Double-tube manufacturing cell

Abstract

Pipe manufacturing cell, including: an extrusion system; a corrugator comprising a plurality of multi-tube forming blocks, each multi-tube forming block comprising a first cavity with a first corrugated forming surface and a second cavity with a second corrugated forming surface; a first pipe die head connected to the extrusion system and designed to provide an initial flow of pipe material to the first cavities of the multitude of multi-pipe forming blocks; and a second pipe die head connected to the extrusion system and designed to provide a second pipe material flow to the second cavities of the multitude of multi-pipe mold blocks, wherein the first pipe nozzle head and the second pipe nozzle head are designed to provide the first and second pipe material flows simultaneously.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This disclosure claims priority to U.S. Provisional Application No. 63 / 584,984, entitled "Double Tube Manufacturing Cell," filed September 25, 2023, which is incorporated herein in its entirety. TECHNICAL FIELD

[0002] This disclosure generally relates to the field of corrugated pipe manufacturing systems for continuous extrusion blow molding. More particularly, and without limitation, the present disclosure relates to innovations in simultaneous twin pipe extrusion and corrugation systems. BACKGROUND

[0003] Drainage pipes have long been used to transport water in various agricultural, residential, civil engineering, and other construction applications. For example, a drainage pipe has been used in areas such as mainstem sewer systems or to create stormwater systems designed to collect and dispose of runoff water. Traditionally, a drainage pipe was made of clay or concrete, making the pipe heavy, expensive, and brittle. To improve the ease of installation, cost-effectiveness, and durability of drainage pipes, pipes are now often manufactured from alternative materials, including various polymers and polymer blends.

[0004] Processes for producing corrugated polymer pipe may include single-wall, double-wall, and triple-wall processes. In a single-wall process, for example, a molten polymer may be fed through a pipe extruder into a die. The die may have one or more channels designed to evenly distribute the polymer onto the inner surfaces of a series of corrugated mold blocks in a corrugator. The molten polymer may adhere to the inner surfaces of the mold, for example, by blast air from within the die, vacuum suction from the mold blocks, or a combination of both. The corrugator may form the polymer into a corrugated pipe shape, cool it through internal or external cooling channels into a hardened structure, and feed the formed pipe to further downstream stations in a pipe manufacturing cell.

[0005] The production of a double-walled pipe may involve steps similar to the single-wall process described above. However, a die may include additional channels for the extrusion of a smooth-walled inner pipe layer that can be bonded to the corrugated exterior. The inner layer can be fed from the same extruder or from a separate extruder designed to produce desired properties such as wall thickness, material composition, etc. Large-diameter corrugated pipes typically have a double-walled construction. Furthermore, one or more walls of a pipe may comprise multiple coextruded layers of material. A multi-layer coextrusion die, for example, may include additional inlets designed to feed the same or different materials to several different layers of a pipe.These layers can be extruded simultaneously into a multi-layer wall, with each layer optimized for specific desired chemical, mechanical, or other properties.

[0006] One problem facing corrugated pipe manufacturers is that manufacturing cells for extra-large diameter pipe (such as 30- to 60-inch diameters) can take up a significant amount of space in a manufacturing facility, regardless of how frequently the cells are used. For example, some manufacturing cells may run 24 hours a day, seven days a week, while others may operate less than 50% of the time. Also, demand for 30- to 60-inch diameter pipe may be neither as high nor as consistent as that for smaller, mid-diameter pipes such as 12- to 30-inch. Meanwhile, periods of peak demand for mid-diameter pipe may require more manufacturing cells in the 12- to 30-inch range than are available. The result is an inefficient use of floor space in a manufacturing facility.By increasing the total area and equipment of the production facility, any desired quantity of demand can be met. However, increasing the total area involves a significant increase in costs and does not contribute to improving overall efficiency by reducing the idle time of larger manufacturing cells. SUMMARY

[0007] Some embodiments of the present disclosure provide systems and methods for modifying a large pipe manufacturing cell to be used to simultaneously manufacture two smaller diameter pipes. For example, a manufacturing cell capable of producing a single 60-inch double-wall pipe can be reconfigured as needed to produce, for example, two 24-inch double-wall pipes in parallel. Some embodiments of the present disclosure provide systems and methods for addressing challenges associated with such a configuration.For example, some embodiments of the present disclosure may provide systems and methods for reliably diverting controlled streams of thermoset or thermoplastic materials to multiple tubular dies using an extrusion system originally designed to feed to a single larger tubular die.

[0008] For example, in some embodiments, the apparatus may include an extrusion system for feeding a thermosetting or thermoplastic material to a corrugator. The extrusion system may include a first extruder, a second extruder, a first tube die head, and a second tube die head. The first and second tube die heads may each be configured to generate the material feeds to produce first and second double-walled corrugated tubes.

[0009] In some embodiments, the first extruder may include a first melt pump and a second melt pump arranged on its outlet side. The first melt pump and the second melt pump may each be connected to a first flow tube and a second flow tube, respectively. The first extruder may be connected to a first inner tubular die inlet of the first tubular die head through the first melt pump and the first flow tube. The first extruder may be connected to a second inner tubular die inlet of the second tubular die head through the second melt pump and the second flow tube.

[0010] In some embodiments, the second extruder may include a third melt pump and a fourth melt pump disposed on its outlet side. The third melt pump and the fourth melt pump may be connected to a third flow tube and a fourth flow tube, respectively. The second extruder may be connected to a first outer tubular die inlet of the first tubular die head through the third melt pump and the third flow tube. The second extruder may be connected to a second outer tubular die inlet of the second tubular die head through the fourth melt pump and the fourth flow tube.

[0011] In some embodiments, the apparatus may further comprise a double-tube corrugator. The double-tube corrugator may comprise a plurality of mold blocks. Each mold block may comprise a first cavity having a first corrugated forming surface and a second cavity having a second corrugated forming surface, configured to receive a material flow from the first nozzle and the second nozzle, respectively. The plurality of mold blocks may be configured to produce two double-walled corrugated tubes simultaneously and in parallel.

[0012] Some embodiments of the present disclosure may provide a pipe manufacturing cell. The pipe manufacturing cell may include: an extrusion system; a corrugator including a plurality of multi-pipe die blocks, each multi-pipe die block having a first cavity with a first corrugated forming surface and a second cavity with a second corrugated forming surface; a first pipe die head connected to the extrusion system and configured to provide a first flow of pipe material to the first cavities of the plurality of die blocks; and a second pipe die head connected to the extrusion system and configured to provide a second flow of pipe material to the second cavities of the plurality of die blocks. The first pipe die head and the second pipe die head may be configured to provide the first and second flows of pipe material simultaneously.

