Sandwich panel with unidirectional composite belt and production method thereof

Abstract

The invention enables the production of optionally wide thermoplastic sandwich panels with 0 / 90 DEG unidirectional laminated composite skins (skins). The composite skin may be comprised of a thermoplastic film or sheet material. The invention allows rapid production of finished thermoplastic honeycomb sandwich panels of different widths. The thermoplastic film or sheet is preferably joined / laminated to the honeycomb core by thermoplastic welding.

Description

[0001] The present invention relates to optionally large width thermoplastic sandwich panels with composite skins having 0 / 90° unidirectional tape layup and methods for producing the same. The composite skins may be constructed from thermoplastic film or sheet materials. The present invention relates to the rapid production of finished thermoplastic honeycomb sandwich panels of varying widths. The thermoplastic film or sheet is preferably joined / laminated to a honeycomb core by thermoplastic welding. The thermoplastic film or sheet is used as a reinforcing material and is preferably joined / laminated to the honeycomb core by thermoplastic welding. The honeycomb core is preferably formed from a plurality of polygonal cells arranged in an array, wherein each polygonal cell has lateral cell walls extending between the vertices of each polygonal cell. Background Art

[0002] Inline lamination of continuously reinforced thermoplastic composite skins on a thermoplastic honeycomb core produces a cost-effective sandwich panel that provides stiffness and strength at minimal weight for use in a wide range of applications in many industries. Continuously produced thermoplastic honeycomb cores, such as the folded honeycomb described in WO 2006 / 053407, enable high volume production of such sandwich panels at significantly reduced costs.

[0003] Typically, a woven thermoplastic composite skin or two unidirectional fiber reinforced thermoplastic tape (UD tape) layers in the form of a 0° / 90° laminate is applied to each major surface of the honeycomb core to produce a sandwich panel with high bending stiffness and strength in the two main directions of the panel. Patent application US2020164624A1 (Wismans, 2018) describes a symmetrical laminate. Patent application US2008047121A1 (Rohr, 2008) proposes a method for joining composite honeycomb panel sections. Patent application US2022001643A1 (Huaping, 2022) describes other methods of joining honeycomb cores before the skin is applied to the joined honeycomb cores.

[0004] Continuously produced thermoplastic honeycomb cores enable the co-production of such sandwich panels. Two layers of thermoplastic tapes are typically laminated together and rolled up in a double belt laminator to form a skin laminate. This laminate is then laminated to both sides of the honeycomb core, for example co-linearly during the production of the continuously produced thermoplastic honeycomb core, to form a composite skin. In this co-linear process, the width of the resulting sandwich panel is limited to the width of the honeycomb production line and the width of the laminate and laminator, which needs to be available. Therefore, the honeycomb core needs to be produced before lamination to the honeycomb core. This can increase the stock that must be stored to be available at any time to meet specific customer requirements. Summary of the invention

[0005] An object of embodiments of the present invention is to enable the manufacture of optionally large width thermoplastic sandwich panels with composite skins having 0° / 90° unidirectional tape layups. The composite skins may be constructed of thermoplastic film or sheet material. Embodiments of the present invention allow for the rapid production of finished thermoplastic honeycomb sandwich panels of varying widths. The thermoplastic film or sheet is used as reinforcement and is preferably joined / laminated to the honeycomb core by thermoplastic welding.

[0006] The honeycomb core is preferably formed by a plurality of polygonal units arranged in an array, wherein each polygonal unit has a lateral unit wall extending between the vertices of each polygonal unit. The honeycomb core is preferably a folded honeycomb core. Preferably, each polygonal unit is defined by a covering layer panel on both sides, and the lateral unit wall of each polygonal unit forms a polygonal ring. For half of the units along one edge of the honeycomb core, the top or bottom of the unit is open, and for the units along the other half of the opposite edge, the top or bottom is closed. This allows trimming operations to be performed on each lateral edge of the enhanced honeycomb core, so that the unit from one enhanced core has an open top and can be cut into two halves, and is joined with a unit with a closed top that can be cut into two halves from an adjacent enhanced core. These trimmed edges can be pushed together with a certain pressure to provide reinforcement at the joint between two honeycomb core materials or honeycomb panels.

[0007] Another object of an embodiment of the present invention is to enable the production of optionally large width thermoplastic honeycomb panels with thermoplastic composite skins with 0° / 90° reinforced layups, which are based on the use of smaller width honeycomb core materials joined together without weak points or severe weakening at the joints of the individual honeycomb cores or with reinforced joints.

[0008] The advantage of the present invention is that the separate lamination steps for producing a 0° / 90° laminate use further processing of a reinforced honeycomb core having a 0° reinforcement layer on both sides of the honeycomb core with a production direction of a 90° turn to apply a second reinforcement layer on both sides of the honeycomb core again at 0° relative to the new production direction. This produces a first and a second laminate with a 0° / 90° stack.

[0009] The separate lamination steps can be performed at different locations. This has the following important advantages: the production of small widths of honeycomb cores with a first 0° reinforcement layer laminated to the honeycomb core can be fast and cost-effective, and the small width panels can be easily transported. The second lamination step to form a larger width sandwich panel with a final 0° / 90° composite laminate skin can be done locally, for example at the location where these panels are joined to a truck trailer box or other application.

[0010] According to an embodiment of the present invention, one or more objects are achieved by producing an intermediate panel with a single layer of UD reinforced skin on both sides of a honeycomb core in the 0° direction consistent with the production direction of the continuously produced honeycomb core. An additional UD reinforcement layer laminated in the 0° direction is applied to the intermediate panel after the machine direction of the method is rotated 90°. Preferably, this includes reinforcement at the joints between the intermediate panels. Such reinforcement may include one or more of the following:

[0011] Overlap and / or interpenetration of adjacent intermediate panels, or

[0012] Adhesive layers or loops are used at the joints between adjacent intermediate panels.

[0013] All of these methods result in a strong joint. The core density in the small area where the two middle panels meet is higher than in the rest of the middle panels. This ensures good support of the outer layer (sometimes called the "skin") and a perfect core-skin bond in the joint area.

[0014] An embodiment of the present invention provides a reinforced honeycomb sandwich panel, comprising: a plurality of honeycomb core sheets, the honeycomb core sheets having edges and having a first core density;

[0015] a first skin layer having 0° fiber reinforcement laminated on both sides of each of a plurality of honeycomb core sheets to form a laminated reinforced honeycomb core sheet;

[0016] A butt joint, wherein the butt joint is in a side-by-side position at the edges of the laminated reinforced honeycomb core material and between the edges of the corresponding laminated reinforced honeycomb core material, so that the edges overlap or penetrate or deform each other to form an area of ​​a second core density at the joint of the laminated reinforced honeycomb core and the first skin layer, wherein the second core density is higher than the first core density, and the first skin layer has a 0° fiber reinforcement layer above and below the position of the edge joint of the honeycomb core; and a second skin layer, wherein the second skin layer has a 90° fiber reinforcement layer on both sides of the laminated reinforced honeycomb core above and below the 0° fiber reinforcement layer to form a laminated reinforced honeycomb sandwich panel.

[0017] An embodiment of the present invention provides a reinforced honeycomb sandwich panel, comprising: a plurality of honeycomb core sheets, the honeycomb core sheets having edges and having a first core density;

[0018] a first skin layer having 0° fiber reinforcement laminated on both sides of each of a plurality of honeycomb core sheets to form a laminated reinforced honeycomb core sheet;

[0019] a butt joint, wherein the butt joint is in a side-by-side position of the edges of the laminated reinforced honeycomb core sheet, between the edges of the respective laminated reinforced honeycomb core sheets, so that the edges overlap or penetrate or deform each other to form an area of ​​a second core density at the joint of the laminated reinforced honeycomb core sheet and the first skin layer, the second core density being higher than the first core density, and the first skin layer having 0° fiber reinforcement layers above and below the location where the edges of the honeycomb core are joined;

[0020] The second skin layer has 90° fiber reinforcement layers on both sides of the laminated reinforced honeycomb core sheet and on the 0° fiber reinforcement layer to form a laminated reinforced honeycomb sandwich panel.

