Production process and equipment for forming plastic tray at one time

Abstract

Production equipment for forming plastic trays at a time comprises an upper bracket, a lower bracket, an upper guide rail, a lower guide rail, a reinforcing rib bracket and a press machine, an upper die is arranged in the press machine, the lower die is vertically opposite, and the upper bracket and the lower bracket are used for bearing an upper sheet and a lower sheet respectively and located on the same side of the press machine at the same time; the upper bracket and the lower bracket are respectively connected to the upper guide rail and the lower guide rail in a sliding manner, form two staggered layers, are opposite to each other up and down after synchronization, and slide between an upper die and a lower die of the press machine along the upper guide rail; the reinforcing rib bracket is located on one side of the upper bracket and matched with a pushing assembly which enables the reinforcing rib bracket to be pushed into the position below the upper bracket or withdrawn from the upper bracket, and a first clamp which can clamp reinforcing ribs to the position below the upper bracket is arranged in the upper bracket. And a liftable second clamp is also arranged at the bottom of the upper bracket. The reinforcing ribs can be automatically added in the production process, the labor cost is saved, the operation time can be saved, and the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to a plastic molding process and equipment, in particular to a production process and equipment for a one-time molding plastic pallet. Background Art

[0002] In the furniture, daily necessities and logistics industries, plastic pallets for material turnover such as bed boards and table boards are widely used. They are used to carry or transport goods to greatly improve logistics efficiency. Existing plastic pallets are generally double-layer blister products, which have the characteristics of ultra-long service life, low temperature resistance, tear resistance, impact resistance, high strength, ability to form complex shapes, convenient processing, low cost, and good cushioning effect, thus gaining wide application. Double-layer blister products are generally formed by melting the upper and lower plastic sheets together. In addition, pre-embedded load-bearing parts in the plastic pallet will make the product more durable, and can greatly improve the pallet's bearing capacity without increasing the material thickness.

[0003] In the prior art, double-layer blister tray processing equipment is usually provided with a left extruder and a right extruder located on both sides of a press, and the left and right extruders cut the upper plastic sheet and the lower plastic sheet respectively, and transport the upper plastic sheet and the lower plastic sheet to the upper mold and the lower mold of the press respectively through the upper bracket and the lower bracket, and finally close the molds and fuse them into a double-layer blister tray. The above structure has the following disadvantages: 1. Since the left extruder and the right extruder need to feed the plastic sheets into the middle press from both sides and use the upper and lower brackets respectively, the equipment is relatively large and occupies a large area; 2. When reinforcing ribs need to be added, they usually need to be added manually. Generally, the reinforcing ribs are added manually at the preset position after the lower plastic sheet is fed into the press, which increases the labor cost; 3. After the upper and lower plastic sheets are conveyed to the press, they are negatively pressurized and heat-sealed. In this step, the lower plastic sheet is conveyed into the press, and then the lower plastic sheet is first clamped by the (upper bracket), and the lower bracket carrying the lower plastic sheet withdraws, and the lower plastic sheet can be placed in the lower mold. After being placed in the lower mold, subsequent actions (adding reinforcement ribs after negative pressure molding) can be performed. In the press, the upper bracket needs to increase the process time after waiting for the lower bracket to completely withdraw, as well as the time for manually adding reinforcement ribs, which makes the working time in the press longer and fails to improve the production efficiency. Summary of the invention The object of the present invention is to provide a production process and equipment for one-step forming of a plastic pallet, which can automatically add reinforcing ribs during the production process, save labor costs, and save operating time in a press, thereby improving production efficiency.

[0004] In order to achieve the above object, the solution of the present invention is: A production equipment for one-time forming plastic pallets, comprising an upper bracket, a lower bracket, an upper guide rail, a lower guide rail, a reinforcing rib bracket, and a press, wherein an upper mold and a lower mold are arranged in the press, and are opposite to each other up and down, and the upper bracket and the lower bracket are used to receive an upper sheet material and a lower sheet material respectively and are located on the same side of the press at the same time; the upper bracket and the lower bracket are slidably connected to the upper guide rail and the lower guide rail respectively, and the upper guide rail is located above the lower guide rail in parallel so that the upper bracket and the lower bracket form two staggered layers, and the upper bracket and the lower bracket are opposite to each other up and down after synchronization, and the upper bracket slides between the upper mold and the lower mold of the press along the upper guide rail; the reinforcing rib bracket is located on one side of the upper bracket and is equipped with a pushing component that pushes the reinforcing rib bracket under the upper bracket or withdraws it outward, and a first clamp that can clamp the reinforcing rib to the bottom of the upper bracket is provided in the upper bracket; a second clamp that can be raised and lowered is also provided at the bottom of the upper bracket, and the second clamp that is lowered will clamp the lower sheet material located below it and then rise again.

