Injection mold of paper-plastic box

Abstract

The invention provides an injection mold of a paper-plastic box, and belongs to the technical field of injection molds. The injection mold of the paper-plastic box comprises an automatic feeding mechanism and an injection molding mechanism, the injection molding mechanism comprises a movable mold, a fixed mold, a mounting plate and a bottom plate, the automatic feeding mechanism comprises a connecting arm fixed to the side face of the fixed mold, a storage frame, a feeding air cylinder, a suction air pump and a supporting plate used for containing paperboards, and the storage frame is fixedly connected with the fixed mold through the connecting arm; a plurality of vertically-arranged guide columns are fixed in the material storage frame, the guide columns are sleeved with the supporting plate, the guide columns are sleeved with supporting springs abutting against the lower end of the supporting plate, the feeding air cylinder is fixed to the upper end of the material storage frame, a feeding base is fixed to the front end of a telescopic rod of the feeding air cylinder, and the material suction air pump is fixed to the feeding base. A suction nozzle connected with a suction air pump is arranged on the lower end face of the feeding base. The injection molding mechanism integrates paperboard bending and plastic frame injection molding, the paperboard is accurately positioned on the fixed mold, integrated injection molding is achieved, and the production efficiency is high.

Description

Technical Field

[0001] The invention belongs to the technical field of injection molds and relates to an injection mold for a paper-plastic box. Background Art

[0002] Disposable paper lunch boxes can be used in restaurants, canteens, street snacks, food packaging lunch boxes, fruit and vegetable boxes, and hotel business supplies, etc. They are very convenient to use, highly degradable, and will not damage the environment. At present, this type of paper lunch box is usually made by folding it and then gluing, snapping or stapler nails. The paper boxes made in this way have many process flows and poor sealing, and cannot be used to hold soup liquids. Paper plastic boxes are born for this reason. Paper plastic boxes have low production costs and are suitable for large-scale production. The production process is simple. The paper and paper are connected by an injection-molded plastic frame, and the sealing is good, so they can hold soup liquids. In the mold cavity of the injection mold, first put the pre-cut cardboard with creases, and fold the cardboard naturally when closing the mold. The current mold cannot quickly and accurately position the cardboard, so it is urgent to develop an injection mold that can quickly and accurately position the cardboard. Summary of the invention

[0003] The purpose of the present invention is to solve the above problems in the existing technology and propose an injection mold for a paper-plastic box, which has an automatic feeding mechanism, accurately positions the paperboard on the fixed mold, and performs integrated injection molding with high production efficiency.

[0004] The purpose of the present invention can be achieved by the following technical solutions: an injection mold for a paper-plastic box, comprising an automatic feeding mechanism and an injection molding mechanism, characterized in that the injection molding mechanism comprises a movable mold, a fixed mold, a mounting plate and a bottom plate, the mounting plate is fixed on the bottom plate, the fixed mold is fixed on the mounting plate, the fixed mold has a convex molding part, the movable mold has a molding cavity matching the molding part, a lifting plate sliding up and down is embedded on the mounting plate, a discharge cylinder driving the lifting plate to move up and down is fixed on the bottom plate, a discharge groove is opened on the upper end surface of the fixed mold, a discharge ring is arranged in the discharge groove, and the discharge ring passes through The unloading rod is fixed to the lifting plate; the automatic feeding mechanism includes a connecting arm fixed to the side of the fixed mold, a storage frame, a feeding cylinder, a suction air pump and a support plate for placing cardboard. The storage frame is fixedly connected to the fixed mold through the connecting arm, and a plurality of vertically arranged guide columns are fixed in the storage frame. The support plate is sleeved on the guide columns, and the guide columns are sleeved with a supporting spring that abuts against the lower end of the support plate. The feeding cylinder is fixed to the upper end of the storage frame, and a feeding seat is fixed to the front end of the telescopic rod of the feeding cylinder. The suction air pump is fixed on the feeding seat, and a suction nozzle connected to the suction air pump is provided on the lower end surface of the feeding seat.