[0021] An embodiment of the present invention provides a method for continuously producing a laminated reinforced honeycomb sandwich panel from a plurality of honeycomb cores as input material, each honeycomb core having two opposing major surfaces, each major surface being located on each side of each honeycomb core, another aspect of the method comprising:

[0022] applying and laminating a first skin layer having a first 0° fiber reinforcement layer by thermoplastic welding, laminating the first skin layer on each major surface of each honeycomb core to form a laminar honeycomb core, the first 0° fiber reinforcement layer having fibers extending in a first machine direction,

[0023] cutting the layered honeycomb core to form first and second intermediate panels having continuous and straight edges,

[0024] trimming the opposing edges of the first intermediate panel and the second intermediate panel to expose the edge connections,

[0025] Rotate the first machine direction by 90° to obtain the second machine direction without rotating the middle panel,

[0026] The first intermediate panel is joined to the second intermediate panel in continuous production to form a joint of the first intermediate panel and the second intermediate panel, and a reinforcement is provided at the joint of the first intermediate panel and the second intermediate panel, wherein the reinforcement comprises one or more of the following:

[0027] overlapping or interpenetrating of the edges of adjacent intermediate panels, or using an adhesive layer or adhesive ring for gluing a first intermediate panel to a second intermediate panel at a butt joint, wherein a co-linear compressive force may optionally be applied to the edge connection of the first intermediate panel and the second intermediate panel or to complete the adhesive butt joint, and

[0028] A second skin layer having a second 0° fiber reinforcement is applied and laminated to the joined first and second intermediate panels by thermoplastic welding, and one second skin layer is laminated to each major surface of the first and second intermediate panels to form a laminated reinforced honeycomb core, wherein on each laminated reinforced honeycomb core, the fiber direction of the second skin layer is 90° relative to the fiber direction of the first skin layer.

[0029] An embodiment of the present invention provides an apparatus for continuously producing a laminated reinforced honeycomb sandwich panel from a plurality of honeycomb cores as input materials, each honeycomb core having two opposite main surfaces, each main surface being located on each side of each honeycomb core, the apparatus comprising:

[0030] a first conveyor for conveying an input material to a laminator in a first machine direction;

[0031] a storage device for storing a first skin layer as a first 0° fiber reinforcement layer;

[0032] a laminator for laminating a first skin layer by thermoplastic welding, one first skin layer being laminated on each major surface of each honeycomb core to form a layered honeycomb core, the first 0° fiber reinforcement layer having fibers extending in a first machine direction;

[0033] a cutting machine for cutting the layered honeycomb core to form a first intermediate panel and a second intermediate panel having continuous and straight edges;

[0034] a trimmer for trimming the opposing edges of the first intermediate panel and the second intermediate panel to expose the edge connection,

[0035] a second conveyor having a second machine direction at 90° to the first machine direction for receiving the laminar honeycomb core without rotating the laminar honeycomb core,

[0036] An apparatus for joining a first laminar honeycomb core to a second laminar honeycomb core in continuous production to form a joint of the first and second honeycomb cores, the first and second laminar honeycomb cores having reinforcement at the joint, the reinforcement at the joint comprising one or more of: overlapping or interpenetration of edges of adjacent intermediate panels, or using an adhesive layer or adhesive ring for gluing the first intermediate panel to the second intermediate panel at a butt joint, wherein a colinear compressive force may optionally be applied to the edge connection of the first intermediate panel and the second intermediate panel or to complete the adhesive butt joint;

[0037] a second reservoir for storing a second skin layer having a second 0° fiber reinforcement layer according to a second machine direction, applied on each face of each laminar honeycomb core, and

[0038] A second laminator is used to laminate a second skin layer by thermoplastic welding, one second skin layer being laminated on each major surface of each layered honeycomb core to form a layered honeycomb core, and a second 0° fiber reinforcement layer having fibers extending in a second machine direction.

[0039] For half of the cells along one edge of the middle panel or honeycomb core material, the top or bottom of the cell is preferably open, and for the other half of the cells along the opposite edge, the top or bottom is closed. This allows a trimming operation to be performed on each lateral edge of the reinforced honeycomb core or middle panel, so that the cell from one reinforced honeycomb core material or middle panel has an open top that can be cut in half and is joined to the cell from the adjacent reinforced honeycomb core or middle panel, the cell of which can be cut in half and has a closed top. These trimmed edges can be pushed together by a certain pressure. Applying the joint of the first 0° fiber reinforcement layer at the position where the honeycomb core materials penetrate each other can increase the local core density of the joint and significantly improve the support of the external 90° UD layer at this critical position.

[0040] An embodiment of the present invention provides a reinforced honeycomb sandwich panel, comprising

[0041] a) Honeycomb core, for example, a folded honeycomb core, such as Fig.14 as shown in .

[0042] b) applying a first skin layer with a first 0° fiber reinforcement on both sides of the honeycomb core by lamination (e.g. thermoplastic welding) to form a honeycomb core sheet, the 0° direction being related to the fiber reinforcement, which is parallel to the first machine direction (ie production direction).

[0043] c) Butt joints or side-by-side positions of the honeycomb core edges, with 0° fiber reinforcement layers laminated above and below the edge joints or positions where the edges of the reinforcement layers are side-by-side or interpenetrating (e.g., a few millimeters). Optionally, joints with a small overlap of 0° fiber reinforced skin layers are also included within the scope of the invention,

[0044] d) A second skin layer with 90° second fiber reinforcement on both sides of the honeycomb core sheet applied to the 0° first fiber reinforced skin layer, one second skin layer is laminated on each major surface of the honeycomb core sheet to form another reinforced honeycomb core sandwich panel. The joint of the first UD 0° layer is arranged at the location where the edges of the honeycomb core sheet penetrate each other, providing reinforcement to the joint and resulting in a substantial improvement in the support of the outer 90° UD layer at this location.

[0045] Embodiments of the invention are defined in the expanded claims and are further developed by the further features of the appendix claims.

[0046] definition

[0047] "Honeycomb core" means an array of honeycomb cells forming a sheet, wherein the longitudinal axis of the cells is at 90° to the sheet. Such a honeycomb core may be formed as Fig.14 Manufactured as shown in .

[0048] "Honeycomb core stock" is a honeycomb core with layers (sometimes called skins) laminated on both sides.

[0049] A "mid-panel" is a honeycomb core sheet having its major surfaces laminated to a fiber reinforcement layer, such as provided by a UD tape, which may optionally have honeycomb on at least the edges, trimmed to provide a connection.

[0050] A "UD tape" is a fiber-reinforced thermoplastic material in film or sheet form that can be laminated (e.g., thermoplastically welded) to a honeycomb core or another fiber-reinforced thermoplastic material in film or sheet form. Such tapes are commercially available, for example:

[0051] https: / / thermoplasticcomposites.de / en / products / ud-tapes /

[0052] https: / / www.profol.de / ud-tape-proud / .

[0053] Tencate, California, offers a product called Cetex TC960 (formerly PMC / Baycomp PP) UD tape, which is a polypropylene-based thermoplastic unidirectional tape. This thermoplastic compound is designed for applications that require high impact resistance. The impact toughness of the fiberglass / polypropylene composite makes it ideal for truck bodies, vehicles and vehicle shells.

[0054] For example, the Saudi Arabian company Sabic also supplies belts commercially.

[0055] "0° fiber reinforced unidirectional tape" means a tape material reinforced by fibers extending along the tape. "90° fiber reinforced unidirectional tape" means an additional tape material reinforced by fibers extending along the tape, but the fibers applied to the tape are perpendicular to the fibers of the 0° fiber reinforced unidirectional tape. "Cross-ply" means a layer of 0° fiber reinforced unidirectional tape, wherein the fibers extend along the tape, and 90° fiber reinforced unidirectional tape is applied in such a way that the fibers of the 0° fiber reinforced unidirectional tape are at 90° to the fibers of the 90° fiber reinforced unidirectional tape.

[0056] BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 A sandwich panel with a cross-ply skin made of UD tapes according to one embodiment of the invention is shown.

[0058] Figure 2 Shown is a side view of a sandwich panel having a cross-ply skin made of UD tapes according to an embodiment of the invention.

[0059] Figure 3 A sandwich panel according to one embodiment of the invention is shown with an optional bonding film between the cross-ply skins and the core sheets.

[0060] Figure 4 A side view of a sandwich panel according to an embodiment of the present invention is shown, wherein the adhesive film is bonded to the core sheet.

[0061] Figure 5 A sandwich panel production process of double UD tape lamination according to an embodiment of the present invention is shown.

[0062] FIG. 6 shows a sandwich panel production process with two-time UD tape lamination and adhesive film according to an embodiment of the present invention.

