a particular type of curing means (or combination of curing means) may be used. For example, a photoreactive resin may require a specific range of frequencies of light (e.g., Ultraviolet (UV), infrared, coherent laser) to be used as a curing means to cure portions 41 of sheet 40 exposed to the light. As another example, the pressure-reactive resin may be cured by applying pressure concentrated on a predetermined portion of the sheet. Further, the thermally reactive resin may be cured by using heat and/or infrared energy directed at the region(s) 41 of the sheet 40 that is desired to be cured, and the chemically reactive resin may be cured by using an appropriate chemical agent (e.g., an activator, an accelerator, a catalyst, etc.) as a curing means. For example, the resin in/on the composite sheet 40 may comprise a first part or "a" part of a two-part "a + B" resin/curing agent system. In such a case, a second part or "B" part (i.e., a hardener, accelerator, or other curing agent for curing the part "a" resin) may be applied to the predetermined portion 41 as part of the curing step 120, such as by a print head that is swept across the sheet 40. When the part "B" component is contacted with the part "a" component in a predetermined portion or region 41, the region 41 is cured due to the chemical interaction of the components "a" and "B". Alternatively, the composite sheet 40 may comprise only structural material (e.g. a woven sheet of carbon fibres) without any resin, and the curing step 120 may comprise applying resin only to the predetermined portions 41, followed by curing the resin by applying suitable curing means/curing media.

It should be noted that "curing" is the process of transitioning a predetermined portion of the sheet where the curing means or curing medium is directed from a first substantially "uncured" state to a second substantially "cured" state. In such a cured state, the resin within the predetermined portion is harder, hardened, densified, etc. than before the curing means or curing medium is applied. As used herein, "curing means" or "curing medium" refers to a substance (e.g., a chemical), a form of energy (e.g., heat or light), or a set of conditions (e.g., applied pressure) that causes, facilitates, accelerates, or otherwise accelerates the curing or transformation of the resin.

In step 130, after predetermined portion 41 of sheet 40 has been cured, sheet 40 is then cut around perimeter 42 of predetermined portion 41 to produce a prior or initial finished sheet 40'. In addition to cutting around (i.e., at or just outside) perimeter 42 of predetermined portion 41, sheets may also be cut within (i.e., inside) perimeter 42 of predetermined portion 41, as shown by apertures 44/46, which are formed by cutting sheets of composite material at respective perimeters 45/47 of apertures 44/46. These internal cuts may be made to "core out" certain portions of the composite product, or to create holes, pockets, internal cavities, internal surfaces, flow channels, and the like. These internal cut portions may be removed and optionally filled with a material (e.g., resin, a material with a lower melting point than the resin, etc.), or the cut portions may be left in place (not removed) to act as "supports" (e.g., to prevent subsidence) for the cured portions in subsequent layers on top of these supports. The cutting step 130 may be accomplished or accomplished by using a laser (e.g., a high power cutting laser), a cutting wheel, a drill bit, a milling tool, a saw, a hot knife, an air jet, a water jet, or similar cutting device.

In step 140, a subsequent composite sheet 50 is added on top of and in contact with the previously processed sheet 40'. Subsequently, in step 150, the predetermined portion 51 of the succeeding sheet 50 is cured to bond the succeeding sheet 50 and the predetermined portion 51/41 of the previously processed sheet 40'. The predetermined portion 51 has a perimeter 52 that is within a perimeter or boundary 53 of the composite sheet 50. Note that regions 58, 54 and 56 are uncured, corresponding to holes 14, 16 and 18 in fig. 1 and 2, respectively. And in step 160, the subsequent sheet 50 is cut around the perimeter 52 of the predetermined portion 51 of the subsequent sheet (and optionally also the subsequent sheet 50 is cut within the perimeter 52 to create uncured regions 54/56/58 defined by their respective perimeters 55/57/59) to create a post/post processed sheet 50'.