[0005] Furthermore, the upper bracket is equipped with an upper extruder, and the lower bracket is equipped with a lower extruder. The screws of the upper extruder and the lower extruder plasticize and extrude the upper sheet and the lower sheet respectively through the die. After the upper sheet is extruded by the upper extruder, it is laid flat on the upper bracket when the upper guide rail slides. After the lower sheet is extruded by the lower extruder, it is laid flat on the lower bracket when the lower guide rail slides.

[0006] Furthermore, the upper bracket includes an upper outer frame, an upper panel, an upper inner frame, multiple upper cylinders, and multiple groups of lower cylinders. The upper panel is located at the top of the upper outer frame, and a slide groove cooperating with the upper guide rail is provided at the bottom of the upper outer frame. The upper cylinder is arranged on the upper outer frame, and the rod end of the piston rod of the upper cylinder is connected to the upper panel. The lower cylinder is arranged at the bottom of the upper outer frame. The upper inner frame is located below the inner side of the upper outer frame. The lower cylinder is connected between the upper outer frame and the upper inner frame to push the upper inner frame to descend and then rise. The first clamp and the second clamp are arranged on the upper inner frame.

[0007] Furthermore, an upper inner plate is provided on the upper inner frame, and the first clamp includes a plurality of clamping robots provided at preset positions of the bottom of the upper inner plate corresponding to the reinforcing ribs; the second clamp includes at least one clamping cylinder provided in at least one group of opposite sides of the upper inner frame, and the cylinder bodies of the clamping cylinders are symmetrically fixed on the outer side surfaces of the upper inner frame, and the piston rods of each clamping cylinder pass through the upper inner frame and the rod ends of the piston rods are respectively connected to the outer ends of a clamping rod; the lower bracket includes a lower panel provided on a lower outer frame, and a second upper top frame is provided on the lower panel, and when the positions of the upper bracket and the lower bracket are synchronized, the clamping rod in the second clamp is located on the outer side of the second upper top frame.

[0008] Furthermore, each group of lower top cylinders includes at least one upper cylinder and at least one lower cylinder, and the cylinder bodies of the upper cylinder and the lower cylinder in the same group of lower top cylinders are connected as a whole, the rod end of the piston rod of the upper cylinder is connected to the upper outer frame, and the rod end of the piston rod of the lower cylinder is connected to the upper inner frame.

[0009] Furthermore, a middle guide rail is provided on the outer side of the upper guide rail, and the middle guide rail is located between the upper guide rail and the lower guide rail in terms of horizontal height. The reinforcement rib bracket includes a push plate slidably connected to the middle guide rail, and the pushing assembly is a cylinder push rod connected to the bottom of the push plate. The reinforcement rib is placed at a preset position above the push plate manually or by a robot.

[0010] Furthermore, the upper bracket, the upper guide rail and the middle guide rail are arranged in the first frame, the lower bracket and the lower guide rail are arranged in the second frame, and a synchronization section is provided between the first frame and the press for synchronizing the positions of the upper bracket and the lower bracket after grabbing the reinforcement ribs. The upper bracket grabs the lower sheet in the synchronization section, the upper guide rail extends from the first frame to the synchronization section and then to the press, and the lower guide rail extends from the second frame to the first frame and then to the synchronization section.