[0063] Figure 7a A honeycomb core is shown that may be used with any embodiment of the present invention. Figure 7b and 7c The bonding of two honeycomb cores according to an embodiment of the present invention is shown. Figure 7b Two honeycomb cores with trimmed edges are shown, placed side by side. Figure 7c , two honeycomb cores overlapped according to an embodiment of the present invention are shown, such that the L cell wall at the left edge of one core sheet is located between the W cell walls on the right side of the adjacent core sheet and in the honeycomb cells.

[0064] Figure 8 On the left side is shown a 3D image of a honeycomb core according to an embodiment of the invention, wherein the left and right edges are trimmed.

[0065] Fig. 9 Two adjacent honeycomb cores are shown, overlapping to create an area of ​​greater core density at the join.

[0066] Fig.10 A side view of two honeycomb cores according to an embodiment of the present invention is shown, wherein the left and right edges are trimmed.

[0067] Fig.11 Shown is a side view of two adjacent honeycomb cores that overlap to create an area of ​​greater core density at the join, according to an embodiment of the present invention.

[0068] Fig.12A side view of two intermediate panels made of honeycomb core sheets with 0° UD tape layers on the honeycomb core sheets according to an embodiment of the present invention is shown. The 0° UD tape layers are laminated to the honeycomb core with a small offset (e.g., equal to one cell wall width a=c / √3 or half of the cell size c).

[0069] Fig.13 It shows how adjacent middle panels are placed together according to one embodiment of the present invention. The outer UD tape layer is the reinforcement provided by the UD tape layer, which is continuous on the connection of the middle panels.

[0070] Fig.14 A panoramic view of the manufacturing process of the folded honeycomb core used in the embodiment of the present invention is shown, and a 0° fiber reinforcement layer is laminated on each side of the finished honeycomb core.

[0071] Detailed Description of Illustrative Embodiments

[0072] Figure 1 A sandwich panel 10 is shown, which has upper (7, 8, 9) and lower (4, 5, 6) inner 0° fiber-reinforced unidirectional tapes (i.e. UD tapes) laminated or more preferably thermoplastically welded along the production direction W (e.g. W direction of a folded honeycomb core) of a continuously produced honeycomb core 1, 2, 3. The edges of the honeycomb core 1, 2, 3 are parallel to the edges of the upper inner and lower inner 0° UD tapes 4, 5, 6, 7, 8, 9. These inner 0° UD tapes 4, 5, 6, 7, 8, 9 have been cut in the length direction by cutting in the cross direction, together with the cutting of the honeycomb core 1, 2, 3. As shown in FIG. Figure 1 As shown in the figure, the inner 0° UD tapes 4, 5, 6, 7, 8, 9 are co-terminous with the honeycomb cores 1, 2, 3. The outer UD tape layers 10, 11 are continuous in the L direction and connect the honeycomb cores 1, 2, 3 and the inner 0° UD tape layers 4, 5, 6, 7, 8, 9 to a larger sandwich panel. In the L direction, there are mechanical weaknesses 12, 13 between a limited number of sections of the honeycomb cores 1, 2, 3.

[0073] The honeycomb core can be made of a single piece. The honeycomb core can consist of a thermoplastic polymer and / or a thermoplastic elastomeric polymer or of a thermoplastic polymer selected from the group consisting of polyolefins, in particular polyethylene or polypropylene, polyesters, in particular polyethylene terephthalate, polytrimethylene terephthalate, butylene terephthalate or polyolefin-1,2-furandicarboxylate, polyamides, in particular polyamide 6 or polyamide 6,6, polycarbonates, polyetherketones, polyetheretherketones, polyetherketoneketone polyethers, polyetheresters, polyphenylene sulfides, polyetherimides, copolymers thereof and mixtures thereof.

[0074] Figure 2 The stack-up and edges of the different layers of honeycomb sheets viewed from / along the W direction are shown.

[0075] In order to avoid or reduce the possibility of reduced shear performance due to interruptions or gaps (caused by cutting and joining) between the honeycomb cores 1 , 2 , 3 in the L direction, reinforcements 15 may be applied to all weak points 12 , 13 between the honeycomb cores 1 , 2 , 3 .

[0076] exist Figure 3 In the figure, reinforcement 15 is shown to be provided by a thermoplastic film 16, such as a thermoplastic adhesive film 17, which can apply an additional ring 18 between adjacent edges of the UD laminate cores 1, 2, 3 to ensure shear force transmission in the cores 1, 2, 3. The thermoplastic film 16 or adhesive film 17 can be applied over the entire length of the UD tape, i.e. the upper and / or lower UD tape, or the entire length between the UD tape and the honeycomb core, in the upper part and / or the lower part.

[0077] The reinforcement 15 may be a thermoplastic or thermosetting adhesive film (less preferred), or may be a thermoplastic coated metal, such as an aluminium layer, which can be bonded to the outer UD tape layer by, for example, induction heating of the aluminium layer.

[0078] Figure 3 It is shown how such reinforcement, such as an adhesive film 17, can sag naturally or be pushed between the spaced UD laminate cores 1, 2, 3, such as by pressure and heat, before the bonding process is completed.

[0079] Figure 4 An adhesive film ring 18 is shown extruded between the middle panels of the honeycomb core 1, 2, 3, allowing the cores 1, 2, 3 to bond to each other at a relatively low temperature and optionally to bond the outer UD tape layers 10, 11 to the middle panels.

[0080] Figure 5 A sandwich panel production process 30 and equipment thereof according to an embodiment of the present invention is illustrated.

[0081] The input 31 material may be a product of a co-linear honeycomb core production (e.g. Fig.14 ), preferably a continuous co-linear honeycomb core production, such as described and shown in WO2006 / 053407, which is incorporated herein by reference. For example, the input material 31 can be a honeycomb core 32 produced by this method, having an array of honeycomb cells 33 (e.g. rectangular, square or hexagonal cells). . The array can have columns 21, 22 and rows. Each polygonal cell 33 has lateral cell walls extending between the vertices of each polygonal cell 33, each polygonal cell 33 is bounded on both sides by a cover layer plane, and the lateral cell walls of each polygonal cell 33 are in the form of polygonal rings. Figure 7a The first column 21 in the example may be cells that are closed at the top, and the second column 22 may be cells that are open at the top. Figure 7aAs shown in FIG. 1 , the first columns 21 alternate with the second columns 22. Figure 7a In the embodiment of the present invention, one edge 23 of the polygonal core can be trimmed to have cells that are open at the top, while the polygonal core can be trimmed on the right edge 24 so that the cells are closed at the top. The honeycomb core can be trimmed longitudinally during the production of the continuously produced honeycomb core to produce suitable edge structures 23, 24 and edge connections 25, 26 to join two or more panels together using the edge connections 25, 26. Alternatively, trimming can be a method step of processing the honeycomb core 32 in the method 30.

[0082] Figure 7a This first trimmed honeycomb core 32 is schematically shown. At the edge with reference numeral 23, the cells have been trimmed so that they are open at the top and connections 25 are produced. Figure 7a Such a second trimmed honeycomb core is also shown, in which the cells have been trimmed at the edge with reference numeral 24 so that the cells are open at the top and connections 26 are produced.

[0083] Such a honeycomb core 32 will have a larger in-plane dimension compared to the cell size, for example, the cell size may be 3 mm to 10 mm, while the honeycomb core 32 may be 400 mm to 1200 mm wide and 2000 mm to 3000 mm long, for example.

[0084] Figure 7a , Figure 7b , Figure 7c A honeycomb core is shown, for example, a 12 mm thick honeycomb core with a smaller cell size, such as a 5 mm cell size. Honeycomb cores from different panels are placed side by side. This can result in small gaps between honeycomb core sheets, for example, because the cutting of the edges is sometimes not perfectly straight. Figure 7c , the honeycomb core sheets are shown penetrating each other.

