A polylactic acid (PLA) sheet production equipment and process.

Abstract

This invention relates to the technical field of polylactic acid (PLA) sheet production, and discloses a PLA sheet production equipment and process method. The equipment includes a suspended conveying mechanism and a suspended housing mounted on the suspended conveying mechanism. The suspended housing contains two sets of pressure-limiting clamping assemblies that can move away from each other in a left-right direction, and a driving assembly. An auxiliary assembly is located below the pressure-limiting clamping assemblies, and an elastic telescopic rod connects the auxiliary assembly to the pressure-limiting clamping assemblies. During operation, the driving assembly drives the two sets of pressure-limiting clamping assemblies to move away from each other, laterally flattening the upper sides of the PLA sheet. Simultaneously, the elastic telescopic rod drives the auxiliary assembly to move away from each other synchronously. At the same time, the auxiliary assembly, under the action of the connecting piece, swings downward relative to the pressure-limiting clamping assemblies to increase the distance between the upper and lower clamping areas, thus longitudinally straightening the PLA sheet. The pressure-increasing guide structure gradually increases the clamping pressure of the pressure-limiting clamping assemblies on the PLA sheet as they move away from each other.

Description

Technical Field

[0001] This invention belongs to the technical field of polylactic acid (PLA) sheet production, and more specifically, relates to a PLA sheet production equipment and process method. Background Technology

[0002] Polylactic acid (PLA) is a biodegradable polymer material with promising applications in sheet forming and processing. During the production of PLA sheets, processes such as conveying, flattening, cooling, and shaping are typically required to ensure the flatness of the sheet surface and its subsequent performance. Especially when the sheet is freshly formed and enters the overhead conveyor, its overall rigidity is low due to its continued temperature, making it prone to deformation during transport.

[0003] The existing technology for producing polylactic acid (PLA) sheets still has the following drawbacks: In the existing technology, when polylactic acid (PLA) sheets are suspended and conveyed, the lack of effective unfolding and continuous limiting of the two sides of the edges can easily lead to edge shrinkage, central bulging, local wrinkling, or insufficient flattening on both sides, resulting in poor overall flatness of the sheet and affecting the subsequent shaping quality.

[0004] In existing technologies, clamping structures mostly adopt fixed clamping methods. In the initial stage of PLA sheet entry, excessive clamping force can easily cause edge damage, jamming, or poor feeding. In the flattening process, insufficient clamping force may cause slippage, displacement, and retraction, making it difficult to meet the force requirements of PLA sheet from feeding to flattening and shaping.

[0005] In existing technologies, suspended conveyor structures typically focus more on lateral guidance or support, making it difficult to simultaneously straighten the sheet material in the vertical direction during conveying. This causes PLA sheets to sag, curl, or warp under their own weight and under hot conditions, further resulting in uneven cooling airflow and affecting the cooling and shaping effect.

[0006] Therefore, in view of this, we have studied and improved the existing structure and its shortcomings, and provided a polylactic acid (PLA) sheet production equipment and process method, in order to achieve a more practical and valuable purpose. Summary of the Invention

[0007] This invention provides a polylactic acid (PLA) sheet production equipment and process method to overcome the above-mentioned defects in the prior art.

[0008] The purpose and effectiveness of this invention, which relates to a polylactic acid (PLA) sheet production equipment and process, are achieved through the following specific technical means: A polylactic acid (PLA) sheet production equipment includes a suspended conveying mechanism and a suspended housing mounted on the suspended conveying mechanism. The suspended housing is provided with two sets of pressure-limiting clamping components that can be moved away from each other in the left-right direction, and a driving component for driving the two sets of pressure-limiting clamping components to move. An auxiliary component is disposed below the pressure-limiting clamping component, and an elastic telescopic rod is provided between the auxiliary component and the pressure-limiting clamping component so that the auxiliary component moves away from the pressure-limiting clamping component. The support components are symmetrically arranged on both sides of the suspension housing. A connector is provided between the auxiliary component and the support component so that the auxiliary component swings downward relative to the pressure-limiting clamping component as they move away from each other. A pressure-boosting guide structure is provided between the suspension housing and the pressure-limiting clamping assembly to gradually increase the clamping pressure of the pressure-limiting clamping assembly on the polylactic acid (PLA) sheet as they move away from each other.

