THERMOFORMING PROCESS WITH A FORMABLE FORMING TOOL

Abstract

A thermoforming device comprises a forming tool with multiple sections. Each section is independently movable. The thermoforming device also includes a set of electromechanical actuators. Each electromechanical actuator is attached to a screw that moves each section of the multiple sections into specific positions. The forming tool is configured to press against a blank to form a product with a shape that corresponds to the specific positions of the multiple sections.

Description

AREA

[0001] The present disclosure relates to a thermoforming process. More specifically, the present disclosure relates to a thermoforming process using a formable mold. GENERAL STATE OF THE 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 die and then cut to create a usable product. Specifically, the sheet is heated in an oven to a sufficiently high temperature that allows it to be stretched into or onto a die and cooled into a finished shape. In some implementations, machines are used to heat, form, and cut the plastic sheet in a continuous, high-speed process, and can produce many thousands of finished parts per hour, depending on the size of the machine and die and the size of the parts being formed. To form a sheet into a different shape, a different die with the desired shape is used.

[0004] Accordingly, exchanging molds with different shapes increases the manufacturing cycle time.

[0005] These problems associated with thermoforming plastic films are addressed by the present disclosure. SUMMARY

[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 sections. Each section is independently relatively movable. The thermoforming apparatus further includes a set of electromechanical actuators. Each electromechanical actuator is attached to a screw that moves each section of the plurality of sections to specific positions. 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 sections.

[0008] In variations of the thermoforming apparatus, which can be implemented individually or in any combination, the following applies: the apparatus 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 apparatus further includes a heater that heats the blank before forming the product; the set of electromechanical actuators is a set of stepper motors, each stepper motor attached to a respective screw for translating rotational motion into longitudinal motion; the apparatus further includes a locking mechanism that secures each section in the specific positions; after a first product is formed, each section is moved to a new position to form a second product.The device further includes a controller that provides instructions to the set of electromechanical actuators, and a computer that transmits instructions through an interface to the controller to position the set of electromechanical actuators based on a computer-aided design (CAD) file loaded into 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 forming tool having a plurality of sections, each section being independently movable; and a set of electromechanical actuators, each electromechanical actuator attached to a screw that moves each section of the plurality of sections to specific positions, wherein the forming tool is configured to press against a blank to form a product having a shape corresponding to the specific positions of the plurality of sections. The forming tool of the first apparatus is pressed against a first side of the blank, and the forming tool of the second apparatus is pressed against a second side of the blank.

[0010] In variations of this assembly, which can be implemented individually or in any combination, the following applies: 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 respective screw to translate rotary motion into longitudinal motion; the assembly further includes a locking mechanism that secures each section in the specific positions;the assembly further includes a controller that provides instructions to the set of electromechanical actuators, and a computer that transmits instructions through an interface to the controller to position the set of electromechanical actuators based on a computer-aided design (CAD) file loaded into the computer;

[0011] In yet another form, a method of thermoforming includes moving a set of actuators to position each section of a plurality of sections, each section being independently movable relative to the other sections, the position of the plurality of sections defining a forming tool; positioning a blank; heating the blank; and forming a product from the blank with the forming tool.

[0012] In variations of this method, which may be implemented individually or in any combination, the product has a shape corresponding to specific positions of the plurality of sections; the method further includes positioning a 3D printed work surface, moving the plurality of sections to a position corresponding to the 3D printed work surface, the product having a shape corresponding to the 3D printed work surface; and replacing the 3D printed work surface with another 3D printed work surface.

[0013] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. DRAWINGS

[0014] In order that the disclosure may be fully understood, various forms thereof will now be described by way of example with reference to the accompanying drawings, in which: Fig. 1 shows a thermoforming assembly in accordance with the principles of the present disclosure; Fig. 2 shows a close-up view of the Fig. 1 in accordance with the principles of the present disclosure; Fig. 3A-3E show a sequence of steps for forming a component with the Fig. 1 in accordance with the principles of the present disclosure; and Fig. 4A-4F show another sequence of steps for forming a component with the Fig. 1 in accordance with the principles of the present disclosure.

