Patent Publication Number: US-2021179199-A1

Title: Composite panel and method for forming the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority under 35 U.S.C. § 119 to U.S. Provisional Patent Application No. 62/947,926, filed Dec. 13, 2019, the entire contents of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     Many storage containers, such as mobile storage containers for box or van-type trailers, include side walls and a roof assembly formed by multiple panel members coupled together. The panel members can be made from various types of materials in different configurations. 
     SUMMARY 
     Some embodiments of the invention can provide a panel for use on a trailer. The panel can include a panel member core with a length and can including a first segment of thermoplastic foam extending the length and a second segment of thermoplastic foam extending the length adjacent the first segment. The first segment can have a first density and the second segment can have a second density. The first density can be greater than the second density. A sheet can extend over the first and second segments and a can be laminated to the panel member core. The panel member core can be formed by extrusion. 
     Other embodiments of the invention can provide a method of forming a panel for use on a trailer. The method can include extruding a panel member core of thermoplastic foam with a first region that can have a first density and a second region, adjacent the first region, that can have a second density. The second density can be less than the first density. The panel member core can be cut at a predetermined length. A sheet can extend over the first and second regions and can be laminated to the panel member core. 
     Other embodiments of the invention can provide a method for forming a panel member core with a length for a panel that can be used in a trailer. The method can include extruding a first region, a second region, a third region, a fourth region, and a fifth to extend along the length in parallel. The first, third, and fifth region can be configured to have a greater density than the second region and the fourth region. The extruded first, second, third, fourth, and fifth regions can be cut to the length. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of embodiments of the invention: 
         FIG. 1  is an isometric view of a trailer with panels; 
         FIG. 2  is a cross-sectional view of a panel shown on the trailer of  FIG. 1 ; 
         FIG. 3  is an isometric view of a first example of a panel member core being formed having areas of various densities; 
         FIG. 4  is an isometric view of the panel member core formed from the process of  FIG. 3 ; 
         FIGS. 5-5B  are isometric views of a second example of a panel member core being formed having areas of various densities; 
         FIG. 6  is an isometric view of the panel member core formed from the process of  FIG. 4 ; and 
         FIG. 7  is an isometric view of a third example of a panel member core being formed having areas of various densities. 
     
    
    
     DETAILED DESCRIPTION 
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
     The following discussion is presented to enable a person skilled in the art to make and use embodiments of the invention. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein can be applied to other embodiments and applications without departing from embodiments of the invention. Thus, embodiments of the invention are not intended to be limited to embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the invention. Skilled artisans will recognize the examples provided herein have many useful alternatives and fall within the scope of embodiments of the invention. 
     For the purposes of promoting an understanding of the principles of the invention, reference will now be made to illustrative embodiments shown in the attached drawings and specific language will be used to describe the same. Some of the discussion below describes a laminated panel member core that can be sandwiched between sheets formed from metal, plastic, reinforced plastic, or high modulus materials such as carbon fiber or aramid fiber. The context and particulars of this discussion are presented as examples only. For example, embodiments of the disclosed invention can be configured in various ways, including with other shapes and arrangements of elements. Similarly, while the concepts of this disclosure are described in relation to a truck trailer, it will be understood that they are equally applicable to other mobile or stationary storage enclosures or containers, as well as refrigerated and un-refrigerated trailers, storage containers, or truck bodies that include wall and/or roof panels joined together. 
     As used herein, directional terms including “top,” “bottom,” “side,” “horizontal,” “vertical,” and so on are used to indicate directional relationships with respect to an arbitrary reference frame (e.g., a reference frame of a particular figure or figures). These directional terms are used consistently relative to a particular embodiment. For example, a “top” feature of an embodiment is opposite a corresponding “bottom” feature, and a “horizontal” feature generally extends perpendicularly to a “vertical” feature. However, unless otherwise defined or limited, these directional terms are not intended to indicate an absolute reference frame for a particular assembly. 
