Lightweight plastic densification equipment

Abstract

Generally, the present disclosure relates to an apparatus that compresses lightweight plastic waste (e.g., used grocery bags, empty trash bags, food wrappers, etc.) and then applies a limited amount of heat to "bake" the compressed plastic into plastic "bricks." The plastic is compressed and then heated sufficiently to retain its compressed shape without melting or substantial outgassing.

Description

[Technical Field]

[0001] This application claims priority to U.S. Patent Application No. 17 / 119,469, filed December 11, 2020, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to the densification of plastic materials and to preparing the materials for further recycling. The present disclosure generally relates to the conversion of non-recyclable lightweight (light) plastic waste into a recyclable form. [Background technology]

[0003] Plastic waste can be a pollutant that is difficult to store and transport for long periods of time. Plastic has many favorable structural qualities: it is light, strong, and inexpensive to manufacture. As a result, lightweight plastics have become a part of everyday life for many people around the world. Summary of the Invention

[0004] The present disclosure includes systems, methods, and apparatus for densifying plastics, such as household plastic waste. One embodiment includes a plastic densification device including a body having an interior volume partially enclosed by an aluminum interior surface. A loading port within the body allows plastic to be loaded into the body, and a lift within the body can, upon activation, reduce the interior volume and compress the plastic within the interior volume. A heating element positioned below and abutting the aluminum surface can be configured to heat the plastic within the body to a temperature ranging from 100°C to 180°C.

[0005] Implementations may optionally include one or more of the following features.

[0006] In some embodiments, the plastic densification apparatus includes a loading mechanism attached to the loading port, the loading mechanism including a roller having a friction surface configured to grip the plastic and draw the plastic into the body, a comb mounted on the roller and configured to remove the plastic from the roller and deposit it through the loading port, and a roller motor configured to rotate the roller. The plastic densification apparatus can also include a controller to control operation of the plastic densification apparatus and a lift motor to actuate the lift.

[0007] In some embodiments, the plastic densification device includes one or more temperature sensors and one or more current sensors that measure current supplied to the lift motor. In some embodiments, the controller adjusts the power supplied to the heating element to maintain the temperature sensed by the temperature sensor within a range of 100°C to 180°C. The controller may also be configured to apply current to the lift motor up to a predetermined threshold. The predetermined threshold may be a current associated with a desired amount of compression of the plastic.

[0008] In some embodiments, a sight glass is provided within the body to allow inspection of the internal volume and plastic within the body.

[0009] In some embodiments, the cover is hinged to the body.

[0010] Generally, the present disclosure contemplates a method for densifying plastic, the method comprising loading the plastic to be densified into a compression chamber, compressing the plastic, applying heat to the plastic to achieve a temperature in the range of 100°C to 180°C, and baking the compressed plastic into a brick shape.

[0011] In some embodiments, during the loading process, the plastic is periodically compressed without the application of heat.

[0012] In some embodiments, heat is applied to the plastic in response to a signal that the compression chamber is full.

[0013] In some embodiments, the plastic is loaded into the compression chamber using a loading mechanism that is automatically activated in response to a signal indicating the presence of plastic in the loading mechanism.

[0014] In some embodiments, the steps of compressing the plastic and applying heat to the plastic are repeated at least once, and in some embodiments, the steps of compressing the plastic and applying heat are repeated in response to an indication that the predetermined compression ratio has not been achieved.

[0015] In some embodiments, the steps of compressing the plastic and applying heat to the plastic are repeated a predetermined number of times.

[0016] The details of these and other aspects and embodiments of the present disclosure are set forth in the accompanying drawings and the following description. Other features, objects, and advantages of the present disclosure will become apparent from the description, drawings, and claims. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is an exterior isometric view of an exemplary plastic densification device.

[0018] [Figure 2] FIG. 2 is a cross-sectional perspective view showing the interior of a plastic densification device.

[0019] [Figure 3] 1 shows an exemplary plastic densification device in a rotated view with some housing components transparent for clarity.

[0020] [Figure 4] 1 shows the plastic densification device with the cover in the open position.

