MXPA00003612A - Spiral formed products and method of manufacture - Google Patents

Abstract

Hollow thermoplastic foam tubes of any desired diameter are easily achieved as well as large sheets or planks of thermoplastic foam material in any width and thickness desired by wrapping and fusing a thermoplastic foam profile (22) having a desired size and shape. By employing a thermoplastic foam extruder (21) to produce a profile (22) having a desired cross-sectional shape or configuration, and advancing the profile onto a rotating support member (30) for being wrapped peripherally surrounding the rotating support and continuously bonding the abutting edges of the profile (22) as it is spirally wound. By employing this unique spiral forming process, a hollow cylindrical thermoplastic foam tube (28) is formed on a continuous basis, with the length thereof being controlled by necessity. In addition, any desired diameter can be formed by employing a rotating support having the desired diameter, with the thickness of the tube being controlled by the thickness of the profile formed by extrusion equipment (21).

Description

PRODUCTS FORMED IN SPIRAL AND METHOD OF ELABORATION OF THE SAME TECHNICAL FIELD This invention relates to foamed thermoplastic products and methods for their manufacture and, more particularly, to foamed thermoplastic products made by a continuous formation in a substantially cylindrical configuration.

BACKGROUND OF ART During the last decades, a substantial effort has been expended and an interest has been developed in the formation and construction of products that use foamed thermoplastic materials. Normally, these products can be formed either by extrusion or foamed molding. However, without taking into account which method is used, there are production limitations in the size and manner in which products can be produced effectively at competitive prices. An example of the type of products produced using the extrusion process is the creation of hollow elongated cylindrical tubes formed of foamed thermoplastic material. These tubes are used in a REF .: 119374 wide variety of products, usually as an insulation for a fluid transported by pipes or ducts. Although the process of extrusion processing to form the cylindrically formed foamed thermoplastic tubes has progressed over the years for an extremely efficient production system, the largest diameters of a tube are approximately 17.78 cm (seven inches) which are incapable of occur in conventional equipment. Although there is a substantial market for larger diameter tubes formed of thermoplastic material, this demand can not be satisfied using conventional extrusion equipment. The manufacturers of larger diameter foam tubes require "1 to invest in the purchase of extremely expensive industrial equipment, in view of this demand it may be appropriate to use the current technology, in view of the substantial investment that must be made by the manufacturing companies in obtaining equipment. To meet the industrial needs for the larger diameter cylindrical pipe members, the products produced to meet this demand are extremely expensive, when compared to the conventional price with respect to the smaller diameter thermoplastic pipes. Demand for the products and the desired industry 'for competitive prices, the prior art technology has not provided a processing method capable of producing larger diameter cylindrical tubes at a real cost, in a competitive price manner. by the hollowed-out cylindrical tubes, of larger diameter, also in There is substantial demand for the foamed thermoplastic material formed in the form of a large sheet with a wide range of thicknesses. Generally, conventional extrusion equipment for forming foamed thermoplastics is incapable of producing foamed polymer sheets having amplitudes greater than about 30.48 cm (12") with a thickness of approximately 1.27 cm (1/2"). Consequently, the demand for the larger foam plastic sheet is unable to be satisfied by conventional manufacturers. To meet the industrial needs for this extremely expensive product, equipment of practical design must be purchased, which produces the most extensive foam sheet products, which is why it is more expensive. In addition, capital recovery for this investment is slow.

Although specialized manufacturers possessing this expensive equipment are capable of producing the foamed thermoplastic sheet material in larger configurations, these manufacturers are still limited in thickness which can be produced on a single sheet. Normally, these extruded anterior art sheets are capable of producing a sheet of material that has a maximum thickness of 1.27 cm (1/2") Therefore, any customer who wishes to have a final product with a thickness of 1.27 cm (1/2"), it is required to have the product produced employing a plurality of sheets that are cut to a size and integrally joined together to build a final product in the desired thickness. As a result, additional processing and expense management is incurred and the final product produced by these specialized procedures increases substantially in cost. To produce a plank material in thicknesses greater than 1.27 cm (1/2"), a plurality of sheets must be laminated or joined together in secondary processes, increasing the thickness of the profile by 1.27 cm (1/2") with each process. The rolling steps substantially increase the complexity of the processing processes as well as increase the proportions of the waste in general. In an effort to allow the production of plank material in thicknesses greater than 1.27 cm (1/2"), accumulators have been built and used with extruders.Using a combination of extruder / accumulator, the foamed plastic is transferred directly from the Extruder in the accumulators until the accumulator is full, then a piston or plunger is used, the accumulated plastic is forced out of the accumulator, using this system, planks with thicknesses above 5.08 cm (2") can be achieved. However, this process is inefficient, since it must be executed intermittently and can not be operated continuously. In addition, a higher waste ratio is obtained due to the intermittent stop / start process. As is evident from these systems, despite the demand to improve the processing techniques, no industrial system for processing the prior art has been developed to reduce the costs involved. Accordingly, it is a principal object of the present invention to provide a method for making larger diameter foam tubes and a plastic foam sheet material, using a production method which is easily realized, highly effective, and comparatively economical. Another object of the present invention is to provide a new industrial processing process having the characteristic features described above which make the larger diameter hollow cylindrical tubes and the large foamed sheet material produced at an extremely economical cost possible. Another object of the present invention is to provide a new industrial process having the characteristic features described above which are capable of being used with a minimum of labor and at optimum production speeds. Other and more specific objects will be partly obvious and partly appear next.