[0011] A production process for a one-step formed plastic pallet comprises the following steps: (1) The upper sheet and the lower sheet extruded by the extruder are laid flat on the upper bracket and the lower bracket respectively, and the upper bracket and the lower bracket form two staggered layers; (2) The reinforcing rib bracket located on one side of the upper bracket pushes the reinforcing rib to the bottom of the upper bracket, the first clamp in the upper bracket clamps the reinforcing rib, and the reinforcing rib bracket withdraws and resets; (3) After the upper bracket with the reinforcing ribs is clamped and the lower bracket is in position, the second clamp in the upper bracket descends, clamps the lower sheet and then rises. After clamping the reinforcing ribs and the lower sheet, the upper bracket continues to move toward the press, while the lower bracket returns to its initial position. (4) The upper bracket with the reinforcing ribs and the lower sheet is sent into the press, the upper sheet rises to the upper die in the upper press, and the lower sheet and the reinforcing ribs are lowered and placed in the lower die in the press; (5) Start the vacuum, the upper sheet and the lower sheet are formed by vacuum forming in the upper mold and the lower mold respectively, and the upper bracket exits the press and returns to the initial position; (6) The upper and lower molds of the press are closed, and the molded upper sheet with reinforcing ribs embedded in the middle and the molded lower sheet are heat-sealed. At the same time, high-pressure gas is blown into the mold cavity to make the upper and lower sheets close to the mold surface, and then cooled and molded. Finally, the molded product is demolded.

[0012] Furthermore, in step (6), after the cooling molding time is reached, the interlayer compressed gas is discharged, the mold is opened, and the product removal bracket enters the press. After the molded product is ejected from the upper mold and falls into the product removal bracket, the product removal bracket retreats to the initial position, the worker inspects and trims the product, and the equipment enters the next cycle of production.

[0013] Furthermore, in step (1), the plastic raw material is plasticized by screws of two extruders and extruded through dies to form an upper sheet and a lower sheet respectively, and the two extruders are located on the same side of the press.

[0014] After adopting the above scheme, the present invention has the following advantages over the prior art: 1. The two extruders for extruding the upper and lower sheets are located on the same side of the press, which can reduce the equipment footprint. The lower sheet can be extruded after the upper sheet is extruded and cut, and transported to the bottom of the upper sheet after the reinforcing ribs are clamped through the lower guide rail, shortening the heat dissipation time of the sheet; 2. A reinforcing rib bracket is provided on one side of the upper bracket, which is automatically pushed in or out of the lower bracket. The bottom of the lower bracket cooperates with a first clamp that can clamp the reinforcing rib according to a preset position, and then drives the reinforcing rib into the press and is placed into the lower die together with the lower sheet, eliminating the step of manually adding reinforcing ribs, saving labor costs and improving the degree of automation; 3. The upper bracket clamps the reinforcing rib and the lower sheet to the bottom of the lower bracket and then puts them into the press together. In the press, there is no need to wait for the lower bracket to exit before hot pressing, which shortens the stay time in the press, saves operation time within the same travel range, and improves work efficiency; 4. The push stroke of the lower push cylinder in the upper bracket can be the sum of the upper push stroke of the upper cylinder and the lower push stroke of the lower cylinder through the cooperation of the upper cylinder and the lower cylinder in the upper bracket, so that the structure is more compact and the volume of the upper bracket is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the device of the present invention; Figure 2 It is a structural schematic diagram of a press machine of the present invention; Figure 3 It is a schematic diagram of the structure of the first frame and the second frame of the present invention (the upper and lower guide rails are omitted); Figure 4 It is a structural schematic diagram of the lower bracket in the present invention; Figure 5 It is a structural schematic diagram of the upper bracket in the present invention; Figure 6 is a side view of the upper bracket of the present invention; Figure 7 It is a schematic diagram of the structural decomposition of the upper bracket in the present invention; Figure 8 It is a bottom view of the upper inner frame in the upper bracket of the present invention. DETAILED DESCRIPTION

[0016] In order to further explain the technical solution of the present invention, the present invention is described in detail below through specific embodiments.

[0017] Combination Figures 1 to 8 As shown, the present invention discloses a production equipment for one-time forming plastic pallets, including an upper bracket 1, a lower bracket 2, an upper guide rail 3, a lower guide rail 4, a reinforcing rib bracket 5, and a press 6. Among them, the press 6 is provided with an upper mold 61 and a lower mold 62 facing each other up and down, and the upper bracket 1 and the lower bracket 2 can have heat preservation and heat insulation functions. The upper bracket 1 and the lower bracket 2 are used to receive the upper sheet and the lower sheet (not shown in the figure) respectively and are located on the same side of the press 6 at the same time. The upper bracket 1 and the lower bracket 2 are slidably connected to the upper guide rail 3 and the lower guide rail 4 respectively, and the upper guide rail 3 is located parallel to the lower guide rail 4 so that the upper bracket 1 and the lower bracket 2 form two dislocated layers, and the upper bracket 1 and the lower bracket 2 face each other up and down after sliding to synchronization. Relative to the lower bracket 2, the upper bracket 1 can continue to slide along the upper guide rail 3 into between the upper mold 61 and the lower mold 62 of the press 6. The reinforcing rib bracket 5 is located at one side of the upper bracket 1 and is equipped with a pushing assembly that pushes the reinforcing rib bracket 5 under the upper bracket 1 or withdraws it from the outside. The upper bracket 1 is provided with a first clamp 7 that can clamp the reinforcing rib 53 to the bottom of the upper bracket 1. The bottom of the upper bracket 1 is also provided with a second clamp 8 that can be raised and lowered. After the second clamp 8 is lowered, it can clamp the lower sheet located below it and then rise again.