[0013] Some embodiments of the present disclosure may provide a tube manufacturing method.The method may include: providing a flow of tubing from an extrusion system to a corrugator, the corrugator comprising a plurality of single-tube forming blocks, each of the plurality of single-tube forming blocks comprising a corrugated forming surface; corrugating a tubing with the corrugator using the plurality of single-tube forming blocks; replacing the plurality of single-tube forming blocks with a plurality of multi-tube forming blocks in the corrugator, each of the plurality of multi-tube forming blocks comprising a plurality of corrugated forming surfaces; modifying the extrusion system to subdivide the flow of tubing; providing the subdivided flow of tubing to the plurality of corrugated forming surfaces of the multi-tube forming blocks; and corrugating a plurality of tubing with the corrugator using the plurality of multi-tube forming blocks. SHORT DESCRIPTION OF THE CHARACTERS Fig. 1A-C are schematic diagrams showing an example of a pipe manufacturing cell, according to comparative examples. Fig. 2A-E are schematic diagrams showing an example of a tube manufacturing cell according to embodiments of the present disclosure. Fig. 3A-B are schematic diagrams showing an example of a tube manufacturing cell according to embodiments of the present disclosure. Fig. 4A-H are schematic diagrams showing various tube corrugator mold blocks according to embodiments of the present disclosure. Fig. 5 is a schematic diagram showing an example of a nozzle stand of a tube manufacturing cell according to embodiments of the present disclosure. Fig. 6 is a process flow diagram showing an example of a tube manufacturing method according to embodiments of the present disclosure. DETAILED DESCRIPTION

[0014] Reference will now be made in detail to the embodiments described above, which are illustrated in the accompanying drawings.

[0015] Fig. 1A-C show a single pipe manufacturing cell 100 according to comparative examples. The pipe manufacturing cell 100 may, for example, be designed to manufacture a large diameter, double-walled corrugated pipe 130. For example, a diameter of the pipe 130 may range from, for example, 30 to 60 inches. The double-walled corrugated pipe 130 may include a smooth inner wall and a corrugated outer wall. For example, the corrugated outer wall may include a series of repeating peaks and valleys when viewed in cross-section. The pipe 130 may comprise a moldable, compliant material. Such moldable, compliant materials may include various moldable polymers, rubbers, plastics, polypropylene (PP), polyethylene (PE), polyurethane (PU), polyvinyl chloride (PVC), etc. The pipe 130 may, for example, comprise a polyethylene material, such asHigh density polyethylene (HDPE), a polypropylene material such as high performance polypropylene (HP), or a polyvinyl chloride material such as PVC with a rigid wall or foam core.

[0016] The pipe manufacturing cell 100 may include an extrusion system 110 with one or more extruders 111, 112, one or more flow tubes 114, pipe die 115 (also referred to as die head), corrugator 120, water cooling chamber 140, water blow-off chamber 150 and cutting station 160.

[0017] The extrusion system 110 may be configured to provide a flow of tubular material into the tubular die 115 via one or more extruders 111, 112. For example, as discussed further below, a first extruder 111 may provide a first flow of tubular material into a first inlet 117 of the tubular die 115, and a second extruder 112 may provide a second flow of tubular material into a second inlet 118 of the tubular die 115. Flow tubes 114 or other connections may be provided for delivering the flows of tubular material from the extruders 111, 112 to the inlets 117, 118 of the tubular die 115. The first inlet 117 may include a channel configured to extrude the first flow of tubular material into a first tubular shape as an inner wall of the tube 130 at an outlet side of the tubular die 115. Therefore, the first inlet 117 may be referred to as an inner tube nozzle inlet or an inner wall inlet.The second inlet 118 may include a further channel configured to extrude the second tubular material flow into a second tubular shape as an outer wall of the tube 130 at an outlet side of the tube die 115. Therefore, the second inlet 118 may be referred to as an outer tube die inlet or an outer wall inlet. The inner and outer tubular tubular material may be formed into a double-walled corrugated tube 130 by the corrugator 120, as discussed below.

[0018] As it is in Fig. As can be seen in Figure 1B, the corrugator 120 may comprise a plurality of mold blocks 121 and a conveyor system 122 configured to continuously rotate the mold blocks 121 in a loop along a direction shown by the arrows. The conveyor system 122 may, for example, comprise a track or other conveyor means, as shown schematically in Fig. 1A-B and will be understood by a person of ordinary skill in the art. Each mold block may comprise one half of a pair of right and left mold blocks that may be mated to form a corrugated forming surface on the outside of the tube 130. The speed at which right and left mold blocks 121 are moved along their respective conveyor systems 122 is substantially identical. In this manner, each pair of cooperating mold blocks 121 is aligned and placed adjacent to one another as they enter a forming zone 123 along the conveyor system 122. The die head 115 may be supported at the beginning of the forming zone 123, e.g., by a die stand 116.Each pair of die blocks 121 may converge at an outlet side of the die head 115 upon entering the forming zone to form a corrugated surface on an outer surface of the extruded tubular pipe material exiting the die head 115. The outer surface of the pipes may adhere to the inner forming surfaces of the die blocks 121, e.g., by blast air supplied from the die head 115, vacuum suction from the die blocks 121, or a combination of both. As the die blocks 121 converge, they may continue to move along the forming zone 123 of the conveyor system 122 in a direction away from the die head 115 along with their respective pipe sections. As the die blocks move in formation along the forming zone 123, they may support the pipe material as it cools to a cured or semi-cured structure. The mold blocks 121 may, for example, include internal cooling channels for the cooling tube 130.As the mold blocks 121 exit the forming zone 123, they can separate from each other to release the hardened pipe section 130. The mold blocks 121 can then continue along the conveyor system 122 to repeat the process. The hardened corrugated pipe 130 can continue to further downstream processing stations.

[0019] Returning to Fig. 1A, the tube 130 may then be further cooled, for example, at the water cooling chamber 140. Water may be blown off the tube at the water blowoff chamber 150 before it is cut to a desired length at the cutting station 160. In general, the tube 130 may be processed as desired for its intended use, and the tube manufacturing cell 100 may include any known stations or components for performing this processing. Such stations may be arranged before, after, or instead of any of the disclosed stations. For example, the tube 130 may be cut to length, and holes, slots, or other perforations may be added, etc. Optional processing steps for conventional corrugated tubes are described in one or more of U.S. Pat. Nos. 10,612,698; 10,550,963; 10,077,856; 10,077,857; 9,958,091; 9,759,354; 3,916,763; 4,003,685; 3,919,367; 3,941,639; 3,990,8273,910,713; 3,919,367; 3,877.831; 3,864,446; 3,784,346; 3,792,941; 3,799,418; 3,831,470; 3,843,758; 3,854,527; 3,870,774; and 3,891,733. Each of these patents is hereby incorporated by reference in its entirety.