Referring to fig. 1-3 and 6, note that layers L1, L2, and L3 may be created using predetermined partial patterns 41 of sheet material 40. Also, the layers L4, L5, and L6 may be produced using the predetermined partial pattern 51 of the sheet 50, and the layers L7 to L12 may be produced using the predetermined partial pattern 61 of the sheet 60. After creating a layer by selectively curing and cutting a composite sheet to create a prior processed sheet, a next/subsequent layer is created by placing an uncured/unprocessed composite sheet on top of the prior/prior processed sheet and then curing and cutting the next/subsequent sheet. This process is repeated layer by layer until the desired composite product is obtained.

Note that the reference numerals 40, 50 and 60 without accents represent green composite sheets that have not yet been cured or cut, while those with accents (i.e., 40 ', 50 ' and 60 ') represent cured and cut/processed sheets. The process of building up a composite product layer by layer may proceed as follows. The first green sheet 40 is positioned, cured and cut to produce a first processed sheet 40' which serves as the layer L1 portion of the composite product and also serves as the "previous" processed sheet for layer L2. Next, a second (subsequent) green sheet 40 is placed on the first (previous) processed sheet 40 'and cured and cut to produce a second processed sheet 40' that serves as layer L2. At this point, only two layers are completed: l1 and L2. Next, a third (subsequent) green sheet 40 is placed on the second (previous) processed sheet 40 'and cured and cut to produce a third processed sheet 40' that serves as layer L3. Note that the same predetermined partial pattern and perimeter 41/42/45/47 are used for the first three layers L1-L3; however, layers L4-L6 utilized slightly different predetermined partial patterns and perimeters 51/52/55/57/59 (i.e., these layers had holes 58 defined by their perimeters 59, while layers L1-L3 did not).

After producing layer L3, a fourth (subsequent) green sheet 50 is placed on the third (prior) processed sheet 40 'and cured and cut to produce a fourth processed sheet 50' that serves as layer L4. Next, a fifth (subsequent) green sheet 50 is placed on the fourth (prior) processed sheet 50 'and cured and cut to produce a fifth processed sheet 50' that serves as layer L5. Next, a sixth (subsequent) green sheet 50 is placed on the fifth (previous) processed sheet 50 'and cured and cut to produce a sixth processed sheet 50' which serves as layer L6. Note that the same predetermined partial pattern and perimeter 51/52/55/57/59 are used for these fourth, fifth, and sixth layers L4-L6; however, layers L7-L17 employ a different predetermined partial pattern and perimeter 61/62/69 (i.e., substantially only an annular region, with holes 68).

After layer L6 has been created, a seventh (subsequent) green sheet 60 having a perimeter or boundary 63 is placed on sixth (prior) processed sheet 50 'and cured and cut to create a seventh processed sheet 60' that serves as layer L7. Next, an eighth (subsequent) green sheet 60 is placed on seventh (prior) processed sheet 60 'and cured and cut to produce eighth processed sheet 50' which serves as layer L8. This process is repeated until the final layer L12 is completed.

When a subsequent composite layer or sheet is positioned on top of a previously cured and cut layer or sheet, the two sheets will contact each other with a predetermined portion or area of the subsequent sheet positioned directly on top of a predetermined portion or area of the previously/previously processed sheet. Then, when a predetermined portion of the subsequent sheet is cured, the resin in curing bonds the two sheets together at the predetermined portion thereof (but does not substantially bond the sheets together at other regions that are not part of the predetermined portion).