[0018] Specifically, the results Figure 1 , Figure 3 As shown, the upper bracket 1 is equipped with an upper extruder A, and the lower bracket 2 is equipped with a lower extruder B. The screws of the upper extruder A and the lower extruder B plasticize and extrude the upper sheet and the lower sheet through the die respectively. After the upper sheet is extruded by the upper extruder A, it passes through the upper bracket 1 and is laid flat on the upper bracket 1 when sliding on the upper guide rail 3. After the lower sheet is extruded by the lower extruder B, it passes through the lower bracket 2 and is laid flat on the lower bracket 2 when sliding on the lower guide rail 4. A cutting device (not shown in the figure) is also fixed at the outlet of each extruder. When the molten plastic sheet extruded by the extruder reaches a predetermined length, the cutter in the cutting device can cut the plastic sheet.

[0019] A middle guide rail 50 is provided on the outer side of the upper guide rail 3, and the middle guide rail 50 is located between the upper guide rail 3 and the lower guide rail 4 in horizontal height. The reinforcing rib bracket 5 may include a push plate 51 slidably connected to the middle guide rail 50, and the pushing assembly may be connected to a cylinder push rod 52 at the bottom of the push plate 51, and the push plate 51 is connected to the rod end of the cylinder push rod 52, and the push plate 51 is pushed inward by the cylinder push rod 52 to be located directly below the upper bracket 1 (in this case, the second clamp 8 in the upper bracket 1 moves downward together with the first clamp 7 and then returns to its original position, and the reinforcing rib 53 is clamped by the first clamp 7 and then returns to its original position), or pushed outward to withdraw (so as to make way for the lower bracket 2 to slide on the lower guide rail 4). The upper reinforcing rib 53 can be placed at a preset position above the push plate 51 manually or by a robot.

[0020] In this embodiment, the upper bracket 1, the upper guide rail 3 and the middle guide rail are arranged in the first frame 10, the lower bracket 2 and the lower guide rail 4 are arranged in the second frame 20, and a synchronization section C is provided between the first frame 10 and the press 6 for synchronizing the positions of the upper bracket 1 and the lower bracket 2 after grabbing the reinforcing rib 53. The upper bracket 1 can slide in the synchronization section C to grab the lower sheet (the upper sheet can be the upper sheet extruded by the upper extruder A and then moved to the synchronization section C and then laid flat on the upper bracket 1), the upper guide rail 3 extends from the first frame 10 to the synchronization section C and then extends to the press 6, and the lower guide rail 4 extends from the second frame 20 to the first frame 10 and then extends to the synchronization section C. During operation, the lower bracket 2 slides from the lower guide rail 4 to the synchronous section C. After completing the grabbing of the reinforcing rib 53 in the first frame 10, the upper bracket 1 slides to the synchronous section C to be opposite to the lower bracket 2 up and down, and then clamps the lower sheet before entering the press 6.