[0009] In this solution, by using the lateral flattening of the pressure-limiting clamping component, the synchronous linkage of the auxiliary component, and the downward swinging of the auxiliary component, the polylactic acid (PLA) sheet can be subjected to both lateral flattening and vertical straightening during the suspended conveying process. Furthermore, the pressure-increasing guide structure enables the pressure-limiting clamping component to dynamically pressurize and clamp the PLA sheet, thereby improving the flatness, stability, and uniformity of cooling and shaping of the PLA sheet during the conveying process.

[0010] Preferably, the pressure-limiting clamping assembly includes a slider and a movable frame disposed below the slider. The movable frame contains a pair of movable plates that can move closer to or further away from each other. A first clamping assembly is disposed below the movable plates. The pressure-boosting guide structure includes a guide member disposed within the suspension housing. The movable plates and the guide member are guided and cooperated to make the movable plates move closer to each other when the slider moves outward.

[0011] Preferably, the movable frame is provided with a fixed rod and an elastic element acting between the two movable plates. The upper part of the movable plate is guided and cooperated with the fixed rod. The guide element has a guide surface that is straight in the middle and inclined on both sides on the side facing the movable plate, so that the movable plates gradually move closer together during the outward movement and move away from each other when resetting.

[0012] Preferably, the first clamping assembly includes a mounting plate and a movable frame movably disposed relative to the mounting plate. The movable frame is provided with at least a pair of rollers and a wear-resistant component that can move toward the PLA sheet. An elastic airbag is provided between the mounting plate and the movable frame so that when the mounting plate and the movable frame are relatively close, the wear-resistant component is driven to move toward the PLA sheet.

[0013] Preferably, the side wall of the movable frame is provided with a pair of movable plates and an elastic V-shaped member connecting the two movable plates, and the wear-resistant member is connected to the middle of the V-shaped member; an air cavity communicating with the elastic airbag is formed in the side wall of the movable frame, so that when the elastic airbag is compressed, it pushes the two movable plates closer to each other, and drives the wear-resistant member forward via the V-shaped member.

[0014] Preferably, the end of the wear-resistant component facing the PLA sheet is the abutting end, and guide slopes are provided on both sides. When the wear-resistant component moves forward, its abutting end first abuts against the side of the PLA sheet, and then its guide slopes on both sides press against the corresponding rollers to restrict the free rolling of the rollers and together with the rollers form a clamping limit.

[0015] Preferably, the auxiliary component includes a group of second clamping components, with multiple second clamping components in the same group arranged at intervals along the PLA sheet conveying direction and hinged to each other; one end and the middle of the second clamping components in the same group are respectively connected to the corresponding first clamping components through two elastic telescopic rods, so that the upper clamping and the lower auxiliary clamping unfold synchronously.

[0016] Preferably, the second clamping component adopts the same or similar rolling introduction and limiting clamping structure as the first clamping component, so that the PLA sheet is supported by rolling during the introduction stage and is reinforced by clamping during the unfolding stage.

[0017] Preferably, the supporting component includes a pair of symmetrically arranged vertical plates, and a pair of rubber parts are provided on opposite sides of the pair of vertical plates; one end of the connector is rotatably connected to the auxiliary component, and the other end is rotatably connected to the vertical plate, so that the auxiliary component swings around the connector and unfolds downward during the lateral outward movement.