[0005] The injection molding machine drives the movable mold to move upward, starts the feeding cylinder, moves the feeding seat horizontally to the top of the support plate, starts the suction air pump, and adsorbs the cardboard on the support plate. After adsorption, the feeding cylinder continues to move horizontally to the top of the fixed mold, turns off the suction air pump, and the cardboard falls on the predetermined position of the fixed mold. The movable mold and the fixed mold are combined to bend the cardboard into a bowl-shaped box, and the plastic raw material is injected into the molding cavity to fill the connecting seam of the box. After cooling and shaping, the production of the paper-plastic box is completed.

[0006] Furthermore, a clamping assembly for clamping the cardboard is provided on the material storage frame, and the clamping assembly includes a freely sliding horizontal axis horizontally penetrated through the four side panels of the material storage frame, a limit spring is sleeved on the horizontal axis and abuts against the side panel, a vertically arranged limit vertical plate is fixed to the inner end of the horizontal axis, the limit vertical plate abuts against the side surface of the cardboard, one end of the limit spring abuts against the limit vertical plate, and a stop block is fixed to the outer end of the horizontal axis.

[0007] Under the action of the limit spring, the limit vertical plates in four directions move closer to the center of the storage frame to limit the cardboard and prevent it from accidentally moving horizontally.

[0008] Furthermore, the support plate is in an X shape. The four side ends of the support plate are sleeved on the guide pillars, and the lateral movement of the limiting vertical plate will not affect the lifting and lowering of the support plate.

[0009] Furthermore, pressing pieces for pressing the cardboard are fixed on the upper ends of the limit vertical plates on both sides of the suction air pump.

[0010] Furthermore, the forming part is in the shape of a square cone, an upper annular forming groove is opened on the upper edge of the forming part, an annular lower forming groove is opened on the lower edge of the forming part, the inner edge of the unloading ring abuts against the lower forming groove, and four straight grooves for forming connecting rods are connected between the upper forming groove and the lower forming groove.

[0011] Furthermore, a first air blowing pipeline and a second air blowing pipeline are provided in the movable mold, a groove is provided at the bottom of the molding cavity of the movable mold, an insert is fixed in the groove, the groove and the side of the insert have air outlet gaps connected to the molding cavity, a plurality of air outlet grooves connected to the air outlet gaps are provided at the bottom of the insert, the outlet of the first air blowing pipeline is connected to the air outlet grooves, and the inlet of the first air blowing pipeline is located on the side of the movable mold; the outlet of the second air blowing pipeline is connected to the bottom of the molding cavity, and the inlet of the second air blowing pipeline is located on the side of the movable mold.

[0012] The first air blowing pipeline and the second air blowing pipeline are connected to an external jet pump. When the mold needs to be opened after the injection molding is completed, the jet pump is turned on. After the air is discharged from the first air blowing pipeline, high-pressure gas is generated between the paper-plastic box and the movable mold, which can loosen the inner wall of the paper-plastic box and the molding cavity. Then the second air blowing pipeline blows the paper-plastic box down to separate the paper-plastic box from the molding cavity, and finally the paper-plastic box remains on the fixed mold.

[0013] Furthermore, an air suction pipeline is provided in the fixed mold, the air suction port of the air suction pipeline is located on the upper end surface of the forming part, and the connection port of the air suction pipeline is located on the side of the fixed mold. The connection port is connected to an external air pump. When the paperboard is sent to the fixed mold by the automatic feeding mechanism, the air suction pump is turned on to firmly adsorb the paperboard on the forming part.

[0014] Furthermore, a plurality of needle valves are fixed on the mounting plate, the front end of the needle valve extends into the fixed mold and is connected to the lower molding groove, and a hot runner module connected to the needle valve is fixed on the bottom plate. A feed pipe for conveying molten plastic raw materials is connected to the hot runner module, the hot runner module is connected to the needle valve, and the high-pressure pump squeezes the plastic raw materials into the hot runner module, and then enters the needle valve through the hot runner module. The hot runner module is a conventional mold accessory, and the plastic raw materials are conveyed to each needle valve through the runner branch in the hot runner module.