[0021] [Figure 5] A cross-sectional side perspective view of a plastic densification apparatus 100 is shown.

[0022] [Figure 6] FIG. 6 is a block diagram illustrating a controller 628 and some of the sensors and systems that the controller may operate. DETAILED DESCRIPTION OF THE INVENTION

[0023] Generally, the present disclosure relates to an apparatus and method for densifying plastic waste. Densified plastic waste is a more compact solid than its non-densified form. Lightweight plastic waste (e.g., used grocery bags, empty garbage bags, food wrappers, etc.) can be difficult to store, transport, and process for recycling. The present disclosure describes a convenient solution that allows users to compress or densify plastic waste at home, making it more easily recyclable, more conveniently stored, or easily transported for further processing.

[0024] The device compresses plastic waste and then applies a limited amount of heat to "bake" the compressed plastic into plastic "bricks." Most plastic materials begin to emit volatile organic compounds (VOCs) above a certain temperature. VOCs are generally toxic and undesirable in residential environments, so the disclosed device does not raise the temperature of the plastic high enough to cause significant outgassing of the plastic by extensive melting. Instead, the plastic is compressed and then heated sufficiently to retain its compressed shape without melting or substantial outgassing.

[0025] FIG. 1 is an exterior isometric view of a plastic densifier 100. The plastic densifier 100 can include a body 102 that houses most of the components and can provide the plastic densifier 100 with an aesthetically pleasing structure. In some embodiments, the body 102 is constructed of plastic, aluminum, steel, or any other suitable material. A cover 106 can be hinged to the body and can be opened to allow removal of densified plastic or maintenance of the plastic densifier 100. In some implementations, the cover 106 is slotted into the body 102 (e.g., via a tongue and groove system) or simply rests on the body 102, although the disclosure is not limited in this regard. The cover 106 is described in more detail below with reference to FIG. 4.

[0026] In some embodiments, the plastic densification apparatus 100 includes a loader 104 or loading mechanism. The loader 104 can be attached to the cover 106 or the body 102 and can assist in feeding the lightweight plastic waste material into the body 102. In some embodiments, the loader 104 includes active power components, which are described in more detail below with reference to FIGS. 2 and 3.

[0027] 2 is a cross-sectional perspective view showing the interior portions of the plastic densification apparatus 100 and some additional components. The body 102 includes an inner wall 208 that may be constructed of an aluminum material. Aluminum is advantageous because it is a good thermal conductor and heated plastic does not stick to it. In some embodiments, the inner wall 208 is steel or another suitable material that has good thermal conductivity, sufficient structural integrity, and does not stick to heated plastic.

[0028] The heating elements 210 can be positioned between the inner wall 208 and the outer wall of the body 102 to surround a portion of the interior volume of the body 102. The heating elements 210 can include resistive heating components such as nichrome 80 / 20 (80% nickel, 20% chromium) strip, silicon carbide, or other elements capable of converting electrical power into heat. The heating elements 210 are positioned to apply heat to the compressed plastic within the body 102 of the plastic densification apparatus 100. In some embodiments, there is a heating element 210 in each wall (e.g., four walls) of the body 102, the cover 106, and the lift 212 to apply heat to the plastic from all directions.

[0029] The lift 212 is a mechanism configured to reduce the volume of the containment space within the body 102 and compress the plastic therein. The lift 212 is shown in a scissor lift configuration having a flat plate supported by multiple cross links. In some embodiments, the lift 212 may have an aluminum top surface with a heating element 210 configured to apply heat to the bottom of the plastic being compressed. The lift 212 may be actuated by any suitable means. In some embodiments, a hydraulic or electric motor may rotate a screw drive that changes the distance between two links of the scissor lift at the bottom. An exemplary lift motor is shown and described in more detail below with respect to FIG. 3.