[0021] Combination Figures 5 to 8 As shown, the upper bracket 1 includes an upper outer frame 11, an upper panel 12, an upper inner frame 13, a plurality of upper cylinders 14, and a plurality of lower cylinders 15. The upper panel 12 is located at the top of the upper outer frame 11, and a first upper frame 121 may also be provided in the top surface of the upper panel 12. The upper sheet falls onto the upper panel 12 and is located at the outer edge of the first upper frame 121. A slide groove 111 that cooperates with the upper guide rail 3 is provided at the bottom of the upper outer frame 11, so that the upper outer frame 11 can slide on the upper guide rail 3. A plurality of upper cylinders 14 are respectively arranged on the upper outer frame 11, and the rod ends of the piston rods 141 of the upper cylinders 14 are connected to the upper panel 12, and the lower cylinders 15 are arranged at the bottom of the upper outer frame 11. In this embodiment, the upper outer frame 11 forms a square frame body, and one set of opposite sides in the upper outer frame 11 is formed on a sliding frame rod that can slide on the upper guide rail 3, and the upper cylinders 14 and the lower cylinders 15 are arranged on the inner frame rods perpendicular to the two sliding frame rods. The upper inner frame 13 is located below the inner side of the upper outer frame 11, and the lower cylinders 15 are connected between the upper outer frame 11 and the upper inner frame 13 to push the upper inner frame 13 down and then up, and the first clamp 7 and the second clamp 8 are arranged on the upper inner frame 13.

[0022] In this embodiment, an upper inner plate 16 is provided on the upper inner frame 13, and the first clamp 7 includes a plurality of gripping manipulators 71 provided at the preset positions corresponding to the reinforcement ribs 53 at the bottom of the upper inner plate 16. Since the first clamp 7 and the second clamp 8 are both provided on the upper inner frame 13, the lower push cylinder 15 brings the upper inner frame 13 down or up as a whole, and after the lowering, drives the gripping manipulators 71 in the upper inner plate 16 to grip the reinforcement ribs 53 on the push plate 51. When the reinforcement member 53 is placed on the push plate 51 according to the predetermined position and the push rod 52 drives it to be located below the upper bracket 1, the lower push cylinder 15 works to drive the upper inner frame 13, so that the gripping manipulators 71 can grip each reinforcement member 53 and return to their original positions.

[0023] The second clamp 8 includes at least one clamping cylinder 81 respectively arranged in at least one set of opposite sides of the upper inner frame 13. In this embodiment, two clamping cylinders 81 are respectively arranged on each frame rod of a set of opposite sides. The cylinder bodies of the clamping cylinders 81 are respectively symmetrically fixed on the outer side of the upper inner frame 13. The piston rod 811 of each clamping cylinder 81 passes through the upper inner frame 13 and the rod end of the piston rod 811 is respectively connected to the outer end of a clamping rod 82. Figure 4 As shown, the lower bracket 2 includes a lower panel 22 provided on a lower outer frame 21, and a second upper frame 23 provided on the lower panel 22. When the upper bracket 1 and the lower bracket 2 are in synchronous position, the clamping rod 82 in the second clamp 8 is located outside the second upper frame 23, so when the clamping cylinder 81 pushes the clamping rod 82 inward, the lower sheet on the lower bracket 2 can be clamped. The inner ends of the second upper frame 23 and the clamping rod 82 of the lower bracket 2 are both serrated, and the serrations at the inner end of the clamping rod 82 penetrate between the serrations of the second upper frame. An inner positioning frame 17 may also be provided on the inner side of the clamping rod 82, and the inner positioning frame 17 may be fixed to the bottom of the upper inner frame 13. When the upper bracket 1 and the lower bracket 2 are in synchronization, the second upper frame 23 on the lower bracket 2 is located between the inner positioning frame 17 and the clamping rod 82. When the lower cylinder 15 drives the upper inner frame 13 to descend, the clamping rod 82 is driven inward by the clamping cylinder 81, and the serrated clamping rod 82 passes through the serrated outer edge of the second upper frame 23 to clamp the lower sheet.

[0024] Combination Figure 6 , Figure 7 As shown, each group of lower push cylinders 15 may include at least one upper cylinder 151 and at least one lower cylinder 152. In this embodiment, two upper cylinders 151 and one lower cylinder 152 are respectively provided in the same group of lower push cylinders 15. The cylinder bodies of the upper cylinders 151 and the lower cylinders 152 in the same group of lower push cylinders 15 are connected as one body. The rod end of the piston rod of the upper cylinder 151 is connected to the upper outer frame 12, and the rod end of the piston rod of the lower cylinder 152 is connected to the upper inner frame 13. Through the cooperation of the upper cylinder 151 and the lower cylinder 152, the pushing stroke of the lower push cylinders 15 in the same group can be the sum of the upper pushing stroke of the upper cylinder 151 and the lower pushing stroke of the lower cylinder, which can meet the requirements of achieving a larger pushing stroke in a shorter installation distance, making the structure more compact and reducing the volume of the upper bracket.