[0020] Fig. 1C shows an example of a multi-walled pipe nozzle head 115, which is used, for example, in the pipe production cell 100 of Fig. 1A-B. The tubular die head 115 may include a first inlet 117 provided between an inner tube 18 and a middle tube 20 of the tubular die head 115. A molten material, such as a molten high-density polyethylene, may be introduced into the first inlet 117 from an extruder, such as the first extruder 111 of Fig. 1AB. The molten material may move through the first passage 23 to a first nozzle outlet 6. The molten material may be ejected from the first nozzle outlet 6 in a substantially tubular shape into a corrugator, such as the corrugator 120 of Fig. 1A-B, to form an inner wall of a multi-walled corrugated pipe. The pipe die head 115 may further comprise a second inlet 118 provided between the middle pipe 20 and the outer pipe 22 of the pipe die head 115. A further molten material may be introduced into the second inlet 118 from an extruder, such as a second extruder 112 of Fig. 1A-B. The additional molten material can move through the second passage 24 to a second nozzle outlet 7. The molten material can be ejected from the second nozzle outlet 7 in a substantially tubular shape into the corrugator to form an outer wall of the multi-wall corrugated tube.

[0021] In some embodiments of the comparative examples of Fig. 1A-C, the tubular die head 115 may comprise a multi-layer coextrusion die with further inlets, passages, tubes, or die outlets for producing additional walls or multi-layer walls. In some embodiments, the tubular die head 115 may comprise divided passages configured to distribute a single material flow to multiple die outlets. For example, in some embodiments, a single extruder may provide a single material flow to the tubular die head 115. The tubular die head 115 may then internally divide the material flow and distribute it, for example, to the first passage 23 and the second passage 24. In some embodiments, additional tubes may be provided to transport other components or auxiliary means. For example, in some embodiments, the middle tube 20 may comprise two separate tubes with an air gap between them. This air gap may serve as a path, for example,of air or wiring of heaters, thermocouples, or other components. In some embodiments, the pipe manufacturing cell 100 may include additional extruders configured to distribute molten material to the additional inlets. Additionally, in some embodiments, the pipe die head 115 may include fewer inlets, passageways, tubes, or die outlets. For example, in some embodiments, the pipe die head 115 may be configured to produce, for example, a single-wall pipe, and the pipe manufacturing cell 100 may include a single extruder. Further details of pipe die heads can be found in one or more of U.S. Pat. Nos. 7,980,841 and 8,496,460. Each of these patents is hereby incorporated by reference in its entirety.

[0022] To achieve these diverse processing steps, manufacturing cells can require large amounts of floor space in a manufacturing facility. One problem is that the largest classes of pipe manufacturing cells, which occupy the most space, can have poor utilization rates compared to smaller pipe manufacturing cells. As discussed above, the demand for large pipes, such as those with diameters of 30 to 60 inches or larger, may not be as high or as consistent as the demand for small to medium-sized pipes, such as those with diameters of 12 to 30 inches.

[0023] Embodiments of the present disclosure provide pipe manufacturing systems and methods for simultaneously producing two corrugated pipes. Double-walled pipe manufacturing cells according to some embodiments of the present disclosure can be adapted from single-walled pipe manufacturing cells by replacing certain components, such as mold blocks, die heads, and certain components of an extrusion system. For example, a manufacturing cell capable of producing a single large double-walled pipe can be reconfigured as needed to produce, for example, two medium-sized double-walled pipes in parallel. In this way, the floor space in a manufacturing facility can be used more efficiently.

[0024] Fig. 2A-B are schematic diagrams illustrating an example of a pipe manufacturing cell 200 according to embodiments of the present disclosure. The pipe manufacturing cell 200 may include, for example, an extrusion system 210 having one or more extruders, such as a first extruder 211 and a second extruder 212, flow splitters 219 connected to one or more of the extruders, a plurality of flow tubes 214, a plurality of die heads 215, such as a first (upper) die head 215a and a second (lower) die head 215b, a corrugator 220, a water cooling chamber 240, a water blow-off chamber 250, and a cutting station 260. The pipe manufacturing cell 200 may also include a plurality of flow control mechanisms 213 connected to each extruder via a flow splitter.

[0025] The pipe production cell 200 can be the pipe production cell 100 from Fig. 1A-C, with certain differences disclosed herein. Elements of the pipe manufacturing cell 200 that correspond to elements in the comparative pipe manufacturing cell 100 may be represented by like numerals increased by 100. For example, the water blow-off chamber 250 may, in some embodiments, be Fig. 2A-B roughly the water blow-off chamber 150 of Fig. 1A-B. Therefore, a detailed discussion of specific elements within the tube manufacturing cell 200 may be omitted here. However, it should be understood that such omissions do not necessarily imply that an element within the tube manufacturing cell 200 is identical to its counterpart in the comparative examples of the tube manufacturing cell 100. For example, the cutting station 260 may be optimized for cutting two tubes simultaneously, or it may include other differences or modifications from the cutting station 160 that would enable it to function satisfactorily on both single and double tube manufacturing cells. The same may apply, for example, to the nozzle stand 216, the conveyor system 222, the water cooling chamber 240, the water blow-off chamber 250, and other components of the present disclosure.In some embodiments, such components may be sized and otherwise configured to accommodate both single and dual tube configurations. For example, in some embodiments, a conveyor system may be configured to transport both single-type, larger-diameter mold blocks 121 and dual-type, medium-diameter mold blocks 221. As described below with reference to FIG. Fig. 6, the nozzle stand 216 may further be optimized to support two tubular nozzles, such as by allowing the upper nozzle head 215a and the lower nozzle head 215b to be independently aligned with their respective cavities in mold blocks 221.

[0026] As it is in Fig. As shown in Figures 2A-B, the pipe production cell 200 may be configured to feed multiple pipe material flows to multiple inlets of multiple dies 215 to corrugate multiple pipes 230 in parallel. The pipe production cell 200 may be configured to divide controlled pipe material flows to multiple pipe die heads 215 using an extrusion system 210. In some embodiments, the extrusion system 210 may be originally designed to feed a single larger pipe die, or it may be convertible between single and dual pipe production configurations.

[0027] For example, the extrusion system 210 may include a first extruder 211 and a second extruder 212. Each of the first and second extruders 211, 212 may include flow dividers 219 for dividing their flows to multiple flow control mechanisms 213. In some embodiments, the flow control mechanisms 213 may include melt pumps. A melt pump may include a conduit with a geared gear arrangement designed to precisely control the flow of molten plastic to reduce surge and backpressure variation in the extruder output. Melt pumps may include internal heaters, pressure and temperature sensors, and other systems for monitoring and controlling flow.By configuring multiple (approximately two) melt pumps on the output side of each of the first extruder 211 and the second extruder 212, the pipe material flows to each inlet of the upper die head 215a and the lower die head 215b can be independently controlled.

