MXPA00008039A - Method for forming structure suitable for use as a core member - Google Patents

Abstract

Core-type structures (10) are formed by extrudingelongated tubular members (24) or sheets of a thermoplastic material that are subsequently cut into segments (30) or plates having a defined length and then assembled into a bundle (42). The bundle (42) is then simultaneously cut at a number of spaced-apart locations along the length of the bundled segments, or plates, whereby a plurality of separate core structures (10) are simultaneously formed.

Description

METHOD FOR FORMING ADEQUATE STRUCTURE FOR USE AS A MEMBER OF NUCLEUS BACKGROUND OF THE INVENTION TECHNICAL FIELD This invention relates generally to a method for forming a suitable structure to be used as a core member, either by itself or as part of a multilayer board, and more particularly to a method for forming such a structure having a plurality of elongated passages positioned parallel to the thickness of the central structure. HISTORY OF THE RELATED ART Many structural arrangements have been proposed for the use of a core member in laminated assemblies such as multi-layered boards having a surface joined to at least one side of the core member. In particular, it has been found that central structures formed of elongated short tubular segments arranged in parallel to the thickness of the core member provide exceptional resistance to compressive deformation and crush damage.

However, because such structures comprise a large number of separate tubes or similar cell components, they have been difficult to assemble and manufacture economically. For example, U.S. Patent 5,032,208, issued July 16, 1991 to Horst Strauss discloses a process for manufacturing a tube bundle by loading the tubes in a channel having a movable end wall. The end wall is displaced in increments to expose one end of the tubes, which are cut and the cut ends cut off where the ends placed adjacently are joined together. The beam is then moved to a position where a second cut can be made, and then moved to a position in which a third cut can be made, and so on, in series, until all the .haz has been cut in the desired number of cores. The Strauss process is not only difficult, allowing only one cross section and one fusion operation at a time, but also depends on a precocious and controlled movement of one end of the channel while maintaining a desired alignment of the uncut tubes in the make. In a prior arrangement, the construction of a structural core board is disclosed in U.S. Patent 2,477,852, issued August 2, 1949 to CE Bacon, in which short tubular members are adhesively bonded throughout their entire length. Alternatively, other shapes, such as corrugated strips may be precisely aligned and adhesively bonded together along mating corrugations and then cut transversely to provide a core. In all the arrangements presented in the Bacon structure, the individual components are adhesively bonded throughout the length, this process is also difficult and time consuming, requiring that the adhesive be cured before moving the structure for subsequent processes, such as application of a cover to the core member. Recently, Patent Application 5,683,782 issued November 4, 1997 to Rainer Duchene describes a process for producing a honeycomb structure in which the individual components of the structure are covered with a heat-activated adhesive prior to assembly. After assembly, the adhesive is activated by heat treatment in which the individual components are bonded along the entire length. Therefore, the Duchene process requires a coating step before assembly and a thermal treatment before subsequent processes. The present invention is directed to overcome the problems indicated above. It is desirable to have a method for forming a suitable structure to be used as a core in which a plurality of cores can be formed with multiple simultaneous cuts of a preassembled stack, or bundle, of components having internal passages. It is also desirable to have such a structure that does not require adhesive bonding of separate components before being formed into a core member. further, it is desirable to have a method by which a structure suitable for use as a core member can be formed without requiring an attachment with a movable end wall by which a single core member is formed before requiring to be moved from the assembled tubes to a subsequent position in which another core can be formed. Additionally, it is desirable to have a. method for forming a plurality of cores simultaneously in which only the selected open ends of the elongated members forming the core are fused together. SUMMARY OF THE INVENTION According to one aspect of the present invention, a method for forming a structure suitable for use as a core member includes extruding a thermoplastic material into an elongated tubular shape, cutting the elongated tubular shape into a plurality of separate segments, and then align the separated segments in relation to one another side by side along their length. The aligned segments are then accommodated in a row that has a pre-selected width, after which the rows are assembled one on top of the other to form a stack of rows. With this the stack has a width substantially equal to the width of the rows of aligned segments, a substantially equal depth along the segments, in the rows, and at the height determined by the number of rows of aligned segments assembled in the stack . The stack of assembled rows is cut transversely to the longitudinal axes of the aligned segments at a plurality of preselected separate distances, forming a plurality of separate cores each of which has a width and a height equal to the width and height of the stack and a thickness determined by the preselected distance between the cross sections. Simultaneously with cutting the stack of assembled rows, the aligned segments are fused with each other at least one of the respective cut ends of the segments. In other aspects of the present invention, the elongate tubular shape may have a hollow circular cross section, a hollow rectangular cross section, a hollow triangular cross section, a hollow hexagonal cross section or may have, at least one internal wall placed transversally forming a plurality of separate elongate hollow cells extending along each of the tubular shapes. Other features of the method for forming a structure, in accordance with the present invention, include in the alignment step that moves the segments along a guide having side walls that converge at a distance apart substantially equal to the length of the segments , shaking at least one of the segments of the guide during the movement of the segments along the guide. Other features of the method for forming a row of aligned segments also include melting at least one of the cut ends of each of the segments aligned to the cut end of when monkeys one of the segments placed adjacently. Fusion of the cut ends may include heating the ends to a temperature sufficient to melt at least partially the cut ends of the aligned segments or mechanically join at least one of the cut ends of the segments aligned to the cut end of at least one segment placed adjacently. Still another feature of the method for forming a structure, according to the present invention, includes cutting the stack of assembled rows of aligned segments by making a plurality of simultaneous cross sections at spaced apart distances along the longitudinal axes of the segments. According to another aspect of the present invention, the method for forming a structure suitable for use as a core member includes a continuous thermoplastic sheet having a predetermined width, at least one surface extending across the width of the sheet, a plurality of parallel elongated passages in which each of the elongated passages has a longitudinal axis parallel to the width of the sheet. The extruded thermoplastic sheet is cut across the width to form a plurality of separate plates, each of a preselected length. The separated plates are assembled one above the other to form a stack of plates in which the elongated passages in each plate are arranged in a common parallel direction perpendicular to the width of the stack. The stack has a width substantially equal to the width of the plates, a depth substantially equal to the preselected length of the plates and a height determined by the number of plates assembled in the stack. The stack of assembled plates is cut in a direction transverse to the longitudinal axes of the elongated passages "in a plurality of separate structures, each having a width and a height substantially equal to the width and height of the stack and a thickness determined by a The preset distance between the cross sections through the stack The method further includes simultaneously melting the plates placed adjacent to each other on at least one of the respective cut ends of the plates, simultaneously with the cut of the stack. The method for forming a structure according to the method immediately indicated above includes the elongated passages having a number of selected cross sections, including the cross-sectional shapes mentioned above, In addition, the elongated passages can be formed at least partially by a base wall that has a primer side defined by a surface extending across the width of the thermoplastic sheet, and a plurality of spaced parallel walls extending from a second side of the base wall in a direction normal to the base wall. Also, the elongated passages may be defined by a plurality of U-shaped channels placed adjacently where the bottoms of the U-shaped channels define a surface extending through the bottom of the thermoplastic sheet.