[0085] return Figure 5The width 34 of the honeycomb core 32 produced by the co-linear honeycomb core production 31 is generally less than the desired width 35 of the final product. The final width 35 of the thermoplastic sandwich panel is obtained by cutting the honeycomb core 32 to a certain length and rotating the machine direction by 90°. To achieve this, the honeycomb core 32 is conveyed toward the laminator 38 (particularly the calibrator and laminator 39) by a conveyor (e.g., a belt conveyor or a crawler (not shown)). Heating (e.g., by infrared lamps) or cooling can be provided so that the honeycomb core 32 reaches the correct processing temperature before entering the laminator 38 or 39. The processing is continuous. Before reaching the laminator 38 or 39, the 0° UD tape 36 is unrolled from the roller and applied to the upper surface of the honeycomb core 32, optionally using temperature and / or pressure. At the same time, the 0° UD tape 37 can be unrolled from the roller and applied to the lower surface of the honeycomb core 32, optionally using temperature and / or pressure. The reinforcing fibers of the OD tapes 36 and 37 extend in the machine direction, that is, the machine direction is 0°. In the laminator 39, for example, the lamination of the UD tapes 36, 37 and the trimming of the edges 23 and 24 to form the edge connections 25 and 26 can be completed. The honeycomb core 32 can be trimmed longitudinally. Alternatively, the trimming can be a method step of processing the honeycomb core 31 in the method 30. The honeycomb core 31 can be trimmed longitudinally during the production of the continuously produced honeycomb core 32 to produce suitable edge structures 23, 24 and edge connections 25, 26. This allows two or more panels to be joined together using edge connections 25, 26. Alternatively, the trimming can be a method step of processing the honeycomb core 31 in the method 30. During processing in the laminator and trimmer 39 or before or after processing therein, the intermediate panel 42 with UD tapes on both sides (which is the output of the laminator and trimmer 47, 49) is cut to a certain length. The length is the length that produces the width 35 in the final product.

[0086] Then, the intermediate panel 42 is moved to a separate production line 50, which extends at 90° to the conveyor. By doing so, the machine direction has been moved through 90°, but the intermediate panel is not rotated.

[0087] The middle panel 42 comprises a honeycomb core 32, wherein the UD tapes 36, 37 are now applied in the cross direction of the new machine direction. The first panel 42 is now joined to the second identical panel 42 by placing the first and second panels side by side and placing the connections 25, 26 side by side, each connection being located in the panel 42. The connections 25, 26 are placed together to join the first and second panels together in the overlap region. The middle panel 42 is conveyed toward the second laminator 43 by a conveyor such as a belt conveyor or a crawler (not shown). The 0° UD tape 44 is unrolled from the drum and optionally applied to the upper surface of the middle panel 42 using temperature and / or pressure. At the same time, the 0° UD tape 45 is unrolled from the drum and optionally applied to the lower surface of the middle panel 42 using temperature and / or pressure. The reinforcing fibers of the OD tapes 44, 45 extend in the machine direction, i.e., the machine direction is 0°. The joined panels are then conveyed to the laminator 43, where the lamination of the UD tapes 44, 45 can be completed. The finished honeycomb sheet with multiple mid-panels 42 exits the laminator 43 where edge connections are completed and cross UD tape reinforcement is applied, with a width 35 greater than the width 34 of the honeycomb core 32, such as 50% greater or greater.

[0088] FIG6 illustrates another embodiment of a sandwich panel production method and equipment. Figure 5 Same as those described, except for the additional steps mentioned below. Figure 6a , the input material can be such as Figures 1 to 5 The same product 32 of the described collinear honeycomb core production 31. The width 34 of the honeycomb core 32 produced by the collinear honeycomb core production 31 is generally less than the desired width 35 of the final product. The apparatus, method and equipment of this embodiment process optional additional reinforcement layers, such as bonding layers, for example, low melting point thermoplastic adhesive films 16. These bonding layers can also be thermosetting adhesive films or thermoplastic adhesive films or thermoplastic coated aluminum layers, which can achieve bonding of the outer UD tape layer by induction heating. Figure 6a and 6b In Figure 3 As shown, reinforcement 15 is shown to be provided by a thermoplastic film 16, such as a thermoplastic adhesive film, which can apply an additional ring 18 between adjacent edges of the UD laminate core 1, 2, 3 to ensure the transmission of shear forces in the core 1, 2, 3. The thermoplastic film or adhesive film 16 can be applied over the entire length of the UD tape (i.e., the upper and / or lower UD tape), or between the UD tape and the honeycomb core, on the upper surface and / or on the lower surface.

[0089] The reinforcement 15 may be a thermoplastic or thermosetting adhesive film (less preferred), or may be a thermoplastic coated aluminium layer which can be bonded to the outer UD tape layer by, for example, induction heating of the aluminium layer.

[0090] Figure 6a It is shown how such a reinforcement, for example an adhesive film 17, may naturally sag or be pushed in between the still somewhat spaced-apart UD laminate cores 1, 2, 3 before completing, for example, a bonding process.

[0091] Figure 6a An adhesive film ring 18 is shown extruded between the middle panels of the honeycomb core 1 , 2 , 3 , allowing the cores 1 , 2 , 3 to bond to each other and optionally to bond the outer UD tape layers 10 , 11 to the middle panels 42 at relatively low temperatures.

[0092] Compared to sandwich panels laminated with woven thermoplastic composite skins or composite skins that have been laminated from 0° / 90° UD tape layers, the advantage is that in embodiments of the present invention, the thermoplastic welding or lamination of the inner UD tapes can be done in a fast and simple continuous process, consistent with the continuous production of the honeycomb core. This produces an intermediate panel with a single ply UD tape reinforced skin.

[0093] The width of the final sandwich panel can be achieved by a 90° rotation of the machine direction used to process the middle panel. The final width can be obtained by cutting the honeycomb core with UD reinforcement tapes to length. These tapes are applied to obtain the middle panel with a single-ply UD reinforcement skin. This reduces waste and results in cost advantages.

[0094] The final panel width is only limited by the width of the second laminator or thermoplastic welding machine. This allows the production of 2m to 3m wide panels with only a 400mm to 1200mm wide honeycomb core being produced as input.

[0095] Faster on-line production speeds of honeycomb cores are possible because less heat flow is required for alignment and lamination of the first skin layer. Less heat must pass through the thinner skin layer material (single ply) in order to reach the core for the core-skin bonding process by thermoplastic welding.

[0096] By placing several rolls of smaller width UD tapes next to each other in one or both of the first and second lamination steps, flexible use of variable tape widths and simple width modifications are possible. This results in cost advantages and makes the sourcing of UD tapes easier. In addition, the dependency on the availability of large width cross-ply production lines is reduced.

[0097] During the cross-ply production, the intermediate unwinding and rolling steps of the UD tape are unnecessary. The handling of the single-ply UD reinforced intermediate panel is easier compared to the separate handling of pre-cut 90° UD tape sheets in the production of cross-ply laminates. In addition, the proposed method enables to improve the surface quality of the final panel due to the lower lamination temperature of the second skin layer.

[0098] When joining core sheets to produce large-sized sandwich panels, a potential disadvantage is that the interruption of the core reduces the shear performance and skin support of the core, which can significantly reduce the mechanical properties of the final large-sized sandwich panel. The present invention avoids this reduction in mechanical properties by providing at least one device and preferably more than one device for reinforcement in or across the gap between the honeycomb core panels in the joint area. The reinforcement can be achieved by interlocking and / or overlapping the core layers and / or the interpenetration of the core edges. This can also be achieved by the colinear edge trimming of the two edges of the honeycomb core panel reinforced by the intermediate single-layer UD, consistent with the production of the honeycomb core that is optionally produced continuously. This trimming and preparation of the edges leads to an enhancement that includes an improved edge of the panel so that the plate can be better joined side by side by the overlap of the core sheets at the joint.

[0099] For high temperature thermoplastics, welding of the thermoplastic composite skin layers must be performed at temperatures >300°C, which does not allow the use of low-cost PTFE belt laminators. Sandwich panel production according to embodiments of the present invention allows the honeycomb core to be laminated or welded to the inner 0°-UD tape (e.g., with high temperature thermoplastics such as PEI / CF or PEEK / CF) via a small width steel belt laminator in line with high temperature thermoplastic honeycomb production. Then, a second outer layer of 0°-UD tape is applied with a low melting point thermoplastic adhesive via a large width PTFE tape laminator (after the machine direction of the honeycomb core with the first inner UD layer is rotated 90°).

[0100] For cost-effective sandwich panels consisting of polypropylene (PP), it is of interest to laminate the UD tapes in the outer layers in a second step at a lower temperature, since the surface quality is improved at a lower lamination temperature. The decorative surface layer can be laminated together with the second UD tape layer in the second lamination step at a lower temperature, which enables to maintain a high quality surface finish even if the decorative layer is made of the same polymer, which is desirable to enable recycling of the entire sandwich panel.

[0101] For large size sandwich panels, for example for side walls of truck trailers or for truck boxes, it is advantageous to produce the final large width panels locally and just in time in a cost effective process to reduce the transportation and storage costs of the sandwich panels.