BRIEF DESCRIPTION OF THE INVENTION Using the present invention, all the difficulties and drawbacks encountered in the prior art systems are eliminated and the hollow thermoplastic foamed tubes of any desired diameter are easily made as well as the large plank sheets of thermoplastic foamed material in any desired width and thickness. In the present invention, all the complex and expensive equipment previously required to satisfy the industrial needs for these products is eliminated and a unique industrial process of easy use is used. In accordance with the present invention, a thermoplastic foam extrusion system is employed to produce a profile having any desired cross-sectional shape or configuration, with the profile being advanced towards a rotating cylindrical handle. When the foamed profile is wound around peripherally the rotating handle, the end edges of the profile continuously melt together in an industrial operation that forms a spiral. In its preferred embodiment, the elongated, extruded thermoplastic profile is advanced towards the rotating cylindrical handle at any desired angle that allows the profile to advance continuously, longitudinally along the length of the handle as the lateral edge of the incoming profile joins the edge of the profile adjacent, wound in a manner that forms a generally continuous spiral. Using this unique process that forms the spiral, a hollow cylindrical thermoplastic foamed tube is formed on a continuous basis, with the length thereof controlled solely by the customer's need. In addition, any desired diameter can be formed using a rotary handle having a desired inside diameter for the product. Both the diameter and the external thickness of the tube are controlled by the thickness of the profile formed by the extrusion equipment. As is clear from this description, a very efficient, economical manufacturing process is performed which is capable of producing hollow cylindrical tubes formed of a thermoplastic foamed material with the tube comprising any desired thickness and any desired diameter. In addition, by cutting the elongated formed tube to any desired length, products are produced to the precise specification desired by the customer. In addition to providing a foamed, elongated, hollow cylindrical plastic tube having any diameter, wall thickness, and length desired by a customer, the process of the present invention also achieves a hollow cylindrical tube member having any shape in section cross section, configuration, or opening model desired by a customer. As is well known in the art, the expanded foamed plastic extrusions can be formed with any desired cross-sectional shape, full configuration, aperture pattern and the like as part of the forming process. Accordingly, by employing these known forming techniques in combination with the spiral forming process of the present invention, cylindrical tubes can be formed incorporating a particularly desired pattern or configuration. In this way, flexibility and improved product design capabilities superior to current processing techniques are achieved by employing the present invention. An additional feature provided by the unique industrial process of the present invention is the ability to produce cylindrically shaped recessed tubes having any desired wall thickness, diameter, and total configuration along with the additional capacity to provide the cylindrical tube members that incorporate two or more layers integrally joined together. Using conventional techniques, such as co-extrusion, extrusion of cutting head, or joining or fusing in line, one or more layers of the additional material can be joined to the initial extrudate layer of foamed plastic emanating from the extrusion equipment.

Once the additional layer or layers of material has been attached to the base layer or profile, as desired, the multi-layer profile is advanced to the industrial equipment forming the spiral of the present invention. In this way, the precise, hollow cylindrical component, hollowed out, sought by the customer is achieved in any desired diameter and thickness. Using this technique, the substantially reinforced speed and production capacities are realized as well as the achievement of the products that had previously been unattainable using conventional, known manufacturing techniques. In addition to providing the hollow cylindrical tubes constructed singularly detailed above, the spiral forming process of the present invention also provides substantially planar sheets or planks of any desired thermoplastic material. It has been found that by initially forming a cylindrical tube in the manner detailed above and then longitudinally cutting or cutting the wall of the tube, the spiral-shaped material is opened in a substantially flat sheet or plank of foamed thermoplastic material. Using this processing process, the sheets or boards of thermoplastic foam of greater amplitude are formed with any desired thickness or configuration, eliminating the costly multi-stage operations of the prior art or the use of extruders and ("Accumulators, which are required to obtain similar product constructions.) Furthermore, the present invention is capable of obtaining a flat sheet or plank of thermoplastic material which is formed in any configuration or pattern required by a consumer. , the present invention also achieves a comparatively cheap thermoplastic foam sheet or board member readily produced which comprises a plurality of layers of different materials that have been fused or joined together to form any configuration or desired construction sought by the user. As detailed above, the present invention obtains a sheet or board of the material formed in a single step with the final product comprising any desired specification sought by the user.

As a result, the whole industrially manufactured sheet or plank is revolutionized by this invention with the final product being obtained using conventional extrusion equipment. Accordingly, the costs to produce any desired product are Substantially reduced.

As is evident from the above description, the present invention is capable of realizing the hollow cylindrical tubes of foamed thermoplastic material in any desired diameter and thickness as well as the substantially smooth sheet or planks formed of foamed thermoplastic material in any thickness, configuration, or appearance desired visual in a way that is produced economically, simply, and directly without employing expensive equipment, especially a designed equipment. In addition, the waste material is reduced, and lots or small amounts of material can be made in any color, size, formulation of the product, etc. desired by a user. Since small quantities can be produced, extensive inventories are eliminated and significant cost reductions are made.