[0015] The drawings described in this document are for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way. DETAILED DESCRIPTION

[0016] 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 corresponding reference characters indicate like or corresponding parts and features throughout the drawings.

[0017] The present disclosure describes a thermoforming system and process in which a mold can change its shape to increase process flexibility and reduce the time required to utilize thermoforming tools with different shapes. Accordingly, a new mold shape is formed in minutes instead of hours. Furthermore, the production of components with complex shapes can be achieved by adding 3D printing to obtain parts based on computer-aided drawings (CAD) in days instead of weeks.

[0018] Based on the understanding of thermoforming as described above, the inventors have discovered several design features to provide a formable mold tool used in a thermoforming system.

[0019] With reference now to Fig. 1, a thermoforming assembly 10 is shown, including a first thermoforming device 11 and a second thermoforming device 13 mounted on a frame 14. The thermoforming assembly 10 receives operating instructions from a controller 15. In some implementations, the controller 15 is a programmable logic controller (PLC). In certain implementations, the thermoforming assembly includes a computer 30, such as a laptop computer. The computer 30 provides an interface with an operator to send instructions to the controller 15.

[0020] Each device 11, 13 includes a respective set of electromechanical actuators 12a, 12b and a forming tool 24a, 24b. Each forming tool 24a, 24b has a plurality of sections, each section being independently movable relative to the other sections. In some implementations, each set of electromechanical actuators 12a, 12b is attached to a respective set of screws 18a, 18b that moves each section of the plurality of sections to specific positions. In various implementations, each set of actuators 12a, 12b is a set of stepper motors, each stepper motor being attached to a screw of the set of screws 18a, 18b. The combination of each screw with a corresponding stepper motor converts rotational movement of the stepper motor into longitudinal movement of the screws 18a, 18b.

[0021] The thermoforming assembly 10 further includes one or more rails 28 that enable movement of a plastic blank 26 between the molds 24a, 24b. Additionally, each device 11, 13 is associated with hydraulic cylinders 16a, 16b that move the molds 24a, 24b toward and away from each other. In some variations, the one or more rails 28 are a pneumatic unit such that the hydraulic cylinders 16a, 16b and the one or more rails 28 receive pressurized gas from a hydraulic unit 20.

[0022] With further reference to Fig. 3A-3B shows a sequence of steps to form a product: the individual sections of each mold 24a, 24b are in an initial state ( Fig. 3A); under the direction of the controller 15, the set of actuators 12a, 12b associated with each mold 24a, 24b moves the sections to define a desired shape, such as a shape 25b, and locking mechanisms, such as locks 22a, 22b, lock the sections in position ( Fig. 3B); the rail 28 places the blank 26 between the forming tools 24a, 24b ( Fig. 3C); the blank 26 is heated to a desired temperature by a heater, and the hydraulic cylinders 16a, 16b move the forming tools 24a, 24b towards each other such that the forming tools 24a, 24b press against the blank 26 to form a product 32 having a shape corresponding to the shape 25b ( Fig. 3D); and the hydraulic cylinders 16a, 16b move the forming tools 24a, 24b away from each other and the rail 28 moves the blank 26 together with the product 32 away from the forming tools 24a, 24b ( Fig. 3E).

[0023] Therefore, the present disclosure describes a thermoforming assembly 10 that can change the shape of the dies 24a, 24b by moving individual sections with actuators 12a, 12b. After the individual sections of the dies 24a, 24b define a desired shape, the individual sections are locked in place and the dies are pressed against a heated blank 26 to form a product 32.