[0018] A process for producing polylactic acid (PLA) sheets includes the following steps: S1. The PLA sheet is introduced into the overhead conveyor station, and the support assembly pre-positions both sides of the PLA sheet. S2. Initially clamp the upper two sides of the PLA sheet using the pressure limiting clamping assembly, and use the auxiliary assembly to assist in clamping the lower two sides of the PLA sheet. S3. Drive the two sets of pressure-limiting clamping components to move away from each other in the left and right directions, and drive the auxiliary components to move away from each other synchronously through the elastic telescopic rod, so as to apply a lateral flattening force to the PLA sheet. S4. As the pressure-limiting clamping components move away from each other, the clamping pressure of the pressure-limiting clamping components on the PLA sheet is gradually increased by the pressure-boosting guide structure. S5. During the process of the auxiliary components moving away from each other, the auxiliary components are swung downward relative to the pressure-limiting clamping components via the connector to increase the distance between the upper and lower clamping areas and apply a longitudinal straightening force to the PLA sheet. S6. Allow the PLA sheet, which is in a tensioned and unfolded state, to enter the cooling zone to complete the cooling and shaping process.

[0019] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a polylactic acid (PLA) sheet production equipment. Through a pressure-limiting clamping assembly that gradually increases clamping force on the PLA sheet as they move away from each other, the PLA sheet can be smoothly introduced with relatively low clamping pressure in the initial stage, reducing edge damage and jamming. During the lateral unfolding process, the clamping pressure gradually increases, thereby improving edge limiting stability and reducing slippage, deviation, and retraction, balancing smooth introduction and flattening stability. Furthermore, by moving the two sets of pressure-limiting clamping assemblies away from each other, two sets of auxiliary assemblies simultaneously unfold to both sides. With the aid of connecting parts, the auxiliary assemblies are swung downwards relative to the pressure-limiting clamping assemblies. This allows the PLA sheet to be subjected to both lateral flattening forces and vertical straightening forces during transport, improving problems such as edge shrinkage, central bulging, localized wrinkling, and sagging deformation, ensuring the PLA sheet remains taut and unfolded as a whole.

[0020] This invention discloses a polylactic acid (PLA) sheet production equipment. Through the coordinated operation of a pressure-limiting clamping assembly, auxiliary components, elastic telescopic rods, and a support assembly, the upper and lower parts of the PLA sheet are simultaneously stressed during the flattening process. This avoids deformation caused by excessive or uneven local stress, thereby improving the flatness and stability of the PLA sheet during suspension and conveying. Furthermore, since the PLA sheet is already in a tensioned and unfolded state before entering the cooling zone, the cooling airflow can act more fully and evenly on the surface of the PLA sheet. This facilitates cooling and shaping of the PLA sheet in a relatively flat state, reducing wrinkles, curling, sagging, and warping, and improving the shaping quality and flatness of the finished product. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Figure 1 This is a schematic diagram of the first isometric structure of the present invention; Figure 2 This is a schematic diagram of the second isometric structure of the present invention; Figure 3 This is a schematic diagram of the third isometric structure of the present invention; Figure 4 for Figure 3 A schematic diagram of the left-side view structure; Figure 5 for Figure 4 Schematic diagram of the cross-sectional structure at point AA; Figure 6 for Figure 2 A front view structural diagram; Figure 7 for Figure 6 Schematic diagram of the cross-sectional structure at point BB; Figure 8 for Figure 6 Schematic diagram of the cross-sectional structure at the CC section; Figure 9 for Figure 8 A magnified schematic diagram of the local structure at point E; Figure 10 for Figure 6 Schematic diagram of the cross-sectional structure at the middle DD section; Figure 11 for Figure 10 A magnified view of the structure at point F in the middle.

[0024] Explanation of reference numerals in the attached figures: The components include: a suspended conveying mechanism 10, a pressure-limiting clamping assembly 12, an auxiliary assembly 13, a support assembly 14, a suspension housing 15, a slider 16, a moving frame 17, a double-threaded lead screw 18, a stepper motor 19, a fixed rod 20, a first clamping assembly 21, a second clamping assembly 22, an elastic telescopic rod 23, a vertical plate 24, a rubber part 25, a mounting plate 26, a T-shaped rod 27, a movable frame 28, an elastic airbag 29, a roller 30, a moving plate 32, a V-shaped part 33, a wear-resistant part 34, a connecting port 35, a limiting block 36, a sliding plate 37, a movable plate 38, an air chamber 39, an elastic part 40, a guide part 41, and a connecting part 42. Detailed Implementation

[0025] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0026] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] As attached Figure 1 To be continued Figure 11 As shown: This invention provides a polylactic acid (PLA) sheet production equipment.