In another arrangement, the surface extending across the width of the thermoplastic sheet can be defined on one side of a corrugated wall and the elongated passages defined by the alternating concave and convex portions on respective sides of the corrugated wall. Other characteristics of the method for the formation of a structure, as indicated above, include the step of simultaneously melting plates placed adjacent to each other by heating at least one of the cut ends of each of the plates at a temperature sufficient for at least partially melting the respective cut ends in which the cut ends are fused together. Other plate assembly features include stacking the plates in a structure having openings provided therein that are adapted to provide access to the stack of plates for the purpose of wrapping at least one strip of plastic material of thermal choice at winch of the pile. Other features of the method include cutting the stack of assembled plates by making a plurality of simultaneous cuts separated in direction and distance along longitudinal axes of the passages of the plates. ? In yet another aspect of the present invention, a method for forming a structure suitable for use as a core member includes extruding a thermoplastic material into an elongated tubular shape, cutting the elongated tubular shape into a plurality of separate segments and aligning the Segments separated in side-by-side relationship along their preselected lengths. The plurality of aligned separate segments is wrapped by shrinkage, with the heat-shrinkable envelope surrounding the separated segment aligned and forming a bundle of shrink-wrapped segments. The bundle of segments wrapped by thermo-shrinkage is cut in the direction transverse to the longitudinal axes of the segments, thereby forming a plurality of separate thermo-shrink wrapped structures, each having a thickness determined by the preselected distances between the cross sections. . At least one of the cut ends of the respective segments is fused simultaneously with the segment placed adjacently in the beam during the cutting operation. Another feature of the above described method of forming a structure includes the elongated tubes having a cross section such as those previously described. In yet another aspect of the present invention, a method for forming a structure suitable for use as a core member includes extruding a thermoplastic material into an elongated tubular shape, cutting the elongated tubular shape into a plurality of separate segments and aligning the Segments spaced side by side along their lengths. The aligned separate segments are deposited in a consumable container formed with a material capable of being cut by a thermal apparatus. The consumable container and the aligned segments deposited therein are cut in a direction transverse to the longitudinal axes of the segments aligned at a plurality of pre-selected spaced apart distances along the axes of the segments. This forms a plurality of separate cores, each having a thickness determined by the preselected distance along the cross sections. Simultaneously with the cutting of the separated segments deposited in the consumable container, aligned segments placed adjacently are simultaneously fused with each other in at least one of the cut ends of the respective segments. Other characteristics of the structure formed, according to the above description, includes the container. -consumable formed of polystyrene- expandable.

Additional features include the consumable container being positioned within a structure having openings provided therein that are adapted to provide access to the container containing the plurality of segments for the purpose of wrapping at least one band of plastic material around the consumable container . Still other methods include depositing separated segments deposited and the consumable container making a plurality of simultaneous cuts, preferably by hot wires, at separated distances along the longitudinal axes of the segments. According to another aspect of the present invention, a member suitable for use as a core has a pair of spaced apart surfaces defining the thickness of the member. The member also has a plurality of rows positioned adjacent to a thermoplastic sheet structure, with the rows being placed in a direction parallel to the thickness of the member. Each row of the thermoplastic sheet structures have a defined width, at least one surface extending across the width and a plurality of elongated passages placed in parallel relationship with the aforementioned surface and one with the other. Each of the elongated passages has a longitudinal axis oriented perpendicular to the direction of the width of the sheet. A portion of at least one surface is melted with a portion of at least one surface of a row positioned adjacent to the thermoplastic sheet structures. Another characteristic of the member suitable for use as a core includes the fused portions of the respective surfaces being placed on at least a pair of the spaced apart surfaces defining the thickness of the member. Also, the elongated passages may have any number of hollow cross sections, including rectangular, triangular, circular, hexagonal, or may have at least one transversely placed wall which forms a plurality of separate hollow cells along the length of each of the passages. BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding of the structure and operation of the present invention can be obtained with reference to the following detailed description when taken in conjunction with the accompanying drawings: FIGURE 1 is a three-dimensional view of a suitable structure to be used as a core member, done in accordance with the. method embodying the present invention; FIGURE 2 is a three-dimensional view of an elongated tubular shape having a hollow circular cross section; FIGURE 3 is a three-dimensional view of an elongated tubular shape having a hollow triangular cross section; FIGURE 4 is a three-dimensional view of an elongated tubular shape having a hollow square cross section; FIGURE 5 is a three-dimensional view of an elongated tubular shape having a hollow hexagonal cross-section; FIGURE 6 is a three-dimensional view of an elongated tubular shape having a plurality of transversely placed internal walls which form a plurality of elongated cells extending along the length of the elongate tubular member; FIGURE 7 is a schematic diagram showing the operational flow of a first embodiment of the method, in accordance with the present invention, of forming a structure suitable for use as a core member; FIGURE 8 is a three-dimensional view of a thermoplastic sheet structure used in one embodiment of the method for forming a structure suitable for use as a core member, in accordance with the present invention; FIGURE 9 is a three-dimensional view of another arrangement of a sheet structure suitable to be used to carry out the method embodying the present invention; FIGURE 10 is a three-dimensional view of another embodiment of a thermoplastic sheet structure suitable for use in a method for forming a structure according to the present invention; FIGURE 11 is a three-dimensional view of another thermoplastic sheet structure suitable for use in a method for forming a structure, in accordance with the present invention; FIGURE 12 is a schematic diagram