[0030] The loader 104 in FIG. 2 is shown with a portion of its outer housing removed to show the rollers 214, bevel gears 216, and combs 218. Note that one roller 214 has been removed from the illustration for clarity. The rollers 214 may include multiple bumps or knobs that can grip the lightweight plastic for feeding into the body 102. The rollers 214 may be rubber, plastic, metal, or a combination thereof suitable for providing traction to draw the plastic into the plastic densification apparatus 100. As shown, the rollers 214 may have a generally spherical shape. In some embodiments, they may be cylindrical or helical, among other shapes. The rollers 214 may be driven by a motor (not shown) that can rotate all of the rollers 214 via the bevel gears 216. While there are three spherical rollers 214 in the illustrated example, more or fewer rollers 214 (e.g., six or two) may be implemented without departing from the scope of this disclosure.

[0031] 3 illustrates an exemplary plastic densification apparatus 100 in a rotated view, with some housing components transparent for clarity. The lift 212 is shown in an extended position, as when compressing plastic. In the illustrated embodiment, the lift 212 is actuated by a lift motor 320, which may be an electric motor (e.g., a brushless DC motor, a stepper motor, an AC motor, etc.) that drives a screw drive that translates a cross beam 324 and extends or retracts the scissor mechanism of the lift 212 based on the direction of rotation of the lift motor 320.

[0032] 3 and can be a single electric motor similar to or different from the lift motor 320. The loader motor 318 in the illustrated embodiment drives three rollers 214 via sets of bevel gears 216.

[0033] A sight window 322 may optionally be provided in the body 102 to provide a user with a means to visually inspect the plastic within the plastic densification apparatus 100. The sight window 322 may be a plexiglass material, glass, quartz, or other suitable transparent material (e.g., Pyrex®). As shown in the illustrated example, two sight windows 322 may be provided, which are vertical windows that indicate the amount of plastic within the body 102 as well as the position of the lift 212. In addition to the vertical windows, a larger window may be provided below to allow for inspection of the densified plastic. In some embodiments, the lower window 322 may be open-ended for easy removal of the densified plastic.

[0034] 4 shows the plastic densification apparatus with the cover 106 in an open position. The open cover 106 can provide access to a storage volume 424 within the body 102 of the plastic densification apparatus 100. The storage volume 424 can be an area where plastic is stored, compressed, and heated for densification. In some embodiments, the open cover 106 allows for easy removal of densified plastic from the storage volume 424.

[0035] Figures 5A and 5B show side cross-sectional views of plastic densification apparatus 100. The area of ​​Figures 5A and 5B having a cross-hash pattern indicates the area of ​​plastic densification apparatus 100 having heating elements for applying heat to the plastic. Generally, the operation of plastic densification apparatus 100 can be divided into two phases: a loading phase and a densification phase.

[0036] During the loading phase, the lift 212 may be maintained near the bottom of the plastic densifier 100, as shown in FIG. 5A. The plastic to be densified is loaded via the loader 104. In some embodiments, the loader includes one or more sensors and is automatically activated when the presence of the loaded plastic is detected. Generally, the loading phase may be a long-term phase. For example, the plastic densifier 100 may be in the loading phase whenever it is not full and may be slowly filled with plastic to be densified (e.g., grocery bags, wrappers, packaging material, etc.) over a predetermined period of time (e.g., once a week, once a month, etc.). Once the plastic densifier 100 is full, the densification phase may begin. In some embodiments, the plastic densifier 100 automatically detects when full and begins densification. In some embodiments, densification begins based on user input (e.g., a user pressing a "compact" or "densify" button).