     In conventional arrangements, panel members can be made from various types of materials in different configurations. For example, panel members can be made with hexagonal honeycomb cores that have a uniform internal structure and in which the axis of each honeycomb cell extends perpendicular to the length and width of the adjacent sheets. Cargo securement elements or fasteners must therefore be located in areas at or near the seams of adjacent panels where additional overlapping material is provided. Another example includes panel members comprising a core partially formed from a foamed thermoplastic and include higher density foam blocks inserted manually in locations in areas needing additional structural support. Although these conventional arrangements of panels can provide adequate structural strength and support for fasteners, mounting and fastening options for cargo securement elements and fasteners are limited and labor can be fairly intensive to manufacture the panel members. 
     Embodiments of the invention can address these or other issues. For example, in some embodiments, a panel member core can include areas of different densities. Some areas may be formed with higher density foam, respectively, for securing mounting elements or fasteners thereto, while other areas may be formed with lower density foam to reduce the overall weight of the panel member. As another example, other regions within the panel core can have densities between the densities of the higher and lower density regions. An example of the process for making a panel member core can include the extrusion and combination of streams of thermoplastic foam having the same or different densities. In some examples, the thermoplastic can be high density polyethylene (HDPE) or polypropylene (PP). 
     As shown in  FIG. 1 , a trailer  10  can comprise a plurality of interconnected panel members  12 . As shown in  FIG. 2 , each of the panel members  12  can be formed by laminating sheets  14 , or skins, to a panel member core  16 . 
       FIG. 3  illustrates a first example of a method of forming a panel member core  116  ( FIG. 4 ) according to an embodiment of the invention. A first extruder  120  extrudes a first set of streams (a first stream  122 , a third stream  124 , and a fifth stream  126 ) of a thermoplastic foam all having a first thickness  128 . A second extruder  130  extrudes a second set of streams (a second stream  132  and a fourth stream  134 ) of a thermoplastic foam all having a second thickness  136 . The first thickness  128  is substantially equal to the second thickness  136 . The first extruder  120  and the second extruder  130  can extrude at the same lineal feet per minute rate. 
     The first, third, and fifth streams  122 ,  124 ,  126  each have a first density, and the second and fourth streams  132 ,  134  each have a second density. In the example, the first density of the first, third, and fifth streams  122 ,  124 ,  126  extruded from the first extruder  120  can be greater than the second density of the second and fourth streams  132 ,  134  extruded from the second extruder  130 . For example, the first density can be in the range of about 14 lb/ft 3  to about 30 lb/ft 3  and the second density can be in the range of about 1 lb/ft 3  to about 13 lb/ft 3 . The streams  122 ,  124 ,  126 ,  132 ,  134  can be thermally welded together to form a single continuous panel member core stream  118 , which can be cut to a predetermined dimension to form the panel member core  116  ( FIG. 4 ). The first, third, and fifth streams  122 ,  124 ,  126  define a first, third, and fifth segment  150 ,  152 ,  154 , respectively, and the second and fourth streams  132 ,  134  define a second and fourth segment  156 ,  158 , respectively, in the panel member core  116 . The segments  150 ,  152 ,  154 ,  156 ,  158  extend parallel with each other along the length  144  of the panel member core  116 . When installed on the trailer  10 , each of the segments  150 ,  152 ,  154 ,  156 ,  158  extends from the top of the trailer  10  to the bottom. 
     The first, third, and fifth segments  150 ,  152 ,  154  are shown with widths that are smaller than the widths of the second and fourth segments  156 ,  158 . However, other configurations with segments of different widths are contemplated, including the inverse of the panel member core  116 , and the figures should not be viewed as limiting. 