of another embodiment of the method for forming a structure suitable for use as a core member, in accordance with the present invention; FIGURE 13 is a three-dimensional view of an alternative embodiment of the method embodying the present invention, in which the elongated segments are aligned within a consumable box; FIGURE 14 is a three-dimensional view of a structure for containing a plurality of segments cut in the course of carrying out a modality; method for - the formation of a structure suitable to be used as a core member according to the present invention; FIGURE 15 is a three-dimensional view of a tube bundle wrapped by thermo-shrinkage according to one aspect of the method for forming a structure embodying the present invention; FIGURE 16 is a side view of a structure to be used as a core member, formed in accordance with the method of the present invention in which a heat-shrinkable film enveloping a bundle as shown in FIGURE 15; and FIGURE 17"is a plan view of a structure, incorporating the present invention, which is suitable for use as a core member DETAILED DESCRIPTION OF THE EXAMPLE MODALITIES PREFERRED OF THE PRESENT INVENTION The present invention is described by reference to various embodiments of a method for the formation of a structure 10, as shown in FIGURE 1, suitable for use as a core member, example: such as cores used in multi-layer boards, various laminate board constructions or individual structural members. These cores and boards are used in many fields, such as transportation, housing, marine, architectural and others. The structure 10 is typically used as a core in which a flat board is applied to one or usually on both sides of the structure 10. the flat boards can be plywood, aluminum or other metal, plastic, fiberglass, cloth as the which is found in wall coverings, carpets or other materials. As shown in FIGURES 2 - 6, in an arrangement of the structure 10, short sections of an elongated tubular shape are arranged normal to the broad surfaces of the board and, due to their short column dimension, advantageously exhibit great strength along the longitudinal axes of the short columns , due to their short column length, they advantageously exhibit great strength along the longitudinal axes of the short columns. Although used in the following description of the exemplary embodiments of the method for the formation of a structure 10 is a circular shape 12 having a substantially uniform wall thickness and an open cross-sectional area along its length. As shown in FIGURE 2, other shapes having uniform open cross-sectional area along their respective lengths such as tubular member 14 having a triangular hollow cross-section as shown in. FIGURE 3, a tubular member 16 having a square hollow cross section as shown in FIGURE 4, a tubular member 18 having a hexagonal cross section, as shown in FIGURE 5 or a tubular member 20 having a more transversely placed inner walls which form a plurality of elongated hollow cells extending along the length of the tubular member 20, as shown in FIGURE 6. Furthermore, if the tubular member 20 is not formed by extrusion, it can having a non-uniform cross-section, this being, the cross-sectional area may vary along to form sharp segments. In carrying out the method embodying the present invention, it is particularly desirable that the elongate tubular members are formed of thermoplastic material such as polyethylene, polypropylene, polyvinyl chloride or other thermoplastic material suitable for high-degree extrusion processes. In a first preferred embodiment of a method, according to the present invention, of forming a structure 10, a thermoplastic material is discharged from an extruder 22 as an elongated tubular shape 24 as shown schematically in FIGURE 7. Extrusion It is a known process in which a semi-soft cold or hot material, such as metal or plastic, is forced through the hole of a die into a continuously formed part having a substantially uniform cross-section with the desired shape of the product. . The tubular form 24 is illustrated and is used herein in a generic sense and may comprise one or more tubular shapes such as those mentioned above with the indicated cross sections, or other variations and alterations of said cross sections. In the shapes having hollow cross section, it is very desirable to extrude the thermoplastic material as a solid bar 26 and then to form the outer wall of the tubular shape 24 by expanding the solid bar 26 in a vacuum apparatus 28 which simultaneously forms a hollow space in the center of the extruded form 24. The extruded form 24, with or without vacuum process is allowed to cool, or is actively cooled, to a temperature at which it is self-supporting and can easily be cut into separate segments 30, each having a preselected length and a longitudinal axis 32 extending along a preselected length of the segments 30. The cutting operation can be advantageously carried out by means of a rotating blade which rotates at a speed coordinated with the extrusion ratio of the tubular member 24 so that each segment 22 has substantially the same length, from end to end. The cut segments 30 are then aligned in side-by-side relationship along their preselected lengths. As shown in the schematic diagram of FIGURE 7, the cut segments 30 are aligned as they move along an inclined guide 34 in which the sides of the guide converge towards a spaced apart distance that is substantially equal to the preselected length of the guide. the segments 30. Therefore, the segments 30 are self-aligned as they pass the inclined guide 34. To assist in the movement of the segments 30, the guide 34 may have a vibrating surface which agitates the segments 30 to assist in the movement and alignment of the segments 30. Alternatively, the guides 34 may use means other than gravity to guide the segments 30 to the right, as presented in FIGURE 7, such as by means of a moving band 36, or assistance by air. A preselected number of aligned segments 30 are formed in a row 40 having the preselected width, determined by the number of aligned segments 30 that are in contact with one another along the width of the row 40. The rows 40 of segments Aligned can be formed by fusing at least one of the cut ends of each of the segments aligned with the segment 30 placed adjacently. The fusion of the cut ends can be carried out by heating the ends to a temperature sufficient to partially melt the cut ends of the aligned segments 30 at a temperature sufficient to partially melt the ends. This can be carried out by means of a hot wire, by a hot plate 38 as shown in FIGURE 7, or by means of other heat sources such as laser or ultrasound. Alternatively, the cut ends of the aligned segments 30 can be joined together mechanically by passing an abrasive surface or mechanical cutting tool through the ends of the segments 30 that form a row 40 of the segments 30. The rows 40 of the segments aligned 30 are then assembled, one above the other, to form a stack 42 of rows 40. Alternatively, stack 42 may have rows 40 aligned vertically in relation to one another. As illustrated in FIGURE 7, the stack 42 has a width W substantially equal to the width of the rows 40, a depth substantially equal to the preselected length L of the segments 30 and a height H determined by the number of rows 40 of segments aligned. assembled in stack 42.