[0025] Combination Figure 1 and Figure 2As shown, in the press machine 6, negative pressure suction holes (not shown in the figure) are respectively provided in the upper mold 61 and the lower mold 62, the upper mold 61 is equipped with a hydraulic cylinder 63, and the upper mold 61 is also provided with an ejection cylinder 64 that can eject the formed product downward, and the ejection cylinder 64 can push the upper and lower sheets from the upper mold 61 after being thermally formed and then demolded, eliminating manual operation. When the upper sheet located on the top surface of the upper bracket 1 is sent to the bottom of the upper mold 61 (at this time, the first clamp 7 and the second clamp 8 have released the reinforcing ribs and the lower sheet to the lower mold 62, or the upper and lower sheets can be sent into the upper and lower molds at the same time), the upper ejection cylinder 14 is started to push the upper sheet upward, and the clamping mechanism (not shown in the figure) outside the upper mold 61 clamps the upper sheet, and the upper ejection cylinder 14 is retracted and reset, and the upper sheet can be formed into a plurality of foot piers by suction molding in the upper mold 61, and at the same time, the upper bracket 1 as a whole exits the press machine along the upper guide rail 3 and returns to the initial position.

[0026] Furthermore, a product removal bracket 9 that can enter the press 6 and take out the product can be provided on the other side of the press 6 relative to the upper and lower extruders. The upper guide rail 3 continues to extend outward from the press 6 to form an outer extension section 31. The outer extension section 31 is mounted on the third frame 30, and the product removal bracket 9 is slidably connected to the outer extension section 31. After the product is formed, the upper mold 61 drives the formed product to rise, and the product removal bracket 9 moves to the bottom of the upper mold 61. The formed and demouldable product is pushed downward by the ejection cylinder 64, and the product falls on the product removal bracket 9. Then, the product removal bracket 9 is retracted to take out the formed product and enter the subsequent links, which has a higher degree of automation.

[0027] The present invention also discloses a production process for a one-step forming plastic pallet, which can be applied or implemented in the above production equipment, combined with Figure 1 The processing equipment shown comprises the following steps: (1) The upper sheet and the lower sheet extruded by the extruder are laid flat on the upper bracket 1 and the lower bracket 2 respectively, and the upper bracket 1 and the lower bracket 2 form two staggered layers; (2) The reinforcing rib bracket 5 located on one side of the upper bracket 1 pushes the reinforcing rib 53 to the bottom of the upper bracket, and the first clamp 7 in the upper bracket 1 clamps the reinforcing rib 53, and the reinforcing rib bracket 5 is withdrawn and reset; (3) After the upper bracket 1 with the reinforcing rib 53 and the lower bracket 2 are in position synchronization, the second clamp 8 in the upper bracket 1 moves downward, clamps the lower sheet and then rises. After clamping the reinforcing rib 53 and the lower sheet, the upper bracket 1 continues to move toward the press 6, and at the same time, the lower bracket 2 returns to its initial position. (4) The upper bracket 1 with the reinforcing rib 53 and the lower sheet is sent into the press 6, the upper sheet rises to the upper die 61 in the upper press, and the lower sheet and the reinforcing rib 53 are lowered and placed in the lower die 62 in the press 6; (5) The vacuum is started, and the upper sheet and the lower sheet are respectively formed by vacuum forming in the upper mold 61 and the lower mold 62, and then the upper bracket 1 exits the press 6, after which the upper and lower molds can begin to close, and the upper bracket 1 simultaneously continues to retreat to the initial position; (6) When the surface of the sheet is still softened, the upper mold 61 and the lower mold 62 of the press are closed to heat-seal the molded upper sheet with reinforcing ribs 53 embedded in the middle and the molded lower sheet. At the same time, high-pressure gas is blown into the mold cavity to make the upper and lower sheets close to the mold surface, cool and shape, and finally demold to obtain the molded product.

[0028] In the above step (6), after the cooling molding time is reached, the interlayer compressed gas is discharged, the mold is opened, and the product removal bracket 9 enters the press 6. After the molded product is ejected from the upper mold 61 and falls into the product removal bracket, the product removal bracket 9 retreats to the initial position, the worker inspects and trims the product, and the equipment enters the next cycle of production.