BRIEF DESCRIPTION OF THE DRAWINGS For a full understanding of the nature and objects of the present invention, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings, in which: Figure 1 is a view in perspective of the processing equipment used to produce the cylindrical tubes formed in a spiral according to the present invention; Figure 2 is a perspective view, mostly enlarged, of a portion of the equipment described in Figure 1 wherein the joining operation employed to form the hollowed tube member of the present invention is described.; Figure 3 is a perspective view of the preferred embodiment of the joint forming head employed in the equipment described in Figure 2; Figure 4 is a schematic perspective view describing the assembly of the rotating mandrel used to form the recessed tubes of the present invention; Figure 5 is a perspective view of the assembled rotary mandrel system fully described in Figure 4; Figure 6 is a perspective view of the rotating cylindrical mandrel of Figure 5 described in the process of forming a tube member hollowed therein; Figure 7 is a perspective view of a hollow cylindrical tube member formed in accordance with the present invention in the opening process to form a substantially smooth sheet or board; Figure 7A is a perspective view of a roller system; Figure 8 is a perspective view of a substantially thermoplastic foamed sheet or plank: > plane formed in accordance with the present invention; Figure 9 is a graphical perspective view describing the formation of a hollow cylindrical tube according to the process of the present invention wherein a second layer of material 0 is fixed to the formed layer extruded prior to the formation of the cylindrical tube; Figure 10 is a perspective view describing an enlarged plank or sheet of the plastic foam material formed with a second layer fixed thereon; Figure 11 is a perspective view of a hollow cylindrical tube graphically described employing the present invention to form a double layer hollow cylindrical member; and Figure 12 is a series of fourteen cross-sectional views of the alternative configurations of the extruded thermoplastic foam profile.

DETAILED DESCRIPTION Referring to Figures 1-12, together with the following detailed description, the construction of the processing equipment, the process of the present invention, and the uniquely constructed products achieved with the present invention can be better understood. However, as will be apparent from this detailed description, variations may be made in the processing equipment, the method steps, and the resulting products without departing from the scope of this invention. Accordingly, the description provided herein, as well as that shown in Figures 1-12, are desired as examples of the present invention and not as a limitation thereof. In Figure 1, the preferred embodiment of the system forming the product 20 of the present invention is fully described. In this embodiment, the product forming system 20 comprises an extruder 21, having a generally conventional configuration, which produces the foamed thermoplastic profile 22, in any desired configuration and has side edges 25 and 26. An extractor 23 is employed for continuously extracting the foamed thermoplastic profile 22 from the extruder 21 and the feed profile 22 to the tube forming machine 24.

Using this invention, any thermoplastic material can be used to form the profile 22. However, the preferred thermoplastic material fc comprises one or more of the one selected from the group consisting of polystyrenes, polyolefins, polyethylenes, polybutanes, polybutylenes, polyurethanes, thermoplastic elastomers, thermoplastic polyesters, thermoplastic polyurethanes, polyesters, ethylene-acrylic copolymers, ethylene vinyl acetate copolymers, or ethylene-ethylacrylate copolymers, ethylene-butyl-acrylate copolymers, isomers, polypropylenes, and polypropylene copolymers. According to the present invention, as shown in Figures 1, 2, 4, and 5, the machine that The tube 24 is constructed to receive the thermoplastic foamed profile 22 in the continuously rotating mandrel 30 in a manner that causes the profile 22 to be wound around the rotating mandrel 30 of the machine forming the tube 24, continuously forming a plurality of spiral winding convolution 27, in a final side-by-side relationship. In this way, the incoming continuous feed of the foamed thermoplastic profile 22 is automatically rotated on the mandrel 30, in a generally spiral, causing the lateral edge 25 of the incoming profile 22 to be brought into terminal contact with lateral edge 26 of the convoluted convolution 27 and previously received. The finished side edges joined together 25 and 26 at this junction point, the hollowed substantially cylindrical tube 28 is formed. To provide the integral attachment coupling of the side edge 25 of the profile 22 with the side edge 26 of the winding 27, a joining or fusion head 31 is employed., the junction / fusion head 31 may comprise a variety of alternative constructions to achieve the desired interengage, fixation, securing interengagement of the edge 25 with the edge 26. In the preferred embodiment, as described in Figures 2 and 3, the junction / fusion head 31 employ hot air. In this preferred embodiment, the junction / fusion head 31 is constructed of hot conductive material and is formed as a recessed housing comprising side surfaces 32 and 33, an upper surface 34 and an edge 35. Supplying hot air to the head 31 a Through the portal 36 formed in the upper surface 34, the temperature of the surfaces 32 and 33 of the head 31 are raised to a level that allows the lateral edges of the profile 22 and the winding 27 which is in contact with the head 31 be elevated to its melting point. Further, in the preferred embodiment, the head 31 also comprises openings 37 formed in the edge 35 that release a continuous flow of hot air directly to the side edges 25 and 26, ensuring that the melting temperature is reached and the edges 25 and 26 they are founded or join firmly with each other. As best seen in Figure 2, the union / fusion head 31 is positioned in the joint region in which the lateral edge 25 of the incoming profile 22 is brought into contact with the lateral edge 26 of the spirally convoluted convolution and received previously 27. Causing the union / fusion head 31 the simultaneous contact of the lateral edge 25 and the lateral edge 26 of these components of the profile 22, the temperature of the surfaces is raised to the melting point, allowing to bring the direct contact of the lateral edge 25 of the incoming profile 22 with the side edge 26 of the first spirally convoluted convolution 27 in a manner that causes the surfaces to be intimately joined together. In the preferred construction, as described in Figures 1 and 2, the machine forming the tube 24 comprises a hot air generator 38, which is directly connected to the junction / fusion head 31 to release the desired hot air to the junction / fusion head 31. Although hot air is preferred for this bonding operation, an alternative fixation means may be employed without departing from the scope of this invention. An alternative is the use of heated adhesives applied directly to the side edges. The machine forming the tube 24 also preferably incorporates the means for receiving the profile 22 contacting the rotating mandrel 30 and for guiding the profile 22 towards the mandrel 30 to form the winding 27. In the embodiment described in Figure 2 , a plurality of guide rollers 40 are employed which are constructed with deferred diameters to impart the desired position for the profile 22 relative to the mandrel 30, allows the profile 22 to be advanced towards the rotary mandrel 30 at the desired angle to form the coils 27 In the embodiment of the machine forming the tube 24 described in Figures 4 and 5, an arcuate curved bent ramp 41 which is used to receive the incoming feed of the thermoplastic profile 22 and guide the profile 22 towards the rotating mandrel 30 in the desired angle achieving the winding 27.