     In other embodiments, other configurations are possible. For example, more or fewer alternating extrusion streams of different or similar densities can be combined to form a panel member core as determined by the predetermined structural and weight requirements. For example, in some embodiments, the first, third, and fifth streams  122 ,  124 ,  126  can each have a different density. In some embodiments, two of the first, third, and fifth streams  122 ,  124 ,  126  can have the same density and the other of the first, third, and fifth streams  122 ,  124 ,  126  can have a lesser or a greater density. In some other embodiments, the densities of the second and fourth streams  132 ,  134  can be different. In some embodiments, at least two of the densities of the first, second, third, fourth, and fifth streams  122 ,  132 ,  124 ,  134 ,  126  can be the same. 
     A weld zone  138  can be formed between any two adjacent, thermally welded extrusion streams, for example, between the second stream  132  and the third stream  124  shown in  FIG. 3 . The weld zone  138  can be formed during the thermal welding process to create a non-porous solid wall of homogenous plastic extending the length  144  and thickness  128 ,  136  of the panel member core stream  118  between the two extrusion streams  132 ,  124 . The weld zone  138  can increase the compressive strength of the panel member core  116 , making it more resistant to compressive loads. The compressive strength of the panel member core  116  can be further aided by the foam of the streams  132 ,  124  provided on either side of the weld zone  138  further resisting deflection. 
       FIGS. 5, 5A, and 5B  illustrate another example of a method of forming a panel member core  216  ( FIG. 6 ) according to another embodiment of the invention. An extruder  220  extrudes a continuous panel member core extrusion  42  having a first set of regions  240  (a first region  222 , a third region  224 , and a fifth region  226 ) and a second set of regions  242  (a second region  232  and a fourth region  234 ). The continuous panel member core extrusion  218  can have a density in a range from about 1 lb/ft 3  to about 25 lb/ft 3 . The first, third, and fifth regions  222 ,  224 ,  226  are extruded at a first thickness  228  and the second and fourth  232 ,  234  are extruded at a second thickness  236  ( FIG. 4A ). The first thickness  228  is greater than the second thickness  236 . For example, the first thickness can be about 1 inch and the second thickness can be about ½ inch. In other embodiments, other configurations are possible. For example, more or fewer regions of different or similar thicknesses can be combined to form a panel member core as determined by the predetermined structural and weight requirements. For example, in some embodiments, the thicknesses of the first, third, and fifth regions  222 ,  224 ,  226  can each have a different thickness. In some embodiments, two of the first, third, and fifth regions  222 ,  224 ,  226  can have the same thickness and the other of the first, third, and fifth regions  222 ,  224 ,  226  can have a smaller or a greater thickness. In some other embodiments, the thicknesses of the second and fourth regions  232 ,  234  can be different. In some embodiments, at least two of the thicknesses of the first, second, third, fourth, and fifth streams  222 ,  232 ,  224 ,  234 ,  226  can be the same. 
     At least the first set of regions  240  of the panel member core stream  218  can be compressed to a third thickness  238  ( FIG. 5B ). The third thickness  238  can be equal to the second thickness  236  to form a panel member core stream  218  of uniform thickness. It is also contemplated that the second set of regions  242  can also be compressed at the same time as the first set of regions  240  to provide a uniform thickness of the panel member core stream  218 . Continuing with the example of the first and second thicknesses  228 ,  236  above, the third thickness  238  can be in the range of about 7/16 inch to about ½ inch. In  FIG. 5 , for example, a set of rollers  260  are shown performing the compression of the panel member core stream  218 . 
     The compression of the first, third, and fifth regions  222 ,  224 ,  226  and the second and fourth regions  232 ,  234  to the third thickness  238  increases the density of the first, third, and fifth regions  222 ,  224 ,  226  relative to the second and fourth regions  232 ,  234 . In the example provided, the density of the first, third, and fifth regions  222 ,  224 ,  226  is approximately double the density of the second and fourth regions  232 ,  234  because the first, third, and fifth regions  222 ,  224 ,  226  were about twice the thickness of the second and fourth regions  232 ,  234  in the panel member core extrusion  218  and were compressed to the same thickness of the second and fourth regions  232 ,  234  in the panel member core stream  218 . 
