Patent Application
20080061466
Other objects, features, and advantages of the present invention will be apparent from the written description and the drawings in which:
Exhibit A details four views of an embodiment of the present invention
The present invention is formed using superior thermoplastic molding systems and process as discussed below and as described in U.S. Pat. No. 6,719,551, U.S. Pat. No. 6,869,558, and U.S. Pat. No. 6,900,547. U.S. Pat. No. 6,719,551, U.S. Pat. No. 6,869,558, and U.S. Pat. No. 6,900,547 are incorporated by reference. By forming the water management chamber using the thermoplastic molding systems and process discussed below, the water management chamber has a high density and smooth surface that provides greater chemical resistance to storm water run-off and septic applications. The water management chamber produced using the thermoplastic molding systems and process also has a high reinforcing fiber concentration and provides a functional shape ideal for collecting sewage and excess rain during and after heavy rains.
Exhibit A portrays the details including dimensions of the water management chamber. The water management chamber is formed from thermoplastic matrix materials using the thermoplastic molding system, also referred to as the extrusion-molding system. The thermoplastic matrix materials that may be utilized to form the composite material include thermoplastic resins as understood in the art. The thermoplastic resins that may be utilized in accordance with the principles of the present invention include any thermoplastic resin that can be melted and blended by the extruder 11. Examples of such thermoplastic resins are provided in TABLE 1 with the understanding that the examples are not intended to be a complete list, and that other thermoplastic resins and materials may be utilized in producing the structural parts utilizing the system. Additionally the thermoplastic resins of TABLE 1 may be used alone or in any combinations thereof.
Particular thermoplastic materials, including polypropylene, polyethylene, polyetheretherketone, polyesters, polystyrene, polycarbonate, polyvinylchloride, nylon, polymethyl, polymethacrylate, acrylic, polyurethane and mixtures thereof, have been especially suitable for the thermoplastic molding system.
The fibers that serve as the reinforcement component for the thermoplastic composite materials generally include those materials that may be utilized to reinforce thermoplastic resins. Fiber materials suitable for use in accordance with the principles of the present invention include, without limitation, glass, carbon, metal and natural materials (e.g., flax, cotton), either alone or in combination. Other fibers not listed may also be utilized as understood in the art. Although the diameter of the fiber generally is not limited, the fiber diameter generally ranges between 1 and 20 μm. It should be understood, however, that the diameter of the fibers may be larger depending on a number of factors, including strength of structural part desired and density of fiber desired. In particular, the effect of improvement of mechanical properties is marked with a fiber having a diameter of approximately one (1) to approximately nine (9) μm.
The number of filaments bundled in the fiber also is not generally limited. However, a fiber bundle of 10,000 to 20,000 filaments or monofilaments is generally desired for handling considerations. Rovings of these reinforcing fibers may be used after surface treatment by a silane or other coupling agent. To improve the interfacial bonding with the thermoplastic resin, for example, in the case of a polyester resin, surface treatment may be performed by a thermoplastic film forming polymer, coupling agent, fiber lubricant, etc. Such surface treatment may be performed in advance of the use of the treated reinforcing fibers or the surface treatment may be performed just before the reinforcing fibers are fed into the extruder of the thermoplastic molding system in order to run the extrusion process to produce the molten thermoplastic composite without interruption. The ratio between the thermoplastic resin and fiber is not particularly limited as it is possible to produce the thermoplastic composite and shaped articles using any ratio of composition in accordance with the final object of use. However, to provide sufficient structural support for the water management chamber, the content of fibers is generally five percent (5%) to fifty percent (50%) by weight. It has been determined that the content of fibers is generally ten (10) to seventy (70) percent by weight, and preferably forty percent (40%) by weight to achieve the desired mechanical properties for the production of the water management chamber.
The average fiber length of the fibers is greater than about one-half inch (½″). However, typically water management chambers produced by the extrusion-molding system 600a described below utilize fiber lengths longer than about one inch. It should be noted that when the average fiber length is less than one inch, the desired mechanical properties for the water management chamber is difficult to obtain. Distribution of the fibers in the thermoplastic composite material is generally uniform so that the fibers and thermoplastic resin do not separate when melted and compressed. The distribution or disbursement of the fibers includes a process by which the fibers are dispersed from a single filament level to a level of multiple filaments (i.e., bundles of several tens of fibers). In one embodiment of the thermoplastic molding system, bundles of about five fibers are dispersed to provide efficiency and structural performance. Further, the “degree of combing” may be evaluated by observing a section of the structure by a microscope and determining the ratio of the number of reinforcing fibers in bundles of ten or more in all of 1000 or more observable reinforcing fibers (total number of reinforcing fibers in bundles of 10 or more/total number of reinforcing fibers×100) (percent). Typical values produced by the thermoplastic molding system result in not more than approximately sixty percent (60%), and generally below thirty-five percent (35%).
It should be noted at this point that the extruder 11 produces the heated extruded slab still containing the heat energy onto the traveling mold half where it is delivered to the compression mold 13 and molded into the water management chamber without having to reheat a sheet of thermoplastic material. As will also be noted hereinafter in connection with
Turning to
Turning to
A thermoplastic molding system is provided which includes selecting a thermoplastic extrusion die 16 or 30 for the extrusion of a thermoplastic slab, which extrusion die can have an adjustable die gate members for varying the thickness of the extruded material in different parts of the extruded slab. The process includes adjusting the thermoplastic extrusion die for various thickness of the extruded material passing therethrough in different parts of the extruded slab and then heating a thermoplastic material to a fluid and extruding a slab of fluid thermoplastic material through the selected and adjusted thermoplastic extrusion die. The thermoplastic slab is then trimmed and directed onto a heated thermoplastic material into a thermoforming mold 19 or 23 and molded in a molding apparatus 13 to form the water management chamber with a variable thickness.