[0028] As it is in Fig. 2B, for example, the upper die head 215a and the lower die head 215b may each have an inner tubular die inlet 217 and an outer tubular die inlet 218. Tubular material flows may be distributed from the extrusion system 210 to the various inlets 217, 218 in various ways. As shown, the first extruder 211 may supply tubular material to the inner tubular die inlets 217, while the second extruder 212 supplies tubular material to the outer tubular die inlets 218. This configuration may be advantageous when the material properties or flow characteristics between the inner and outer tubular die inlets 217 and 218 differ significantly. For example, an inner tubular die inlet 217 may require a flow rate, temperature, or other parameter that is significantly different from that required by the outer tubular die inlet 218.By dedicatedly using an extruder for the inner tube nozzle inlets and an extruder for the outer tube nozzle inlets, independent control of the flow characteristics by each flow control mechanism 213 can be simplified. Furthermore, the inner tube nozzle inlets 217 and the outer tube nozzle inlets 218 may have different requirements that cannot be controlled by a melt pump or other flow control mechanism 213, such as a different material composition.

[0029] Additionally, this flow division arrangement can be advantageous when a pipe production cell is designed to be adaptable between single-pipe and double-pipe production. For example, if the first extruder 111 and the second extruder 112 are Fig. 1A are designed for the production of inner and outer walls of a single corrugated pipe, respectively, the second extruder can be larger than the first. Therefore, an extruder designed to produce a single large outer wall can be converted to produce two medium outer walls, and an extruder designed to produce a single large inner wall can be converted to produce two medium inner walls.

[0030] Alternatively or additionally, in some embodiments, the first extruder 211 may supply flows to the inner and outer tube die inlets 217, 218 of the upper tube die head 215a, and the second extruder 212 may supply flows to the inner and outer tube die inlets 217, 218 of the lower tube die head 215b. In some embodiments, a single extruder with four melt pumps or other flow control mechanisms 213 may be used.

[0031] Furthermore, in some embodiments, a separate flow control mechanism between an extruder and tubular die inlets may not be necessary. For example, in some embodiments, flow control may be achieved by the extruders themselves or by the tubular die heads. Examples of such embodiments are further described with reference to Fig. 2C-2E discussed below.

[0032] A plurality of tubular die heads 215, such as the upper tubular die head 215a and the lower tubular die head 215b, may be supported by a die stand 216. While the upper and lower tubular die heads 215a, 215b are shown as separate components, in some embodiments they may be provided as a single integrated unit. The upper and lower tubular die heads 215a, 215b may be disposed at the beginning of the forming zone 223 to introduce a plurality of inner and outer tubular material tubes into the corrugator 220.

[0033] The corrugator 220 may comprise a plurality of multi-tube mold blocks 221, as shown in Fig. 2B. Multi-tube mold blocks 221 may, for example, comprise double tube cavities with corrugated forming surfaces for parallel production of two tubes. For example, the two tubes may be of the same size, and multi-tube mold blocks 221 may, for example, be formed as blocks 425 of Fig. 4B. Alternatively, the two tubes may have different sizes and multi-tube mold blocks 221 may be designed, for example, as blocks 427 of Fig. 4D. The corrugator 220 and the multi-tube forming blocks 221 may function in a manner similar to that described above with respect to the single corrugator 120. For example, pairs of multi-tube forming blocks 221 may be converged onto the multiple tube die heads at the beginning of the forming zone 223 by a conveyor system 222. Because the flows to each tube die inlet are precisely and independently controlled, the forming blocks 221 may be moved synchronously by the conveyor system without causing formation errors in the individual tubes 230. In other words, the independent control of flow rates and other characteristics may allow each individual flow to be adapted to the movement of the multi-tube forming blocks 221, allowing multiple tubes to be produced simultaneously.

[0034] While tube nozzle inlets 217 and 218 are discussed above with reference to the fabrication of inner walls and outer walls, respectively, embodiments of the present disclosure are not so limited. For example, tube nozzle heads 215a and 215b may include more or fewer inlets, or they may include multiple inlets dedicated to each wall of tubes 230. For example, in some embodiments, tube nozzle heads 215a and 215b may include multi-layered nozzles, e.g., having multiple inner tube nozzle inlets 217 or multiple outer tube nozzle inlets 218. In this way, an individual wall of tubes 230 may be formed from multiple material flows. In some embodiments, the material flow to the multiple inlets may be divided and controlled as discussed above.

[0035] While mold blocks 221 are shown as being segmented in the vertical direction, it is further understood that other configurations are contemplated within the embodiments of the present disclosure. For example, mold blocks 221 could alternatively be segmented along, for example, a horizontal direction, with the conveyor system 222, the extrusion system 210, and related components being adapted accordingly.

[0036] In some embodiments, mold blocks 221 could be divided into more than two parts, such as three or four. For example, mold blocks 221 could be divided in both the horizontal and vertical directions, with the conveyor system 222, the extrusion system 210, and related components being adapted accordingly.

[0037] Fig. 2C-2E are schematic diagrams showing further examples of the pipe manufacturing cell 200, according to embodiments of the present disclosure. As mentioned above, in some embodiments, material flow distribution may be achieved using more or fewer extruders than in Fig. 2A, or it can be achieved with or without the use of dedicated flow control mechanisms 213 such as melt pumps or by using flow dividers 219 arranged at positions other than an outlet side of the extruders. For example, as shown in Fig. 2C Flow splitters 219 may be integrated into flow tubes 214. For example, flow splitters 219 may include fittings or other mechanisms designed to receive flow from a single flow tube 214 and distribute the flow to multiple flow tubes 214. In this manner, an extruder may be reconfigured from a single-tube mode to a dual-tube mode simply by modifying or replacing its associated flow tubes 214.

[0038] As it is in Fig. 2D and discussed above, a pipe die head may further include divided passages configured to distribute a single material flow to multiple die outlets. For example, each of the first pipe die head 215a or the second pipe die head 215b may include an internal flow splitter 219 such that a single inlet (or set of inlets) can receive a single material flow and divide the material flow to multiple walls or multiple outlets. In this manner, when the pipe manufacturing cell is used to manufacture a single large pipe, the first extruder 211 may provide material flow to a first wall (such as an outer wall) of the single pipe, and the second extruder 212 may provide material flow to a second wall (such as an inner wall) of the single pipe. When reconfiguring the pipe manufacturing cell to manufacture two smaller pipes, the first extruder 211 may then, for example,B. provide material flow to both the inner and outer walls of a first smaller tube, and the second extruder 212 can provide material flow to both the inner and outer walls of a second smaller tube.

[0039] Furthermore, as mentioned above, such configurations can be achieved using a single extruder. As described in Fig. 2E, for example, a single extruder 211 may provide a single material flow that may be divided into two different tubular die heads 215a and 215b at a first divider 219a. For example, the first divider 219a may be located on an outlet side of the extruder 211, or it may be as shown in Fig. 2E can be integrated with the flow tubes 214. Then, second dividers 219b can be, for example, internal flow dividers within the tube nozzle heads 215a and 215b, or they can also be integrated with the flow tubes 214.

