Thermoforming process using reformable moldes
By adopting independently movable multi-section molds and intelligent control systems in the thermoforming equipment, the problem of long mold replacement time and difficult production of complex shapes is solved, and the effect of rapid mold replacement and efficient production of complex shape parts is achieved.
Patent Information
- Application Number
- CN202410792430.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-06-23
- Filing Date
- 2024-06-19
- Publication Date
- 2024-12-31
AI Technical Summary
In the existing thermoforming process, frequent replacement of molds of different shapes increases the manufacturing cycle time and it is difficult to quickly produce parts of complex shapes.
A thermoforming device and method is designed, using a mold with multiple segments, each segment can be moved independently, combining an electromechanical actuator, a pneumatic actuator and a heater to control the position of the mold through a computer-aided design document and shape changes to achieve rapid replacement and formation of products with complex shapes.
Reduces mold replacement time, enables new mold shapes to be formed in minutes, and produces complex-shaped parts in a few days through 3D printing technology, improving process flexibility and production efficiency.
Smart Images
Figure CN119217693A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a thermoforming process. More particularly, the present disclosure relates to a thermoforming process utilizing a re-formable mold. Background Art
[0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
[0003] Thermoforming is a manufacturing process in which a plastic sheet is heated to a pliable forming temperature. The sheet is formed into a specific shape in a mold and then trimmed to form a usable product. Specifically, the sheet is heated in a furnace to a sufficiently high temperature that allows the sheet to be stretched into or onto a mold and cooled to the finished shape. In some embodiments, a machine is used to heat, form and trim the plastic sheet in a continuous, high-speed process, and thousands of finished parts can be produced per hour, depending on the machine and mold size and the size of the part being formed. In order to form the sheet into a different shape, another mold with the desired shape is used.
[0004] Therefore, changing the mold to have a different shape increases the manufacturing cycle time.
[0005] The present disclosure addresses these problems associated with thermoforming of plastic sheets. Summary of the invention
[0006] This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features.
[0007] In one form of the present disclosure, a thermoforming apparatus includes a mold having a plurality of segments. Each segment is relatively independently movable. The thermoforming apparatus also includes a set of electromechanical actuators. Each electromechanical actuator is attached to a screw that moves each of the plurality of segments to a specific position. The mold is configured to press against a blank to form a product having a shape corresponding to the specific positions of the plurality of segments.
[0008] In a variation of the thermoforming apparatus that can be implemented individually or in any combination: the apparatus also includes a pneumatic actuator that moves the blank to a specified position; the pneumatic actuator moves the blank after the product is formed; the apparatus also includes a heater that heats the blank before the product is formed; the set of electromechanical actuators is a set of stepper motors, each stepper motor is attached to a corresponding screw to transfer rotational movement into longitudinal movement; the apparatus also includes a locking mechanism that fixes each section at a specific position; after forming the first product, each section is moved to a new position to form a second product; the apparatus also includes: a controller that provides instructions to the set of electromechanical actuators; and a computer that transmits instructions to the controller through an interface to position the set of electromechanical actuators based on a computer-aided design (CAD) file loaded in the computer; and the controller is a programmable logic controller (PLC).
[0009] In another form, a thermoforming assembly includes a first apparatus and a second apparatus, each apparatus including: a die having a plurality of segments, each segment being independently movable; and a set of electromechanical actuators, each electromechanical actuator being attached to a screw that moves each of the plurality of segments to a specific position, the die being configured to be pressed against a blank to form a product having a shape corresponding to the specific position of the plurality of segments. The die of the first apparatus is pressed against a first side of the blank, and the die of the second apparatus is pressed against a second side of the blank.
[0010] In a variation of the assembly that may be implemented individually or in any combination: the assembly further includes a pneumatic actuator that moves the blank to a specified position; the pneumatic actuator moves the blank after the product is formed; the assembly further includes a heater that heats the blank before the product is formed; the set of electromechanical actuators is a set of stepper motors, each stepper motor attached to a corresponding screw to transfer rotational movement into longitudinal movement; the assembly further includes a locking mechanism that fixes each section at a specific position; the assembly further includes: a controller that provides instructions to the set of electromechanical actuators; and a computer that transmits instructions to the controller via an interface to position the set of electromechanical actuators based on a computer-aided design (CAD) file loaded in the computer.
[0011] In yet another form, a thermoforming method includes moving a set of actuators to position each of a plurality of segments, each segment being independently movable relative to the other segments, the positions of the plurality of segments defining a die; positioning a blank; heating the blank; and forming a product from the blank using the die.