It should be clear at this time that a thermoplastic molding system has been provided which allow for the thermoforming of the water management chamber with a variable thickness using an extrusion die which can be continuously controlled to vary the thickness of different parts of the extruded slab being molded and that the molding is accomplished while the thermoplastic slab is still heated to utilize the heat energy from the extrusion process. Although the extruded material is described sometimes as a generally flat plate slab, it is also described as follows: (i) containing heat energy when delivered to the compression mold 13 to obviate reheating, (ii) having a variable thickness throughout its width, (iii) being a hot melt when charged into the mold half 19 from the extruder 11, (iv) using a plurality of gated plates 35 to vary the thickness across the width of the extruded material and in different parts of the extruded material, and finally (v) extruding molten thermoplastic material through the selected and adjusted extrusion die to achieve a variable thickness in the water management chamber. Thus, the extruder generally provides a molten flow of thermoplastic composite material through the dynamic die, gravitating onto a mold half or lower mold in variable quantities in the vertical plane and across both horizontal directions on the mold.
The thermoplastic molding system described above is ideal for manufacturing the water management chamber reinforced with glass, carbon, metal or organic fibers to name a few. The thermoplastic molding system includes a computer-controlled extrusion system that integrates and automates material blending or compounding of the matrix and reinforcement components to dispense a profiled quantity of molten composite material that gravitates into the lower half of a matched-mold, the movement of which is controlled while receiving the material, and a compression molding station for receiving the lower half of the mold for pressing the upper half of the mold against the lower half to form the desired structure or part. The lower half of the matched-mold discretely moves in space and time at varying speeds to enable the deposit of material more thickly at slow speed and more thinly at faster speeds.
Unprocessed resin (which may be any form of regrind or pelletted thermoplastic or, optionally, a thermoset epoxy) is the matrix component fed into a feeder or hopper of the extruder, along with reinforcement fibers greater than about one-half inch (½″) in length. The composite material may be blended and/or compounded by the extruder 11, and “intelligently” deposited onto the lower mold half 19 by controlling the output of the extruder 11 with the gates 35 and the movement of the lower mold half 19 relative to the position of the extruder 11
The thermoplastic molding system described in
The material receiving unit 602 may include one or more hoppers or feeders 614 and 615 for receiving materials M1 and M2, respectively, that will be extruded to form a thermoplastic composite. It should be understood that additional feeders may be utilized to receive additional materials or additives to formulate different compounds. In the instant example, materials M1 and M2 represent the starting material i.e., reinforced thermoplastic materials preferably in the form of pellets. M1 and M2 may be the same or different reinforced thermoplastic material. The thermoplastic materials may be reinforced by fibers, such as glass or carbon fibers, as understood in the art. It should be further understood that non-thermoplastic material may be utilized in accordance with the principles of the present invention.
A heater 618 preheats the thermoplastic materials M1 and M2. The extruder 604 is coupled to the feeder channel 616 and operable to mix the heated thermoplastic materials M1 and M2 via an auger 620. The extruder 604 further melts the thermoplastic materials. The auger 620 may be helical or any other shape operable to mix and flow the composite material through the extruder 604. An extruder output channel 622 is coupled to the extruder 604 and is utilized to carry the composite material to a dynamic die 606.
The dynamic die 606 includes multiple flow control elements 624a-624n (collectively 624). The flow control elements 624 may be individual gates, valves, or other mechanisms that operate to control the extruded composite material 625 from the dynamic die 606, where the extruded composite material 625a-625n (collectively 625) varies in volumetric flow rates across a plane P at or below the flow control elements 624. The outputting of the different volumetric flow rates ranges between approximately zero and 3000 pounds per hour. A more preferable range for the volumetric flow rate ranges between approximately 2500 and 3000 pounds per hour. In one embodiment of the extrusion-molding system, the flow control elements 624 are gates that are raised and lowered by separate actuators, such as electrical motors, (e.g., stepper motors), hydraulic actuators, pneumatic actuators, or other actuator operable to alter flow of the composite material from the adjustable flow control elements 624, individually or collectively. The flow control elements 624 may be adjacently configured to provide for a continuous separating adjacent flow control elements 624. Alternatively, the flow control elements 624 may be configured separately such that the composite material flowing from adjacent flow control elements 624 remains separated until the composite material spreads on a mold. It should be understood that the flow control elements 624 suitably may operate as a trimmer 17. In an embodiment of the extrusion-molding system, the molten composite material may be delivered to an accumulator, placed between the extruder 604 and the dynamic die 606, from which the composite material may be delivered into a lower mold using a plunger or other actuating mechanism.
The trolley 608 may be moved beneath the dynamic die 606 so that the extruded composite material 625 gravitates to or is deposited on a lower mold 626, which passes below the dynamic die 606 at a predetermined vertical distance, the “drop distance” (d). The lower mold 626 defines cavities 630 that are used to form the water management chamber. The extruded composite material 625 is deposited 628 on the lower mold 626 to fill the volume defined by the cavities 630 in the lower mold 626 and an upper mold 632 to form the water management chamber. In a two-axis controlled process, the composite material 625a may be deposited on the lower mold 626 at a substantially constant volumetric flow rate from the dynamic die 606 or across a vertical plane (P), based on discrete movement and variable speeds, to form the composite material layer 628 having substantially the same thickness or volume along the vertical plane (P) to fill the cavities 630 in the lower and upper molds 626 and 632. In a three-axis controlled process, the composite material may be deposited on the lower mold 626 at different volumetric flow rates from the dynamic die 606 across the vertical plane (P) to form the composite material layer 628 having different thickness or volume along the vertical plane (P) to fill the cavities 630 in the lower and upper molds 626 and 632. It should be understood that the two-axis controlled process may be utilized to deposit the composite material to molds that have cavities 630 substantially constant in depth in the vertical plane and that the three-axis controlled process may be utilized to deposit the composite to molds that have cavities 630 that vary in depth.