[0029] In step (1), the plastic raw material is plasticized by the screws of two extruders and extruded through the die to form an upper sheet and a lower sheet respectively. The upper bracket and the lower bracket may have a heat preservation and heat insulation function. The extruded sheet is laid flat on the upper bracket or the lower bracket as the upper bracket or the lower bracket slides, and the two extruders are located on the same side of the press.

[0030] In the above step (3), the upper bracket 1 and the lower bracket 2 with the reinforcing rib 53 can achieve position synchronization in a synchronization section C, that is, the upper bracket 1 after grasping the reinforcing rib 53 slides to the synchronization section C, and is opposite to the lower bracket 2 that slides to the synchronization section C. The upper bracket 1 with the reinforcing rib 53 grasps the lower sheet carried by the lower bracket 2, and then continues to move directly toward the press 6 and enters the press 6.

[0031] Compared with the prior art, the present invention saves the sum of the time t1 for the second upper frame 23 of the lower bracket 2 to return and the time t2 for the lower bracket 2 to withdraw outward (because the lower sheet can fall into the lower mold only after the lower bracket withdraws) in the press 6. The present invention synchronizes the upper and lower brackets to the synchronization section C outside the press first (the two extruders are on the same side and the upper and lower sheets do not conflict, and the lower sheet can arrive synchronously with the upper sheet). When the upper bracket 1 clamps the lower sheet, there is no need to wait for the lower bracket to withdraw, and the upper bracket can immediately move toward the press 6. By comparison, it is found that compared with the prior art, the present invention at least saves the time t1+t2 required to wait for the lower bracket to return and withdraw in the press, saves the waiting time required in the press, saves the operation time within the same stroke range, shortens the production cycle time, and improves production efficiency.

[0032] The above embodiments and drawings do not limit the product form and style of the present invention. Any appropriate changes or modifications made by ordinary technicians in the relevant technical field should be deemed to be within the patent scope of the present invention.

Claims

1. A production equipment for one-step forming plastic pallets, characterized by: The utility model comprises an upper bracket, a lower bracket, an upper guide rail, a lower guide rail, a reinforcing rib bracket and a press. An upper die and a lower die are arranged in the press and are opposite to each other up and down. The upper bracket and the lower bracket are used to receive the upper sheet and the lower sheet respectively and are located on the same side of the press at the same time. The upper bracket and the lower bracket are slidably connected to the upper guide rail and the lower guide rail respectively. The upper guide rail is arranged parallelly above the lower guide rail so that the upper bracket and the lower bracket form two staggered layers. The upper bracket and the lower bracket are opposite to each other up and down after synchronization. The upper bracket slides between the upper die and the lower die of the press along the upper guide rail. The reinforcing rib bracket is located on one side of the upper bracket and is equipped with a pushing component which pushes the reinforcing rib bracket under the upper bracket or withdraws it outward. A first clamp which can clamp the reinforcing rib to the bottom of the upper bracket is arranged in the upper bracket. A second clamp which can be raised and lowered is also arranged at the bottom of the upper bracket. After being lowered, the second clamp clamps the lower sheet under it and then rises back.

2. The one-step forming plastic pallet production equipment according to claim 1, characterized in that: The upper bracket is equipped with an upper extruder, and the lower bracket is equipped with a lower extruder. The screws of the upper extruder and the lower extruder plasticize and extrude the upper sheet and the lower sheet respectively through the die. After the upper sheet is extruded by the upper extruder, it passes through the upper bracket and is laid flat on the upper bracket when the upper guide rail slides. After the lower sheet is extruded by the lower extruder, it passes through the lower bracket and is laid flat on the lower bracket when the lower guide rail slides.

3. The one-step forming plastic pallet production equipment according to claim 1, characterized in that: The upper bracket includes an upper outer frame, an upper panel, an upper inner frame, multiple upper cylinders, and multiple groups of lower cylinders. The upper panel is located at the top of the upper outer frame. The bottom of the upper outer frame is provided with a slide groove that cooperates with the upper guide rail. The upper cylinder is arranged on the upper outer frame, and the rod end of the piston rod of the upper cylinder is connected to the upper panel. The lower cylinder is arranged at the bottom of the upper outer frame. The upper inner frame is located below the inner side of the upper outer frame. The lower cylinder is connected between the upper outer frame and the upper inner frame to push the upper inner frame down and then up. The first clamp and the second clamp are arranged on the upper inner frame.