The stack 42 of rows 40 assembled from segments 30 (shown with 90 degree rotation for clarity) is cut along lines that are in a direction transverse to the longitudinal axis 32 of the aligned segments 30 in a plurality of spaced apart distances. lengthwise of the longitudinal axis 32. Advantageously, the cutting can be effected by a plurality of hot wires 44 which, as described below, simultaneously fuse the cut ends placed adjacently of the segments 30 with one another without substantially reducing the cross-sectional area of the cut ends of the segments as illustrated in the step of FIGURE 7. The separation distances of the cuts will determine the final thickness of the structure 10. For example, if the assembled stack 42 has a width of forty-eight inches (121.92 centimeters), a length of forty-eight inches (121.92 centimeters) and a height of forty-eight inches (121.92 centimeters) ), and it is desired that the resulting structure 10 have a thickness of one inch (2.54 centimeters), the hot wires 44 will be separated one inch (2.54 centimeters). Therefore, a stack of 4 feet x 4 feet x 4 feet (121.92 centimeters x 121.92 centimeters x 121.92 centimeters) will have forty-eight 10-inch structures ("2.54 centimeters) thick with height and width of 4 feet x 4 feet (121.92 centimeters x 121.92 centimeters) Alternatively, instead of using hot wires 44, other thermal methods can be used, such as lasers, hot blades, saw blades which can provide sufficient heat to cut and melt the cut ends of the segments 30, or other methods If desired, the rows 40 of assembled segments 30 can be assembled in a stack 42 by placing the rows 40 within a consumable container 46 formed of a material that is capable of being contained in a thermal apparatus, such as the above-mentioned hot wire Desirably, the consumable container 46 is formed by expanded or foamed plastic material which is easily cut by the heat source, such as omo expanded polystyrene. Other materials suitable for the construction of the consumable container 46 include recycled waste tubes, cardboard and polyethylene. In making the final cross sections of the stacked rows 40, it may be desirable to simultaneously cut the outer ends of each elongate segment 30 to ensure that the exterior structures 10 have a uniform thickness and an open cross-sectional area at the cut ends substantially equal to open area of transverse section at any point of the length of the elongated segments 30, as illustrated in the final step of FIGURE 7. This may also compensate for any misalignment of the segments 30 which may result in an uneven surface in the outer structures 10. Also, as described in more detail below, the consumable container 46, if desired, can be wrapped with a shrinkable plastic material before cutting the stack of assembled rows. When a thermal apparatus, such as the hot wire 44 mentioned above, is used, the heat produced by the thermal apparatus must not only cut, being sectioned, the segments 30 contained within the stack 42, but also provide sufficient heat to at least partially melt the cut ends of the segments 30 and melt the ends of cut segments adjacent to one another. If it is desired to later use the structure 10 in a board assembly having curved surfaces, or for other uses in which a curved core is desired, a surface of the structure 10 must be fused and the opposite surface of the structure 10 must not be being melted, this being, the open ends of the segments 30 are not joined together. This can be easily accomplished using the method embodying the present invention. For example, during the cutting operation illustrated to the right of the schematic diagram of FIGURE 7, the temperature of the hot wires 44 can be controlled so that a set of wires has a temperature sufficient to cut and melt the cut ends of the segments. , wherein an alternate set of hot wires 44 has a temperature sufficient to blanket only the segments 30 without melting the cut ends. For example, the first hot wire 44, placed to the left of the stack 42, can be controlled to have a sufficient temperature not only to cut the ends 30, but also to melt the cut ends, where the second wire 44 on the left it can be controlled at a temperature sufficient to cut only the segments 30. Similarly, a third wire 44 on the left can be controlled at a temperature sufficient to cut and melt the segments 44. therefore, the two structures on the left side 10 cut from the stack 42 each has a surface on which the cut segments are fused and an opposing surface on which the cut segments are not fused together. This allows the structure 10 to be bent into a shape where the uncut surface can be bent into a convex curve, with the corresponding molten surface curved ep a concave surface.