[0102] The honeycomb core material according to an embodiment of the present invention has an array of polygonal cells (such as hexagonal, rectangular or square cells) having rows and columns. Each polygonal cell has a lateral cell wall extending between the vertices of each polygonal cell, each polygonal cell is bounded on both sides by a cover layer plane, and the lateral cell wall of each polygonal cell is in the form of a polygonal ring. Figure 7a The first column 21 in the example may be cells that are closed at the top, and the second column 22 may be cells that are open at the top. Figure 7a As shown in FIG. 1 , the first columns 21 alternate with the second columns 22. Figure 7a In one embodiment, one edge 23 of the core sheet may have cells that are open at the top, while the core sheet is trimmed on the right edge 24 so that the cells are closed at the top. The honeycomb core sheet may be trimmed longitudinally during the production of a continuously produced honeycomb core to produce a suitable edge structure to join two or more panels together using edge connections made with the trimmed honeycomb core having a first edge connection 25 and a second edge connection 26.

[0103] Figure 7a Such a trimmed honeycomb core sheet is schematically shown. On the edges 23, the cells have been trimmed so that the cells are open at the top and connections 25 are created.

[0104] Typically, such a core sheet will have larger in-plane dimensions compared to the cell dimensions, for example the cell dimensions may be 3 mm to 10 mm, whereas the core sheet may be 400 mm to 1200 mm wide and 2000 mm to 3000 mm long, for example.

[0105] Figure 7b and 7c The bonding of two honeycomb core sheets according to an embodiment of the present invention is shown. Figure 7b Two honeycomb core sheets with trimmed edges are shown placed side by side. Figure 7c , two honeycomb core sheets are shown with overlap, such that the L cell wall of the left edge of one core sheet is located between the right upper W cell walls of the adjacent core sheet and in the honeycomb cells.

[0106] This results in some interpenetration at the joint locations, which results in regions of higher core density, ie, in the overlap region of two adjacent honeycomb sheets.

[0107] Figure 8 A 3D image of a honeycomb core sheet according to the present invention is shown on the left, wherein the left and right edges are trimmed.

[0108] Fig. 9 Two adjacent honeycomb core sheets are shown, overlapping to create a region of greater core density.

[0109] Fig.10A side view of two honeycomb cores is shown, wherein the left and right edges of adjacent panels are trimmed according to the invention to provide edge connections. This creates the possibility that the two honeycomb cores can be pushed together to form an overlap. Each honeycomb core 32 is preferably formed by a plurality of polygonal cells arranged in an array, wherein each polygonal cell has lateral cell walls (shown as vertical lines), each polygonal cell being bounded on both sides by a cover layer plane, and the lateral cell walls of each polygonal cell forming a polygonal ring. Such cores and their manufacture are, for example, Fig.14 Shown in.

[0110] Fig.11 Shown as Figure 1 Shown is a side view of two adjacent cores 32 (eg, 1, 2, 3) which have been joined together by an overlap formed by a trimming step to form a limited area of ​​greater core density at the join and thus provide some reinforcement.

[0111] Fig.12 A side view of two intermediate panels with 0° UD tapes 36, 37 on a honeycomb core 32 is shown. The UD tape layers 36, 37 are laminated to the honeycomb core 32, whereby Fig.12 The top layer 36 on the left hand side and the bottom layer 37 on the right hand side are formed with a small offset, for example equal to one cell wall width a=c / √3 or half the cell dimension c. This provides further reinforcement at the joint between the two panels.

[0112] Fig.13 It shows how those adjacent middle panels are placed together. The outer UD tape layers 44, 45 are continuous over the connection of the middle panels. Underneath these layers are layers 36, 37. This provides further reinforcement at the joint between the two panels.

[0113] refer to Fig.14 , describes an example of honeycomb core manufacturing, such as a folded honeycomb core that can be used with any embodiment of the present invention. An advantage of this honeycomb is that it can be manufactured continuously. Some of the ends of the cells are open. Fig.14 The use of a flat sheet or web made of a plastically deformable material is shown. The plastically deformable material may be a thermoplastic polymer material, or a fiber composite material, or the like, wherein the sheet consists of a thermoplastic polymer and / or a thermoplastic elastomeric polymer or of a thermoplastic polymer selected from the group consisting of polyolefins, in particular polyethylene or polypropylene, polyesters, in particular polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate or polyethylene-1,2-furandicarboxylate, polyamides, in particular polyamide 6 or polyamide 6,6, polycarbonates, polyetherketones, polyetheretherketones, polyetherketoneketones, polyethers, polyetheresters, polyphenylene sulfides, polyetherimides, copolymers thereof and mixtures thereof.

[0114] According to this embodiment, a flat web or sheet has plastic deformations 101, 102 formed therein that are mainly perpendicular to the web of the material. In regions 101 and 102, the material is deformed from the plane of the web, such as polygonal, such as trapezoidal, or sinusoidal, or arcuate, etc. These deformations form ridges 108 and valleys 109, whereby each of these ridges and valleys is not continuous. For example, the ridges are composed of a linear series of deformation segments 101, 102, such as polygonal, such as trapezoidal, or sinusoidal, or arcuate segments, etc. Preferably, the ridges have a top surface that can be initially (e.g., as formed) parallel to the plane of the web of the material. When the 3D structure is rotated (also called "folded") to form a honeycomb unit, two such surfaces will abut each other.

[0115] The production direction is preferably as follows Fig.14 As shown in , however, directions perpendicular thereto (parallel to axes 105 and 106) may also be used.

[0116] The regions 101 and 102 are preferably formed to be inclined, i.e. rotated towards each other about axes 105 and / or 106 to form additionally U-shaped or V-shaped connecting regions 103 and 104. The connecting regions 103 and 104 separate the ridge segments 101, 102, for example polygonal (e.g. trapezoidal) or sinusoidal or arcuate segments etc. in a row of regions 101, 102. One connecting region 103, 104 is placed between two ridge segments 101, 102 and the connecting regions 103 alternate with the connecting regions 104 along the row of regions 101, 102. The connecting regions 103, 104 form cross valleys, i.e. perpendicular to the valleys 109. Adjacent cross valleys are on opposite sides of the web material. The rotation of the ridge segments 101, 102 to bring them to Fig.14 The initial position of the web is preferably performed while the deformation is placed in the material web. The web material is stretched at the transition between the ridge segments 101 and 102 to form connection areas 103 and 104, which are substantially perpendicular to the outer surfaces of the ridge segments 101 and 102. The angle between the connection areas 103, 104 on the different ridge segments allows a part of the tool to enter and thus form these segments. In the direction of its width, the material web can change its dimensions in the direction of the axis 105 and the axis 106, while the length of the material web does not change in dimension in the production direction.

[0117] The deformation of the web or sheet material in the areas 101 and 102 serves the purpose of forming three-dimensional shapes which form the walls of the cell halves in the folded final product. The cells thus formed are structural and load-bearing elements of the folded honeycomb core, whose walls extend transversely to the longitudinal direction of the folded final product. The cells formed by folding are preferably cylindrical in cross section, the axis of the cylinder extending transversely to the longitudinal direction of the folded final product and in the thickness direction of the finally produced planar honeycomb core. The basic cross-sectional shape of the cell can be chosen as desired, for example circular or polygonal, in particular even-numbered polygons, such as hexagons. The final cell shape is determined by the shape of the deformed ridge segments 101, 102 in the initial web and how they are folded together. As Fig.14 As schematically shown on the right-hand side, when the web is fully folded, each unit is formed by two half units. These units are arranged in rows. Each final unit is formed by the bottom and side of two longitudinally adjacent (in the sheet or web material) valley segments 109. These half units are preferably connected together across the contact surface of the ridge segments 108 from two longitudinally adjacent (in the web material). Therefore, a folded honeycomb structure is provided, which is formed by a plurality of units arranged in rows, and the unit has the following characteristics: these units have lateral cell walls that are adjacent to each other in the form of rings and are defined by the two open sides of the cover layer plane toward the unit, whereby each unit is bridged or completely closed in one or the other of the cover layer planes. The folded honeycomb structure can be formed by a substantially uncut flat web, that is, a continuous sheet that is not porous. The sheet can be extruded. The plastic deformation of the sheet forms a 3D structure. Thus, the folded honeycomb structure comprises a plurality of 3D structures, such as polygonal, sinusoidal or arcuate regions (101 and 102) formed by plastic deformation and connection regions (103 and 104) in the plane of the covering layer produced by plastic deformation. At least a portion of the adjacent cell walls is preferably fully or partially permanently connected to each other, for example by glue or bonding or welding. After the above-described manufacturing process, the honeycomb core 32 is conveyed toward a laminator 38 (in particular a calibrator and a laminator 39) by a conveyor, such as a belt conveyor or a crawler (not shown). - See Figure 5 and Figure 6. The 0° UD tape 36 is unwound from a roll and applied to the upper surface of the honeycomb core 32, optionally using temperature and / or pressure.