Referring to Figures 1, 2 and 4-6, together with the following detailed analysis, the construction and operation of the preferred embodiment of the machine forming the tube 24 can be better understood. In this preferred embodiment, the machine forming the tube 24 comprises a support housing 45 which incorporates the rotatable cylindrical handle 46 mounted therein, constructed to rotate continuously about the central axis thereof. In addition, as best seen in Figure 4, the mandrel 30 is integrally interconnected with the mounting plate 47, while the ramp 41 is integrally interconnected with the mounting plate 48. To provide the desired continuous rotary movement of the mandrel 30 with In relation to the stationary lift ramp 41, the mounting plate 47 is fixed firmly to the rotating cylindrical handle 46. In addition, the mounting plate 48 is fixedly secured to the housing 45, such that the lift ramp 41 is mounted firmly to the housing 45 in a stationary position while the mandrel 30 continuously rotates about its central axis due to the continuous rotation of a cylindrical handle 46. Also the machine forming the tube 24 preferably incorporates a support frame 50 mounted in association with the rotating mandrel. 30 and support housing 45. Although the support frame 50 can be constructed in a variety of alternative embodiments, as described in the drawings The purpose of the support frame 50 will be positioned to receive the hollow cylindrical tube 28, when the tube 28 is formed, and provides any support that may be required to support the tube 28 as the tube 28 is formed and axially extended next to the housing 45. Although a wide variety of alternative constructions can be employed to ensure support control, continuous, guided recessed cylindrical tube 28, as the tube 28 is formed by the forming machine 24, the preferred components incorporated with the supporting frame 50 they include a plurality of rollers 51 that are specifically constructed for a desired or adjustable diameter to fit any desired diameter of the tube 28. In the preferred construction, the rollers 51 are mounted to the frame 50 and positioned to contact the outer surface of the tube 28 as tube 28 is formed and axially extends exteriorly of housing 45. Prop by orienting the support rollers, the continuous rotary movement of the tube 28, as well as its axial, longitudinal movement next to the housing 45 is able to be easily accommodated.

Using the present invention, the cylindrical tube 28 can be formed in any desired diameter by altering only the diameter of the mandrel 30. By constructing the mandrel 30 with an outer diameter substantially equivalent to the desired inner diameter for the tube 28, the precisely desired internal diameters are obtained of the tube 28. As a result, the larger diameter of the hollow cylindrical tubes can be quickly and easily formed, without requiring the use of expensive, sophisticated, specially designed industrial equipment. In addition to using mandrels of varying diameters to achieve the tube dimension of the desired inner diameter, both the outer diameter and the thickness of the tube 30 are controlled by the formation of the profile 22 with the desired dimensions and thickness.