[0012] In a variation of the method that can be implemented individually or in any combination: the product has a shape corresponding to specific positions of multiple segments; the method also includes positioning a 3D printed worksurface, multiple segments are moved to positions corresponding to the 3D printed worksurface, and the product has a shape corresponding to the 3D printed worksurface; and replacing the 3D printed worksurface with another 3D printed worksurface.
[0013] Further areas of applicability will become apparent from the description provided herein.It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In order that the present disclosure may be better understood, various forms of the present disclosure will now be described by way of example with reference to the accompanying drawings, in which:
[0015] Figure 1 A thermoforming assembly according to the principles of the present disclosure is shown;
[0016] Figure 2 The invention shows a method according to the principle of the present invention. Figure 1 A close-up view of the assembly is shown;
[0017] FIG. 3A to FIG. 3E The invention shows the use of the principle of the present invention Figure 1 A series of steps for forming a component from a thermoforming assembly as shown; and
[0018] 4A to 4F The invention shows the use of the principle of the present invention Figure 1 The thermoforming assembly shown forms another series of steps for the component.
[0019] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. DETAILED DESCRIPTION
[0020] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate the same or corresponding parts and features.
[0021] The present disclosure describes a thermoforming system and process in which the mold can change its form to increase the flexibility of the process and reduce the time of utilizing thermoforming molds of different shapes. Thus, new mold shapes are formed in minutes rather than hours. In addition, the production of parts with complex shapes can be achieved by adding 3D printing to obtain parts based on computer-aided drawings (CAD) in days rather than weeks.
[0022] Based on an understanding of thermoforming as described above, the present inventors have discovered several design features for providing a reformable mold for utilization in a thermoforming system.
[0023] Reference now Figure 1 , a thermoforming assembly 10 is shown, which includes a first thermoforming device 11 and a second thermoforming device 13 attached to a frame 14. The thermoforming assembly 10 receives operating instructions from a controller 15. In some embodiments, the controller 15 is a programmable logic controller (PLC). In certain embodiments, the thermoforming assembly includes a computer 30, such as, for example, a laptop computer. The computer 30 provides an interface for an operator to send instructions to the controller 15.
[0024] Each device 11, 13 includes a set of electromechanical actuators 12a, 12b and molds 24a, 24b, respectively. Each mold 24a, 24b has a plurality of sections, each of which can be moved independently relative to other sections. In some embodiments, each set of electromechanical actuators 12a, 12b is attached to a set of corresponding screws 18a, 18b, and the set of corresponding screws moves each of the plurality of sections to a specific position. In various embodiments, each set of actuators 12a, 12b is a set of stepper motors, each of which is attached to a screw in the set of screws 18a, 18b. The combination of each screw and the corresponding stepper motor converts the rotational movement of the stepper motor into the longitudinal movement of the screws 18a, 18b.
[0025] The thermoforming assembly 10 also includes one or more rails 28 that enable the plastic blank 26 to move between the molds 24a, 24b. In addition, hydraulic cylinders 16a, 16b are associated with each device 11, 13, which move the molds 24a, 24b toward and away from each other. In some variations, the one or more rails 28 are pneumatic units, so that the hydraulic cylinders 16a, 16b and the one or more rails 28 receive pressurized gas from the hydraulic unit 20.
[0026] Further references FIG. 3A to FIG. 3B , showing a series of steps for forming a product: each section of each mold 24a, 24b is in an initial state ( Figure 3A ); under the direction of the controller 15, the set of actuators 12a, 12b associated with each mold 24a, 24b moves the segments to define a desired shape (such as, for example, shape 25b), and a locking mechanism (such as a lock 22a, 22b) locks the segments in place ( Figure 3B ); the guide rail 28 places the blank 26 between the molds 24a, 24b ( Figure 3C); the blank 26 is heated to a desired temperature with a heater, and the hydraulic cylinders 16a, 16b move the dies 24a, 24b toward each other so that the dies 24a, 24b are pressed against the blank 26 to form a product 32 having a shape corresponding to the shape 25b ( Figure 3D ); and the hydraulic cylinders 16a, 16b move the dies 24a, 24b away from each other, and the guide rails 28 move the blank 26 together with the product 32 away from the dies 24a, 24b ( Figure 3E ).
[0027] Thus, the present disclosure describes a thermoforming assembly 10 that can change the form of a mold 24a, 24b by moving the various segments with actuators 12a, 12b. After the various segments of the mold 24a, 24b define the desired shape, the various segments are locked in place and the mold is pressed against the heated blank 26 to form a product 32.