[0118] The present invention includes a final foldable product having a mixture of units of different sizes or shapes.

[0119] An important improvement in the performance of sandwich panels is the support of the skin by the honeycomb core. Small areas of higher core density at the joints of the intermediate panels including the honeycomb core ensure that the final large-scale sandwich panel has no weak points at the connection between the panels.

[0120] The edge of the panel can be cut with a bevel, but with a trim knife for a standard edge, it is easier to cut the panel straight, with the core and skin cut at the same position across the width. The small offset of no 0° UD tape layer on the honeycomb core is preferably caused by an offset during the lamination process. Alternatively, a small strip of UD tape is removed after the UD tape has been laminated and the complete panel edge has been trimmed.

[0121] The aim is to ensure that there is slightly more skin material and especially slightly more core material to better support the outer 0° UD tape layers and therefore create better mechanical properties at the panel connections.

[0122] As opposed to honeycomb core materials that overlap at the joints between the middle panels when the panels are pushed together, because the UD tapes do not have much in-plane tensile strength in the direction transverse to the UD fiber orientation (in the 90° direction of panel connection), in order to avoid positioning of the UD tapes and additional trimming of the UD tapes to create an offset, pushing the UD tape layers together and creating an overlap is also an option.

[0123] One edge of the honeycomb core sheet is cut at the end of the L-shaped cell wall, and the other edge of the honeycomb core sheet is cut at the beginning of the L-shaped cell wall.

[0124] At the location where the edges of two honeycomb core sheets penetrate each other, for example up to a few millimeters, the density of the honeycomb core is higher, for example twice as high, than anywhere else in the honeycomb core. The amount of penetration can be, for example, up to one cell wall length (a=cell size / √3) without deformation of the cell, which leads to a significant improvement in the core compressive strength and core shear resistance, and thus increases the local bending strength of the panel. In addition to the production advantages of the present invention, having a joint of the first 0° UD layer at the location where the honeycomb core sheets penetrate each other leads to a significant improvement in the support of the outer 90° UD layer at this critical location.

[0125] Further features of the invention are disclosed in the following aspects of the invention, each of which is an embodiment of the invention:

[0126] A first aspect of a method for continuously producing a laminated reinforced honeycomb sandwich panel from a plurality of honeycomb cores as input material, each honeycomb core having two opposing major surfaces, one major surface being located on each side of each honeycomb core, another aspect of the method comprising:

[0127] applying and laminating a first skin layer having a first 0° fiber reinforcement layer by thermoplastic welding, laminating the first skin layer on each major surface of each honeycomb core to form a laminar honeycomb core, the first 0° fiber reinforcement layer having fibers extending in a first machine direction,

[0128] cutting the layered honeycomb core to form first and second intermediate panels having continuous and straight edges,

[0129] trimming the opposing edges of the first intermediate panel and the second intermediate panel to expose the edge connections,

[0130] Rotate the first machine direction by 90° to obtain the second machine direction without rotating the middle panel,

[0131] The first intermediate panel is joined to the second intermediate panel in continuous production to form a joint of the first intermediate panel and the second intermediate panel, and a reinforcement is provided at the joint of the first intermediate panel and the second intermediate panel, wherein the reinforcement comprises one or more of the following:

[0132] overlapping or interpenetrating of the edges of adjacent intermediate panels, or using an adhesive layer or adhesive ring for gluing a first intermediate panel to a second intermediate panel at a butt joint, wherein a co-linear compressive force may optionally be applied to the edge connection of the first intermediate panel and the second intermediate panel or to complete the adhesive butt joint, and

[0133] A second skin layer having a second 0° fiber reinforcement is applied and laminated to the joined first and second intermediate panels by thermoplastic welding, and a second skin layer is laminated to each major surface of the first and second intermediate panels to form a laminated reinforced honeycomb core, wherein on each laminated reinforced honeycomb core, the fiber direction of the second skin layer is 90° relative to the fiber direction of the first skin layer.

[0134] 2. Another aspect of the method according to aspect 1, wherein trimming of the opposing edges to expose edge connections is performed before the cutting step, after the cutting step, or simultaneously with the cutting step.

[0135] 3. Another aspect of the method according to aspect 1 or 2, wherein the honeycomb core has polygonal cells in an array, the polygonal cells having cell walls having a cell wall length between the vertices of the polygons, and the edge connections of the first intermediate panel and the second intermediate panel interpenetrate up to one cell wall length.

[0136] 4.4. The method according to any of the preceding aspects, further comprising joining the first 0° fiber reinforcement layer at locations where adjacent intermediate panels interpenetrate each other.

[0137] 5. Another aspect of the method according to aspect 3 or 4, wherein for half of the polygonal cells along one edge, the top or bottom of the cell is open, and for the other half of the cells along the opposite edge, the top or bottom is closed.

[0138] 6. Another aspect of the method according to aspect 5, wherein on the edge of the reinforced honeycomb core, a trimming operation is performed so that a cell from one reinforced honeycomb core has an open top and is cut in half and is joined with a cell from an adjacent reinforced honeycomb core that is cut in half and has a closed top.

[0139] 7.7. The method according to any of the preceding aspects, wherein the honeycomb core is a folded honeycomb core.

[0140] 8. Another aspect of the method according to any of the preceding aspects, wherein the honeycomb core is made of a sheet consisting of a thermoplastic polymer and / or a thermoplastic elastomeric polymer, or consisting of a thermoplastic polymer selected from the group consisting of polyolefins, in particular polyethylene or polypropylene, polyesters, in particular polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate or polyolefin-1,2-furandicarboxylate, polyamides, in particular polyamide 6 or polyamide 6,6, polycarbonates, polyetherketones, polyetheretherketones, polyetherketoneketone polyethers, polyetheresters, polyphenylene sulfides, polyetherimides, copolymers and mixtures thereof.

[0141] 9. The method of aspect 8, wherein the thermoplastic polymer sheet or thermoplastic elastomeric polymer sheet is joined or laminated to each honeycomb core by thermoplastic welding.

[0142] 10. Another aspect of the method according to any preceding aspect, wherein a further reinforcement is applied to the joint between the honeycomb cores.

[0143] 11. Another aspect of the method according to aspect 10, wherein the further reinforcement is provided by applying an additional ring of thermoplastic film or thermoplastic adhesive film between adjacent edges of the laminated honeycomb core.

[0144] 12. Another aspect of the method according to aspect 10 or 11, wherein the further reinforcement is a means for ensuring the transmission of shear forces into the honeycomb core.

[0145] 13. The method according to any one of aspects 10 to 12, wherein the further reinforcement is a thermoplastic film or a thermosetting adhesive film or a thermoplastic-coated aluminum layer that allows induction heating of the aluminum layer.

[0146] 14. The method according to any one of aspects 11 to 13, wherein the further reinforcement is sagged between the honeycomb cores, optionally by pressure and heat, prior to completing the bonding process.

[0147] Aspect 15. A reinforced honeycomb sandwich panel, comprising: a plurality of honeycomb core sheets, the honeycomb core sheets having edges and having a first core density;

[0148] a first skin layer having 0° fiber reinforcement laminated on both sides of each of a plurality of honeycomb core sheets to form a laminated reinforced honeycomb core sheet;

[0149] A butt joint, wherein the butt joint is in a side-by-side position of the edges of the laminated reinforced honeycomb core sheets, between the edges of the respective laminated reinforced honeycomb core sheets, so that the edges overlap or penetrate or deform each other to form an area of ​​a second core density at the connection of the laminated reinforced honeycomb core to the first skin layer, the second core density being higher than the first core density, and having a 0° fiber reinforcement layer above and below the position where the edges of the honeycomb core are joined;

[0150] The second skin layer has 90° fiber reinforcement layers on both sides of the laminated reinforced honeycomb core above and below the 0° fiber reinforcement layer to form a laminated reinforced honeycomb sandwich panel.