[0024] With reference now to Fig. 4A-4F, another implementation of the thermoforming assembly 10 is shown, illustrating a sequence of steps that 3D printing implements to form a product: under the guidance of the controller 15, the individual sections of each mold tool 24a, 24b are placed in an initial state to define a work surface structure 27 ( Fig. 4A); a 3D-printed surface 34 is positioned between the mold tools 24a, 24b above the work surface structure 27 ( Fig. 4B); the rail 28 places the blank 26 between the forming tools 24a, 24b ( Fig. 4C); the blank 26 is heated to a desired temperature by a heater and the hydraulic cylinders 16a, 16b move the forming tools 24a, 24b towards each other ( Fig. 4D); the forming tools 24a, 24b press the blank 26 against the 3D-printed surface 34 to form a product 36 that corresponds to the shape of the 3D-printed surface 34 ( Fig. 4E); and the hydraulic cylinders 16a, 16b move the forming tools 24a, 24b away from each other and the rail 28 moves the blank 26 together with the product 36 away from the forming tools 24a, 24b ( Fig.4F). Therefore, for complex shapes, the thermoforming assembly 10 can be used as a mold tool holder of a 3D-printed surface to form a product 36. Such an arrangement reduces downtime typically associated with tool changes.

[0025] Unless expressly stated otherwise herein, all numerical values ​​indicating mechanical / thermal properties, composition percentages, dimensions and / or tolerances, or other characteristics are to be understood as modified by the word "about" or "approximately" when describing the scope of the present disclosure. This modification is desirable for various reasons, including industrial practice, material, manufacturing and assembly tolerances, and testability.

[0026] As used in this document, the phrase "at least one of A, B, and C" should be interpreted to mean a logical (A OR B OR C) using a non-exclusive logical OR, and should not be interpreted to mean "at least one of A, at least one of B, and at least one of C."

[0027] 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 combinational logic circuit; a field programmable gate array (FPGA); processor circuitry (shared, dedicated, or group) that executes code; memory circuitry (shared, dedicated, or group) that stores code executed by the processor circuitry; other suitable hardware components (e.g.,an operational amplifier circuit integration circuit as part of the heat flow data module) that provide the described functionality; or a combination of some or all of the foregoing, such as in a single-chip system.

[0028] The term "memory" is a subset of the term "computer-readable medium." As used herein, the term "computer-readable medium" does not include transitory electrical or electromagnetic signals propagating through a medium (such as a carrier wave); therefore, the term "computer-readable medium" can be considered tangible and non-transitory.Non-limiting examples of a non-transitory, tangible computer-readable medium include non-volatile memory circuits (such as a flash memory circuit, an erasable programmable read-only memory circuit, or a mask read-only memory circuit), volatile memory circuits (such as a static random access memory circuit or a dynamic random access memory circuit), magnetic storage media (such as an analog or digital magnetic tape or a hard disk drive), and optical storage media (such as a CD, a DVD, or a Blu-ray Disc).

[0029] The devices and methods described in this application may be implemented in part or in whole by a special-purpose computer created by configuring a general-purpose computer to perform one or more specific functions embodied in computer programs. The functional blocks, flowchart components, and other elements described above serve as software specifications that can be translated into computer programs through the routine work of a skilled technician or programmer.

[0030] The description of the disclosure is merely exemplary in nature, and thus variations that do not depart from the essence of the disclosure are intended to be within the scope of the disclosure. Such variations should not be considered a departure from the spirit and scope of the disclosure.

[0031] According to the present invention, there is provided a thermoforming apparatus comprising: a mold having a plurality of sections, each section being independently movable; and a set of electromechanical actuators, each electromechanical actuator being attached to a screw that moves each section of the plurality of sections to specific positions, wherein 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 sections.

[0032] According to one embodiment, the invention is further characterized by a pneumatic actuator that moves the blank to a specified position.

[0033] According to one embodiment, the pneumatic actuator moves the blank after the product is formed.

[0034] According to one embodiment, the invention is further characterized by a heater that heats the blank before forming the product.

[0035] 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 rotary motion into longitudinal motion.

[0036] According to one embodiment, the invention is further characterized by a locking mechanism that secures each section in the specific positions.