[0037] During the densification phase, the lift 212 rises, compressing the lightweight plastic into a smaller volume that includes the heated zone 526. In some embodiments, a predetermined amount of pressure is applied by the lift 212. For example, the current supplied to the electric motor that operates the lift 212 can be measured to determine how much torque, and therefore how much pressure, is being applied. In some embodiments, additional sensors (e.g., force or pressure sensors) can be used to determine the height to which the lift 212 is raised. Once the plastic is compressed, a heating element can apply heat to "bake" the plastic, causing it to harden and retain its compressed shape without significant melting or outgassing. The applied heat maintains the plastic between 100°C and 180°C, preferably below 120°C. The 180°C upper limit prevents significant outgassing and the release of toxic VOCs. The 100°C lower limit ensures that any moisture present in the plastic is vaporized and escapes from the densified plastic. In some embodiments, once the plastic is within the desired temperature range, the lift is further activated, applying additional pressure to further compress the plastic. This may be a cyclical, repeating process of applying heat and pressure. In some embodiments, this process is performed a predetermined number of times (e.g., three or five times). In some embodiments, the process may be performed until a predetermined criterion (e.g., compression ratio or target volume) is met. For example, this process may be repeated until a compression ratio of less than 5% is achieved. Following densification, the heating element may be de-energized, and the densified plastic may return to ambient temperature. The lift 212 may retract to allow more plastic to be deposited on top of the densified plastic brick, or to maintain position, allowing for easy removal of the brick. In some embodiments, opening a cover or an access port in the plastic densification apparatus 100 may cause the lift 212 to raise the brick, partially removing it from the densification apparatus 100 for easy removal.

[0038] 6 is a block diagram illustrating a controller 628 and some of the sensors and systems that the controller may operate. The plastic densification apparatus 100 may be communicatively coupled to the controller 628. Although shown as a separate component in FIG. 6, the controller 628 or portions of the controller 628 may be integrated into the plastic densification apparatus 100.

[0039] The controller 628 may receive inputs 630 from various sensors within the plastic densification apparatus 100. These inputs may include temperature signals from one or more temperature sensors 634. The temperature sensors 634 may be thermocouples, resistance temperature detectors (RTDs), thermistors, or other suitable temperature sensors. The temperature sensors 634 may be located within the plastic densification apparatus or near the heating elements 650, which may be similar to or different from the heating elements 210 described with reference to FIG. 2. The temperature sensors 634 may provide signals indicative of the temperature of the heating elements 650, the internal temperature of the plastic densification apparatus 100, the measured or estimated temperature of the plastic within the plastic densification apparatus 100, or any combination thereof. The controller 628 may further receive inputs 630 from one or more current sensors 636, which may provide an indication of the current supplied to various components within the plastic densification apparatus 100 (e.g., compressor motor 642, loader motor 644, heating elements 650, etc.). One or more position sensors 638 may also provide inputs 630 to the controller. The position sensor 638 may be, for example, an encoder connected to an actuator associated with a loader or lift (e.g., the lift 212 and loader 104 described with respect to FIG. 2). In some embodiments, the position sensor 638 may be a Hall Effect sensor, or an array of Hall Effect sensors, that sense magnetic fields and can determine the position of various components of the plastic densification apparatus 100 (e.g., the lift 212, the cover 106, etc.).

[0040] One or more presence detectors 640 can sense the presence of plastic within the plastic densification apparatus 100. The presence detectors 640 may be, for example, infrared (IR) range finders or ultrasonic sensors that detect the presence of solid objects within a particular area. The presence detectors 640 can determine whether a piece of plastic has entered a loader (e.g., loader 104) and enable the controller 628 to activate a loader motor 644 accordingly. The presence detectors 640 can also detect or sense the estimated volume of plastic within the plastic densification apparatus (e.g., within storage volume 424).

[0041] The controller 628 may include or provide signals to a display 631, which may generally provide a user with information regarding the current status and operation of the plastic densification apparatus 100. The display 631 may be an LCD display, an OLED display, or any other suitable display. The display 631 may provide a graphical user interface for relaying information to the user and receiving one or more inputs from the user (e.g., via a touch screen and soft keys or buttons associated with the display).

[0042] The controller 628 may provide one or more outputs 632 to the system, including, but not limited to, drive current or control signals to a compressor motor 642, which may be similar to or different from the lift motor 320 described with respect to Figure 3, a loader motor 644, which may be similar to or different from the loader motor 318 described with respect to Figure 3, an extraction door 646, which in some embodiments may be the cover 106 described with respect to Figure 1, a cover lock 648, and one or more heating elements 650. The outputs 632 may be electrical, digital, or analog signals, or mechanical signals and outputs (e.g., motor or gear rotation).