[0040] Thus, embodiments of the present disclosure enable the efficient use of floor space in a pipe manufacturing facility. In some embodiments, a single-pipe manufacturing cell for large-diameter pipes can be temporarily converted into a single-pipe manufacturing cell for small- or medium-diameter pipes, such as by replacing mold blocks or modifying extrusion systems as discussed above.

[0041] Fig. 3A-B are schematic diagrams illustrating an example of a pipe manufacturing cell 300 according to embodiments of the present disclosure. Pipe manufacturing cell 300 may be similar to pipe manufacturing cell 200, except as described below.

[0042] Alternatively, or in addition to the configurations discussed above, the pipe manufacturing cell 300 may include a dedicated extruder for each pipe die inlet or each pipe wall. For example, the pipe manufacturing cell 300 may include a first extruder 311a, a second extruder 312a, a third extruder 311b, and a fourth extruder 312b. The first extruder 311a and the third extruder 311b may direct pipe material flows to inner pipe die inlets 317 of the upper and lower pipe die heads 315a, 315b. Meanwhile, the second extruder 312a and the fourth extruder 312b may direct pipe material flows to outer pipe die inlets 318 of the upper and lower pipe die heads 315a, 315b. Providing dedicated extruders for each inlet may provide even greater independent control of the material flows.In some embodiments, each dedicated extruder 311a, 311b, 312a, and 312b may include a flow control mechanism (not shown) such as a melt pump, as discussed above.

[0043] Fig. 4A-F are schematic diagrams showing various tube corrugator mold blocks 424-427, according to embodiments of the present disclosure. Fig. 4A shows a pair of large-diameter single-pipe forming blocks 424. The forming blocks 424 may be designed, for example, to produce a pipe with a diameter of, for example, 30 to 60 inches or more. Fig. 4B shows a pair of medium-diameter, double-pipe mold blocks 425. The mold blocks 425 may be configured, for example, to produce two pipes each having a diameter of, for example, 12 to 30 inches. Each mold block 425 may include a first cavity having a first corrugated forming surface and a second cavity having a second corrugated forming surface. The first cavity and the second cavity may, for example, be substantially semicircular or generally correspond to one half of an outer contour of the pipe to be produced. While the number and size of forming surfaces of an interior of the mold blocks 424 and 425 may differ, in some embodiments, the overall size and outer shapes of the mold blocks 424 and 425 may be substantially identical.Thus, the two pairs of mold blocks 424 and 425 may be compatible with the same conveyor system to allow easy conversion therebetween, thereby enabling a manufacturing facility to meet the changing requirements for different pipe sizes. Furthermore, other mold block configurations may also be provided. For example, FIG. Fig. 4C a pair of small to medium sized triple mold blocks 426. The mold blocks 426 may be designed, for example, to produce three pipes each with a diameter of, for example, 6 to 24 inches. Fig. 4D shows a pair of double-sized mold blocks 427. For example, the mold blocks 426 may be configured to produce two tubes, the first tube having a first diameter and the second tube having a second diameter different from the first. In general, any number of configurations can be achieved based on the principles disclosed above.

[0044] Furthermore, cooling channels for any of the above mold blocks may be appropriately arranged in mold blocks of the present disclosure to achieve uniform cooling and curing of each individual tube. For example, as described in Fig. As can be seen in Figures 4E-F, single-tube mold blocks 424 or double-tube mold blocks 425 may include cooling channels 428. Cooling channels 428 may be configured with port openings 429 for supplying and reclaiming cooling fluid for cooling and curing the corrugated tube.

[0045] Additionally, mold blocks 424-427 can be designed in a modular manner to allow for easier change from one configuration to another. As is the case, for example, in Fig. 4G, single-tube mold blocks 424 and dual-tube mold blocks 425 may each be configured for installation in a common block carrier 429. In some embodiments, the common block carrier 429 may remain attached to a conveyor system when switching between single- and dual-tube modes. Furthermore, cooling channels for circulation may be arranged in the common block carrier, similar to Fig. 4E-F. For example, the channels could circulate only through the common block carrier 429, or they could have port openings designed to mate with additional cooling channels arranged in the mold blocks 424, 425.

[0046] As it is in Fig. As shown in Figure 4H, modularity can further enable the use of different size combinations. For example, a single tube mold block 424 can be used as a replacement for two individual mold blocks 429a and 429b to allow even greater flexibility in size configurations.

[0047] Fig. 5 is a schematic diagram showing an example of a nozzle stand 516 configured to support a plurality of tubular nozzle heads 515 (such as the upper tubular nozzle head 515a or the lower tubular nozzle head 515b), according to embodiments of the present disclosure. The tubular nozzle heads 515 and the nozzle stand 516 may be used in any of the embodiments discussed above. To ensure that molten tubing is evenly distributed as the blank is extruded from the tubular nozzle heads 515 into their respective mold block cavities (not shown), each of the tubular nozzle heads 515 must be properly aligned with their respective cavities in the mold blocks. Consequently, the nozzle stand 516 may be configured to independently adjust the alignment of the upper tubular nozzle head 515a and the lower tubular nozzle head 515b.In this context, “orientation” may refer to a longitudinal axis of a tubular die head 515 being concentric, on center, and parallel to a centerline of a mold cavity tunnel, as discussed further below.

[0048] In this context, "independent" alignment may refer to the ability to change the relative positions or orientations of two or more tube nozzle heads with respect to each other, but it does not necessarily mean that the actuation systems used to move each of the tube nozzle heads are completely decoupled from each other. For example, in some embodiments, the upper tube nozzle head 515a may be stacked or otherwise supported on the lower tube nozzle head 515b, such that movement of the lower tube nozzle head 515b (e.g., movement relative to a floor or frame 581 of the nozzle stand 516) also causes movement of the upper tube nozzle head 515a. In such a case, independent alignment may still be possible, e.g., by further movement of the upper tube nozzle head 515a relative to the lower tube nozzle head 515b.