[0029] See attached document Figure 1 To be continued Figure 11 It includes a suspension conveying mechanism 10 and a suspension housing 15 mounted on the suspension conveying mechanism 10. The suspension housing 15 is provided with two sets of pressure limiting clamping components 12 that can be moved away from each other in the left and right directions, and a drive component for driving the two sets of pressure limiting clamping components 12 to move. An auxiliary component 13 is located below the pressure limiting clamping component 12. An elastic telescopic rod 23 is provided between the auxiliary component 13 and the pressure limiting clamping component 12 so that the auxiliary component 13 moves away from the pressure limiting clamping component 12. The support assembly 14 is symmetrically arranged on both sides of the suspension housing 15. A connector 42 is provided between the auxiliary assembly 13 and the support assembly 14 so that the auxiliary assembly 13 swings downward relative to the pressure-limiting clamping assembly 12 as they move away from each other. A pressure-boosting guide structure is located between the suspension housing 15 and the pressure-limiting clamping assembly 12, which is used to gradually increase the clamping pressure of the pressure-limiting clamping assembly 12 on the polylactic acid PLA sheet as they move away from each other.

[0030] In practice, after the PLA sheet enters the suspended conveyor station, the drive assembly drives the two sets of pressure-limiting clamping assemblies 12 to move away from each other in the left and right directions, so that the upper two sides of the PLA sheet are flattened outward. At the same time, the auxiliary assembly 13 moves away from each other synchronously under the drive of the elastic telescopic rod 23, applying an auxiliary flattening effect to the lower two sides of the PLA sheet. Furthermore, under the cooperation of the connector 42 and the support assembly 14, the auxiliary assembly 13 swings downward relative to the pressure-limiting clamping assembly 12, thereby increasing the vertical distance between the upper and lower clamping areas. During this process, the pressure-increasing guide structure gradually increases the clamping pressure of the pressure-limiting clamping assembly 12 on the PLA sheet as they move away from each other.

[0031] Preferred options are shown in the appendix. Figure 5 To be continued Figure 8 Appendix Figure 11 The pressure-limiting clamping assembly 12 includes a slider 16, which slides within the suspension housing 15. Several movable frames 17 are fixedly provided on the lower side of the slider 16. A pair of movable plates 38 are symmetrically slidably provided inside each movable frame 17. A fixed rod 20 is fixedly provided inside each movable frame 17. The upper part of each pair of movable plates 38 slides in contact with the outer wall of the fixed rod 20. An elastic element 40 is connected between each pair of movable plates 38. A first clamping assembly 21 is provided at the lower part of the movable plate 38.

[0032] Preferred options are shown in the appendix. Figure 7 The pressurization guide structure includes a guide member 41 located inside the suspension housing 15. The movable plate 38 is guided and cooperated with the guide member 41 so that the movable plates 38 move closer to each other when the slider 16 moves outward. The guide member 41 has a guide surface that is flat in the middle and inclined on both sides on the side facing the movable plate 38 so that the movable plates 38 gradually move closer to each other during the outward movement and move away from each other when resetting.

[0033] Preferred options are shown in the appendix. Figure 8 To be continued Figure 9The first clamping assembly 21 includes a mounting plate 26. Several T-shaped rods 27 are vertically spaced and slidably arranged on the mounting plate 26. A movable frame 28 is fixedly provided at one end of each T-shaped rod 27. A pair of rollers 30 are symmetrically rotated inside the movable frame 28. A wear-resistant part 34 is slidably provided in the middle of the movable frame 28. An elastic airbag 29 is connected between the mounting plate 26 and the movable frame 28. A pair of moving plates 32 are symmetrically slidably arranged in the side wall of the movable frame 28. A V-shaped part 33 is connected to the pair of moving plates 32. The middle part of the V-shaped part 33 is connected to the wear-resistant part 34. A sliding plate 37 is provided at one end of the wear-resistant part 34. The sliding plate 37 slides in the side wall of the movable frame 28. An air cavity 39 communicating with the connection port 35 is formed inside the side wall of the movable frame 28. The moving plate 32 is slidably arranged in the air cavity 39 and is sealed to the wall of the air cavity 39 so that the gas after the elastic airbag 29 is compressed can push the moving plate 32 to move stably. A pair of limiting blocks 36 are symmetrically fixed in the side wall of the movable frame 28.