Clearly, by forming the profile 22 with the desired thickness as part of the extrusion process that is processed by the extruder 21, the desired thickness for the tube 28 is achieved. In addition, as further detailed below, the variant configurations and the shapes in Cross section are also produced by the extruder 21 to achieve the specially constructed tube configurations. In addition to producing hollow cylindrical tubes having any desired diameter and thickness, the present invention also produces hollow cylindrical tubes having any desired length. As detailed above, the profile 22 is continuously received by the machine forming the tube 24 which continuously joins the incoming profile 22 to the end of the previously received connecting coils 27 forming the tube 28. As a result, the cylindrical tube recessed 28 axially continuously advances immediately. of the support housing 45 in a manner that allows the formed hollow cylindrical tube 28 to increase continuously in length up to the cut. In this way, any of the desired tube lengths can be accommodated easily and efficiently in an economical manner. In Figure 1, an embodiment is described for cutting the hollow cylindrical tube 28 to a desired length. In this embodiment, the cutting assembly 54 incorporates a blade housing 55 into which the cutting blade 56 is held and continuously rotated. Finally, in this embodiment, the blade housing 55 is mounted on the vertical posts 57 mounted on opposite sides of the frame assembly 50. Using this embodiment for a tube cutting system, when a desired length of the tube 28 has been formed , the blade housing 55 is upwardly advanced along the support post 57, by placing the cutting blade 56 in contact with at least the lower portion of the tube 28. Subsequently the tube 28 continuously rotates about its central axis, the portion of the recessed tube 28 is brought into contact with the changes of the cutting blade 56, thereby enabling the cutting blade 56 to effectively cut the tube 28 completely to achieve the desired length. As shown in Figure 1, once the desired length of the tube 28 is achieved, it can be transported in a conveyor system to any desired location and allows the next length of the hollow cylindrical tube 28 to be formed and cut in a similar manner. An additional element that can be incorporated in the machine forming the tube 24 if desired is an alignment roller 60, described in Figure 6. If employed, the alignment roller 60 is mounted in the support housing 45 in association direct with the position where the profile 22 firmly attaches to the previously rolled convolution 27. By employing the alignment roller 60, which preferably comprises a total length greater than the amplitude of the profile 22, it is ensured that the incoming profile provided 22 is attached to the convolution 27 previously received in a flat, uniform, substantially continuous configuration. In this way, the outer surface of the tube 28 is maintained with an outer surface substantially continuous, flat, uniform, formed integrally therewith. As detailed above, the product forming system 20 of the present invention allows the efficient production of hollow cylindrical tubes 28 with virtually any desired diameter and wall thickness, without requiring the use of expensive, specially designed industrial equipment. As a result, a substantial advance is achieved in the formation of larger diameter cylindrical tubes. In addition to the substantial breakthrough and unique discovery in the production of hollowed-out larger diameter cylindrical tubes, the present invention also achieves the equally effective production of sheets or boards of greater amplitude than thermoplastic foamed material in virtually any desired thickness. As shown in Figure 7, a substantially flat sheet or plank of foamed thermoplastic material is easily achieved from the hollow cylindrical tube using cutting means 65.

To achieve a subtially flat sheet or plank of foamed thermoplastic material 70, the cutting means 65 with the circular cutting blade 66 is mounted and supported in a conventional manner to cut longitudinally through the wall of the hollow cylindrical tube 28. As the tube 28 is cut longitudinally in the manner described in Figure 7, the thermoplastic material forming the tube 28 is allowed to extend outwardly, forming a planar or subtially flat sheet 70 of thermoplastic material. If the length of the tube 28 does not correspond to the desired length for the sheet / plank 70, the plank / sheet 70 only runs to the desired length to obtain the plank / sheet 70 described in Figure 8. As is clear from the description above, the plank / sheet 70 is constructed to any desired width only by forming the hollow cylindrical tube 28 with a diameter, or circumference, which will produce the desired amplitude when the tube 28 is cut longitudinally and formed in the plank / leaf 70. In addition , any desired thickness sought for the plank / sheet 70 is easily achieved by forming the profile 22 with the precisely desired thickness. As a result, using the present invention, the plank / sheet is constructed in any amplitude and thickness in a single production step, whereby the need to use expensive, specially designed industrial equipment as well as employing numerous repetitive steps required for construct the products that have a thickness greater than 1.27 cm (1/2"). The transition or transformation of the thermoplastic material of the hollow cylindrical tube 28 to a plank / sheet 70 subtially smooth, flat, depends on the temperature of the profile 22 during the formation of the tube 28. as well as the temperature of the plastic material when the tube 28 is cut longitudinally In the preferred operation, the cylindrical tube 28 is formed using a heated profile 22, and the tube 28 is cut while the foamed thermoplastic material retains the enough heat from the extrusion process.Thus, the plank / sheet 70 is formed automatically or easily formed by single Place the plank / sheet 70 in a flat configuration and allow the plank / sheet 70 to cool in this configuration. If desired, a roller system may be employed as described in Figure 7A. As shown therein, the rollers 80 and 81 are mounted in the housing 82 and are interconnected with the driving means (not shown) which is connected to the rotary driving rollers 80 and 81 in opposite directions.

In the preferred constructions, the rollers 80 and 81 are rotationally driven to allow the plank / sheet 70 to be received by the rollers 80 and 81 and automatically advance between the rollers by the rotary movement thereof. In addition, the plank / sheet 70 advances immediately from the rollers 80 and 81 by the action of the roller 80 with the support board 83, after being wound on the roller 80. In those cases where the plank / sheet 70 incorporates a curved residual shape due to its formation from a cylindrical tube, the roll system described in Figure 13 can be used to eliminate the residual curve. Feeding the plank / sheet 70 between the rollers 70 and 81 and causing the plank / sheet 70 is wound on the roller and emerges from the roller 80 in the table 83, the residual curve incorporated in the plank / sheet 70 is eliminated by neutralizing this residual curve with the curl curl of the plank / sheet 70 on the roller 80 .

Using this roller system, any residual curve in the plank / sheet 70 is quickly and easily removed, to produce the plank / sheet 70 with any desired dimension in the precisely desired planar configuration.