At step 170, if the composite product is not complete, the process continues by repeating the steps of adding, curing, and cutting a subsequent sheet (step 140/150/160) for a number of cycles until the method 100 is complete (step 180) and a three-dimensional composite product is produced. The composite product may optionally be further processed, such as sanding, buffing, polishing, priming, painting, plating, autoclaving, drilling or cutting a portion, adding other reinforcements, and the like. For example, holes and voids created during the layer-by-layer build method 100 or drilled/cut into the composite product at the end of the method 100 may be equipped with additional structural reinforcement (e.g., metal stakes, brackets, etc. pressed into the holes, secured into the voids), or the holes/voids may be filled with additional resin and oriented fibers to improve the out-of-plane strength of the composite product. Likewise, after laying a subsequent sheet of composite material on top of a previously processed sheet, the subsequent sheet may be stamped or pressed with a tool at selected locations within predetermined partial areas of the subsequent sheet to complete a "pinning" or "interlayer staking" where the stamped or pressed areas of the subsequent sheet are pressed/urged into the preceding sheet below. Additional resin and/or structural material may be added to such stamped or pressed areas, asIn order to create small gaps there. In addition, after each layer or sheet has been initially cured as part of the aforementioned method 100 and the layer-by-layer build process is completed, the composite product may be subjected to a further curing or "post-curing" step. This can increase adhesion, improve mechanical properties and improve temperature resistance and can be done by exposing the finished product to elevated temperatures for a prescribed period of time on the same machine that produces the assembly or in a separate oven, autoclave, or the like. In addition, one or more of the sheets or layers may also include one or more perforations or seams P formed as part of the cutting step₄₀/P₅₀/P₆₀Where perforations or seams P are present₄₀/P₅₀/P₆₀Extending from a perimeter 42/52/62 of each predetermined portion 41/51/61 to an edge or boundary 43/53/63 of the respective sheet 40/50/60. These perforations or seams P₄₀/P₅₀/P₆₀May be cut completely through or only partially through the sheet 40/50/60, may be cut in a straight line or non-straight line, and may be cut in a continuous line or in perforated lines, segmented lines, or "dashed lines". Such a perforation P₄₀/P₅₀/P₆₀Separation and removal of the finished composite product 10 from the surrounding uncured sheet layer may be facilitated. Although not shown in the figures, perforations may also be included inside perimeter 42/52/62 of predetermined portion 41/51/61 to facilitate removal of the uncured interior portion of sheet material 40/50/60.

Fig. 8 shows a flow diagram of an additive manufacturing method 200 for producing a composite product according to another embodiment of the present disclosure. In step 210, a composite sheet is positioned, in step 220, a predetermined portion of the sheet is cured, and in step 230, the sheet is cut around the perimeter of the predetermined portion of the sheet to produce a previously processed sheet. In step 240, a subsequent composite sheet is added on top of and in contact with the previously processed sheet, and in step 250, a predetermined portion of the subsequent sheet is cured to bond the subsequent sheet and the predetermined portion of the previously processed sheet together. In step 260, the subsequent sheet is cut around a perimeter of the predetermined portion of the subsequent sheet to produce a post-processed sheet. In step 270, if the composite product is not complete, the process continues by repeating the steps of adding, curing, and cutting a subsequent sheet (step 240/250/260) for a number of cycles until the composite product is complete (step 280).

Between the adding step 240, an additional step 234 of applying adhesive to a predetermined portion of the previously processed sheet may be performed. The adhesive may be the same resin used in the composite sheet, or it may be a different material with compatible adhesion, acceleration or other beneficial properties. Prior to this step 234 of applying adhesive, another additional step 232 of masking at least a portion of the previously processed sheet material other than the predetermined portion of the sheet material may be performed. The mask may contain apertures of a shape and size corresponding directly to predetermined portions of the previously processed sheet material such that when the mask is placed in register on the previously processed sheet material, predetermined portions of the previously sheet material are exposed through the apertures while other portions of the previously sheet material are masked (i.e. covered or covered) such that adhesive may be applied to (and only to) predetermined portions of the previously processed sheet material.

After the step 240 of adding the subsequent composite sheet to the previously processed sheet, but before the step 250 of curing the predetermined portion of the subsequent sheet, an additional step 242 of masking at least a portion of the subsequent sheet other than the predetermined portion may be performed. Similar to the mask described above for step 234, the mask in step 242 may contain an aperture having a shape and size corresponding directly to the predetermined portion of the subsequent sheet such that when the mask is placed in register on the subsequent sheet, the predetermined portion of the subsequent sheet is exposed through the aperture while other portions of the subsequent sheet are masked (i.e., covered or covered). In the event that only a predetermined portion of the subsequent sheet is exposed through the aperture, the curing means or curing method of step 250 may be applied to (and only to) the predetermined portion of the subsequent sheet.