[0028] Now go to 4A to 4F , shows another embodiment of the thermoforming assembly 10, which shows a series of steps for implementing 3D printing to form a product: under the instruction of the controller 15, each section of each mold 24a, 24b is placed in an initial state to define a working surface setting 27 ( Figure 4A ); 3D printing surface 34 is positioned between molds 24a, 24b on work surface setting 27 ( Figure 4B ); the guide rail 28 places the blank 26 between the molds 24a, 24b ( Figure 4C ); the blank 26 is heated to a desired temperature by a heater, and the hydraulic cylinders 16a, 16b move the dies 24a, 24b toward each other ( Figure 4D ); the molds 24a, 24b press the blank 26 against the 3D printing surface 34 to form a product 36 corresponding to the shape of the 3D printing surface 34 ( Figure 4E ); and the hydraulic cylinders 16a, 16b move the dies 24a, 24b away from each other, and the guide rails 28 move the blank 26 together with the product 36 away from the dies 24a, 24b ( Figure 4F ). Thus, for complex shapes, the thermoforming assembly 10 can be used as a mold holder for a 3D printed surface to form the product 36. Such an arrangement reduces downtime typically associated with tool changes.
[0029] Unless otherwise expressly indicated herein, all numerical values indicating mechanical / thermal properties, composition percentages, dimensions and / or tolerances or other characteristics when describing the scope of the present disclosure should be understood to be modified by the word "about" or "approximately". Such modifications are desirable for a variety of reasons, including: industrial practice; material, manufacturing and assembly tolerances; and testing capabilities.
[0030] As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical "or", and should not be construed to mean "at least one of A, at least one of B, and at least one of C."
[0031] In this application, the terms "controller" and / or "module" may refer to, be part of, or include: an application-specific integrated circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinatorial logic circuit; a field programmable gate array (FPGA); a processor circuit (shared, dedicated, or group) that executes code; a memory circuit (shared, dedicated, or group) that stores code executed by the processor circuit; other suitable hardware components that provide the described functionality (e.g., an operational amplifier circuit integrator as part of a heat flux data module); or a combination of some or all of the above, such as in a system on a chip.
[0032] The term memory is a subset of the term computer-readable medium. The term computer-readable medium as used herein does not encompass transient electrical or electromagnetic signals propagated through a medium (such as on a carrier wave); therefore, the term computer-readable medium may be considered to be tangible and non-transitory. Non-limiting examples of non-transitory tangible computer-readable media are non-volatile memory circuits (such as flash memory circuits, erasable programmable read-only memory circuits, or mask read-only circuits), volatile memory circuits (such as static random access memory circuits or dynamic random access memory circuits), magnetic storage media (such as analog or digital tape or hard drives), and optical storage media (such as CDs, DVDs, or Blu-ray discs).
[0033] The apparatus and methods described in this application may be implemented partially or completely by a special-purpose computer, which is created by configuring a general-purpose computer to perform one or more specific functions embodied in a computer program. The functional blocks, flow chart components, and other elements described above are used as software specifications, which can be translated into a computer program by routine work of a technician or programmer.
[0034] The description of the present disclosure is merely exemplary in nature, and thus, variations that do not depart from the essence of the present disclosure are intended to be within the scope of the present disclosure. Such variations should not be regarded as a departure from the spirit and scope of the present disclosure.
[0035] According to the present invention, a thermoforming device is provided, which has: a mold having a plurality of segments, each segment being independently movable; and a group of electromechanical actuators, each electromechanical actuator being attached to a screw, which moves each of the plurality of segments to a specific position, and the mold is configured to be pressed against a blank to form a product having a shape corresponding to the specific positions of the plurality of segments.
[0036] According to one embodiment, the invention also features a pneumatic actuator that moves the blank to a designated position.
[0037] According to one embodiment, the pneumatic actuator moves the blank after the product has been formed.
[0038] According to one embodiment, the invention also features a heater that heats the blank prior to forming the product.
[0039] According to one embodiment, the set of electromechanical actuators is a set of stepper motors, each stepper motor being attached to a respective screw to convert a rotational movement into a longitudinal movement.
[0040] According to one embodiment, the invention also features a locking mechanism that secures each segment in a specific position.
[0041] According to one embodiment, after forming the first product, each segment is moved to a new position to form the second product.
[0042] According to one embodiment, the present invention is also characterized by: a controller, which provides instructions to the set of electromechanical actuators; and a computer, which transmits instructions to the controller through an interface to position the set of electromechanical actuators based on a computer-aided design (CAD) file loaded in the computer.