In a second preferred embodiment of forming a structure 10, according to the present invention, suitable for use as a core member, a continuous thermoplastic sheet 48, having a predefined width W, is used in the initial step of the method as is illustrated in FIGURE 12. In a first embodiment illustrated in FIGURE 8, a thermoplastic sheet 48 has a plurality of open cross sectional areas of elongated passages 52 that are placed in parallel relationship with at least one continuous surface 50 of the sheet 48 and one with the other. Each of the elongate passages 52 has a longitudinal axis 54 that is positioned perpendicular to the width direction W of the sheet 48. Alternate shapes of the thermoplastic sheet 48 are shown in FIGURES 8 through 11 in FIGURE 8, the longitudinal passages. 52 has a substantially rectangular hollow cross section. Other shapes of hollow cross sections may be formed between the pair of flat surfaces of the sheet 48 and include hollow circular cross sections, hollow triangular cross sections, hollow hexagonal cross sections and other arrangements as described above with respect to the extruded tubular shapes. elongated 24. In the structure shown in FIGURE 9, the elongated passages 56 are formed at least partially by a base wall 58 having a first side 60 which defines the surface across the width of the thermoplastic sheet, and by a plurality of parallel parallel walls 62 extending from a second side of the base wall 58 in a direction normal to the base wall 58. The upper portion of the passages 56 are closed when a second sheet is assembled on top of the first sheet, with which completes the closure around passage 56. Another arrangement of the thermoplastic sheet, illustrated in FIGURE 10, it has the form of a series of U-shaped channels 64 positioned adjacently where the bottom of the U-shaped channels define a surface 66 extending across the width of the sheet. In FIGURE 11, the thermoplastic sheet is defined by a side 68 of a corrugated wall 70 and elongated passages 72 are defined by alternate concave and convex portions on respective sides of the corrugated wall 70. the corrugated wall 70 extends across the width of the thermoplastic sheet. After being expelled by the extruder 22, a thermoplastic sheet such as the sheet 48 shown in FIGURE 8, is passively or actively heated and cut transversely across the width of the sheet 48 to form a plurality of spaced plates 74, as shown in FIG. shows schematically in FIGURE 12. Each of the sheets 74 has a preselected length L extending in a direction parallel to the longitudinal axes 54 of the passages 52. The separated plates 74 are then assembled one on top of the other to form a stack 76 having a width substantially equal to the width of the plates 74, a depth D substantially equal to the preselected length L of the plates 74, and a height H determined by the number of plates 74 assembled in the stack 76. The stack 76 of plates assembled 74 are cut simultaneously in a plurality of locations, in a direction transverse to the longitudinal axes 54 of the elongated passages 52. The operation The multiple cut section divides the stack 76 into a plurality of separate structures 84, as illustrated in plan view in FIG. 17. Each of the structures 84 has a width and a height substantially equal to the width and height of the stack. 76, and a thickness determined by the preselected distance between the cross sections through the stack 76. As described above, desirably the stack 76 is cut simultaneously by a plurality of hot wires 44 that pass through the stack 76 where the space between the wires 44 determines the thickness of the cut structure 84. Also, as described above and illustrated in the last step in FIGURE 12 and in FIGURES 16 and 17, the cut end of the plates 74 is desirably melted without substantially reducing the transverse open area of the cut ends on at least one surface of the structure 84. The temperatures of the hot wires 44 passing through the stack 76 will determine whether the plates 74, in the transverse position, are cut only or cut and simultaneously fused to adjacent plates 74. Before cutting the assembled plates 74, the plates 74 can be stacked in a support or structure 78, as illustrated in FIGURE 14, having side openings and a bottom space provided therein that provides access to the stack 76 of plates 50 assembled within the support 78, to wrap at least one band of plastic material around the stack 76. Preferably, the plastic material is a heat-shrinkable film. The shrink wrap is defined as a plastic film having preformed stresses in which stresses are released by increasing the temperature of the film, causing the film to shrink around an object around which it is wrapped, this being , the. stack 76., Therefore,: 'it can be appreciated that the method indicated above provides a structure, or member, 84 as illustrated in FIGURE 17, suitable to be used as a core having a plurality of rows placed adjacently of thermoplastic plates 74 in which the passages 52 in the rows 40 are positioned in a direction normal to the thickness of the member 84. Each of the thermoplastic plates 74 has a defined width, at least one surface extending across the width of the plate 74. , and a plurality of elongated passages 52 placed in parallel relation to at least one surface 60 of member 84 and one with the other. Also, each of the elongated passages 52 has a longitudinal axis 54 that is perpendicular to the width direction of the plate 74. Each of the plates 74 has separate ends 53, one of which is visible in FIGURE 17. it, the end portions 53 are perpendicular to the width of the structures of the plates 74. It is important, a portion of at least one end portion 53 of each row 40 adjacent to the broad surface of the member 84 is fused with a portion of end 53 of a row 40 positioned adjacent to the thermoplastic plates 74. As described above, and illustrated in FIGURE 17, the ends of the passages 52 are not deformed during the cutting and melting operation / being this the ends cut from each passage 52 have an open cross-sectional area substantially equal to the open cross-sectional area at any point along the passageway 52. It can also be easily seen that the member 84 may have any cross-sectional shape described above with respect to the tubular shapes 24 of the thermoplastic sheets 48. In a third embodiment of the method, embodying the present invention, the shape of the structure 10 suitable for use as a member of core, separate segments 30 are provided as described above, by extruding a thermoplastic material into an elongated tubular shape 24, cutting the elongated tubular shape 24 into a plurality of spaced segments 30 which have a preselected length and a longitudinal axis 32, aligning the separated segments 30 in side-by-side relationship along their preselected lengths as shown in FIGURE 15. The elongated tubular shape 24 may have the cross-sectional shape described above, and as an aid to align the separated segments 30, the segments 30 can be moved along a guide 34 as described above, which has side walls converging at a substantially equal distance apart along the segments; 30. If desired, either the guide 34 or the segments 30 can be agitated during movement to ensure that the segments 30 are aligned in relation to one another along their length. The aligned segments 30 are wrapped by thermo-shrinking with a heat-shrinkable film 80 whereby a bundle of segments 30 is provided. The beam can be cut simultaneously to a plurality of separate locations, in a direction transverse to the longitudinal axes 32 of the segments 30 as described above. Therefore, a plurality of thermo-shrink wrapped structures 10 which have a film 80 of the thermo-shrinkable envelope around the outer periphery of the structure 10 as illustrated in FIGURE 16. It has been found that the thermo film - shrinkable 80 can be easily cut by thermal devices, such as hot wires 44 used to cut and / or melt thermoplastic segments 30 or plates 50. In a fourth preferred embodiment of the method for forming a structure 10, According to the present invention, which is suitable for use as a core member, a thermoplastic material is extruded into an elongated tubular form 24 as described above. Also, as described above, the elongate tubular shapes 24 are then cut into a plurality of spaced segments 30, each having a preselected length L and a longitudinal axis 32. The spaced apart segments 30 are then aligned in side-by-side relationship. along their respective lengths, as described above, and are deposited within a consumable container 82, as illustrated in FIGURE 13. The consumable container is desirably formed of expandable polystyrene or other material that can be easily cut by a thermal apparatus, such as by a hot wire 44. After being deposited inside a consumable container 82, as shown in FIGURE 13, the separated segments 30 and the container 82 can be cut simultaneously in a direction transverse to the longitudinal axes of the separated segments 30 in a plurality of pre-selected separate distances in a direction along the is longitudinal 32 of the segments 30. This operation, as described at several points above, forms a plurality of structures 10 each separated by having a thickness determined by the preselected distance between the cross sections. Simultaneously, depending on the temperature of the thermal device, selected cut ends can be fused with adjacent cut ends - in at least one other segment 30. In this method, the elongated tubes 24- can have any cross-sectional shape defined above although, for ease of the description in the schematic diagrams, a circular cross section has been used for illustrative purposes in the drawings. Also, the method described immediately above may include agitating the segments 30 along the guide 34, as shown in FIGURE 7, during the movement of the segments 30 along the guide 34 for the purpose of aligning the ends of the segments 300 and place the segments.30 in relation side by side. Therefore, it can be seen that the methods described above, that the structure 10, or plate 84, can be easily formed economically. The methods described herein do not require adhesive bonding or the use of a transfer channel or abutment to retain an aligned beam of tubular segments when cut, one step at a time. The formation of a single structure at the same time consumes time and intensive work. In addition, increased segment handling during one-step cutting operations can lead to misalignment of segments between successive cuts. Although the present invention is described in terms of the preferred exemplary embodiments, with specific illustrative shapes of the tubular members and thermoplastic sheet structures and suitable thermoplastic materials, those skilled in the art will recognize that changes in those shapes, arrangements and materials can be carried out without departing from the spirit of the invention. Said changes are intended to remain within the scope of the following claims. Other aspects, features and advantages of the present invention can be obtained from the study of this disclosure and in the drawings, together with the appended claims.