In alternative production situations, that is to say where the tube 28 is formed using the profile 22 heated but allowed to cool before cutting or in situations where the profile 22 has cooled prior to the formation of the tube 28, some residual curvature may remain after the tube 28 has been cut longitudinally. However, in any situation, the curved sheet or plank is located only in a heat chamber in a manner that allows the sheet / plank 70 to be formed in a substantially planar configuration. Once the sheet / plank 70 has been formed in a flat, substantially smooth configuration, the sheet / plank 70 retains the smooth configuration after cooling. Using this process, which is usually referred to as thermoforming, the sheet / plank 70 can be formed in any desired cross sectional configuration. As a result, if desired, the sheet 70 can be formed in any desired way, like a rectangle and placed in a heat chamber. Once it is sufficiently heated, the foamed thermoplastic material is removed from the heat chamber and allowed to cool in the newly formed form. Once cooled, the thermoplastic material remains in the new configuration until it is reheated and put into a new configuration. Many foaming products are formed with a plurality of separate and distinct layers to achieve a final product that is capable of satisfying the specific conditions required by the user. Examples of such products include hollowed-out, rolled cylindrical foamed tubes with an outer cover for durability or weather protection; the foamed tubes incorporate an elongated longitudinal opening in combination with a pressure sensitive adhesive to close the opening after installation; 'Laminated tubes, laminated with an inner cover for protection of high temperatures or protection from moisture; foamed sheets laminated with special adhesives and / or protective coatings; foamed sheets or laminated profiles with different colored materials; and the foamed tubes coextruded with dissimilar materials, such as wire, to improve the structural properties. Although conventional production techniques of the prior art are capable of efficiently producing sheets and foamed profiles having multiple layers for these purposes, as detailed above, the ability to produce similar products in the form of tubes with larger diameters is extremely expensive. Similarly, the production of the thermoplastic material in large sheets with a plurality of layers is also extremely difficult and expensive to produce. However, using the present invention, these difficulties and incapacities of the prior art are eliminated and an efficient, sophisticated, low cost and very competitive production system is achieved to produce hollow cylindrical tubes of multiple layers and sheets or planks in flat or any shape or configuration desired. With reference to Figure 9, a method for applying a second layer to the profile 22 is graphically described. In this embodiment, although not shown, the tube 28 is produced using a tube forming machine 24 detailed above. In this example process, the second layer 72 is firmly attached to the thermoplastic foamed profile 22 by adhesive means 73. As described, an adhesive application head 74 is positioned in co-operating relationship with a second layer 72 by applying the adhesive 73 to the adhesive. a surface thereof as the layer 72 is removed from the roll of layers 75. When the adhesive means 73 is applied to a surface of the layer 72, the layer carrying the adhesive is applied directly to a profile surface 22, joining and firmly securing the layer 72 to the profile 22. As is clear to one skilled in the art, a plurality of alternative layers and construction methods can be employed to attach a second layer 72 to the profile 22. The method shown in Figure 9 is only employed for example purposes and it is not desired in any way to limit the present invention, since numerous alternate methods can be used without departing from the scope of this invention. Once the layer 72 is firmly fixed to the profile 22, the dual layer component is advanced towards the machine forming the tube 24 in a detailed manner above to form a hollow cylindrical tube 28 incorporating an internal center foamed with a outer surface comprising the second layer 72. In Figure 10, the dual layer material produced in Figure 9 is described as a substantially flat sheet or plank 70. Since the dual layer material is employed as the source material , the plank or sheet 70 of Figure 10 comprises the layer 72 intimately joined to the thermoplastic material comprising the profile 22.