Between the step 240 of adding the subsequent sheet and the step 250 of curing a predetermined portion thereof, a further additional step 244 of applying pressure on at least a predetermined portion of the subsequent sheet may be performed. If the resin is pressure reactive, the pressure can be used to cure the resin; however, even if the resin is not pressure reactive, the applied pressure may be assisted in other ways, such as during curing when the resin is thermally reactive.

Similar to the method 100 described earlier, the cutting step 230/260 of the method 200 may also include cutting the sheet material within the perimeter of the predetermined portion of the sheet material (e.g., to create the holes and voids shown in fig. 1-3 and 6) in addition to cutting around the perimeter of the predetermined portion of the preceding or subsequent sheet material. In addition, after each layer or sheet has been initially cured as part of the aforementioned method 200 and the layer-by-layer build process is completed, the composite product may be further cured or "post-cured" on the same machine that produced the assembly or in a separate oven, autoclave, or the like.

Fig. 9 shows a schematic view of an additive manufacturing machine 300, according to an embodiment of the present disclosure. Machine 300 includes a subsystem 310 for positioning a composite sheet, a subsystem 320 for curing a predetermined portion of the sheet, and a subsystem 330 for cutting the sheet around the perimeter of the predetermined portion to produce a finished sheet. The machine 300 also includes a controller 350 operatively connected to the sub-system for positioning 310, the sub-system for curing 320, and the sub-system for cutting 330. The controller 350 has logic to perform the following steps: (i) positioning the composite sheet, (ii) curing a predetermined portion of the sheet, (iii) cutting the sheet around the perimeter of the predetermined portion to produce a previously processed sheet, (iv) adding a subsequent composite sheet on top of and in contact with the previously processed sheet, (v) curing a predetermined portion of the subsequent sheet to bond the subsequent sheet and the predetermined portion of the previously processed sheet together, (vi) cutting the subsequent sheet around the perimeter of the predetermined portion of the subsequent sheet to produce a subsequently processed sheet, and (vii) repeating the steps of adding, curing, and cutting the subsequent sheet for a plurality of cycles.

The subsystem 310 for positioning may include an automated material handling apparatus. The subsystem 320 for curing may include a heat source, a light source, a pressure source, and/or an activator source. The selection of an appropriate subsystem 310 for curing depends on the desired curing means or curing method for the resin used. The subsystem 330 for cutting may include a laser, cutting wheel, drill bit, milling tool, saw, hot knife, air jet, and/or water jet.

The machine 300 may further include one or more additional subsystems 340 (represented by dashed lines in fig. 9). This may include a subsystem 340 for masking at least a portion of the selected composite sheet material other than the predetermined portion of the sheet material, where the controller 350 is operatively connected to the subsystem for masking and has logic to perform the steps of: (viii) (ix) masking at least a portion of the selected composite sheet other than the predetermined portion of the sheet, and (ix) repeating the masking step for a plurality of cycles. The machine 300 may also include a means of positioning the composite sheet in multiple directions. This may be particularly useful when using composite sheets in which the fibers or structural components are laid in a substantially unidirectional manner, thereby allowing multiple fiber orientations to increase the strength of the resulting product. This may be accomplished by subsystem 310 for positioning or as a separate subsystem 340, and may include a build platform or platen that rotates about the Z (vertical) axis, or the subsystem for positioning the composite sheet may rotate about the build platform or platen. The machine may also include a subsystem 340 for post-curing the composite product after the layer-by-layer build process is complete, which may include an arrangement of heating elements and insulating walls for containing heat generated by the heating elements. When any additional subsystems 340 are provided, a controller 350 is operatively connected to each subsystem 340 and contains logic for controlling and/or performing the activities associated with each subsystem 340.