[0043] According to one embodiment, the controller is a programmable logic controller (PLC).
[0044] According to the present invention, a thermoforming assembly is provided, which has: a first device and a second device, each device including: a mold having a plurality of segments, each segment being independently movable; and a group of electromechanical actuators, each electromechanical actuator being attached to a screw, which moves each of the plurality of segments to a specific position, the mold being configured to be pressed against a blank to form a product having a shape corresponding to the specific positions of the plurality of segments, wherein the mold of the first device is pressed against a first side of the blank, and the mold of the second device is pressed against a second side of the blank.
[0045] According to one embodiment, the invention also features a pneumatic actuator that moves the blank to a designated position.
[0046] According to one embodiment, the pneumatic actuator moves the blank after the product has been formed.
[0047] According to one embodiment, the invention also features a heater that heats the blank prior to forming the product.
[0048] According to one embodiment, the set of electromechanical actuators is a set of stepper motors, each stepper motor being attached to a respective screw to transfer a rotational movement into a longitudinal movement.
[0049] According to one embodiment, the invention also features a locking mechanism that secures each segment in a specific position.
[0050] According to one embodiment, the present invention is also characterized by: a controller, which provides instructions to the set of electromechanical actuators; and a computer, which transmits instructions to the controller through an interface to position the set of electromechanical actuators based on a computer-aided design (CAD) file loaded in the computer.
[0051] In one aspect of the invention, a thermoforming method includes: moving a set of actuators to position each of a plurality of segments, each segment being independently movable, the positions of the plurality of segments defining a mold; positioning a blank; heating the blank; and forming a product from the blank using the mold.
[0052] In one aspect of the invention, the product has a shape corresponding to the specific positions of the plurality of segments.
[0053] In one aspect of the invention, the method includes positioning a 3D printing work surface, a plurality of segments are moved into positions corresponding to the 3D printing work surface, and the product has a shape corresponding to the 3D printing work surface.
[0054] In one aspect of the invention, the 3D printed work surface is replaced with another 3D printed work surface.
Claims
1. A thermoforming device comprising: A mold having multiple sections, each section being able to move independently; as well as A set of electromechanical actuators, each electromechanical actuator is attached to a screw, the screw moving each of the plurality of segments to a specific position, the die being configured to be pressed against the blank to form a product having a shape corresponding to the specific position of the plurality of segments.
2. The apparatus of claim 1, further comprising a pneumatic actuator that moves the blank into a specified position.
3. The apparatus of claim 2, wherein the pneumatic actuator moves the blank after the product is formed.
4. The apparatus of claim 1 further comprising a heater that heats the blank prior to forming the product.
5. The apparatus of claim 1, wherein the set of electromechanical actuators is a set of stepper motors, each stepper motor being attached to a respective screw to convert rotational movement into longitudinal movement.
6. The apparatus of claim 1 further comprising a locking mechanism to secure each segment at the specific position.
7. The apparatus of claim 1 wherein after forming a first product, each segment is moved to a new position to form a second product.
8. The apparatus of claims 1 to 7, further comprising: a controller providing instructions to the set of electromechanical actuators; and a computer that transmits instructions to the controller via an interface to position the set of electromechanical actuators based on a computer-aided design (CAD) file loaded into the computer.
9. The apparatus of claim 8, wherein the controller is a programmable logic controller (PLC).
10. A thermoforming assembly comprising: A first device and a second device, each device comprising: a mold having multiple sections, each section being independently movable; and a set of electromechanical actuators, each electromechanical actuator being attached to a screw that moves each of the plurality of segments to a specific position, the die being configured to be pressed against the blank to form a product having a shape corresponding to the specific position of the plurality of segments, wherein the die of the first device is pressed against a first side of the blank and the die of the second device is pressed against a second side of the blank.
11. The assembly of claim 10, further comprising a pneumatic actuator that moves the blank to a designated position.
12. The assembly of claim 10, further comprising a heater that heats the blank prior to forming the product.
13. The assembly of claim 10, wherein the set of electromechanical actuators is a set of stepper motors, each stepper motor being attached to a respective screw to transfer rotational movement into longitudinal movement.
14. The assembly of claim 10, further comprising a locking mechanism to secure each segment in the particular position.
15. The assembly of claims 10 to 14, further comprising: a controller providing instructions to the set of electromechanical actuators; and a computer that transmits instructions to the controller via an interface to position the set of electromechanical actuators based on a computer-aided design (CAD) file loaded into the computer.