The trolley 608 may further include wheels 634 that provide for translation along a rail 636. The rail 636 enables the trolley 608 to roll beneath the dynamic die 606 and into the press 610. The press 610 operates to press the upper mold 632 into the lower mold 626. Even though the principles of the extrusion-molding system provide for reduced force for the molding process than conventional thermoplastic molding processes due to the composite material layer 628 being directly deposited from the dynamic die 606 to the lower mold 626, the force applied by the press 610 is still sufficient to damage the wheels 634 if left in contact with the rail 636. Therefore, the wheels 634 may be selectively engaged and disengaged with an upper surface 638 of a base 640 of the press 610. In an embodiment, the trolley 608 is raised by inflatable tubes (not shown) coupled thereto so that when the tubes are inflated, the wheels 634 engage the rails 636 so that the trolley 608 is movable from under the die 606 to the press 610. When the tubes are deflated, the wheels 634 are disengaged so that the body of the trolley 608 is seated on the upper surface 638 of a base 640 of the press 610. It should be understood that other actuated structural components may be utilized to engage and disengage the wheels 634 from supporting the trolley 608, but that the functionality to engage and disengage the wheels 634 is to be substantially the same. For example, the upper surface 638 of the base 640 of the press 610 may be raised to contact the base plate 642 of the trolley 608.
The controller 612 is electrically coupled to the various components that form the extrusion-molding system 600. The controller 612 is a processor-based unit that operates to orchestrate the forming of the water management chamber. In part, the controller 612 operates to control the composite material being deposited on the lower mold 626 by controlling temperature of the composite material, volumetric flow rate of the extruded composite material 625, and the positioning and rate of movement of the lower mold 626 via the trolley 608 to receive the extruded composite material 625. The controller 612 is further operable to control the heater 618 to heat the thermoplastic materials. The controller 612 may control the rate of the auger 620 to maintain a substantially constant flow of composite material through the extruder 604 and into the dynamic die 606. Alternatively, the controller 612 may alter the rate of the auger 620 to alter the volumetric flow rate of the composite material from the extruder 604. The controller may further control heaters (not shown) in the extruder 604 and the dynamic die 606. A predetermined set of parameters may be established for the dynamic die 606 to apply the extruded composite material 625 to the lower mold 626. The parameters may be defined such that the flow control elements 624 may be selectively positioned such that the movement of the trolley 608 is positionally synchronized with the volumetric flow rate of the composite material in accordance with the cavities 630 that the define the water management chamber.
The trolley 608 may further include a heater (not shown) that is controlled by the controller 612 and is operable to maintain the extruded composite material 625 in a heated or melted state. The controller may, by varying the required speeds of the trolley, control the trolley 608 during the extruded composite material 625 being applied to the lower mold 626. Upon completion of the extruded composite material 625 being applied to the lower mold 626, the controller 612 drives the trolley 608 into the press 610. The controller then signals a mechanism (not shown) to disengage the wheels 634 from the track 636 as described above so that the press 610 can force the upper mold 632 against the lower mold 626 without damaging the wheels 634.
The controller 612 may be configured to support multiple water management chamber so that the extrusion-molding system 600b may simultaneously form the multiple or different structural parts via the different presses 610a and 610b. Because the controller 612 is capable of storing parameters operable to form multiple structural parts, the controller 612 may simply alter control of the dynamic die 606 and trolleys 608a and 608b by utilizing the parameters in a general software program, thereby providing for the formation of two different structural parts using a single extruder 604 and dynamic die 606. It should be understood that additional presses 610 and trolleys 608 may be utilized to substantially simultaneously produce more structural parts via a single extruder 604 and dynamic die 606.
As indicated by the variation in shading of the extruded composite material 625 associated with each of the flow control elements 624, the flow control elements 624 may be dynamically adjusted via the lower and upper molds 626 and 632. Accordingly, the flow control elements 624 may be adjusted to alter the volumetric flow rates of the extruded composite material 625 over finite regions of the lower and upper molds 626. In other words, based on the cavities 630 defined by the lower and upper molds 626 and 632, the composite material layer 628 may be varied in thickness. For example, the composite material layer region 628a is thinner than composite material layer region 628b, which is thicker to sufficiently fill the cavity 630a, which has a deeper draft than other locations of the cavity 630 in the lower mold 626. In other words, the extruded composite material layer 628 is dynamically altered based on the depth of the cavity 630 defined by the molds 626 and 632. In both the two- and three-axis controlled processes capable of being performed on the extrusion-molding system 600a, the extruded composite material layer 628 may be dynamically altered in terms of thickness based on the volumetric flow rate of the extruded composite material 625 and the speed of travel of the trolley 608.
Depositing the extruded composite material onto the lower mold may be performed by controlling the amount of extruded composite material deposited in two or three axes. For the two-axis control, the movement of the trolley may be controlled along the axis of movement to deposit the extruded composite material in various amounts along the axis of deposit. For the three-axis control, the output of the extruder may utilize a dynamic die that includes flow control elements, thereby providing for different volumetric flow rates to be simultaneously deposited onto the lower mold along the axis perpendicular to the axis of movement. It should be understood that other embodiments may provide for off-axis or non-axis control to deposit the extruded composite material in specific locations on the lower mold.