The subsystems 310/320/330/340 are each adapted to engage and communicate with the controller 350 to perform the processes described above (which may be similar to the method 100/200 described earlier in this disclosure). The controller logic for performing the foregoing steps may be any suitable combination of hardware, software, and/or firmware.

The above-described method 100/200 and machine 300, and the composite product produced thereby, present a number of advantages over previously known 3DP/AM methods, machines, and products. For example, method 100/200 and machine 300 may use commercially available prepreg sheets (containing resin) or "dry" sheets (containing only structural material, no resin) to create the individual layers, while other 3DP/AM methods cannot utilize composite sheets, but rely on a very large number of small, individual deposits to create the individual layers. Thus, the method 100/200 and machine 300 of the present disclosure greatly reduce the cost of raw materials and the time required to create each layer as compared to other known methods. Furthermore, the range of materials that may be used in method 100/200 and machine 300 (e.g., carbon fiber, aramid, bamboo, polyester, etc., as well as various resin systems/curing methods), plus the arrangement and form of the structural materials used in the composite sheet (e.g., unidirectional fibers, multidirectional fibers, cloth, ribbon, batting, woven fabric, mat, etc.) is much greater than other known methods.

The above description is intended to be illustrative, and not restrictive. While various specific embodiments have been set forth, those skilled in the art will recognize that the disclosure can be practiced with modification within the spirit and scope of the claims. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the scope thereof. While the dimensions and types of materials described herein are intended to be illustrative, they are by no means limiting and are exemplary embodiments. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. Furthermore, in the following claims, any use of the terms "first," "second," "top," "bottom," and the like are used merely as labels, and are not intended to impose numerical or positional requirements on their objects. Furthermore, the limitations of the following claims are not written in a means-plus-function or step-plus-function format, and are not intended to be so interpreted, unless and until such claim limitations explicitly use the phrases "means for … …" or "step for … …," followed by a statement of function without further structure. As used herein, an element or step recited in the singular and proceeded with the word "a" or "an" should be understood as not excluding plural of such elements or steps, unless such exclusion is explicitly recited. Furthermore, any reference to a particular embodiment or example is not intended to be construed as excluding the existence of additional embodiments or examples that also incorporate the recited features. Furthermore, unless explicitly stated to the contrary, embodiments "comprising" or "having" an element or a plurality of elements having a particular property may also include additional such elements not having that property.

The flowchart and block diagrams in the figures illustrate the architecture, functionality, and/or operation of possible implementations of systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. These computer program instructions may also be stored in a computer-readable medium that can direct a controller or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable medium produce an article of manufacture including instructions which implement any function and/or act specified in the flowchart and block diagram block or blocks.

This written description uses examples, including the best mode, to enable any person skilled in the art to make and use the devices, systems, and compositions of matter, and to practice the methods, in accordance with the present disclosure. It is the following claims, including all equivalents, that define the scope of this disclosure.

The invention discloses the following embodiments:

scheme 1. an additive manufacturing method comprising:

positioning the composite sheet;

curing a predetermined portion of the sheet;

cutting the sheet around a perimeter of the predetermined portion to produce a previously processed sheet;

adding a subsequent composite sheet on top of and in contact with the previously processed sheet;

curing a predetermined portion of the subsequent sheet to bond the subsequent sheet and the predetermined portion of the previously processed sheet together; and

cutting the subsequent sheet around a perimeter of a predetermined portion of the subsequent sheet to produce a post-processed sheet.

Scheme 2. the method of scheme 1, further comprising:

the steps of adding, curing and cutting subsequent sheets are repeated for a number of cycles.

Scheme 3. the method of scheme 1, further comprising, prior to the adding step:

applying an adhesive to a predetermined portion of the previously processed sheet material.

Scheme 4. the method of scheme 3, further comprising, prior to the applying step:

masking at least a portion of the previously processed sheet except for a predetermined portion.

Scheme 5. the method of scheme 1, further comprising, prior to the step of curing the predetermined portion of the subsequent sheet:

masking at least a portion of the subsequent sheet other than the predetermined portion.