[0151] 16. Another aspect of the panel according to aspect 15, wherein the honeycomb core material has polygonal cells in an array form, the polygonal cells having cell walls with a cell wall length between the vertices of the polygons, and the interpenetration of the edge connection portions of the first middle panel and the second middle panel of the honeycomb core material is up to one cell wall length.

[0152] 17. Another aspect of the panel according to aspect 15 or 16, further comprising a joint having a first 0° fiber reinforcement layer at a location where adjacent honeycomb core sheet intermediate panels interpenetrate each other.

[0153] 18. Another aspect of the panel according to aspects 16 or 17, wherein for half of the polygonal cells along one edge, the top or bottom of the cell is open, and for the other half of the cells along the opposite edge, the top or bottom is closed.

[0154] 19. Another aspect of the panel according to aspect 18, wherein on the edge of the laminated reinforced honeycomb core material, cells from one reinforced honeycomb core material have an open top and are cut in half, and these cells are joined with cells from an adjacent reinforced honeycomb core material that are cut in half and have a closed top.

[0155] 20. Another aspect of the panel according to any one of aspects 15 to 19, wherein the honeycomb core is a folded honeycomb core.

[0156] 21. Another aspect of the panel according to any one of aspects 15 to 20, wherein the honeycomb core is made of a sheet consisting of a thermoplastic polymer and / or a thermoplastic elastomeric polymer, or consisting of a thermoplastic polymer selected from the group consisting of polyolefins, in particular polyethylene or polypropylene, polyesters, in particular polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate or polyolefin-1,2-furandicarboxylate, polyamides, in particular polyamide 6 or polyamide 6,6, polycarbonates, polyetherketones, polyetheretherketones, polyetherketoneketone polyethers, polyetheresters, polyphenylene sulfides, polyetherimides, copolymers and mixtures thereof.

[0157] 22. The panel of aspect 21, wherein the thermoplastic polymer sheet or thermoplastic elastomeric polymer sheet is joined or laminated to each honeycomb core by thermoplastic welding.

[0158] 23. Another aspect of the panel according to any one of aspects 15 to 22, wherein a further reinforcement is applied to the joints between the honeycomb cores.

[0159] 24. Another aspect of the panel according to aspect 23, wherein the further reinforcement is provided by a thermoplastic film or a thermoplastic adhesive film having an additional ring between adjacent edges of the laminated honeycomb core.

[0160] 25. Another aspect of the panel according to aspect 23 or 24, wherein the further reinforcement is a means for ensuring the transfer of shear forces into the honeycomb core.

[0161] 26. A panel according to any one of aspects 23 to 25, wherein the further reinforcement is a thermoplastic film or a thermosetting adhesive film or a thermoplastic coated aluminium layer that allows induction heating of the aluminium layer.

[0162] 27. A panel according to any one of aspects 24 to 26, wherein the further reinforcement is sagged between the honeycomb core, optionally by pressure and heat, prior to completing the bonding process.

[0163] Aspect 28. An apparatus for continuously producing laminated reinforced honeycomb sandwich panels from a plurality of honeycomb cores as input material, each honeycomb core having two opposing major surfaces, one major surface being located on each side of each honeycomb core, another aspect of the apparatus comprising:

[0164] a first conveyor for conveying an input material to the laminating machine in a first machine direction,

[0165] a storage device for storing a first skin layer as a first 0° fiber reinforced layer,

[0166] a laminating machine for laminating a first skin layer by thermoplastic welding, one first skin layer being laminated on each major surface of each honeycomb core to form a layered honeycomb core, the first 0° fiber reinforcement layer having fibers extending in a first machine direction,

[0167] A cutting machine for cutting the layered honeycomb core to form a first intermediate panel and a second intermediate panel having continuous and straight edges,

[0168] a trimmer for trimming the opposing edges of the first intermediate panel and the second intermediate panel to expose the edge connection,

[0169] a second conveyor having a second machine direction at 90° to the first machine direction for receiving the laminar honeycomb core without rotating the laminar honeycomb core,

[0170] An apparatus for connecting a first laminar honeycomb core to a second laminar honeycomb core in continuous production to form a joint of the first and second honeycomb cores, the first and second laminar honeycomb cores having reinforcement at the joint, the reinforcement at the joint comprising one or more of the following: overlapping or interpenetration of edges of adjacent intermediate panels, or using an adhesive layer or adhesive ring for gluing the first intermediate panel to the second intermediate panel at a butt joint, wherein a colinear compressive force may optionally be applied to the edge connections of the first intermediate panel and the second intermediate panel or a butt joint may be bonded,

[0171] a second reservoir for storing a second skin layer having a second 0° fiber reinforcement layer according to a second machine direction, applied on each face of each laminar honeycomb core, and

[0172] A second laminator for laminating a second skin layer by thermoplastic welding, one second skin layer being laminated on each major surface of each laminar honeycomb core to form the laminar honeycomb core, the second 0° fiber reinforcement layer having fibers extending in a second machine direction.

[0173] 29. Another aspect of the apparatus according to aspect 28, wherein the trimmer is configured to trim the opposing edges to expose the edge connection, the trimming being performed before the cutter, after the cutter, or simultaneously with the cutter.

[0174] 30. Another aspect of the apparatus according to aspect 28 or 29, wherein the honeycomb core has polygonal cells in an array, the polygonal cells having cell walls having a cell wall length between vertices of the polygon, and the edge connections of the first intermediate panel and the second intermediate panel interpenetrate up to one cell wall length.

[0175] 31. Another aspect of the apparatus of any one of aspects 28 to 30, wherein the trimmer is configured to perform a trimming operation such that cells from an edge of one honeycomb core have an open top and are cut in half and are joined to cells from an adjacent reinforced honeycomb core and wherein the cells are cut in half and have a closed top on the edge of the reinforced honeycomb core.

[0176] 32. Another aspect of the apparatus according to any one of aspects 28 to 31, wherein the other aspect of the apparatus is configured to manufacture a folded honeycomb core.

[0177] 33. Apparatus for the continuous production of laminated reinforced honeycomb sandwich panels, the apparatus being configured to carry out any of the methods of aspects 1 to 14.

Claims

1. A reinforced honeycomb sandwich panel, comprising: a plurality of honeycomb core sheets having edges and a first core density; a first skin layer having 0° fiber reinforcement laminated on both sides of each of the plurality of honeycomb core sheets to form a laminated reinforced honeycomb core sheet; a butt joint, wherein the butt joint is in a side-by-side position of the edges of the laminated reinforced honeycomb core sheet, between the edges of the corresponding laminated reinforced honeycomb core sheet, so that the edges overlap or penetrate or deform each other to form an area of ​​a second core density at the connection between the laminated reinforced honeycomb core and the first skin layer, the second core density is higher than the first core density, and the first skin layer has a 0° fiber reinforcement layer above and below the position where the edges of the honeycomb core are joined, A second skin layer having 90° fiber reinforcement layers on both sides of the laminated reinforced honeycomb core on the 0° fiber reinforcement layer to form a laminated reinforced honeycomb sandwich panel.

2. The panel according to claim 1, characterized in that The honeycomb core sheet has polygonal cells in an array having cell walls having a cell wall length between vertices of the polygon, and the edge connections of the honeycomb core sheet interpenetrate up to one cell wall length.

3. The panel according to claim 1 or 2, characterized in that: The invention also includes a joint portion, wherein the joint portion has the first 0° fiber reinforcement layer at a position where adjacent honeycomb core sheets interpenetrate each other.

4. The panel according to claim 2 or 3, characterized in that: For half of the polygonal unit along one edge, the top or bottom of the unit is open, and for the other half of the unit along the opposite edge, the top or bottom is closed, or wherein on the edge of the laminated reinforced honeycomb core material, the unit from one reinforced honeycomb core material has an open top and is cut in half and joined to a unit from an adjacent reinforced honeycomb core material that has a closed top and is cut in half.

5. A panel as claimed in any one of the preceding claims, characterised in that The honeycomb core is a folded honeycomb core.

6. A panel as claimed in any one of the preceding claims, characterised in that The honeycomb core is made of a sheet material, and the sheet material is composed of a thermoplastic polymer and / or a thermoplastic elastic polymer.