[0015] Compared with the prior art, the injection mold of the paper-plastic box has the following advantages:

[0016] 1. The injection mold has its own automatic feeding mechanism, which does not require manual placement of cardboard, which improves safety and greatly improves the degree of automation.

[0017] 2. The injection molding mechanism integrates the bending cardboard and the injection-molded plastic frame. The cardboards are connected together through the injection-molded plastic frame, and the sealing effect is good, which enhances the compressive strength and anti-deformation ability of the box.

[0018] 3. Convenient material withdrawal. The first and second air blowing pipelines are set in the movable mold to blow the paper-plastic box out of the molding cavity, and then the paper-plastic box is pushed out of the molding part through the unloading ring.

[0019] 4. A plastic buckle joint is formed on the upper edge of the paper-plastic box to facilitate buckling with the box cover.

[0020] 5. Integrated injection molding presses the cardboard into the molding cavity, which simplifies the production process of paper-plastic boxes and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the injection mold of the paper plastic box.

[0022] Figure 2 It is a structural diagram of the injection molding mechanism.

[0023] Figure 3 It is a cross-sectional view of the injection molding mechanism.

[0024] Figure 4 It is a schematic diagram of the structure after the fixed mold is installed.

[0025] Figure 5 It is a structural diagram of the moving mold.

[0026] Figure 6 It is a cross-sectional view of the movable mold.

[0027] Figure 7 It is a schematic diagram of the structure of the insert.

[0028] Figure 8 It is a cross-sectional view of the fixed mold.

[0029] Fig. 9 This is the assembly drawing of the mounting plate.

[0030] Fig.10 It is a top view structural diagram of the automatic feeding mechanism.

[0031] Fig.11 It is a three-dimensional structural diagram of the automatic feeding mechanism.

[0032] Fig.12 This is the product picture of the paper-plastic box.

[0033] Fig.13 It is a schematic diagram of the plastic frame structure of the paper-plastic box.

[0034] Fig.14 It is a schematic diagram of the structure of cardboard.

[0035] In the figure, 1, movable mold; 101, molding cavity; 102, first blowing pipeline; 103, second blowing pipeline; 104, insert; 105, air outlet slit; 106, air outlet groove; 2, fixed mold; 201, molding part; 202, upper molding groove; 203, lower molding groove; 204, straight groove; 205, suction pipeline; 3, mounting plate; 301, needle valve; 302, hot runner module; 4, bottom plate; 5, lifting plate; 6, unloading cylinder; 7. Discharge ring; 8. Discharge rod; 9. Connecting arm; 10. Storage frame; 11. Loading cylinder; 12. Suction air pump; 13. Support plate; 14. Guide column; 15. Support spring; 16. Feed seat; 17. Horizontal axis; 18. Limit spring; 19. Limit vertical plate; 20. Stopper; 21. Pressing sheet; 22. Paper-plastic box; 221. Paperboard; 222. Plastic frame; 223. Anti-cut edge; 224. Connecting rod; 225. Bottom edge. DETAILED DESCRIPTION

[0036] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0037] The injection molded product of this embodiment is as follows Fig.12 , Fig.13 , Fig.14As shown, the paper-plastic box 22 is composed of a cardboard 221 and a plastic frame 222. The cardboard 221 is folded along the crease to form a bowl-shaped box. The plastic frame 222 connects the cardboards 221 together and forms a ring-shaped anti-cut edge 223 on the upper edge. The plastic frame 222 includes the anti-cut edge 223, a connecting rod 224 and a bottom edge 25. The connecting rod 224 connects the anti-cut edge 223 and the bottom edge 25.

[0038] like Figure 1-3 As shown, the injection mold of the paper-plastic box includes an automatic feeding mechanism and an injection mechanism, and the injection mechanism includes a movable mold 1, a fixed mold 2, a mounting plate 3 and a bottom plate 4, the mounting plate 3 is fixed on the bottom plate 4, the fixed mold 2 is fixed on the mounting plate 3, the fixed mold 2 has a raised molding portion 201, the movable mold 1 is provided with a molding cavity 101 matching the molding portion 201, a lifting plate 5 that slides up and down is embedded on the mounting plate 3, a discharge cylinder 6 that drives the lifting plate 5 to move up and down is fixed on the bottom plate 4, a discharge groove is provided on the upper end surface of the fixed mold 2, a discharge ring 7 is provided in the discharge groove, and the discharge ring 7 is fixed to the lifting plate 5 through a discharge rod 8.