Claims (1)

1. CLAIMS A method for forming a structure suitable for use as a core member, comprising: forming a row, having a preselected width, of aligned segments having an elongated tubular shape, each of said segments having a thermoplastic composition, a pair of separated ends defining the length of said segments, and a longitudinal axis extending along said length, said aligned segments are placed substantially in abutting relation along their respective lengths and melted only at least one of the cut ends of each of said segments aligned in said row only on the cut end of at least one segment placed adjacent to said row; assembling said rows of segments aligned in abutting relationship with another of said rows to form a stack of said rows of aligned segments, said stack having a width substantially equal to the width of said rows of aligned segments, a depth substantially equal to the preselected length of said segments and a height determined by one of the several rows of aligned segments assembled in said stack and the preselected width of said rows; and cutting said stack of assembled rows of segments aligned in a direction transverse to the longitudinal axes of the aligned segments at a plurality of preselected separate distances in a direction along said longitudinal axis and forming a plurality of separate structures each having a width and a height substantially equal to the width and height of said stack and a thickness determined by the preselected distance between said transverse cuts; and simultaneously fusing only at least one end of the cut ends of each row of segments aligned with only the transverse cut end of the adjacently placed row of aligned segments. A method for the formation of a structure, as set forth in claim 1, wherein said segments having an elongated tubular shape are formed by extruding a thermoplastic material into a tubular shape having a continuous length and subsequently cutting said tubular shape. extruded in said segments having an elongated tubular shape. A method for the formation of a structure, as set forth in claim 1, wherein said formed one row of aligned segments having an elongated tubular shape, includes forming a row of elongated tubes having a hollow circular cross section. A method for the formation of a structure, as set forth in claim 1, wherein said formed one row of aligned segments having an elongated tubular shape, includes forming a row of elongated tubes having a hollow rectangular cross section. A method for forming a structure, as set forth in claim 1, wherein said formed one row of aligned segments having an elongated tubular shape includes forming a row of elongated tubes having a hollow triangular cross section. A method for forming a structure, as set forth in claim 1, wherein said formed one row of aligned segments having an elongated tubular shape, includes forming a row of elongated tubes having a hollow hexagonal cross section. A method for the formation of a structure, as set forth in claim 1, wherein said formed of a row of aligned segments having an elongated tubular shape, includes forming a row of elongated tubes having a transverse internal wall forming a plurality of separate hollow cells extending along the length of said tube. A method for the formation of a structure, as set forth in claim 1, wherein said alignment of the plurality of segments separated in side-by-side relation includes moving said segments along a guide having converging side walls. at a distance separated substantially equal to the length of said segments. A method for the formation of a structure, as set forth in claim 7, wherein said method includes agitating at least one of said segments and said guide during the movement of said segments along said guide. . A method for the formation of a structure, as set forth in claim 1, wherein said merging of the cut ends of said aligned segments includes heating said ends to a temperature sufficient to at least partially melt the cut ends of said aligned segments. . A method for the formation of a structure, as set forth in claim 1, wherein said row formation of said plurality of aligned segments includes mechanically joining only at least one of the cut ends of each of said aligned segments on only the cut ends of at least one of the segments placed adjacently. A method for the formation of a structure, as set forth in claim 1, wherein said assembling of said rows of segments aligned one over the other includes depositing said rows in a consumable container formed of a material capable of being cut by a thermal device. 13. A method for the formation of a structure, as set forth in claim 12, wherein said thermal apparatus is a hot wire. A method for the formation of a structure, as set forth in claim 13, wherein said consumable container is formed of expandable polystyrene. A method for forming a structure, as set forth in claim 12, wherein said consumable container is positioned within a structure having openings provided therein which are adapted to provide access to said stack of segments rows aligned to wrap at least one band of plastic material around said stack. 16. A method for forming a structure, as set forth in claim 15, wherein said plastic material is a film having preformed stresses in which stresses are released by increasing the temperature of the film, causing the film to shrinks around said pile. A method for the formation of a structure, as set forth in claim 1, wherein said assembling of said rows of segments - aligned one over the other includes wrapping said stack of said rows of segments aligned with heat-shrinkable envelope before to cut said battery. 18. A method for forming a structure, as set forth in claim 1, wherein said cutting of said stack of assembled rows of aligned segments includes making a plurality of simultaneous cuts in. said distances separated in said direction along the longitudinal axes of the segments. 19. A method for forming a structure, as set forth in claim 18, wherein said simultaneous cuts are made by simultaneously passing a plurality of hot wires through said stack. . A method for forming a structure suitable for use as a core member, comprising: selecting a plurality of plates each of which are formed of a thermoplastic material having a predefined length and width, at least one surface that extends across said width, and a plurality of elongated passages placed in parallel relation along said length, and a plurality of elongated passages placed in parallel relation along said length, each of said elongated passages having a longitudinal axis perpendicular to the direction of the width of said plates; assembling said plates in abutment relationship with each other of said plates to form a stack of said plates in which the elongated passages in each plate are arranged in a common parallel direction transverse to the width of said stack, said stack having a width substantially equal to the width of said plates, a depth substantially equal to the preselected length of said plates, and a height determined by the number of plates assembled in said stack and the width of the rows; and cutting said stack of assembled plates in a direction transverse to the longitudinal axes of the longitudinal passages in a plurality of preselected separate distances in a direction along said longitudinal axes of the elongated passages and forming a plurality of separate structures each having a width and height substantially equal to the width and height of said stack and a thickness determined by the preselected distance between said cross sections through the stack, and simultaneously melting at least one of the cross sections of each plate with only one end transversely cut from a plate placed transversally one with the other. A method for the formation of a structure, as set forth in claim 20, wherein said method initially includes extruding a continuous thermoplastic sheet having a plurality of said elongated passages and said predetermined width, and cutting said thermoplastic sheet through of said width and forming said plurality of plates each selected having a predetermined length. 