In Figure 11, an alternative construction is alternatively described to form a cylindrical dual layer hollow tube 28. In this embodiment, the layer 77 of the desired material is firmly fixed to the bottom of the profile 22 to produce the hollow cylindrical tube 28 having an internal center comprising the layer 77 of the desired material. As detailed above, this embodiment of the tube 28 is formed identically using the machine forming the tube 24. Using this construction, a higher temperature insulating material can be used for the layer 77, thereby providing a 'tube 28 cylindrical hollowed out best cost able to withstand high temperatures in applications where this requirement is necessary. In addition, using this invention, the tube 28 can be constructed with this dual layer configuration to achieve a tube having any desired diameter and the thickness required for a particular application. In addition to form the hollow cylindrical tube 28 in the manner detailed above as either a single layer of foamed thermoplastic material or as a multi-layer product incorporating additional layers of the material bonded thereto, both the cylindrical tube and the substantially flat sheet or plank produced by the present invention can be formed in a wide variety of shapes or configurations I I alternatives. In this way, any desired configuration sought for a final product can be achieved using the present invention. In Figure 12, several example forms are provided which represent the cross-sectional shape produced by the extrusion machine 21 described in Figure 1. Although these forms alternatives are not exhaustive of the wide variety of cross-sectional configurations and interior cavities capable of being produced using conventional extrusion equipment, the shapes are provided as an example of the various configurations that can be achieved. In addition, by employing the present invention, the interengagement of joining the side edges of the adjacent profiles when wound around the mandrel 30 allows to achieve the wide variety of configurations of the final product. For example, the cross-section described in cross-section "A" of Figure 12 depicts an overlapping cover edge to produce a hollow cylindrical tube having an overlapping overlapping edge configuration joining each convolution 2. 5 adjacent to it. Further, if desired, a substantially flat sheet or plank can also be produced from the hollow cylindrical tube formed from the profile represented by the cross section WA "of Figure 12. The cross sections" G "," I ", and" J "are examples of profiles produced with interior cavities These cross-sectional shapes are only examples of the wide variety of cross-sectional configurations that may occur, including the number, position, and shape of the interior cavity. of this general configuration are of particular importance to produce the substantially planar sheets or planks that incorporate the longitudinally extending interior cavities.To produce a final product of this nature, a hollow cylindrical pipe is produced and cut longitudinally as detailed above. However, to ensure a substantially continuous open area, which extends longitudinally, through the entire sheet or panel, the resulting panel / sheet product will be cut or fixed at the appropriate angle to achieve a final configuration where each of the profiles forming the sheet or panel is parallel with the lateral edge, whereby it allows the inner cavity contained therein to extend longitudinally through the entire sheet or panel. In this way, several products, such as shock absorbing mats, protectors, coatings, floats, etc. they are produced in an efficient way, with a highly effective cost. As is clear from the above-described description, the present invention achieves unique product configurations, production equipment, and processing processes that have previously been unattainable at least requiring the use of expensive production equipment and expensive processing steps. . However, using the process and equipment detailed herein, products that previously have been unreachable using prior art technologies are now produced. Accordingly, although certain examples have been provided as a description of the present invention, it is understood that these examples are only to show the total invention and are not intended to limit the present invention. It will thus be seen that the objectives indicated above, between those clearly made from the previous description, are effectively achieved and, since certain changes can be made by carrying out the above process, and the construction of the equipment detailed above, as well as the resulting product described in the present, without departing from the scope of the invention, it is desired that all the material contained in the above description or shown in the accompanying drawings will be construed as illustrative and not in a sense of limitation.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects or products to which it refers.

Claims (27)