[0039] like Figure 4 As shown, the forming portion 201 is in the shape of a square cone, an upper annular forming groove 202 is formed on the upper edge of the forming portion 201, an annular lower forming groove 203 is formed on the lower edge of the forming portion 201, the inner edge of the unloading ring 7 abuts against the lower forming groove 203, and four straight grooves 204 for forming connecting rods 224 are connected between the upper forming groove 202 and the lower forming groove 203.

[0040] like Figure 5-7 As shown, the movable mold 1 is provided with a first air blowing pipeline 102 and a second air blowing pipeline 103, the bottom of the molding cavity 101 of the movable mold 1 is provided with an embedding groove, an insert 104 is fixed in the embedding groove, the sides of the embedding groove and the insert 104 are provided with an air outlet slit 105 connected to the molding cavity 101, the bottom of the insert 104 is provided with a plurality of air outlet grooves 106 connected to the air outlet slit 105, the outlet of the first air blowing pipeline 102 is connected to the air outlet grooves 106, and the inlet of the first air blowing pipeline 102 is located on the side of the movable mold 1; the outlet of the second air blowing pipeline 103 is connected to the bottom of the molding cavity 101, and the inlet of the second air blowing pipeline 103 is located on the side of the movable mold 1.

[0041] The first air blowing pipeline 102 and the second air blowing pipeline 103 are connected to an external jet pump. When the mold needs to be opened after the injection molding is completed, the jet pump is turned on. After the first air blowing pipeline 102 exhausts air, high-pressure gas is generated between the paper molding box 22 and the movable mold 1, which can loosen the inner wall of the paper molding box 22 and the molding cavity 101. Then the second air blowing pipeline 103 blows the paper molding box 22 off to separate the paper molding box 22 from the molding cavity 101, and finally the paper molding box 22 remains on the fixed mold 2.

[0042] like Figure 8-9As shown, the fixed mold 2 is provided with an air suction pipeline 205, the air suction port of the air suction pipeline 205 is located at the upper end surface of the forming part 201, and the connection port of the air suction pipeline 205 is located at the side of the fixed mold 2. The connection port is connected to an external air pump, and when the paperboard 221 is sent to the fixed mold 2 by the automatic feeding mechanism, the air suction pump is turned on to firmly adsorb the paperboard 221 on the forming part 201.

[0043] A plurality of needle valves 301 are fixed on the mounting plate 3, the front end of the needle valve 301 extends into the fixed mold 2 and is connected to the lower molding groove 203, and a hot runner module 302 connected to the needle valve 301 is fixed on the bottom plate 4. A feed pipe for conveying molten plastic raw materials is connected to the hot runner module 302, and the hot runner module 302 is connected to the needle valve 301. The high-pressure pump squeezes the plastic raw materials into the hot runner module 302, and then enters the needle valve 301 through the hot runner module 302. The hot runner module 302 is a conventional mold accessory, and the plastic raw materials are conveyed to each needle valve 301 through the runner branch in the hot runner module 302.

[0044] like Figure 10-11 As shown, the automatic feeding mechanism includes a connecting arm 9 fixed to the side of the fixed mold 2, a storage frame 10, a feeding cylinder 11, a suction air pump 12 and a support plate 13 for placing the cardboard 221. The storage frame 10 is fixedly connected to the fixed mold 2 through the connecting arm 9. A plurality of vertically arranged guide columns 14 are fixed in the storage frame 10. The support plate 13 is sleeved on the guide column 14. The guide column 14 is sleeved with a support spring 15 that abuts against the lower end of the support plate 13. The feeding cylinder 11 is fixed to the upper end of the storage frame 10. A feeding seat 16 is fixed to the front end of the telescopic rod of the feeding cylinder 11. The suction air pump 12 is fixed on the feeding seat 16. A suction nozzle connected to the suction air pump 12 is provided on the lower end surface of the feeding seat 16.