Scheme 6. the method of scheme 1, further comprising, prior to the step of curing the predetermined portion of the subsequent sheet:

applying pressure on at least a predetermined portion of the subsequent sheet.

Scheme 7. the method of scheme 1, wherein the composite material comprises an X + Y structural component/resin combination, wherein structural component X is at least one of carbon fiber, aramid, bamboo, and glass fiber, and resin Y is at least one of a thermally reactive material, a photoreactive material, a pressure reactive material, and a chemically reactive material.

Scheme 8. the method of scheme 1, wherein each curing step comprises directing at least one of heat, light, pressure, and an activator at the respective predetermined portion.

Scheme 9. the method of scheme 1, wherein each cutting step is achieved by at least one of a laser, a cutting wheel, a drill bit, a milling tool, a saw, a hot knife, an air jet, and a water jet.

Scheme 10. the method of scheme 1, wherein at least one of the cutting steps further comprises:

cut within the perimeter of the predetermined portion.

Scheme 11. an additive manufacturing method for producing a composite product, comprising:

positioning the composite sheet;

curing a predetermined portion of the sheet;

cutting the sheet around a perimeter of the predetermined portion to produce a previously processed sheet;

adding a subsequent composite sheet on top of and in contact with the previously processed sheet;

curing a predetermined portion of the subsequent sheet to bond the subsequent sheet and the predetermined portion of the previously processed sheet together;

cutting the subsequent sheet around a perimeter of a predetermined portion of the subsequent sheet to produce a post-processed sheet; and

the steps of adding, curing and cutting subsequent sheets are repeated for a number of cycles.

Scheme 12. the method of scheme 11, further comprising, prior to the adding step:

applying an adhesive to a predetermined portion of the previously processed sheet material.

Scheme 13. the method of scheme 12, further comprising, prior to the applying step:

masking at least a portion of the previously processed sheet except for a predetermined portion.

Scheme 14. the method of scheme 11, further comprising, prior to the step of curing the predetermined portion of the subsequent sheet:

masking at least a portion of the subsequent sheet other than the predetermined portion.

Scheme 15 the method of scheme 11, further comprising, prior to the step of curing the predetermined portion of the subsequent sheet:

applying pressure on at least a predetermined portion of the subsequent sheet.

Scheme 16. the method of scheme 11, wherein at least one of the cutting steps further comprises:

cut within the perimeter of the predetermined portion.

Scheme 17. an additive manufacturing machine, comprising:

a subsystem for positioning the composite sheet;

a subsystem for curing a predetermined portion of the sheet;

a subsystem for cutting the sheet around the perimeter of the predetermined portion to produce a finished sheet; and

a controller operatively connected to the subsystem for positioning, curing and cutting, the controller having logic to perform the steps of:

the composite sheet is positioned such that,

curing the predetermined portion of the sheet of material,

cutting the sheet around the perimeter of the predetermined portion to produce a previously processed sheet,

adding a subsequent composite sheet on top of and in contact with the previously processed sheet,

curing a predetermined portion of the subsequent sheet to bond the subsequent sheet and the predetermined portion of the previously processed sheet together,

cutting the subsequent sheet around a perimeter of a predetermined portion of the subsequent sheet to produce a post-processed sheet, an

The steps of adding, curing and cutting subsequent sheets are repeated for a number of cycles.

Scheme 18. the additive manufacturing machine of scheme 17, wherein the subsystem for curing comprises at least one of a heat source, a light source, a pressure source, and an activator source.

Scheme 19. the additive manufacturing machine of scheme 17, wherein the subsystem for cutting comprises at least one of a laser, a cutting wheel, a drill bit, a milling tool, a saw, a hot knife, an air jet, and a water jet.

Scheme 20. the additive manufacturing machine of scheme 17, further comprising:

a subsystem for masking at least a portion of the selected composite sheet other than the predetermined portion of the sheet, wherein the controller is operatively connected to the subsystem for masking and has logic for performing the steps of:

masking at least a portion of the selected composite sheet other than the predetermined portion of the sheet, and

the masking step is repeated for a number of cycles.