[0049] The tubular die heads 515 may each include a die cylinder 572 and a die base 571 configured to support the cylinder 572. The die stand 516 may include a frame including a first support structure 581 and a second support structure 582; and one or more substands 583, 593. Each substand 583, 593 may be configured to support a die base 571 of its respective tubular die head 515 through first and second base plates 587, 597 and to align the tubular die head 515 with its respective mold block cavity, for example, by using one or more actuating stages. As can be seen, for example, the first substand 583 may include a first stage 584, and the second substand 593 may include a second stage 594. Furthermore, the first sub-stand 583 may include a third step 585 and the second sub-stand 593 may include a fourth step 595.The stages can each be supported on base plates 587, 597. Each stage can include at least one actuator configured to move the respective tubular nozzle head 515 in at least one degree of freedom. For example, the first stage 584 can include a first actuator 586 configured to move the first tubular nozzle head 515a in a first degree of freedom, and the second stage 594 can include a second actuator 596 configured to move the second tubular nozzle head 515b in a second degree of freedom. Actuators can include, for example, mechanical, electrical, hydraulic, or other suitable devices for moving a stage in at least one degree of freedom. For example, the actuators can include a mechanical pivot about which the first stage 584 can be rotated using adjustment screws (not shown).In some embodiments, the third stage 585 may include a third actuator (not shown) configured to move the first tube nozzle head 515a in a third degree of freedom, and the fourth stage 595 may include a fourth actuator (not shown) configured to move the second tube nozzle head 515b in a fourth degree of freedom.

[0050] The movement of each tube nozzle head 515 can be described in a coordinate frame using the tube nozzle head longitudinal axis (such as a longitudinal axis of the nozzle cylinder 572) as a reference axis Y. This is illustrated schematically with respect to a front view of a nozzle cylinder 572 in the upper left corner of Fig. 5. In this view, the Y-axis comes directly from the page. An X-axis may be perpendicular to the Y-axis. For example, the X-axis may be horizontal, i.e., parallel to the floor of a build space or to a platform 582 at least in a nominal non-tilted orientation of the stages 584 and 585 (or 594 and 595). A Z-axis may be perpendicular to the X and Y axes. For example, the Z-axis may be vertical when the X-axis is horizontal. For example, the upper tube nozzle head 515a may be oriented with respect to the X coordinate frame. a , Y a , Z a and the lower tube nozzle head 515b can be positioned relative to the coordinate frame X b , Y b , Z bFor brevity, the discussion may in some cases be limited to a single tube nozzle head 515 or to a single set of XYZ axes. However, it should be understood that each tube nozzle head 515 may be oriented according to its own independent coordinate frame because the reference axes of the upper and lower tube nozzle heads 515a and 515b may not be fixed with respect to one another.

[0051] In the first sub-stand 583, the first stage 584 may be configured to move the upper tube nozzle head 515a in a first degree of freedom by the first actuator 586. In some embodiments, the first degree of freedom may be, for example, rotation about a first axis (such as the X a-axis). The third stage 585 may be configured to move the upper tube nozzle head 515a in the third degree of freedom by the third actuator. The third degree of freedom may, for example, be rotation about a third axis (such as the Z a -axis). As can be seen, one of the first stage 584 and the third stage 585 may be stacked or otherwise supported on the other of the first stage 584 and the third stage 585. Thus, in some embodiments, the third stage 585 may move the upper tube nozzle head 515a by moving the first stage 584. In some embodiments, the first sub-stand 583 may be configured to move the upper tube nozzle head 515a in alternative or additional degrees of freedom, such as by translating along the X a , Y a or Z a -axis, or by rotation around the Y a-axis. Furthermore, one or more stages in the first sub-column may be configured for movement in more than one degree of freedom. For example only, the first stage 583 may be configured for both translation along and rotation about the X a -axis.

[0052] The second stage 594 and the fourth stage 595 may be configured to move the second tubular nozzle head 515b in second and fourth degrees of freedom, which may be similar to the description of the first and third degrees of freedom above. Furthermore, the second sub-post 593 may also be configured to move in the alternative or additional degrees of freedom discussed above with respect to the first sub-post 583. It should also be noted that the first and second sub-posts 583 and 593 do not necessarily have to be identical or include the same number or design of stages.

[0053] In some embodiments, the first sub-stand 583 and the second sub-stand 593 may be supported separately on first and second support structures 581, 582 of the frame, such as by first and second base plates 587, 597. This placement may serve to decouple the movement of the upper tube nozzle head 515a from the lower tube nozzle head 515b.

[0054] In some embodiments, the first sub-stand 583 may be supported, for example, on the lower nozzle base 571b. In this case, the movement of the upper and lower tube nozzle heads 515a and 515b may be coupled to each other, because the movement of the lower nozzle base 571b would cause a movement of the first sub-stand 583. The first sub-stand 583 and the second sub-stand 593 may nevertheless be capable of independently aligning the upper and lower tube nozzle heads 515a and 515b. Furthermore, this arrangement may have advantages over the Fig. 5. For example, the size of the stand 516 may be reduced, e.g., by modifying or eliminating first or second platform support structures 581 or 582. This reduced size may allow for closer placement of the upper and lower tube die heads 515a and 515b, which may allow for greater adaptability with existing single-tube manufacturing cells.

[0055] By coupling the movement of the two sub-stands, it may additionally be possible to eliminate superfluous stages or actuators. For example, if it is determined that alignment tolerances allow uniform movement of all tube nozzle heads in at least one degree of freedom, it may be sufficient to perform the alignment in that degree of freedom for all tube nozzle heads using a single stage, e.g., arranged in the second sub-stand 593. Alternatively or additionally, it may be possible to use a single stage for coarse alignment in the at least one degree of freedom and provide smaller actuators for fine independent alignment of at least one of the upper tube nozzle head 515a or the lower tube nozzle head 515b.

[0056] By providing a dual-tube die rack 516 according to embodiments of the present disclosure, the tube die heads can be independently and accurately aligned to ensure sufficient quality control in all corrugated tube strings of a multi-tube manufacturing cell.

[0057] Fig. 6 is a process flow diagram illustrating an example of a tube manufacturing method 600, according to embodiments of the present disclosure. The method 600 may be performed using any of the embodiments discussed above.

[0058] In step 601, a single corrugated pipe may be manufactured on a pipe manufacturing cell. The pipe may be, for example, a large double-walled pipe with a diameter of, for example, 30 inches or more. The pipe manufacturing cell may include a plurality of single-pipe forming blocks. In some embodiments, the pipe manufacturing cell may be configured as a conventional single-pipe manufacturing cell. In some embodiments, components of the single-pipe manufacturing cell may be optimized for operation in both single- and multi-pipe manufacturing modes.

[0059] In steps 602-606, production of the individual corrugated pipe may cease, and the manufacturing cell may be converted for use as a multi-pipe manufacturing cell. For example, in step 602, the individual pipe forming blocks may be replaced with any of the multi-pipe forming blocks described above. In step 603, an individual pipe die head may be removed. In step 604, an individual die stand may be converted into, or replaced with, a multi-pipe die stand. For example, the multi-pipe die stand may be Fig.6 with the cavities of the multi-tube mold blocks as discussed above. In step 605, dual tube die heads may be attached to the multi-tube die stand. In step 606, an extrusion system may be converted for use with multiple tubes. For example, a number or type of extruders may be changed, or a new or existing extruder may be designed with flow dividers or flow control mechanisms such as melt pumps as described above.