[0045] The injection molding machine drives the movable mold 1 to move upward, starts the feeding cylinder 11, and translates the feeding seat 16 to the top of the support plate 13. The suction air pump 12 is started to adsorb the cardboard 221 on the support plate 13. After adsorption, the feeding cylinder 11 continues to translate to the top of the fixed mold 2, and the suction air pump 12 is closed. The cardboard 221 falls on the predetermined position of the fixed mold 2. The movable mold 1 is molded with the fixed mold 2, and the cardboard 221 is bent into a bowl-shaped box. The plastic raw material is injected into the molding cavity 101 to fill the connecting seam of the box. After cooling and shaping, the production of the paper-plastic box 22 is completed.

[0046] A clamping assembly for clamping a cardboard 221 is provided on the material storage frame 10, and the clamping assembly includes a freely sliding horizontal axis 17 horizontally penetrated through the four side panels of the material storage frame 10, and a limit spring 18 is sleeved on the horizontal axis 17 and abuts against the side panel, a vertically arranged limit vertical plate 19 is fixed to the inner end of the horizontal axis 17, the limit vertical plate 19 abuts against the side of the cardboard 221, one end of the limit spring 18 abuts against the limit vertical plate 19, and a stopper 20 is fixed to the outer end of the horizontal axis 17.

[0047] Under the action of the limiting spring 18 , the limiting vertical plates 19 in four directions move toward the center of the material storage frame 10 to limit the cardboard 221 to prevent the cardboard 221 from accidentally moving horizontally.

[0048] The support plate 13 is X-shaped, and the four edges of the support plate 13 are sleeved on the guide column 14, and the lateral movement of the limit vertical plate 19 will not affect the lifting of the support plate 13. The upper ends of the limit vertical plates 19 on both sides of the suction air pump 12 are fixed with pressing sheets 21 that press the cardboard 221.

[0049] Working process: the pre-made cardboard 221 is stacked on the support plate 13, and the limiting vertical plates 19 around it limit the cardboard 221. Under the action of the supporting spring 15, the cardboard 221 is pressed against the pressing sheet 21. In the mold opening state, the feeding cylinder 11 is started, and the feeding seat 16 is translated to the top of the support plate 13. The suction air pump 12 is turned on to suck the top cardboard 221, and then the feeding cylinder 11 continues to drive the telescopic rod forward to transfer the cardboard 221 to the top of the fixed mold 2, and then the cardboard 221 is placed on the forming part 201, and the vacuum pump is turned on to firmly adsorb the cardboard 221 on the fixed mold 2, and the telescopic rod of the feeding cylinder 11 is retracted. The injection molding machine is turned on, and the movable mold 1 and the fixed mold 2 are attached. The paperboard 221 is pressed into a box shape in the mold. Then, the plastic raw material is injected into the molding cavity 101. After the upper molding groove 202, the lower molding groove 203, and the straight groove 204 are filled, the jet pump is turned on after cooling, and the paper-molded box 22 is separated from the movable mold 1 through the first blowing pipeline 102 and the second blowing pipeline 103, and finally the mold is opened. The unloading cylinder 6 is started to drive the lifting plate 5 to rise, and the unloading ring 7 is driven to lift the paper-molded box 22. At this time, the paper-molded box 22 can be easily taken out of the mold.