22. A method for forming a structure, as set forth in claim 20, wherein said selection of a plurality of plates having a plurality of elongated passages includes a selection of plates having a plurality of elongated passages each having a section of circular cross section. . A method for the formation of a structure, as set forth in claim 20, wherein said selection of a plurality of plates having a plurality of elongated passages includes a selection of plates having a plurality of elongated passages each having a section rectangular cross section. . A method for the formation of a structure, as set forth in claim 20, wherein said selection of a plurality of plates having a plurality of elongated passages includes a selection of plates having a plurality of elongated passages each having a section triangular cross section. . A method for the formation of a structure, as set forth in claim 20, wherein said selection of a plurality of plates having a plurality of elongated passages includes a selection of plates having a plurality of elongated passages each having a section of hexagonal cross section. 26. A method for forming a structure, as set forth in claim 20, wherein said plurality of elongated passages each formed at least partially by a base wall having a first side defined by said surface extending through of the width of said thermoplastic plate and a plurality of parallel parallel walls extending from a second side of said base wall in a direction normal to said base wall. 27. A method for the formation of a structure, as set forth in claim 20, wherein said elongated passages are defined by a plurality of U-shaped channels placed adjacently where the bottoms of said U-shaped channels define when monos a surface that extends across the width of said thermoplastic sheet. 28. A method for forming a structure, as set forth in claim 20, wherein said at least one surface extending across the width of said thermoplastic sheet is defined on one side of a corrugated wall and said elongated passages. they are defined by convex portions on respective sides of said corrugated wall. . A method for the formation of a structure, as set forth in claim 20, wherein said simultaneous fusion only at least one of the transverse ends of each plate with only one end cut transversely of a plate transverse to each other includes heating at least one cut end of each. one of the plates at a temperature sufficient to at least partially melt the respective cut ends of plates placed adjacent to said stack which, upon cooling, said cut ends are mutually fused together. . A method for the formation of a structure, as set forth in claim 20, wherein said assembly of said plates includes stacking said plates in a structure having provided openings that are adapted to provide access to said stack of plates to wrap at least a band of plastic material around said pile. . A method for the formation of a structure, as set forth in claim 30, wherein said plastic material is a film having preformed stresses in which stresses are released by increasing the temperature of the film, causing the film to shrink in around said pile. . A method for forming a structure, as set forth in claim 20, wherein said cutting of said stack of assembled plates includes a plurality of simultaneous cuts at said distances spaced in said direction along the longitudinal axes of the passages. in said plates. . A method for the formation of a structure, as set forth in claim 32, wherein said simultaneous cuts are effected simultaneously by passing a plurality of hot wires through said stack. . A method for forming a structure suitable for use as a core member, comprising: selecting a plurality of separate segments formed of thermoplastic material, each of said separate segments being formed of thermoplastic material having a preselected length and an axis longitudinal extending along said pre-selected length; aligning said plurality of said separated segments in side-by-side relationship along their preselected length; shrinking said plurality of segmented segments aligned in a bundle of segments wrapped by shrinkage; and cutting said bundle wrapped by shrinkage in a direction transverse to the longitudinal axes of the segments in said bundle at a plurality of preselected separate distances in a direction along said longitudinal axes and forming a plurality of shrink wrapped structures each having a thickness determined by the preselected distance between said transverse cuts, and simultaneously fusing segments aligned adjacently in said bundle with each other in at least one of the cut ends of the respective segments. 35. A method for forming a structure, as set forth in claim 34, wherein before said selection of separate segments, said method includes extruding a thermoplastic material into an elongated tubular shape of continuous length and cutting said elongated tubular shape. in a plurality of separate segments each having a preselected length. 36. A method for the formation of a structure, as set forth in claim 35, wherein said extrusion of a thermoplastic material into an elongated tubular shape includes extruding an elongated tubular shape having a hollow circular cross section. 37. A method for forming a structure, as set forth in claim 35, wherein said extrusion of a thermoplastic material into an elongated tubular shape includes extruding an elongated tubular shape having a hollow rectangular cross section. 38. A method for forming a structure, as set forth in claim 35, wherein said extrusion of a thermoplastic material into an elongated tubular shape includes extruding an elongated tubular shape having a hollow triangular cross section. 39. A method for the formation of a structure, as set forth in claim 35, wherein said extrusion of a thermoplastic material into an elongated tubular shape includes extruding an elongated tubular shape having a hollow hexagonal cross section. 40. A method for forming a structure, as set forth in claim 35, wherein said extrusion of a thermoplastic material into an elongated tubular shape includes extruding an elongated tubular shape having an internal transverse torques placed forming a plurality of elongated, separate hollow cells extending along the length of said tubular shape. 41. A method for forming a structure, as set forth in claim 34, wherein aligning a plurality of spaced segments in side-by-side relationship includes moving said segments along a guide having side walls that converge at a distance apart substantially equal to the length of said segments. 