By providing for control of the trolley and composite material being applied to the lower mold, any pattern may be formed on the lower mold, from a thick continuous layer to a thin outline of a circle or ellipse, any two-dimensional shape that can be described by discrete mathematics can be traced with material. Additionally, because control of the volume of composite material deposited on a given area exists, the water management chamber may be created to provide with deep draft and/or hidden ribs. Once the water management chamber is cooled, ejectors may be used to push the consolidated material off of the mold. The principles of the present invention may be designed so that two or more unique parts may be produced simultaneously, thereby maximizing production efficiency by using a virtually continuous stream of composite material.
It should be clear at this time that several embodiments of thermoplastic molding systems have been provided which allow for the thermoforming of a water management chamber. However, while the thermoplastic molding systems described above are ideal for manufacturing the present invention, it should also be clear that the present invention is not to be considered limited to the molding systems shown which are to be considered illustrative rather than restrictive.
With the extrusion-molding system, large long-fiber reinforced plastic parts may be produced in-line and at very low processing costs. Features of the extrusion system provide for a reinforced plastic components production line that offers (i) materials flexibility, (ii) deposition process, (iii) low-pressures, and (iv) machine efficiency. Materials flexibility provides for savings in both material and machine costs from in-line compounding, and further provides for material property flexibility. The deposition process adds value in the material deposition process, better material flow, and ease of inclusion of large inserts in the mold. The low-pressures are directed to reduced molding pressures, which lessen the wear on both the molds and the machines, and lock very little stress into the water management chamber. The machine efficiency provides for the ability to use two or more completely different molds at once to improve the efficiency of the extrusion system, thereby reducing the required number of machines to run a production operation. Additionally, the material delivery system according to the principles of the present invention may be integrated with many existing machines.
The extrusion-molding process allows custom composite blends to be compounded using several different types of resin and fiber. The extrusion system may produce water management chambers with several resins as described above. With traditional compression molding, pre-manufactured thermoplastic sheets, commonly known as blanks that combine a resin with fibers and desired additives are purchased from a thermoplastic sheet producer. These blanks, however, are costly because they have passed through several middle-men and are usually only sold in pre-determined mixtures. By utilizing the extrusion-molding process according to the principles described above, these costs may be reduced by the in-line compounding process utilizing the raw materials to produce the water management chamber without having to purchase the pre-manufactured sheets. Labor and machine costs are also dramatically reduced because the extrusion-molding system does not require ovens to pre-heat the material and operators to move the heated sheets to the mold. Since the operator controls the compounding ratios as desired, nearly infinite flexibility is added to the process, including the ability to alter properties while molding or to create a gradual change in color, for example. Also, unlike sheet molding, the extrusion-molding system does not require the material to have a melt-strength, giving the system added flexibility. In one embodiment, the extrusion-molding system may utilize thermoset resins to produce the water management chamber. The extrusion-molding system may also use a variety of fiber materials, including carbon, glass and other fibers as described above, for reinforcement with achievable fiber volume fractions of over 50 percent and fiber lengths of one to four inches or longer with 85 percent or higher of the fiber length being maintained from raw material to finished part.
The extrusion system, according to the principles described above, allows for variable composite material lay-down; in regions of the mold where more material is to be utilized for deep draft or hidden ribs, for example, thereby minimizing force utilized during molding and pressing. The variable composite material lay-down results in more accuracy, fuller molds, and fewer “short-shots” as understood in the art than with typical compression molding processes. Variable lay-down also allows for large features to be molded on both sides of the water management chamber, as well as the placement of inserts or cores into the water management chamber. Lastly, since the material has a relatively very low viscosity as it is being deposited in a molten state onto the mold (as opposed to being pre-compounded into a sheet and then pressed into a mold), fibers are able to easily enter ribs and cover large dimensional areas without getting trapped or becoming undesirably oriented.
The thermoplastic composite material being deposited during the extrusion-molding process is much more fluid than that from a heated pre-compounded sheet, thus allowing the thermoplastic composite material to flow much easier into the mold. The fluidity of the composite material being deposited onto the mold results in significantly reduced molding pressure requirements over most other molding processes. Presses for this process generally operate in the range of 100 pounds per square inch, compared with 1,000 pounds per square inch of pressure used for compression molding. This lower pressure translates to less wear, thereby reducing maintenance on both the molds and the press. Because of the lower pressures, instead of needing a steel tool that could cost over $200,000, an aluminum mold, capable of 300,000 cycles, and may be manufactured for as little as $40,000. Less expensive tooling also means more flexibility for future design changes. Since the thermoplastic resin is relocated and formed on the face of the mold under lower pressures, less stress is locked into the material, thereby leading to better dimensional tolerance and less warpage.
Because the extrusion-molding process may use two or more molds running at the same time, there is a reduction in the average cycle time per part, thus increasing productivity as the first mold set may be cooled and removed while a second mold is filled and compressed. Also, the extrusion-molding system utilizes minimal redundant components. In one embodiment, the extrusion system utilizes a separate press for each mold, but other equipment may be consolidated and shared between the mold sets and may be easily modified in software to accommodate other molds. The extrusion and delivery system 600a further may be integrated into current manufacturing facilities and existing compression molds and presses may be combined.
The composite material is extruded at step 826. In the extrusion process, the auger 620 or other mechanism utilized to extrude the composite material is configured to substantially avoid damaging the fibers such that the original fiber lengths are substantially maintained (e.g., 85 percent or higher). For example, in the case of using a screw type auger 620, the thread spacing is selected to be larger than the length of the fibers, thereby substantially avoiding damaging the fibers.