[0037] According to one embodiment, after a first product is formed, each section is moved to a new position to form a second product.

[0038] According to one embodiment, the invention is further characterized by a controller that provides instructions to the set of electromechanical actuators, and a computer that transmits instructions through an interface to the controller to position the set of electromechanical actuators based on a computer-aided design (CAD) file loaded into the computer.

[0039] According to one embodiment, the controller is a programmable logic controller (PLC).

[0040] According to the present invention, there is provided a thermoforming assembly comprising: a first apparatus and a second apparatus, each apparatus comprising: a forming tool having a plurality of sections, each section being independently movable; and a set of electromechanical actuators, each electromechanical actuator being attached to a screw that moves each section of the plurality of sections to specific positions, wherein the forming tool is configured to press against a blank to form a product having a shape corresponding to the specific positions of the plurality of sections, wherein the forming tool of the first apparatus is pressed against a first side of the blank and the forming tool of the second apparatus is pressed against a second side of the blank.

[0041] According to one embodiment, the invention is further characterized by a pneumatic actuator that moves the blank to a specified position.

[0042] According to one embodiment, the pneumatic actuator moves the blank after the product is formed.

[0043] According to one embodiment, the invention is further characterized by a heater that heats the blank before forming the product.

[0044] 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 translate a rotational movement into a longitudinal movement.

[0045] According to one embodiment, the invention is further characterized by a locking mechanism that secures each section in the specific positions.

[0046] According to one embodiment, the invention is further characterized by a controller that provides instructions to the set of electromechanical actuators, and a computer that transmits instructions through an interface to the controller to position the set of electromechanical actuators based on a computer-aided design (CAD) file loaded into the computer.

[0047] In one aspect of the invention, a method of thermoforming includes: moving a set of actuators to position each of a plurality of sections, each section being independently movable, the position of the plurality of sections defining a forming tool; positioning a blank; heating the blank; and forming a product from the blank with the forming tool.

[0048] In one aspect of the invention, the product has a shape corresponding to specific positions of the plurality of sections.

[0049] In one aspect of the invention, the method includes positioning a 3D printed work surface, wherein the plurality of sections are moved to a position corresponding to the 3D printed work surface, wherein the product has a shape corresponding to the 3D printed work surface.

[0050] In one aspect of the invention, the 3D printed work surface is replaced by another 3D printed work surface.

Claims

[1] Thermoforming device comprising: a mold having a plurality of sections, each section being independently movable; and a set of electromechanical actuators, each electromechanical actuator being attached to a screw that moves each section of the plurality of sections to specific positions, wherein the forming tool is configured to press against a blank to form a product having a shape corresponding to the specific positions of the plurality of sections. [2] The apparatus of claim 1, further comprising a pneumatic actuator that moves the blank to 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 rotary motion into longitudinal motion. [6] The apparatus of claim 1, further comprising a locking mechanism that secures each section in the specific positions. [7] The apparatus of claim 1, wherein after a first product is formed, each section is moved to a new position to form a second product. [8] The apparatus of claims 1-7, further comprising a controller providing instructions to the set of electromechanical actuators, and a computer transmitting instructions through an interface to the controller 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] Thermoforming assembly comprising: a first device and a second device, each device comprising: a mold having a plurality of sections, each section being independently movable; and a set of electromechanical actuators, each electromechanical actuator being attached to a screw that moves each section of the plurality of sections into specific positions, wherein the forming tool is configured to press against a blank to form a product having a shape corresponding to the specific positions of the plurality of sections, wherein the forming tool of the first device is pressed against a first side of the blank and the forming tool 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 specified 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 for translating rotary motion into longitudinal motion. [14] The assembly of claim 10, further comprising a locking mechanism that secures each section in the specific positions. [15] The assembly of claims 10-14, further comprising a controller providing instructions to the set of electromechanical actuators, and a computer transmitting instructions through an interface to the controller to position the set of electromechanical actuators based on a computer-aided design (CAD) file loaded into the computer.

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