[0034] Preferred options are shown in the appendix. Figure 9 The end of the wear-resistant part 34 facing the PLA sheet is the abutting end, and there are guide slopes on both sides. When the wear-resistant part 34 moves forward, its abutting end first abuts against the side of the PLA sheet, and then its guide slopes on both sides press against the corresponding rollers 30 to restrict the free rolling of the rollers 30 and together with the rollers 30 form a clamping limit.

[0035] Preferred options are shown in the appendix. Figure 1 To be continued Figure 5 The auxiliary component 13 includes a group of second clamping components 22. Multiple second clamping components 22 in the same group are arranged at intervals along the PLA sheet conveying direction and are hinged to each other. One end and the middle of the second clamping components 22 in the same group are connected to the corresponding first clamping components 21 through two elastic telescopic rods 23, so that the upper clamping and the lower auxiliary clamping are deployed synchronously.

[0036] Preferred options are shown in the appendix. Figure 1 To be continued Figure 5 The second clamping component 22 and the first clamping component 21 adopt the same or similar rolling introduction and limiting clamping structure so that the PLA sheet is supported by rolling during the introduction stage and is reinforced by clamping during the unfolding stage.

[0037] Preferred options are shown in the appendix. Figure 1 To be continued Figure 8 The supporting component 14 includes a pair of symmetrically arranged vertical plates 24, and a pair of rubber parts 25 are provided on opposite sides of the pair of vertical plates 24; one end of the connector 42 is rotatably connected to the auxiliary component 13, and the other end is rotatably connected to the vertical plate 24, so that the auxiliary component 13 swings around the connector 42 and unfolds downward during the lateral outward movement.

[0038] Preferred options are shown in the appendix. Figure 5The suspension housing 15 is equipped with a double threaded screw 18 for rotation. A stepper motor 19 is installed at one end of the suspension housing 15. The output end of the stepper motor 19 is connected to one end of the double threaded screw 18. Two sliders 16 are in threaded contact with the two double threaded screws 18 respectively. The threads on the outer walls of the two ends of the double threaded screw 18 are in opposite directions.

[0039] A process for producing polylactic acid (PLA) sheets includes the following steps: S1. The PLA sheet is introduced into the overhead conveyor station, and the support assembly 14 pre-positions both sides of the PLA sheet. S2. The upper two sides of the PLA sheet are initially clamped using the pressure limiting clamping assembly 12, and the lower two sides of the PLA sheet are further clamped using the auxiliary assembly 13. S3. Drive the two sets of pressure-limiting clamping components 12 to move away from each other in the left and right directions, and drive the auxiliary components 13 to move away from each other synchronously via the elastic telescopic rod 23, so as to apply a lateral flattening force to the PLA sheet. S4. As the pressure-limiting clamping components 12 move away from each other, the clamping pressure of the pressure-limiting clamping components 12 on the PLA sheet gradually increases through the pressure-boosting guide structure. S5. As the auxiliary components 13 move away from each other, the auxiliary components 13 are swung downward relative to the pressure-limiting clamping components 12 via the connector 42 to increase the distance between the upper and lower clamping areas and apply a longitudinal straightening force to the PLA sheet. S6. Allow the PLA sheet, which is in a tensioned and unfolded state, to enter the cooling zone to complete the cooling and shaping process.