At step 828, the extruded composite material 625 may be dynamically output at different volumetric flow rates across a plane to provide for control of depositing the extruded composite material 625 onto the lower mold 626. The lower mold 626 may be positionally synchronized to receive the extruded composite material 625 in relation to the different volumetric flow rates across the plane P at step 830. In an embodiment, the positional synchronization of the mold 626 is performed in accordance with flow control elements 624 that are located at a height d above the trolley 608, which may be translated at a substantially constant or adjustable rate. For example, to deposit a constant or flat extruded composite material layer 628, the trolley 608 is moved at a substantially constant rate, but to increase or decrease the volume of the extruded composite material layer 628, the trolley 608 may be moved at a slower or faster rate, respectively. At step 832, the extruded composite material 625 that is formed into the extruded composite material layer 628 is pressed into the mold 626 to form the thermoplastic water management chamber. The water management chamber forming process ends at step 834.
The feeder(s) 614 may include a speed and temperature controller 902 that is operable to control speed and temperature of the feeder(s) 614 for mixing the composite material M1 and fiber material M2. The feeder speed and temperature controller(s) 902 may be formed of single or multiple controllers to control motor(s) and heater(s). The controller 612 is operable to specify or command the velocity or rate and temperature of the feeder(s) 614, while the speed and temperature controller 802 of the feeder(s) 614 is operable to execute the commands received by the controller 812. For example, based on the amount of composite material being extruded via the dynamic die 606, the controller 612 may increase the rate of the materials M1 and M2 being fed into the extruder 606.
The controller 612 is further in communication with the heater controller 904. The controller 612 may communicate control data to the heater controller 904 based on feedback data received from the heater controller 904. For example, if the temperature of the heater controller 904 decreases during feeding operations, then the controller 612 may issue commands via the control data 1018 to the heater controller 904 to increase the temperature of the heater 618. Alternatively, the heater controller 904 may regulate the temperature utilizing a feedback regulator loop as understood in the art to the temperature commanded by the controller 612 and simply report the temperature to the controller 612 for monitoring purposes.
The controller 612 is further in communication with an extruder speed and temperature controller 906, which provides control over the speed of the auger 620 and temperature of the extruder 604. The extruder speed and temperature controller 906 may be operable to control multiple heaters within zones of the extruder 604 and communicate the temperatures of each heater to the controller 612. It should be understood that the extruder speed and temperature controller 906 may be formed of multiple controllers.
The controller 612 is further in communication with a dynamic die controller 908 that controls the flow control elements 624 of the dynamic die 606. The dynamic die controller 908 may operate to control each of the flow control elements 624 collectively or individually. Alternatively, each flow control element 624 may be individually controlled by separate controllers. Accordingly, the controller 612 may operate to issue commands to the dynamic die controller 908 to set the position for each of the flow control elements 624 in an open-loop manner. For example, a stepper motor may be utilized in an open-loop manner. Actual position of each flow control elements 624 may be communicated back to the controller 612 via the feedback data 1022 for the controller 612 to utilize in controlling the positions of the flow control elements 624.
The controller 612 is further in communication with a trolley controller 910 that is coupled to the trolley 608 and is operable to control position of the trolley 608 and temperature of the lower mold 626. The controller 612 may provide control signals 1018 to the trolley controller 910 that operates as a servo to drive the trolley 608 to the positions commanded by the controller 612, which, in the case of depositing the extruded composite material 625 onto the lower mold 626, positions the lower mold 626 accordingly. Although the extruded composite material layer 628 that is deposited onto the lower mold 626 is molten at the time of deposition, the extruded composite material layer 628 deposited first tends to cool as the later extruded composite material 625 is being deposited. Therefore, the controller 612 may communicate control data 1018 to the trolley controller 910 to maintain the temperature of the extruded composite material layer 628, either at a substantially constant temperature, based on time of deposition of the extruded composite material 625, and/or based on other factors, such as thermoplastic material M1 molten state temperature requirements. Feedback data 1022 may provide current temperature and status of the position and velocity of the trolley 608 and temperature of the lower mold 626 so that the controller 612 may perform management and monitoring functions.
The controller 612 is further in communication with a heat/cool controller 912, which is operable to control temperature of heaters and/or coolers for the extrusion-molding system 600a. The heat/cool controller 912 may receive the control data 1018 from the controller 612 that commands the heat/cool controller 912 to operate at a specific or variable temperature based on a number of factors, such as thermoplastic material M1, ambient temperature, characteristics of the water management chamber being produced, production rates, etc. The heat/cool controller 912 may control system-level heaters and coolers or component-level heaters and coolers. Feedback data 1022 may provide current temperature and status of the heaters and coolers so that the controller 612 may perform management and monitoring functions.
The controller 612 is further in communication with a press controller 914, which is operable to control press operation and temperature of the upper mold 632. The press controller 914 may be a standard controller that the manufacturer of the press 610 supplies with the press 610. Similarly, the press controller 914 may include a temperature controller to control the temperature of the upper mold 932. Alternatively, the temperature controller may not be associated with the press controller 914 provided by the manufacturer of the press 910. Feedback data 612 may provide current position and force of the press and temperature of the upper mold 632 so that the controller 612 may perform management and monitoring functions.
The controller 612 is further in communication with an extraction tool controller 916 that is operable to control extraction operations on the molded water management chamber. In response to the controller 612 receiving notification from the press controller 914 that the press 610 has completed pressing operations, the controller 612 may issue control signals 1018 to the extraction tool controller 916 to initiate extraction of the molded water management chamber. Accordingly, feedback data 1022 may be utilized to indicate current operation of the extraction tool. If the feedback data 1022 indicates that the extraction tool is having difficulty extracting the molded water management chamber, an operator of the extrusion-molding system 600a may be notified that a problem exists with the extraction tool, the lower or upper molds 626 and 632, the press 610, the heater or cooler of the upper or lower mold 626 and 632, or other component or function of the extrusion-molding system 600a.