RE IVINDICATIONS
1. Having described the invention as above, the content of the following claims is claimed as property: 1. A method for the production of foamed thermoplastic products characterized in that it comprises the steps of: A. extruding a foamed thermoplastic member in a substantially continuous length, which extends longitudinally, elongated having a desired cross-sectional shape; B. advancing the foamed thermoplastic member extending longitudinally in association with the forming means; C. winding in a controlled manner the longitudinally extending foamed thermoplastic member elongated in the forming means in a manner to cause opposite sides of the foamed thermoplastic member to be positioned in an adjacent, side by side, juxtaposed relationship; and D. joining together the adjacent side edges, spaced, juxtaposed, of the foamed thermoplastic member; whereby the foamed, recessed thermoplastic products having any desired size or shape are provided. v
2. 2. The method according to claim 1, characterized in that the foamed thermoplastic member comprises at least one selected from the group consisting of polystyrenes, polyolefins, polyethylenes, polybutanes, polybutylenes, 10 polyurethanes, thermoplastic elastomers, thermoplastic polyesters, thermoplastic polyurethanes, polyesters, ethylene-acrylic copolymers, ethylene vinyl acetate copolymers, ethylene-methylacrylate copolymers, ethylene-butyl-acrylate copolymers, 15 ionomers, polypropylenes, and polypropylene copolymers.
3. 3. The method according to claim 1, characterized in that the form
4. The cross section of the foamed thermoplastic member comprises one selected from the group consisting of rectangles, squares, parallelograms, polygons, ellipses, circles, ovals, and combinations thereof. 4. The method according to claim 3, characterized in that a cross section of the foamed thermoplastic member is additionally defined as a solid.
5. 5. The method according to claim 3, characterized in that a cross section of the foamed thermoplastic member is further defined as comprising at least one opening extending longitudinally through the substantially entire length thereof.
6. 6. The method according to claim 1, characterized in that the forming means are further defined as they comprise a support member constructed to receive and coil in a controlled manner the substantially continuous, longitudinally extending, elongated foamed thermoplastic member and to cause in a controlled manner that a first side surface of the elongate foamed thermoplastic member is carried in side-by-side, juxtaposed relationship, with a second side surface thereof.
7. 7. The method according to claim 6, characterized in that the support member is further defined as it comprises a cylindrically shaped mandrel constructed to rotate continuously about the central axis thereof and positioned to receive the foamed, substantially continuous, elongated thermoplastic member. which extends longitudinally and allowing the foamed, elongated thermoplastic member to be continuously wound onto the surface thereof, producing a foamed, elongated cylindrically formed product peripherally surrounding and endurablely held therein.
8. 8. The method according to claim 7, characterized in that the cylindrically formed mandrel is further defined as it comprises a circular shape and movably mounts to rotate the support member to allow mandrels of different diameters to be used.
9. 9. The method according to claim 7, characterized in that the mandrel is further defined as it comprises guiding means formed thereon for receiving the elongated continuous, longitudinally extending foamed thermoplastic member and controlled advancement of the foamed thermoplastic member on the outer surface of the mandrel in a generally spiral configuration, whereby the side surfaces of the thermoplastic member are brought into a connection relationship, and in juxtaposition with each other.
10. 10. The method according to claim 9, characterized in that the joining step is carried out by heating the lateral surfaces of the elongated foamed thermoplastic member which extends longitudinally as the side surfaces are brought together in a juxtaposed connection relationship.
11. 11. The method according to claim 9, characterized in that the joining step is performed by applying the adhesive means to a side surface of the foamed thermoplastic member to cause a firm attachment coupling when the opposite side surfaces contact each other.
12. 12. The method according to claim 1, characterized in that it additionally comprises the step of E. cutting the hollow thermoplastic foamed product formed in a plane substantially perpendicular to the central axis thereof, whereby foamed thermoplastic products recessed to a precisely desired length are provided. .
13. 13. The method according to claim 12, characterized in that it additionally comprises F. supporting the foamed thermoplastic product hollowed when the product is produced, whereby the undesired distortions of the product are prevented.
14. 14. The method according to claim 12, characterized in that it additionally comprises the steps of F. longitudinally cutting the foamed thermoplastic product hollowed along a wall of the formed after the diametral cutting step has been performed; and G. opening the thermoplastic product longitudinally cut into a substantially flat plank member having any desired length and amplitude thereby forming a plank member of any desired dimension.
15. 15. The method according to claim 14, characterized in that it additionally comprises the step of: H. passing the open plank member through the roller means to remove any curvature retained therein from the forming process.
16. 16. The method according to claim 14, characterized in that it additionally comprises the steps of: H. placing the open plank member in a heat chamber and allowing the plank to be heated until it is flat; and I. cooling the plank in a flat configuration.
17. 17. The method according to claim 1, characterized in that it additionally comprises the steps of: E. applying at least one additional layer of material to a surface of the foamed thermoplastic member before passing to the forming machine; and F. attaching the additional layer to the surface of the foamed thermoplastic member, whereby a multi-layer recessed product is produced having any desired size and shape.
18. 18. The method according to claim 17, characterized in that the joining step is carried out using at least one selected from the group consisting of adhesives and heat.
19. 19. A system for producing elongated foamed thermoplastic members, substantially cylindrical in shape, hollowed out in a continuous production operation, the system characterized in that it comprises A. an extruder for producing elongate, substantially continuous lengths of the foamed thermoplastic member having the cross sectional shape desired B. a forming machine comprising a support surface for receiving the elongated, continuous foamed thermoplastic member from the extruder and winding the thermoplastic member continuously in direct association with the support surface, whereby a first side surface of the thermoplastic member is takes in alignment, spaced and in juxtaposition with a second surface thereof; and C. joining the means positioned in association with the forming machine in cooperating relationship with the foamed thermoplastic member to join the side surfaces of the elongate foamed thermoplastic member as the side surfaces are brought into contact with each other, causing the surfaces as a whole to fix firmly; whereby a hollow elongated foamed thermoplastic member is produced having any desired length and any desired hollow shape.
20. 20. The system according to claim 19, characterized in that the joining means are further defined as they comprise heat means positioned in cooperating relationship with the forming machine in cooperating relationship with the foamed thermoplastic member as the side surfaces thereof are carried each in juxtaposed alignment, the heat means that are formed from one or more of the selected group consisting of the means for releasing hot air and heated surfaces.
21. 21. The system according to claim 19, characterized in that the joining means are further defined as they comprise the adhesive means.
22. 22. The system according to claim 19, characterized in that the support surface of the forming machine is defined because it comprises a cylindrical shape to produce elongated foamed members having hollow cylindrical shapes, with the cylindrically formed member mounted for continuous rotation on its central axis, whereby the foamed thermoplastic member is allowed to be continuously wound on it.
23. 23. The system according to claim 22, characterized in that the system additionally comprises cam means mounted to the supporting surface of the forming machine to receive the elongated foamed thermoplastic member from the extruder and advancing in a guided manner the foamed thermoplastic member towards the cylindrically rotating support surface and allowing the first side surface of the foamed thermoplastic member to be carried in a juxtaposed, spaced apart relationship with the second side surface thereof.
24. 24. The system according to claim 19, characterized in that the system additionally comprises cutting means for longitudinally cutting the foamed thermoplastic member, in a recessed manner, through at least one wall thereof, whereby a thermoplastic panel is produced. foamed substantially flat.
25. 25. The system according to claim 19, characterized in that the system further comprises the roll means cooperatively associated with the forming machine for aligning at least one surface of the incoming foamed thermoplastic member with the corresponding surface of the previously rolled thermoplastic member.
26. 26. The system according to claim 19, characterized in that the elongated foamed thermoplastic member is further defined because it has a cross sectional shape comprising one selected from the group consisting of rectangles, squares, parallelograms, polygons, ellipses, circles, ovals and combinations
27. 27. The system according to claim 19, characterized in that the foamed thermoplastic member comprises one selected from the group consisting of polystyrene, polyolefins, polyethylenes, polybutanes, polybutylenes, thermoplastic elastomers, thermoplastic polyesters, thermoplastic polyurethanes, polyesters, ethylene-acrylic copolymers, copolymers of ethylene vinyl acetate, ethylene-methylacrylate copolymers, ethylene-butyl acrylate copolymers, ionomers, polypropylenes and polypropylene copolymers.