[0040] Specific usage of this invention: During the production process, after the polylactic acid (PLA) sheet enters the suspended conveyor station, the two pairs of vertical plates 24 and rubber parts 25 in the supporting assembly 14 initially limit and support the left and right ends of the PLA sheet to facilitate its entry into the predetermined conveying position. Then, the two sets of upper pressure-limiting clamping assemblies 12 clamp and position the upper sides of the PLA sheet. At this point, the clamping force of the pressure-limiting clamping assemblies 12 is relatively small, ensuring smooth entry of the PLA sheet while preventing damage to the upper end of the sheet during initial entry. Next, the two sets of lower auxiliary assemblies 13 clamp and position the lower sides of the PLA sheet. The clamping force of the auxiliary assemblies 13 is also relatively small, facilitating smooth entry of the lower end of the PLA sheet into the clamping area and preventing initial damage. The rollers 30, in rolling mode, contact the surface of the PLA sheet, reducing the frictional resistance of the two sets of pressure-limiting clamping assemblies 12 and the two sets of auxiliary assemblies 13 during lateral unfolding, facilitating subsequent horizontal movement away from each other.

[0041] Subsequently, driven by the stepper motor 19, the stepper motor 19 drives the double-threaded screw 18 to rotate. After the double-threaded screw 18 rotates, it drives the two sliders 16 to move away from each other in opposite directions. The two sliders 16 moving away from each other further drives the two sets of pressure-limiting clamping assemblies 12 to move away from each other in the horizontal direction. When the two sets of upper pressure-limiting clamping assemblies 12 move away from each other, the four sets of elastic telescopic rods 23 simultaneously drive the two sets of lower auxiliary assemblies 13 to move away from each other in the horizontal direction, thereby applying outward pulling force to the left and right ends of the PLA sheet, so that the PLA sheet gradually unfolds and flattens in the width direction. Among them, a set of elastic telescopic rods 23 connected between a set of first clamping assemblies 21 and a set of second clamping assemblies 22 constitutes a set of elastic telescopic rods 23. Since each set of pressure-limiting clamping assemblies 12 has two symmetrically distributed sets of first clamping assemblies 21, the whole is formed into four sets of elastic telescopic rods 23, which are used to realize the synchronous linkage between the upper clamping and the lower auxiliary clamping. As the two sets of pressure-limiting clamping components 12 and the two sets of auxiliary components 13 move away from each other in the horizontal direction, the wear-resistant part 34 gradually moves closer to the PLA sheet, preparing for the subsequent enhanced limiting clamping effect.

[0042] Meanwhile, as the two sets of pressure-limiting clamping components 12 continue to move outward, the movable plate 38 is guided by the inclined surface of the guide member 41, causing the pair of movable plates 38 within the same moving frame 17 to move closer to each other. After the two movable plates 38 move closer, they drive the corresponding two first clamping components 21 to move closer together, thereby gradually increasing the clamping force of the first clamping components 21 on both sides of the upper part of the PLA sheet within the pressure-limiting range. This prevents the PLA sheet from slipping or shifting during the flattening process, improving the stability and efficiency of lateral flattening. Furthermore, during the process of the two movable plates 38 moving closer together, the elastic member 40 is compressed and generates a restoring force. Under the action of the elastic member 40, the two movable plates 38 can be pushed away from each other and reset when needed.

[0043] Furthermore, when the two first clamping components 21 approach each other, they also cause the two mounting plates 26 to approach each other. Due to the contact and abutment between several pairs of rollers 30 and the PLA sheet, the distance between the mounting plates 26 and the movable frame 28 gradually decreases. After the mounting plates 26 move relative to the movable frame 28, they compress the elastic airbag 29, causing the gas inside the elastic airbag 29 to enter both ends of the side wall of the movable frame 28 through the two connecting ports 35, and using the gas to push the two moving plates 32 closer together. When the two moving plates 32 approach each other, they compress and deform the V-shaped part 33, causing the middle of the V-shaped part 33 to push the wear-resistant part 34 towards the PLA sheet. In this way, one end of the wear-resistant part 34 can contact the side of the PLA sheet and form a compression clamp, while the inclined surfaces on both sides of the wear-resistant part 34 contact the outer walls of the two rollers 30, thereby creating frictional limiting for the two rollers 30. Therefore, after the wear-resistant part 34 and the roller 30 gradually come to a standstill from rolling, they can work together to form a more stable clamping and fixing effect on the PLA sheet, thereby further preventing the PLA sheet from slipping or shifting during the flattening process and improving the stability and efficiency of lateral flattening.