It should be understood that while the controller 612 may be configured to be a master controller for each of the components of the extrusion-molding system 600a, that the controller 612 may be configured to manage the components in a more distributed controller manner. In other words, the controllers of the components may operate as more intelligent controllers that use the parameters of the water management chamber to compute operating and control parameters and less as servos that are commanded by the controller 612 to perform a function. It should be further understood that the controller 612 may be programmed to accommodate different mechanical configurations of the extrusion-molding system 600a. For example, if the extrusion-molding system 600a were configured such that the output of the extruder 606 translated or otherwise moved relative to a stationary lower mold 626, which may or may not be coupled to a trolley 608, then the controller 612 may be programmed to control the movement of the output of the extruder 606 rather than movement of the trolley 608.
The processor 1002 is operable to execute software 1014 utilized to control the various components of the extrusion-molding system 600a and to manage the databases 1012. In controlling the extrusion-molding system 600a, the software 1014 communicates with the extrusion-molding system 600a via the I/O unit 1008 and control bus 1016. Control data 1018 is communicated via data packets and/or analog control signals across a control bus 1016 to the extrusion-molding system 600a. It should be understood that the control bus 1016 may be formed of multiple control busses, whereby each control bus is associated with a different component of the extrusion-molding system 600a. It should be further understood that the control bus 1016 may operate utilizing a serial or parallel protocol.
A feedback bus 1020, which may be a single or multiple bus structure, is operable to feedback data 1022 from the extrusion-molding system 600a during operation. The feedback data 1022 may be sensory data, such as temperature, position, velocity, level, pressure or any other sensory information measured from the extrusion-molding system 600a. Accordingly, the I/O unit 1008 is operable to receive the feedback data 1022 from the extrusion-molding system 600a and communicate the feedback data 1022 to the processor 1002 to be utilized by the software 1014. The software 1014 may store the feedback data in the database 1012 and utilize the feedback data 1022 to control the components of the extrusion-molding system 600a. For example, in the case of the temperature of the heater being fed-back by the heater controller 904 to the controller 612, if the temperature of the heater 618 becomes too low, then the controller 612 may issue a command via the control data 1018 to the heater 618 to increase the temperature thereof. The controller 612 or component (e.g., heater) may include an automatic control system as understood in the art for performing the control and regulation of the component.
In operation, the controller 612 may store control parameters for producing one or more water management chambers by the extrusion-molding system 600a. For example, data associated with parameters of the molds 626 and 632, such as dimensions of the cavities 630, may be stored in the database 1012. By storing multiple sets of parameters for various water management chamber, the extrusion-molding system 600a may be utilized to form the water management chambers substantially simultaneously. The processor 1002 may execute the software 1014 with the different sets of parameters in parallel to form the water management chambers substantially simultaneously. That is, when one water management chamber is being pressed, another may be formed via the dynamic die 606 by applying the extruder composite material 625 onto the lower mold 626.
The operator interface 1102 is utilized to provide an interface for an operator of the extrusion-molding system 600a to control the extrusion-molding system 600a manually or establish programs and/or profiles for producing the water management chamber. The operator interface 1102 communicates with a program selector 1108, which, when previously programmed, allows the operator to select programs for producing the water management chamber. For example, a program that is established to produce a water management chamber may be selected via the operator interface 1102 by an operator so as to control the extrusion-molding system 600a to produce the water management chamber as defined by the present invention in accordance with the lower and upper molds 626 and 632. In one embodiment, the program selector 1108 merely selects a generic program that produces the water management chamber by controlling the extrusion-molding system 600a by utilizing a specific sets of parameters for controlling the components accordingly. The program selector 1108 may communicate with a parameter selector/editor 1110 that allows the operator to select a particular set of parameters to form the water management chamber and/or edit the parameters to alter the process for forming the water management chamber of the present invention. The parameter selector/editor 1110 may interface with the database manager 1106 for selecting a particular set of parameters from a variety of different parameter datafiles available for the controller 612 to drive the components of the extrusion-molding system 600a to form multiple water management chambers. It should be understood that each of the components of the extrusion-molding system 600a may be controlled by generic drivers and that the parameters selected for producing water management chamber may alter the behavior of each of the components of the extrusion-molding system 600a accordingly.
The system drivers 1104 may be utilized to integrate with the components of the extrusion-molding system 600a as understood in the art. For example, individual system drivers 1104 may be utilized to control the feeders 614, heater 618, extruder 604, dynamic die 606, trolley 608, and press 610. The system drivers 1104 may be customized by the operator of the extrusion-molding system 600a or be a generic driver provided by a manufacturer of a particular component, such as the press 610. During operation of the extrusion-molding system 600a producing the water management chamber, the system drivers 1104 may utilize the parameters selected to produce the water management chamber to drive the components of the extrusion-molding system 600a.
In controlling the components of the extrusion-molding system 600a, a database 1012 and status alert feedback manager 1114 are utilized to provide feedback control for each of the components of the extrusion-molding system 600a. For example, the heater 618 may feedback the actual temperature via a temperature sensor (not shown). Based on the measured temperature of the heater 618, a system driver 1104 utilized to control the heater 618 may increase or decrease the temperature of the heater 618 in accordance with the actual temperature measurement. Accordingly, other sensors may be utilized to feedback temperature, pressure, velocity, weight, position, etc., of each component and/or composite material within the extrusion-molding system 600a. In the case of a critical failure of a component, alerts may be fed-back to the controller 612 and detected by the status alert feedback manager 1114. If an alert is deemed to be a major failure, the system drivers 1104 may shut down one or more components of the extrusion-molding system 600a to prevent damage to hardware or personal injury to an operator. In response to such an alert, the system manager 1100 may trigger the operator interface 1102 to display the failure and provide notice as to corrective actions or otherwise.