4. The one-step forming plastic pallet production equipment according to claim 3, characterized in that: An upper inner plate is provided on the upper inner frame, and the first clamp includes a plurality of clamping manipulators provided at preset positions of the bottom of the upper inner plate corresponding to the reinforcing ribs; the second clamp includes at least one clamping cylinder provided in at least one group of opposite sides of the upper inner frame, and the cylinder bodies of the clamping cylinders are symmetrically fixed on the outer side surfaces of the upper inner frame, and the piston rods of each clamping cylinder pass through the upper inner frame and the rod ends of the piston rods are respectively connected to the outer ends of a clamping rod; the lower bracket includes a lower panel provided on a lower outer frame, and a second upper top frame is provided on the lower panel, and when the positions of the upper bracket and the lower bracket are synchronized, the clamping rod in the second clamp is located on the outer side of the second upper top frame.

5. The one-step forming plastic pallet production equipment according to claim 3, characterized in that: Each group of lower top cylinders includes at least one upper cylinder and at least one lower cylinder. The cylinder bodies of the upper cylinder and the lower cylinder in the same group of lower top cylinders are connected as a whole. The rod end of the piston rod of the upper cylinder is connected to the upper outer frame, and the rod end of the piston rod of the lower cylinder is connected to the upper inner frame.

6. The one-step forming plastic pallet production equipment according to claim 1, characterized in that: A middle guide rail is provided on the outer side of the upper guide rail, and the middle guide rail is located between the upper guide rail and the lower guide rail in terms of horizontal height. The reinforcement rib bracket includes a push plate slidably connected to the middle guide rail, and the pushing assembly is a cylinder push rod connected to the bottom of the push plate. The reinforcement rib is placed at a preset position above the push plate manually or by a robot.

7. The one-step forming plastic pallet production equipment according to claim 6, characterized in that: The upper bracket, the upper guide rail and the middle guide rail are arranged in the first frame, the lower bracket and the lower guide rail are arranged in the second frame, and a synchronization section is provided between the first frame and the press machine for synchronizing the positions of the upper bracket and the lower bracket after grabbing the reinforcement ribs. The upper bracket grabs the lower sheet in the synchronization section, the upper guide rail extends from the first frame to the synchronization section and then to the press, and the lower guide rail extends from the second frame to the first frame and then to the synchronization section.

8. A production process for a one-step formed plastic pallet, characterized in that: The following steps are involved: (1) The upper sheet and the lower sheet extruded by the extruder are laid flat on the upper bracket and the lower bracket respectively, and the upper bracket and the lower bracket form two staggered layers; (2) The reinforcing rib bracket located on one side of the upper bracket pushes the reinforcing rib to the bottom of the upper bracket, the first clamp in the upper bracket clamps the reinforcing rib, and the reinforcing rib bracket withdraws and resets; (3) After the upper bracket with the reinforcing ribs is clamped and the lower bracket is in position, the second clamp in the upper bracket descends, clamps the lower sheet and then rises. After clamping the reinforcing ribs and the lower sheet, the upper bracket continues to move toward the press, while the lower bracket returns to its initial position. (4) The upper bracket with the reinforcing ribs and the lower sheet is sent into the press, the upper sheet rises to the upper die in the upper press, and the lower sheet and the reinforcing ribs are lowered and placed in the lower die in the press; (5) Start the vacuum, the upper sheet and the lower sheet are formed by vacuum forming in the upper mold and the lower mold respectively, and the upper bracket exits the press and returns to the initial position; (6) The upper and lower molds of the press are closed, and the molded upper sheet with reinforcing ribs embedded in the middle and the molded lower sheet are heat-sealed. At the same time, high-pressure gas is blown into the mold cavity to make the upper and lower sheets close to the mold surface, and then cooled and molded. Finally, the molded product is demolded.

9. A production process for a one-step molded plastic pallet as claimed in claim 8, characterized in that: In step (6), after the cooling molding time is reached, the interlayer compressed gas is discharged, the mold is opened, and the product removal bracket enters the press. After the molded product is ejected from the upper mold and falls into the product removal bracket, the product removal bracket retreats to the initial position, the worker inspects and trims the product, and the equipment enters the next cycle of production.

10. The production process of a one-step molded plastic pallet according to claim 8, characterized in that: In step (1), the plastic raw material is plasticized by the screws of two extruders and extruded through the die to form an upper sheet and a lower sheet respectively, and the two extruders are located on the same side of the press.

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