[0043] In some embodiments where the removal door 646 is automated, the controller 628 can automatically open the removal door 646 upon completion of the densification stage for easy removal of the densified plastic. In some embodiments, the cover lock 648 can be activated when the heating element 650 is activated or when the compressor motor 642 is activated, preventing a user from inadvertently opening the plastic densification apparatus 100 when the plastic is under high temperature and / or pressure.

[0044] The foregoing figures and accompanying description depict exemplary processes and systems. However, the described systems (or their software or other components) suggest using, implementing, or performing any suitable techniques for performing these and other tasks. It will be understood that these processes are for illustrative purposes only, and that the described or similar techniques may be performed simultaneously, in parallel, or in combination at any time. Additionally, many of the operations in these processes may occur simultaneously, in parallel, and / or in a different order than that shown. Furthermore, the described systems and flows may employ processes and / or components that involve or perform additional, fewer, and / or different operations, so long as the methods and systems remain appropriate.

[0045] In other words, while the present disclosure has been described with respect to particular embodiments and generally associated methods, modifications and permutations of these embodiments and methods will be apparent to those skilled in the art. Accordingly, the above description of exemplary embodiments does not define or constrain the present disclosure. Other modifications, substitutions, and alterations are also possible without departing from the spirit and scope of the present disclosure.

Claims

1. A plastic densification device, comprising: a controller configured to control operation of the plastic densification machine; a body at least partially enclosing an interior volume having an aluminum interior surface; a cover hinged to the body and pivotable to open to provide access to the interior volume; a loading port in the cover configured to allow plastic to be loaded into the interior volume; a loading mechanism attached to the loading port, a roller having a friction surface configured to grip and pull plastic into the body; a comb attached to the roller, the comb configured to remove plastic from the roller and deposit it through the loading port; a roller motor configured to rotate the roller; a lift within the body configured, upon actuation, to reduce the interior volume and compress plastic within the interior volume; a lift motor configured to operate the lift; a current sensor for measuring the current supplied to the lift motor; a heating element located below and in contact with the aluminum surface, the heating element configured to heat the plastic within the body to a temperature in the range of 100°C to 145°C; a temperature sensor for measuring the temperature inside the main body; Plastic densification equipment.

2. the controller is configured to adjust the power supplied to the heating element to maintain the temperature sensed by the temperature sensor within a range of 100°C to 145°C; 10. The plastic densification apparatus of claim 1.

3. the controller is configured to apply a current to the lift motor up to a predetermined threshold, the predetermined threshold being a current associated with a desired amount of compression of the plastic; 10. The plastic densification apparatus of claim 1.

4. a sight glass within the body to allow visual inspection of the plastic within the body; 10. The plastic densification apparatus of claim 1.

5. A system for densifying plastics, comprising: a controller configured to control operation of the system; a body at least partially enclosing an interior volume having an aluminum interior surface; a cover hinged to the body and pivotable to open to provide access to the interior volume; a loading port in the cover configured to allow plastic to be loaded into the interior volume; a loading mechanism attached to the loading port, a roller having a friction surface configured to grip and pull plastic into the body; a comb attached to the roller, the comb configured to remove plastic from the roller and deposit it through the loading port; a roller motor configured to rotate the roller; a lift within the body configured, upon actuation, to reduce the interior volume and compress plastic within the interior volume; a lift motor configured to operate the lift; a current sensor for measuring the current supplied to the lift motor; a heating element located below and in contact with the aluminum surface, the heating element configured to heat the plastic within the body to a temperature in the range of 100°C to 145°C; a temperature sensor for measuring the temperature inside the main body; system.

6. the controller is configured to adjust the power supplied to the heating element to maintain the temperature sensed by the temperature sensor within a range of 100°C to 145°C; The system of claim 5.

7. the controller is configured to apply a current to the lift motor up to a predetermined threshold, the predetermined threshold being a current associated with a desired amount of compression of the plastic; The system of claim 5.

8. a sight glass within the body to allow visual inspection of the plastic within the body; The system of claim 5.

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