TABLES 2-10 are exemplary data tables that are utilized to control the components of the extrusion-molding system 600a. Specifically, the tables provide for the control data 1018 for controlling the components and feedback data 1022 received by the controller 612 from the components. TABLE 2 provides for control of the feeders 614 that are used to feed thermoplastic composite material M1, fiber material M2, and any other materials (e.g., color) to form the water management chamber. As shown, the control data 1018 includes the rate that each feeder 614 is delivering material to the extrusion-molding system 600a and the feedback data 1022 includes the level of the material currently in each feeder 614. During operation of the extrusion-molding system 600a, the rate of the material being delivered from the feeder 614 is controlled and level of the material in the feeders 614 is measured, the operator may be notified of the level of the material in response to the in the feeder 614 reaching a minimum amount so that the operator may apply additional material to the feeder 614.
TABLE 3 is an exemplary table that provides for temperature control for heaters in the extruder 604. In the case that the extruder 604 is defined as having seven temperature zones 1-n, the temperatures for each zone may be set by the extruder temperature control being defined as being set to heat or cool, on or off, and/or a specific temperature (not shown). The feedback data 1022 may include the actual temperature of each zone of the extruder 604. Accordingly, temperature sensors are integrated into each zone of the extruder 604 and the temperatures sensed are fed-back via the feedback bus 1020 to the controller 612 for feedback control.
TABLE 4 is an exemplary table that provides for speed control for a motor (not shown) driving the auger 620 operating in the extruder 604. The control data 1018 includes a speed control setting to drive the motor. Actual speed and load of the motor are fed-back via the feedback data 1022 to the system driver 1104 utilized to control the rate of the auger 620 extruder 604 via the control data 1018.
TABLE 5 defines the temperature control for heaters in the dynamic die 606. The control data 1018 may be defined by zones 1-n within the dynamic die 606. Similar to the temperature control of the extruder 604, the heater 618 may include heating and cooling controls and/or on and off settings for controlling and/or regulating the temperature of the different zones within the dynamic die 606. Accordingly, the feedback data 1022 may include the actual temperature for each of the zones within the dynamic die 606 for control thereof.
TABLE 6 is an exemplary table for control of the flow control elements 624 of the dynamic die 606. As shown, the control data includes flow control elements 1-n and positions for each flow control element 624 ranging from 1-m. It should be understood that the flow control elements 624 may have a nearly infinite number of positions. However, for practical purposes, the flow control element positions are typically set to have certain predetermined positions, such as each quarter-inch ranging from zero to six inches, for example. In controlling the positions of the flow control elements 624, a stepper motor or other type of motor may be utilized. Accordingly, the feedback data 1022 for the flow control elements 624 include the current positions of the flow control elements 624 so that any deviation of position between the control data 1018 communicated by the controller 612 to the dynamic die 606 may be corrected by a feedback loop via the feedback data 1022 as understood in the art.
TABLE 7 is an exemplary table that provides for temperature control for the lower mold 626. It should be understood that a similar table may be utilized to control the temperature of the upper mold 632. As shown, the lower mold 626 may be segmented into a number of zones 1-n, where heaters and/or coolers may be applied to each zone to heat and cool the lower mold 626 as commanded by the control data 1018. Accordingly, feedback data 1022 may provide for the actual temperature of the lower mold 626 so that feedback control may be performed by the controller 612 to regulate the temperature of the lower mold 626. For example, as the extruded composite material 625 is applied to the lower mode 626, the temperature of the lower mold 626 may be regulated across the zones to regulate the temperature of the extruded composite material layer 628 based on time and other factors as the composite material is deposited onto the lower mold 626 and until the water management chamber is removed from the molds 626 and 632.
TABLE 8 is an exemplary table that provides exemplary control parameters for controlling the trolley 608. As shown, the control data 1018 includes position, speed, and lift control for the trolley 608. It should be understood that additional control data 1018 may be included to control motion of the trolley 608. For example, acceleration, rotation or angular position, or other dynamic control data may be utilized to move or synchronize the trolley 608 to properly align the lower mold 626 with respect to the application of the extruded composite material 625 being deposited or gravitated onto the lower mold 626. The feedback data 1022 for the trolley 608 may include actual position and current speed of the trolley 608. The lift control data may be utilized to engage and disengage the wheels 634 of the trolley 608 both during depositing of the extruded composite material 625 to the lower mold 626 and pressing the extruded composite material layer 628 into the molds 626 and 632 via the press 610, respectively. The actual position of the lift may be fed-back so as to ensure that the press 610 is not activated until the wheels 634 are disengaged via the lift mechanism (e.g., air tubes).
TABLE 9 is an exemplary table that provides for control of the press 610. The control data 1018 may include lock control data and cycle press time. The feedback data 1022 may include position of the trolley 608 in the press 610 and position of the press platen. Other control and feedback parameters additionally may be included to control the press. For example, temperature control of the upper mold 632, force of the press 610, etc., may also be included.
TABLE 10 provides an exemplary table for control of an extraction tool (not shown) for extracting a formed water management chamber from the molds 626 and 632 after completion of the pressing and, optionally, cooling processes in forming the water management chamber. The control data 1018 may include a start extraction cycle and feedback data 1022 may include a single extraction tool position. It should be understood that multiple extraction tools or elements of an extraction tool may be utilized and other sensory feedback data may be sensed and fed-back to the controller 612.