[0050] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. An injection mold for a paper-plastic box, comprising an automatic feeding mechanism and an injection mechanism, characterized in that: The injection molding mechanism comprises a movable mold (1), a fixed mold (2), a mounting plate (3) and a bottom plate (4); the mounting plate (3) is fixed on the bottom plate (4); the fixed mold (2) is fixed on the mounting plate (3); the fixed mold (2) has a protruding molding portion (201); the movable mold (1) has a molding cavity (101) matching the molding portion (201); a lifting plate (5) sliding up and down is embedded on the mounting plate (3); a discharge cylinder (6) driving the lifting plate (5) to move up and down is fixed on the bottom plate (4); a discharge groove is formed on the upper end surface of the fixed mold (2); a discharge ring (7) is provided in the discharge groove; the discharge ring (7) is fixed to the lifting plate (5) through a discharge rod (8); the automatic feeding mechanism comprises a connecting arm (9) fixed to the side of the fixed mold (2); A material storage frame (10), a feeding cylinder (11), a material suction air pump (12) and a support plate (13) for placing paperboards (221); the material storage frame (10) is fixedly connected to a fixed mold (2) through a connecting arm (9); a plurality of vertically arranged guide columns (14) are fixed in the material storage frame (10); the support plate (13) is sleeved on the guide columns (14); a support spring (15) is sleeved on the guide columns (14) and abuts against the lower end of the support plate (13); the feeding cylinder (11) is fixed to the upper end of the material storage frame (10); a feeding seat (16) is fixed at the front end of the telescopic rod of the feeding cylinder (11); the material suction air pump (12) is fixed on the feeding seat (16); and a suction nozzle connected to the material suction air pump (12) is provided on the lower end surface of the feeding seat (16).

2. The injection mold for a paper-plastic box according to claim 1, characterized in that: A clamping assembly for clamping a paperboard (221) is provided on the material storage frame (10), and the clamping assembly comprises a freely sliding horizontal shaft (17) horizontally penetrated through four side plates of the material storage frame (10), a limit spring (18) abutting against the side plate is sleeved on the horizontal shaft (17), a vertically arranged limit vertical plate (19) is fixed to the inner end of the horizontal shaft (17), the limit vertical plate (19) abuts against the side surface of the paperboard (221), one end of the limit spring (18) abuts against the limit vertical plate (19), and a stopper (20) is fixed to the outer end of the horizontal shaft (17).

3. The injection mold for a paper-plastic box according to claim 2, characterized in that: The support plate (13) is X-shaped.

4. The injection mold for a paper-plastic box according to claim 3, characterized in that: A pressing sheet (21) for pressing the paperboard (221) is fixed to the upper ends of the limiting vertical plates (19) on both sides of the suction air pump (12).

5. The injection mold for a paper-plastic box according to claim 1, characterized in that: The forming part (201) is in the shape of a square cone, an upper annular forming groove (202) is formed on the upper edge of the forming part (201), an annular lower forming groove (203) is formed on the lower edge of the forming part (201), the inner edge of the discharge ring (7) abuts against the lower forming groove (203), and four straight grooves (204) for forming connecting rods (224) are connected between the upper forming groove (202) and the lower forming groove (203).

6. The injection mold for a paper-plastic box according to claim 5, characterized in that: The movable mold (1) is provided with a first air blowing pipeline (102) and a second air blowing pipeline (103); the bottom of the molding cavity (101) of the movable mold (1) is provided with an embedding groove, an insert (104) is fixed in the embedding groove, the sides of the embedding groove and the insert (104) are provided with an air outlet slit (105) connected to the molding cavity (101), the bottom of the insert (104) is provided with a plurality of air outlet grooves (106) connected to the air outlet slits (105), the outlet of the first air blowing pipeline (102) is connected to the air outlet grooves (106), and the inlet of the first air blowing pipeline (102) is located on the side of the movable mold (1); the outlet of the second air blowing pipeline (103) is connected to the bottom of the molding cavity (101), and the inlet of the second air blowing pipeline (103) is located on the side of the movable mold (1).

7. The injection mold for a paper-plastic box according to claim 6, characterized in that: An air suction pipeline (205) is provided in the fixed mold (2), the air suction port of the air suction pipeline (205) is located on the upper end surface of the molding part (201), and the connection port of the air suction pipeline (205) is located on the side of the fixed mold (2).

8. The injection mold for a paper-plastic box according to claim 7, characterized in that: A plurality of needle valves (301) are fixed on the mounting plate (3), the front ends of the needle valves (301) extend into the fixed mold (2) and are connected to the lower molding groove (203), and a hot runner module (302) connected to the needle valves (301) is fixed on the bottom plate (4).

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