42. A method for forming a structure, as set forth in claim 41, wherein said method includes shaking said guide during the movement of said segments along said guide. A method for the formation of a structure, as set forth in claim 34, wherein said cutting of said bundle wrapped by shrinkage includes a plurality of simultaneous cuts at said distance spaced in said direction along the longitudinal axes of the segments in said beam. 4. A method for the formation of a structure, as set forth in claim 43, wherein said simultaneous cuts are made by simultaneously passing a plurality of hot wires through said bundle wrapped by shrinkage. . A method for forming a structure suitable for use as a core member, comprising: selecting a plurality of separate segments formed with a thermoplastic material, each of the separate segments being formed of a thermoplastic material having a preselected length and a longitudinal axis extending along said pre-selected length; aligning a plurality of said separate segments in side-by-side relationship along their preselected lengths; depositing said plurality of aligned separate segments within a consumable container formed of a material that is capable of being cut by a thermal apparatus; cutting through said separate segments deposited within said consumable container in a direction transverse to the longitudinal axes of the aligned segments at a plurality of preselected separate distances in a direction along the longitudinal axes and forming a plurality of separate structures each one having a thickness determined by the preselected distance between said transverse cuts, and simultaneously fusing aligned segments positioned adjacent one to the other at least one cut end of the respective segments. 46. A method for forming a structure, as set forth in claim 45, wherein prior to said selection of a plurality of spaced segments, said method includes extruding a thermoplastic material into an elongated tubular shape having a continuous length and cutting said elongated tubular shape into a plurality of separate segments each having a preselected length. 47. A method for forming a structure, as set forth in claim 46, wherein said extrusion of a thermoplastic material into an elongated tubular shape includes extruding an elongated tubular shape having a hollow circular cross section. 48. A method for forming a structure, as set forth in claim 46, wherein said extrusion of a thermoplastic material into an elongated tubular shape includes extruding an elongated tubular shape having a hollow rectangular cross section. 49. A method for forming a structure, as set forth in claim 46, wherein said extrusion of a thermoplastic material into an elongated tubular shape includes extruding an elongated tubular shape having a hollow triangular cross section. 50. A method for forming a structure, as set forth in claim 46, wherein said extrusion of a thermoplastic material into an elongated tubular shape includes extruding an elongated tubular shape having a hollow hexagonal cross section. 51. A method for the formation of a structure, as set forth in claim 46, wherein said extrusion of a thermoplastic material into an elongated tubular shape includes extruding an elongated tubular shape having an internal transverse torques placed forming a plurality of elongated, separate hollow cells extending along the length of said tubular shape. 52. A method for forming a structure, as set forth in claim 45, wherein aligning a plurality of spaced segments in side-by-side relation includes moving said segments along a guide having side walls that converge at a distance apart substantially equal to the length of said segments. . A method for forming a structure, as set forth in claim 45, wherein said method includes shaking said guide during the movement of said segments along said guide. . A method for forming a structure, as set forth in claim 45, wherein said fusing of the cut ends of said aligned segments includes heating said ends to a temperature sufficient to at least partially melt the cut ends of said aligned segments. . A method for forming a structure, as set forth in claim 45, wherein said consumable container is formed of expanded polystyrene. . A method for forming a structure, as set forth in claim 45, wherein said consumable container is positioned within a structure having openings provided therein which are adapted to provide access to said consumable container containing a plurality of segments for wrapping at least one band of plastic material around said consumable container. . A method for the formation of a structure, as set forth in claim 45, wherein said cutting of said aligned segments deposited in said consumable container includes making a plurality of cuts simultaneous to said separated distances in said direction along the axes. longitudinals of the segments. . A method for forming a structure, as set forth in claim 57, wherein said simultaneous cuts are made by simultaneously passing a plurality of hot wires through said separate deposited segments and said consumable container. . A member suitable for use as a core, said member having a pair of spaced apart surfaces defining the thickness of the member, said member comprising: a plurality of adjacently placed rows of preformed thermoplastic plate structures, said rows of preformed plate structures being placed in a direction normal to the thickness of the member, each of said plate structures having a predefined width, at least one continuous surface extending through said width, each end having an end portion perpendicular to said width and a plurality of elongate passages placed in parallel relation to said at least one surface and each other, each said elongated passages having a longitudinal axis perpendicular to the width direction of said plate and a section of uniform cross section along the length of the length of the tickets; wherein only an end portion of at least one of said spaced ends of each plate structure is fused with only the end portion of at least said spaced apart ends of an adjacent thermoplastic plate structure, and the cross sectional area The openness of the passages in each of the spaced ends is equal to the open cross sectional area at any point over the length of said passages. . A member, as set forth in claim 59, wherein said fused portions of said adjacently placed rows of the thermoplastic plate structures are positioned on at least one of the pair of spaced apart surfaces defining the thickness of said member. . A member, as set forth in claim 59, wherein said passages have a hollow rectangular cross section. 62. A member, as set forth in claim 59, wherein said passages have a hollow triangular cross section. 63. A member, as set forth in claim 59, wherein said passages have a hollow circular cross section. 64. A member, as set forth in claim 59, wherein said passages have a hollow hexagonal cross section. 65. A member, as set forth in claim 59, wherein said passages have at least one transversely placed inner wall forming a plurality of separate elongated hollow cells extending along the longitudinal axis of each of said passages.