Control for depositing the extruded composite material 625 along the x-, y-, and z-axes may be performed using a variety of techniques, including: (1) controlling the volumetric flow rate of the composite material from the extruder 604 via the rate of rotation of the auger 620; (2) controlling the rate of movement of the trolley 608 in a single axis; (3) controlling the aperture of the output of the extruder 604 having a single flow control element 624 or multiple flow control elements 624 operating uniformly; (4) individually controlling the multiple flow control elements 624; and (5) controlling motion of the trolley 608 in multiple axes. Each of these techniques assume that other variables are held constant. For example, technique (1) assumes that the output aperture of the extruder 604 is fixed and that the trolley 608 travels at a constant rate below the output aperture. Technique (2) assumes that the volumetric flow rate of the composite material from the extruder 604 is constant and that the output aperture of the extruder 604 is fixed. It should be understood, however, that the techniques may be combined to provide additional control of the placement of the extruded composite material 625 onto the lower mold 626 as discussed with regard to
Finally, rather than controlling movement of the lower mold 626, the extruded composite material 625 may be deposited onto a stationary or moving lower mold 626 using moving output apertures from the extruder 604. For example, output apertures traveling along rails or other mechanical structure may be controlled to deposit the composite material in specific locations on the lower mold 626. An analogy for such a mechanism is a laser jet printer.
Referring again to
TABLES 11 and 12 provide for the positional synchronization between the flow control element 624 and the movement of the trolley 608. By orchestrating the movement between the two components (i.e., dynamic die 606 and trolley 608), the extruded composite material 625 may be deposited at positions along the lower mold 626 as specified by the volume of the cavities 630 of the lower and upper molds 626 and 632. In other words, the extruded composite material 625 is deposited onto the lower mold 626 to form the extruded composite material layer 628 thick enough to fill the cavities 630 of the lower and upper molds 626 and 632, thereby providing the ability to form deep drafts and hidden ribs in certain locations of water management chamber.
Exhibit A provides exemplary perspective views of the water management chamber produced by the extrusion-molding system. The water management chamber maintains an arched housing with ribs and stress relief notches extending down the entire arched body of the water management chamber. The water management chamber further maintains a top portal and two side portals, each on opposing sides of the water management chamber. The top portal is positioned on one end of the water management chamber while the two side portals are on the opposite end of the water management chamber. The extrusion-molding system allows for the insertion of the portals within the ribs and stress relief notches. As shown, the stress relief notches, portals and ribs all maintain different depths. Further, the top and side portals maintain voids below the ribs of the water management chamber. By controlling the deposition of the extruded composite material 625 onto the lower mold 626 utilizing the principles of the extrusion-molding system, the water management chamber having features, such as the portals, ribs, and stress relief notches with voids and differing depths in specific regions of the structural parts may be formed using stiffener material M2 (e.g., long-strand fibers).
Exhibit A provides perspective views of the water management chamber having the side and top portals inserted within the ribs and stress relief notches. As shown, the portals are variable in height, but have a definite volume over one or more zones. Therefore, by depositing more extruded composite material 625 over the zones having the portals and less extruded composite material 625 over the zones without the portals, less material is wasted. Because the water management chamber is formed as a single molded composite structure using the extrusion-molding system, the water management chamber has fewer weaknesses in the structure compared to a water management chamber that is formed of multiple parts.
In addition to forming the water management chamber using composite material having fibers blended therein to provide strength in forming large parts, the water management chamber is further structurally improved by having other components, such as attachments, fasteners, and/or stiffeners, inserted or embedded in certain regions. For example, water management chambers that are to provide interconnectivity may utilize metallic parts extending from the composite material to provide strong and reliable interconnections. The water management chamber includes the thermoplastic material, which may be formed of the thermoplastic material M1 and fibers M2, and a fastener, which is formed of metal.
In forming the water management chamber, a fastener is positioned or configured in the lower mold 608 so that the extruded composite material layer 628 forms a bond layer with the fastener to maintain the position thereof. To further secure the fastener to the water management chamber, holes (not shown) may be included in the fastener to allow the extruded composite material layer 628 to fill in the holes. During the formation process, actuators may be configured in the lower mold 626 to maintain the position of the fastener during the extrusion-molding process and released via the controller 612 while the extruded composite material layer 628 is still in molten form. It should be understood that the fastener alternatively may be configured in the upper mold 632.
The water management chamber may also include inserts encapsulated in the composite material that forms the water management chamber. The insert may be a carbon fiber tube so that the water management chamber may be stiffened, lightweight, and x-ray transparent. In encapsulating the insert, the lower mold 626 may have actuators or simple pins maintain the insert in place while the extruded composite material layer 628 forms a bond layer 1616 therewith. Again, while the extruded composite material layer 628 is in a molten state, the actuators and/or pins may be released such that the extruded composite material layer 628 fills in any voids left from the actuators or pins. It should be understood that the insert may be substantially any material based on the particular application which the water management chamber is to be used.
At step 1710, if any supports are used to configure the insert in the lower 626 or upper 632 mold, then the supports are removed. The supports, which may be actuator controlled, simple mechanical pins, or other mechanism capable of supporting the insert during deposition of the extruded composite material 625 onto the lower mold 626, are removed before the extruded composite material layer 628 is hardened at step 1712. The extruded composite material layer 628 may be hardened by natural or forced cooling during pressing, vacuuming, or other operation to form the structural part. By removing the supports prior to the extruded composite material layer 628 being hardened, gaps produced by the supports may be filled in, thereby leaving no trace of the supports or weak spots in the structural part. At step 1714, the structural part with the insert at least partially embedded therein is removed from the mold 626 and 632. The insertion process ends at step 1716.
In another embodiment of the invention, an insert is encapsulated by a process of the claimed invention. In a manner analogous to the process described in
The foregoing description is of a preferred embodiment for implementing and forming the invention, and the scope of the invention should not be limited by this description. The scope of the present invention is instead defined by the following claims.