[0044] Furthermore, during the operation of the pressure-limiting clamping assembly 12, due to the varying degrees to which the first clamping assemblies 21 are guided by the inclined surface of the guide member 41, the clamping force and clamping position applied by each pair of first clamping assemblies 21 to different positions on the upper sides of the PLA sheet differ. This allows for adaptive clamping based on the force requirements of different areas of the PLA sheet. Simultaneously, the two sets of elastic telescopic rods 23 drive the two sets of second clamping assemblies 22 to move closer to each other synchronously with the two sets of first clamping assemblies 21, thereby maintaining synchronous clamping of the upper and lower sides of the PLA sheet and making the force on the PLA sheet more uniform throughout the flattening process.

[0045] Furthermore, as the two sets of auxiliary components 13 move away from each other horizontally, the auxiliary components 13 rotate in conjunction with the vertical plate 24 through the connection between the connector 42 and the vertical plate 24. This causes the auxiliary components 13 to unfold downwards relative to the upper pressure-limiting clamping component 12, thereby increasing the vertical distance between the upper pressure-limiting clamping component 12 and the lower auxiliary components 13, thus creating a straightening effect on the PLA sheet in the vertical direction. In this way, the PLA sheet is subjected not only to the flattening force in the left and right directions but also to the straightening force in the vertical direction during the conveying process, thus keeping the whole sheet in a taut and unfolded state. Among them, the elastic telescopic rod 23 has telescopic properties.

[0046] Finally, the PLA sheet, which is in a stretched and unfolded state, enters the cooling zone. The cooling airflow can act more fully and evenly on the surface of the PLA sheet, allowing the PLA sheet to complete cooling and shaping while flattened and straightened. This effectively reduces wrinkles, curling, sagging, and warping, and improves the flatness and shaping effect of the PLA sheet.

[0047] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A polylactic acid (PLA) sheet production equipment, comprising a suspended conveying mechanism (10) and a suspended housing (15) mounted on the suspended conveying mechanism (10), characterized in that, The suspension housing (15) is provided with two sets of pressure-limiting clamping assemblies (12) that can be moved away from each other in the left and right directions, and a driving assembly for driving the two sets of pressure-limiting clamping assemblies (12) to move. An auxiliary component (13) is provided below the pressure limiting clamping component (12). An elastic telescopic rod (23) is connected between the auxiliary component (13) and the pressure limiting clamping component (12) so that the auxiliary component (13) moves away from the pressure limiting clamping component (12). The support assembly (14) is symmetrically arranged on both sides of the suspension housing (15). A connector (42) is provided between the auxiliary assembly (13) and the support assembly (14) so ​​that the auxiliary assembly (13) swings downward relative to the pressure limiting clamping assembly (12) as they move away from each other. A pressure-boosting guide structure is provided between the suspension housing (15) and the pressure-limiting clamping assembly (12) to gradually increase the clamping pressure of the pressure-limiting clamping assembly (12) on the polylactic acid (PLA) sheet as they move away from each other.

2. The polylactic acid (PLA) sheet production equipment according to claim 1, characterized in that: The pressure-limiting clamping assembly (12) includes a slider (16) and a movable frame (17) disposed below the slider (16). The movable frame (17) contains a pair of movable plates (38) that can move closer to or further away from each other. The lower part of the movable plate (38) is provided with a first clamping assembly (21). The pressure-boosting guide structure includes a guide member (41) disposed in the suspension housing (15). The movable plate (38) and the guide member (41) are guided and cooperated so that the movable plates (38) move closer to each other when the slider (16) moves outward.

3. The polylactic acid (PLA) sheet production equipment according to claim 2, characterized in that: The movable frame (17) is provided with a fixed rod (20) and an elastic element (40) acting between the two movable plates (38). The upper part of the movable plate (38) is guided and engaged with the fixed rod (20). The guide element (41) has a guide surface that is straight in the middle and inclined on both sides on the side facing the movable plate (38), so that the movable plates (38) gradually move closer together during the outward movement and move away from each other when resetting.