[0060] In step 607, the modified pipe manufacturing cell can be used to simultaneously produce multiple corrugated pipes. For example, the modified pipe manufacturing cell can be used to simultaneously produce two pipes with a smaller diameter than the single pipe produced in step 601.

[0061] In some embodiments, method 600 may include further steps to return to the original single tube configuration and remanufacture a single corrugated tube, as shown in steps 608-613.

[0062] It should be noted that the disclosed steps of method 600 need not be performed in the precise order described above. For example, in some embodiments, steps 602-606 may be performed in any order or concurrently, and the same may apply to steps 608-612. Furthermore, method 600 may alternatively begin with a multi-tube configuration and transition to a single-tube configuration.

[0063] Embodiments of the present disclosure may be further described with reference to the following figures: 1. Pipe production cell, comprising: an extrusion system; a corrugator comprising a plurality of multi-tube mold blocks, each multi-tube mold block comprising a first cavity having a first corrugated molding surface and a second cavity having a second corrugated molding surface; a first tube die head connected to the extrusion system and configured to provide a first flow of tube material to the first cavities of the plurality of multi-tube die blocks; and a second pipe die head connected to the extrusion system and configured to provide a second pipe material flow to the second cavities of the plurality of multi-pipe mold blocks, wherein the first tube nozzle head and the second tube nozzle head are configured to simultaneously provide the first and second tube material flows. 2. Pipe production cell according to paragraph 1, wherein the extrusion system comprises: a first extruder configured to provide the first pipe material flow to the first pipe die head; and a second extruder configured to provide the second pipe material flow to the second pipe die head. 3. Pipe production cell according to paragraph 2, where: the first extruder is designed to provide a third pipe material flow to the second pipe die head; and the second extruder is designed to provide a fourth pipe material flow to the first pipe die head. 4. Pipe production cell according to paragraph 3, further comprising: a first flow control mechanism configured to control the first pipe material flow from the first extruder to the first pipe die head; a second flow control mechanism configured to control the second pipe material flow from the second extruder to the second pipe die head; a third flow control mechanism configured to control the third pipe material flow from the first extruder to the second pipe die head; and a fourth flow control mechanism configured to control the fourth pipe material flow from the second extruder to the first pipe die head. 5. The pipe manufacturing cell of claim 4, wherein one of the first, second, third, and fourth flow control mechanisms comprises a melt pump. 6. The pipe manufacturing cell of claim 4, wherein each of the first, second, third, and fourth flow control mechanisms comprises a melt pump. 7. Pipe production cell according to one of the numbers 3 to 6, further comprising: a first flow divider configured to divide an output of the first extruder into the first tubular material flow and the third tubular material flow; and a second flow divider configured to divide an output of the second extruder into the second tubular material flow and the fourth tubular material flow. 8. Pipe production cell according to paragraph 2, where: the first extruder is designed to provide a third pipe material flow to the first pipe die head; and the second extruder is designed to provide a fourth pipe material flow to the second pipe die head. 9. Pipe production cell according to item 2, wherein the extrusion system further comprises: a third extruder configured to provide a third pipe material flow to the first pipe die head; and a fourth extruder configured to provide a fourth pipe material flow to the second pipe die head. 10. Pipe production cell according to one of the numbers 1 to 9, further comprising: a first flow control mechanism disposed between the extrusion system and the first tube die head; and a second flow control mechanism disposed between the extrusion system and the second tube die head. 11. The pipe manufacturing cell of item 10, wherein the first flow control mechanism or the second flow control mechanism comprises a melt pump. 12. Pipe manufacturing cell according to one of the numbers 1 to 11, wherein within each multi-pipe mold block the first cavity comprises a diameter equal to the second cavity. 13. Pipe manufacturing cell according to one of the numbers 1 to 11, wherein within each multi-pipe mold block the first cavity comprises a larger diameter than the second cavity. 14. A pipe manufacturing cell according to any one of claims 1 to 13, wherein each multi-pipe forming block includes a third cavity having a third corrugated forming surface. 15. Pipe production cell according to one of the numbers 1 to 14, further comprising: a variety of common block carriers, wherein each multi-tube mold block is adapted to be mounted in one of the plurality of common block supports. 16. The pipe manufacturing cell of any one of paragraphs 1 to 15, wherein each of the plurality of multi-pipe mold blocks is removable. 17. Pipe manufacturing cell according to one of the numbers 1 to 16, comprising: a conveyor system configured to rotate the multi-pipe mold blocks in a loop. 18. Pipe production cell according to one of the numbers 1 to 17, further comprising: a nozzle stand designed to: aligning the first tube die head with the first cavities of the plurality of multi-tube mold blocks; aligning the second tube die head with the second cavities of the plurality of multi-tube mold blocks; and to perform a relative movement between the first pipe nozzle head and the second pipe nozzle head. 19. Pipe manufacturing cell according to paragraph 18, wherein the nozzle stand further comprises: a first support stand configured to support the first tube nozzle head, the first support stand comprising a first stage configured to move the first tube nozzle head in a first degree of freedom; and a second support stand configured to support the second tubular nozzle head, the second support stand including a second stage configured to move the second tubular nozzle head in a second degree of freedom. 20. Pipe production cell according to paragraph 19, where: the first support column comprises a third stage configured to move the first tube nozzle head in a third degree of freedom different from the first degree of freedom; and the second support column comprises a fourth stage configured to move the second tubular nozzle head in a fourth degree of freedom different from the second degree of freedom. 21. Pipe production cell according to paragraph 19 or 20, where: the first degree of freedom comprises a rotation about a first axis perpendicular to a longitudinal axis of the first tube nozzle head; and the second degree of freedom comprises a rotation about a second axis perpendicular to a longitudinal axis of the second tube nozzle head. 22. Pipe production cell according to paragraph 19 or 20, where: the first degree of freedom comprises a displacement along a first axis perpendicular to a longitudinal axis of the first tube nozzle head; and the second degree of freedom comprises a displacement along a second axis perpendicular to a longitudinal axis of the second tube nozzle head. 23. Pipe manufacturing cell according to any one of items 19 to 22, wherein the nozzle stand further comprises: a frame configured to support at least one of the first support stand and the second support stand. 24. Pipe manufacturing process comprising: Providing a pipe material flow from an extrusion system to a corrugator, the corrugator comprising a plurality of single pipe forming blocks, each of the plurality of single pipe forming blocks comprising a corrugated forming surface, Corrugating a tube through the corrugator using the plurality of single tube forming blocks; replacing the plurality of single-tube forming blocks with a plurality of multi-tube forming blocks in the corrugator, each of the plurality of multi-tube forming blocks comprising a plurality of corrugated forming surfaces; Modifying the extrusion system to subdivide the pipe material flow; Providing the divided pipe material flow to the plurality of corrugated forming surfaces of the multi-pipe forming blocks; and Corrugating a variety of tubes through the corrugator using the multi-tube forming blocks. 25. Pipe manufacturing process comprising: Providing a divided pipe material flow from an extrusion system to a corrugator, the corrugator comprising a plurality of multi-pipe forming blocks, each of the plurality of multi-pipe forming blocks comprising a plurality of corrugated forming surfaces, and Corrugating a plurality of tubes through the corrugator using the plurality of multi-tube forming blocks.