7. A panel as claimed in any one of the preceding claims, characterised in that The honeycomb core is made of a sheet consisting of a thermoplastic polymer selected from the group consisting of polyolefins, in particular polyethylene or polypropylene, polyesters, in particular polyethylene terephthalate, polytrimethylene terephthalate, butylene terephthalate or polyolefin-1,2-furandicarboxylate, polyamides, in particular polyamide 6 or polyamide 6,6, polycarbonates, polyetherketones, polyetheretherketones, polyetherketoneketone polyethers, polyetheresters, polyphenylene sulfides, polyetherimides, copolymers and mixtures thereof.

8. The panel according to claim 6 or 7, characterized in that A sheet of thermoplastic polymer or a sheet of thermoplastic elastomeric polymer is joined or laminated to each honeycomb core by thermoplastic welding.

9. A panel as claimed in any one of the preceding claims, characterised in that A further reinforcement is applied to the joints between the honeycomb cores.

10. The panel according to claim 9, characterized in that The further reinforcement is provided by a thermoplastic film or a thermoplastic adhesive film having an additional ring between adjacent edges of the honeycomb core, or wherein the further reinforcement is a device for ensuring the transmission of shear forces in the honeycomb core, or wherein the further reinforcement is a thermoplastic film or a thermosetting adhesive film or a thermoplastic coated aluminum layer allowing inductive heating of the aluminum layer, or The further reinforcement may optionally be sagged between the honeycomb cores by pressure and heat before completing the bonding process.

11. An apparatus for continuously producing laminated reinforced honeycomb sandwich panels from a plurality of honeycomb cores as input material, each of said honeycomb cores having two opposite major surfaces, one major surface being located on each side of each of said honeycomb cores, said apparatus comprising: a first conveyor for conveying the input material to the laminator in a first machine direction, a storage device for storing a first skin layer as a first 0° fiber reinforced layer, a laminator for laminating the first skin layer by thermoplastic welding, one first skin layer being laminated on each major surface of each of the honeycomb cores to form a layered honeycomb core, the first 0° fiber reinforcement layer having fibers extending in a first machine direction, a cutting machine for cutting the layered honeycomb core to form a first intermediate panel and a second intermediate panel having continuous and straight edges, a trimmer for trimming the opposing edges of the first intermediate panel and the second intermediate panel to expose edge connections, a second conveyor having a second machine direction at 90° to the first machine direction for receiving the laminar honeycomb core without rotating the laminar honeycomb core, An apparatus for joining a first laminar honeycomb core to a second laminar honeycomb core in continuous production to form a joint of the first honeycomb core and the second honeycomb core, the first laminar honeycomb core and the second laminar honeycomb core having reinforcement at the joint, the reinforcement at the joint comprising one or more of the following: overlapping or interpenetration of edges of adjacent intermediate panels, or using adhesive layers or adhesive rings for gluing the first intermediate panel to the second intermediate panel at a butt joint, wherein a collinear compressive force may optionally be applied to the edge connection of the first intermediate panel and the second intermediate panel or a bonded butt joint is completed, a second reservoir for storing a second skin layer having a second 0° fiber reinforcement layer according to the second machine direction applied on each face of each of the laminar honeycomb cores, and A second laminator is used to laminate the second skin layer by thermoplastic welding, one second skin layer is laminated on each major surface of each of the layered honeycomb cores to form a layered honeycomb core, and the second 0° fiber reinforcement layer has fibers extending in the second machine direction.

12. The apparatus according to claim 11, characterized in that The trimmer is configured to trim the opposing edges to expose edge connections, the trimming being performed before, after, or simultaneously with the cutter.

13. The apparatus according to claim 11 or 12, characterized in that The honeycomb core has polygonal cells in an array having cell walls having a cell wall length between vertices of the polygon, and the edge connections of the first and second intermediate panels interpenetrate up to one cell wall length.

14. The apparatus according to any one of claims 11 to 13, characterized in that The trimmer is configured to perform a trimming operation such that cells from an edge of one honeycomb core have open tops and are cut in half and are joined with cells from an adjacent reinforced honeycomb core on the edge of the reinforced honeycomb core that are cut in half and have closed tops.

15. The apparatus according to any one of claims 11 to 14, characterized in that The apparatus is configured to manufacture a folded honeycomb core.

16. Apparatus for the continuous production of laminated reinforced honeycomb sandwich panels, the apparatus being configured to carry out any of the methods of claims 17 to 27.

17. A method for continuously producing laminated reinforced honeycomb sandwich panels from a plurality of honeycomb cores as input material, each of said honeycomb cores having two opposing major surfaces, one major surface being located on each side of each of said honeycomb cores, said method comprising: - applying and laminating by thermoplastic welding a first skin layer having a first 0° fiber reinforcement layer having fibers extending in a first machine direction, said first skin layer being laminated on each major surface of each of said honeycomb cores to form a laminar honeycomb core, - cutting the laminar honeycomb core to form a first intermediate panel and a second intermediate panel having continuous and straight edges, - trimming the opposing edges of the first intermediate panel and the second intermediate panel to expose the edge connections, - rotating the first machine direction by 90° to obtain a second machine direction without rotating the intermediate panel, - joining the first intermediate panel to the second intermediate panel in continuous production to form a junction of the first intermediate panel and the second intermediate panel, with a reinforcement at the junction of the first intermediate panel and the second intermediate panel, the reinforcement comprising one or more of the following: overlapping or interpenetrating of the edges of adjacent intermediate panels, or using an adhesive layer or adhesive ring for gluing the first intermediate panel to the second intermediate panel at a butt joint, wherein a co-linear compressive force may be optionally applied to the edge connection of the first intermediate panel and the second intermediate panel or to complete the adhesive butt joint, and A second skin layer having a second 0° fiber reinforcement is applied and laminated to the joined first and second intermediate panels by thermoplastic welding, and a second skin layer is laminated to each major surface of the first and second intermediate panels to form a laminated reinforced honeycomb core, wherein on each laminated reinforced honeycomb core, the fiber direction of the second skin layer is 90° relative to the fiber direction of the first skin layer.

18. The method according to claim 17, characterized in that Trimming of the opposing edges to expose edge connections is performed before the cutting step, after the cutting step, or simultaneously with the cutting step.

19. The method according to claim 17 or 18, characterized in that The honeycomb core has polygonal cells in an array having cell walls having a cell wall length between vertices of the polygon, and the edge connections of the first and second intermediate panels interpenetrate up to one cell wall length.

20. The method according to any one of claims 17 to 19, characterized in that Also included is joining the first 0° fiber reinforcement layer at locations where adjacent intermediate panels interpenetrate each other.

21. The method according to claim 19 or 20, characterized in that For half of the polygonal cell along one edge, the top or bottom of the cell is open and for the other half of the cell along the opposite edge, the top or bottom is closed.

22. The method according to claim 21, characterized in that On the edges of the reinforced honeycomb cores, a trimming operation is performed so that a cell from one reinforced honeycomb core having an open top and cut in half is joined to a cell from an adjacent reinforced honeycomb core cut in half having a closed top.

23. The method according to any one of claims 17 to 22, characterized in that The honeycomb core is a folded honeycomb core.

24. The method according to any one of claims 17 to 23, characterized in that The honeycomb core is made of a sheet material consisting of a thermoplastic polymer and / or a thermoplastic elastomeric polymer, or consisting of a thermoplastic polymer selected from the group consisting of polyolefins, in particular polyethylene or polypropylene, polyesters, in particular polyethylene terephthalate, polytrimethylene terephthalate, butylene terephthalate or polyolefin-1,2-furandicarboxylate, polyamides, in particular polyamide 6 or polyamide 6,6, polycarbonates, polyetherketones, polyetheretherketones, polyetherketoneketone polyethers, polyetheresters, polyphenylene sulfides, polyetherimides, copolymers and mixtures thereof.

25. The method of claim 24, wherein: A sheet of thermoplastic polymer or a sheet of thermoplastic elastomeric polymer is joined or laminated to each honeycomb core by thermoplastic welding.

26. The method according to any one of claims 17 to 25, characterized in that A further reinforcement is applied to the joints between the honeycomb cores.

27. The method of claim 26, wherein: The further reinforcement is provided by a thermoplastic film or a thermoplastic adhesive film which is applied with an additional ring between adjacent edges of the honeycomb core, or wherein the further reinforcement is a device for ensuring the transmission of shear forces in the honeycomb core, or wherein the further reinforcement is a thermoplastic film or a thermosetting adhesive film or a thermoplastic coated aluminum layer allowing inductive heating of the aluminum layer, or The further reinforcement may optionally be sagged between the honeycomb cores by pressure and heat before completing the bonding process.

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