4. The polylactic acid (PLA) sheet production equipment according to claim 2, characterized in that: The first clamping assembly (21) includes a mounting plate (26) and a movable frame (28) movably disposed relative to the mounting plate (26). The movable frame (28) is provided with at least a pair of rollers (30) and a wear-resistant component (34) movable toward the PLA sheet. An elastic airbag (29) is provided between the mounting plate (26) and the movable frame (28) to drive the wear-resistant component (34) to move toward the PLA sheet when the mounting plate (26) and the movable frame (28) are relatively close.

5. The polylactic acid (PLA) sheet production equipment according to claim 4, characterized in that: The side wall of the movable frame (28) is provided with a pair of movable plates (32) and an elastic V-shaped member (33) connecting the two movable plates (32). The wear-resistant member (34) is connected to the middle of the V-shaped member (33). An air cavity (39) communicating with the elastic airbag (29) is formed in the side wall of the movable frame (28), so that the elastic airbag (29) pushes the two movable plates (32) closer to each other after being compressed, and drives the wear-resistant member (34) to move forward via the V-shaped member (33).

6. The polylactic acid (PLA) sheet production equipment according to claim 5, characterized in that: The wear-resistant part (34) has an abutment end facing the PLA sheet, and guide slopes on both sides. When the wear-resistant part (34) moves forward, its abutment end first abuts against the side of the PLA sheet, and then its guide slopes on both sides press against the corresponding rollers (30) to restrict the free rolling of the rollers (30) and together with the rollers (30) form a clamping limit.

7. The polylactic acid (PLA) sheet production equipment according to claim 1, characterized in that: The auxiliary component (13) includes a group of second clamping components (22). Multiple second clamping components (22) in the same group are arranged at intervals along the PLA sheet conveying direction and are hinged to each other. One end and the middle of the second clamping components (22) in the same group are connected to the corresponding first clamping components (21) through two elastic telescopic rods (23) to make the upper clamping and the lower auxiliary clamping unfold synchronously.

8. The polylactic acid (PLA) sheet production equipment according to claim 7, characterized in that: The second clamping component (22) adopts the same rolling inlet and limiting clamping structure as the first clamping component (21) so that the PLA sheet is supported by rolling during the inlet stage and is reinforced by clamping during the unfolding stage.

9. The polylactic acid (PLA) sheet production equipment according to claim 1, characterized in that: The supporting component (14) includes a pair of symmetrically arranged vertical plates (24), and a pair of rubber parts (25) are provided on opposite sides of the pair of vertical plates (24); one end of the connector (42) is rotatably connected to the auxiliary component (13), and the other end is rotatably connected to the vertical plate (24), so that the auxiliary component (13) swings around the connector (42) and unfolds downward during the lateral outward movement.

10. A process for producing polylactic acid (PLA) sheets, based on the PLA sheet production equipment according to any one of claims 1-9, characterized in that, Includes the following steps: S1. The PLA sheet is introduced into the suspension conveyor station, and the support assembly (14) pre-positions both sides of the PLA sheet. S2. The upper two sides of the PLA sheet are initially clamped using the pressure limiting clamping assembly (12), and the lower two sides of the PLA sheet are further clamped using the auxiliary assembly (13). S3. Drive the two sets of pressure-limiting clamping components (12) to move away from each other in the left and right directions, and drive the auxiliary components (13) to move away from each other synchronously via the elastic telescopic rod (23) to apply a lateral flattening force to the PLA sheet. S4. As the pressure-limiting clamping components (12) move away from each other, the clamping pressure of the pressure-limiting clamping components (12) on the PLA sheet gradually increases through the pressure-increasing guide structure. S5. During the process of the auxiliary components (13) moving away from each other, the auxiliary components (13) are swung downward relative to the pressure-limiting clamping components (12) via the connector (42) to increase the distance between the upper and lower clamping areas and apply a longitudinal straightening force to the PLA sheet. S6. Allow the PLA sheet, which is in a tensioned and unfolded state, to enter the cooling zone to complete the cooling and shaping process.

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