     After compression, the first, third, and fifth regions  222 ,  224 ,  226  can have a first density and the second and fourth regions  232 ,  234  can have a second density. The first density can be in the range of about 14 lb/ft 3  to about 30 lb/ft 3  and the second density can be in the range of about 1 lb/ft 3  to about 13 lb/ft 3 . The panel member core stream can be cut to a predetermined dimension to form the panel member core  216  ( FIG. 6 ). 
     Similar to the example method of forming the panel member core  116  described above, the panel member core stream  218  can be cut to a predetermined dimension to form the panel member core  216  ( FIG. 6 ). The first, third, and fifth regions  222 ,  224 ,  226  can define first, third, and fifth segments  250 ,  252 ,  254 , respectively, and the second and fourth regions  232 ,  234  can define second and fourth segments  256 ,  258 , respectively, in the panel member core  216 . The segments  250 ,  252 ,  254 ,  256 ,  258  extend parallel with each other along the length  244  of the panel member core  216 . When installed on the trailer  10 , each of the segments  250 ,  252 ,  254 ,  256 ,  258  extends from the top of the trailer  10  to the bottom. 
     The first, third, and fifth segments  250 ,  252 ,  254  are shown with widths that are smaller than the widths of the second and fourth segments  256 ,  258 . However, other configurations with segments of different widths are contemplated, including the inverse of the panel member core  216 , and the figures should not be viewed as limiting. 
     In other embodiments, other configurations are possible. For example, more or fewer alternating extrusion stream regions of different thicknesses and different or similar densities can be formed to provide a panel member core  216 as determined by the predetermined structural and weight requirements. 
       FIG. 7  illustrates an example of a method of forming a panel member  312  according to an embodiment of the invention. An extruder forms a panel member core  316  having a first thickness  328  and a first density, both of which are uniform throughout the panel member core  316 . A sheet  314  is laminated to one or both sides of the panel member core  316 . The example in  FIG. 7  shows a sheet  314  laminated to both sides of the panel member core  316 . The combination of the sheets  314  and the panel member core  316  is then processed, wherein at least one predetermined area along the length  344  of the panel member  312  is designated to have a higher density. The predetermined area is heated locally with heaters  364  and compressed to a second thickness  336 , which is less than the first thickness  328 , to from the panel member  312 , wherein the compressed area has a greater density than the non-compressed area. As shown, the compression may be performed by rollers  366  along the sides of the panel member  312 . Excess material  362  may be trimmed with a trimming apparatus  368  as needed. Similar density values as provided above with respect to the other methods of forming a panel member core may be achieved in the regions having the first thickness  328  and the second thickness  336 . It should be noted that in some embodiments additional or fewer areas of compression are contemplated. For example, one of the rollers  366  can be removed or at least one additional roller can be added. In some embodiments, a panel member can have another area with a thickness different than the first and second thicknesses  328 ,  336 . For example, the rollers  366  can be configured to compress the panel member to different thicknesses (e.g., by using rollers of different diameters). In another example, another roller configured to compress the panel member to a third thickness can be added. 
     Thus, the above-described methods for forming panel member cores can form panel member cores having different strength and weight characteristics. Areas within the panel member cores having a greater density can provide additional strength to reduce fastener tear out where hardware is bonded thereto or where panels are joined together. Areas within the panel member cores having a lower density, respectively, can reduce overall panel weight in areas in which additional strength is not required. 
     While the invention has been illustrated and described in detail in the foregoing drawings and description, the same is to be considered as illustrative and not restrictive in character, it being understood that only illustrative embodiments thereof have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. Furthermore, it will be understood that the embodiments discussed above are presented as examples only, and that other embodiments are possible. Moreover, it is intended and will be appreciated that embodiments may be variously combined or separated without parting from the invention. For example, it will be appreciated that all preferred features described herein are applicable to all aspects of the invention described herein. 
     The description herein of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.