[0064] The above description is for illustrative purposes only. It is not exhaustive and does not limit the invention to the precise forms or embodiments disclosed. Modifications and adaptations of the invention will become apparent to those skilled in the art upon consideration of the specification and practice of the disclosed embodiments of the inventions disclosed herein. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 584,984

[0001] US 10,612,698

[0019] US 10,550,963

[0019] US 10,077,856

[0019] US 10,077,857

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[0019] US 9,759,354

[0019] US 3,916,763

[0019] US 4,003,685

[0019] US 3,919,367

[0019] US 3,941,639

[0019] US 3,990,8273

[0019] US 910,713

[0019] US 3,877,831

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[0019] US 7,980,841

[0021] US 8,496,460

[0021] Cited non-patent literature

[0000] Double pipe production cell”, filed on 25 September 2023

[0001]

Claims

[1] Pipe manufacturing cell, comprising: an extrusion system; a corrugator comprising a plurality of multi-tube mold blocks, each multi-tube mold block comprising a first cavity having a first corrugated molding surface and a second cavity having a second corrugated molding surface; a first tube die head connected to the extrusion system and configured to provide a first flow of tube material to the first cavities of the plurality of multi-tube die blocks; and a second pipe die head connected to the extrusion system and configured to provide a second pipe material flow to the second cavities of the plurality of multi-pipe mold blocks, wherein the first tube nozzle head and the second tube nozzle head are configured to simultaneously provide the first and second tube material flows. [2] Pipe manufacturing cell according to claim 1, wherein the extrusion system comprises: a first extruder configured to provide the first pipe material flow to the first pipe die head; and a second extruder configured to provide the second pipe material flow to the second pipe die head. [3] Pipe manufacturing cell according to claim 2, wherein: the first extruder is designed to provide a third pipe material flow to the second pipe die head; and the second extruder is designed to provide a fourth pipe material flow to the first pipe die head. [4] Pipe manufacturing cell according to claim 3, further comprising: a first flow control mechanism configured to control the first pipe material flow from the first extruder to the first pipe die head; a second flow control mechanism configured to control the second pipe material flow from the second extruder to the second pipe die head; a third flow control mechanism configured to control the third pipe material flow from the first extruder to the second pipe die head; and a fourth flow control mechanism configured to control the fourth pipe material flow from the second extruder to the first pipe die head. [5] The pipe manufacturing cell of claim 4, wherein one of the first, second, third and fourth flow control mechanisms comprises a melt pump. [6] The pipe manufacturing cell of claim 4, wherein each of the first, second, third and fourth flow control mechanisms comprises a melt pump. [7] Pipe manufacturing cell according to one of claims 3 to 6, further comprising: a first flow divider configured to divide an output of the first extruder into the first tubular material flow and the third tubular material flow; and a second flow divider configured to divide an output of the second extruder into the second tubular material flow and the fourth tubular material flow. [8] Pipe manufacturing cell according to claim 2, wherein: the first extruder is designed to provide a third pipe material flow to the first pipe die head; and the second extruder is designed to provide a fourth pipe material flow to the second pipe die head. [9] The pipe manufacturing cell of claim 2, wherein the extrusion system further comprises: a third extruder configured to provide a third pipe material flow to the first pipe die head; and a fourth extruder configured to provide a fourth pipe material flow to the second pipe die head. [10] Pipe manufacturing cell according to one of claims 1 to 9, further comprising: a first flow control mechanism disposed between the extrusion system and the first tube die head; and a second flow control mechanism disposed between the extrusion system and the second tube die head. [11] The pipe manufacturing cell of claim 10, wherein the first flow control mechanism or the second flow control mechanism comprises a melt pump. [12] A pipe manufacturing cell according to any one of claims 1 to 11, wherein within each multi-pipe mold block the first cavity comprises a same diameter as the second cavity. [13] A pipe manufacturing cell according to any one of claims 1 to 11, wherein within each multi-pipe mold block, the first cavity comprises a larger diameter than the second cavity. [14] A pipe manufacturing cell according to any one of claims 1 to 13, wherein each multi-pipe mold block comprises a third cavity having a third corrugated forming surface. [15] Pipe manufacturing cell according to one of claims 1 to 14, further comprising: a variety of common block carriers, wherein each multi-tube mold block is adapted to be mounted in one of the plurality of common block supports. [16] A pipe manufacturing cell according to any one of claims 1 to 15, wherein each of the plurality of multi-pipe mold blocks is removable. [17] A pipe manufacturing cell according to any one of claims 1 to 16, comprising: a conveyor system configured to rotate the multi-pipe mold blocks in a loop. [18] Pipe manufacturing cell according to one of claims 1 to 17, further comprising: a nozzle stand designed to: aligning the first tube die head with the first cavities of the plurality of multi-tube mold blocks; aligning the second tube die head with the second cavities of the plurality of multi-tube mold blocks; and to perform a relative movement between the first pipe nozzle head and the second pipe nozzle head. [19] A pipe manufacturing cell according to claim 18, wherein the nozzle stand further comprises: a first support stand configured to support the first tube nozzle head, the first support stand comprising a first stage configured to move the first tube nozzle head in a first degree of freedom; and a second support stand configured to support the second tubular nozzle head, the second support stand including a second stage configured to move the second tubular nozzle head in a second degree of freedom. [20] Pipe manufacturing cell according to claim 19, wherein: the first support column comprises a third stage configured to move the first tube nozzle head in a third degree of freedom different from the first degree of freedom; and the second support column comprises a fourth stage configured to move the second tubular nozzle head in a fourth degree of freedom different from the second degree of freedom. [21] Pipe manufacturing cell according to claim 19 or 20, wherein: the first degree of freedom comprises a rotation about a first axis perpendicular to a longitudinal axis of the first tube nozzle head; and the second degree of freedom comprises a rotation about a second axis perpendicular to a longitudinal axis of the second tube nozzle head. [22] Pipe manufacturing cell according to claim 19 or 20, wherein: the first degree of freedom comprises a displacement along a first axis perpendicular to a longitudinal axis of the first tube nozzle head; and the second degree of freedom comprises a displacement along a second axis perpendicular to a longitudinal axis of the second tube nozzle head. [23] Pipe manufacturing cell according to one of claims 19 to 22, wherein the nozzle stand further comprises: a frame configured to support at least one of the first support stand and the second support stand.

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