Printing machine for plastic bag production

Abstract

The utility model relates to the field of plastic package processing machinery, in particular to a printing machine for producing plastic bags, which comprises a support base and four fixing frames, the printing machine is mounted in the middle of the support base, sliding grooves are arranged on the front and rear portions of the left and right sides of the support base, and the four fixing frames are slidably connected with the support base through the sliding grooves. A first motor is installed between one fixing frame and the other fixing frame on the same side, a movable frame is connected to the other fixing frame in a sliding mode, an output shaft of the first motor penetrates through the fixing frames and is connected with a rotating shaft, the rotating shaft is connected with the movable frame in a sliding mode, and an adjusting assembly for adjusting the heights of the fixing frames on the two sides is arranged on the front side of the supporting base. And through a second motor, a gear, racks, a connecting plate and a sliding groove, the second motor drives the gear to drive the racks on the two sides to move reversely, the unwinding end fixing frame ascends, the winding end fixing frame descends synchronously, the horizontal tension of the printing section plastic bag is kept in real time, the position consistency of printing patterns is guaranteed, and the printing quality is guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of plastic packaging processing machinery, and in particular to a printing machine for producing plastic bags. Background Technology

[0002] Plastic bags are lightweight, durable, and inexpensive plastic products widely used in the packaging industry, typically made of materials such as polyethylene and polypropylene. Printing is a crucial step in the production of plastic bags, used to print brand logos, product information, or decorative patterns on the bag's surface. This enhances the product's aesthetics and strengthens brand recognition and commercial value.

[0003] Currently, plastic bag printing machines typically employ continuous roll-to-roll printing. Their basic structure includes an unwinding device, a printing device, and a rewinding device. For example, a printing machine for PO plastic packaging bags, with publication number CN217021939U, releases the plastic film via an unwinding roller, prints the pattern using the printing mechanism, and then rewinds it using a rewinding roller. In similar devices, the plastic film maintains tension between the unwinding and rewinding rollers during the printing process to ensure printing accuracy and stability.

[0004] However, existing printing presses have certain drawbacks in actual operation: initially, the plastic film roll diameter on the unwind roller is relatively large, while the take-up roller diameter is relatively small; as printing progresses, the unwind roller diameter gradually decreases, while the take-up roller diameter continuously increases. This dynamic change causes fluctuations in the angle and tension of the plastic film as it passes through the printing device, thus affecting the positioning accuracy and clarity of the printed pattern. Furthermore, plastic film is quite sensitive to tension; uneven tension changes may cause the film to stretch and deform, further reducing print quality. Utility Model Content

[0005] To overcome the drawbacks of print quality caused by variations in roll diameter and tension fluctuations, this invention provides a printing machine for plastic bag production that offers stable print quality.

[0006] A printing machine for producing plastic bags includes a support base and fixed frames. The printing machine is mounted in the middle of the support base. Guide ramps are provided on both the left and right sides of the top of the support base. Sliding grooves are provided on the front and rear parts of both sides of the support base. Four fixed frames are slidably connected to the support base through the sliding grooves. Between two fixed frames on the same side, one is equipped with a first motor, and the other is slidably connected to a movable frame. The output shaft of the first motor passes through the fixed frame and is connected to a rotating shaft. The rotating shaft is slidably connected to the movable frame. An adjustment component for adjusting the height of the fixed frames on both sides is provided on the front side of the support base.

[0007] Furthermore, it is particularly preferred that the adjustment assembly includes a mounting plate, a gear, a connecting plate, a rack, and a second motor. The mounting plate is connected to the middle of the front side of the support base, and the second motor is mounted on the front side of the mounting plate. The two adjacent ends of the two front fixing brackets are each connected to a connecting plate, and the adjacent ends of the two connecting plates are each connected to a rack. The rear end of the mounting plate is rotatably connected to a gear, which is connected to the output shaft of the second motor and meshes with the rack.

[0008] Furthermore, it is particularly preferred that the device also includes a stop bar, and the bottom of the fixing frame on the same side of the left and right sides is connected to a base plate. The base plate has several limiting holes. The left and right ends of the stop bar are slidably connected to bolts. The bolts are interference-fitted with the limiting holes. The stop bar is engaged with the base plate through the bolts. The top of the stop bar is in contact with the rotating shaft.

[0009] Furthermore, it is particularly preferred that the base plate is provided with a plurality of identification cards, the positions of which correspond to the limiting holes.

[0010] Furthermore, it is particularly preferred that a plurality of ball bearings are rotatably connected to the top of the stop lever, and the ball bearings are in contact with the rotating shaft.

[0011] Furthermore, it is particularly preferred that a placement box is connected to the base plate.

[0012] Furthermore, it is particularly preferred that the fixed frame connected to the movable frame is provided with a magnet, the movable frame being a magnetic metal, and the magnet being used to magnetically attract the movable frame.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0014] 1. Through the second motor, gear, rack, connecting plate and slide, the second motor drives the gear to drive the rack on both sides to move in opposite directions, so that the unwinding end fixing frame rises and the rewinding end fixing frame descends synchronously, maintaining the horizontal tension of the plastic bag in the printing section in real time, ensuring the consistency of the printed pattern position and guaranteeing the printing quality.

[0015] 2. The stop bar, bolt, ball bearings and base plate are connected. The bolt bar is inserted into the preset limit hole to fix the stop bar. The ball bearings abut against the end face of the cardboard tube to form rolling support. The cardboard tube is centered and the rotational resistance is minimized to avoid printing ghosting caused by the lateral displacement of the plastic bag. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0017] Figure 2 This is a schematic diagram of the connection structure of the gear and rack of this utility model.

[0018] Figure 3 This is a schematic diagram showing the connection relationship between the rotating shaft and the movable frame of this utility model.

[0019] Figure 4 This is a schematic diagram showing the connection relationship between the stop bar and the bolt bar of this utility model.

[0020] The above-mentioned attached drawings include the following reference numerals: 1. Support base, 2. Printing machine, 3. Slide groove, 4. Fixing frame, 5. First motor, 6. Rotating shaft, 7. Movable frame, 8. Mounting plate, 9. Gear, 10. Connecting plate, 11. Rack, 12. Second motor, 13. Base plate, 14. Limiting hole, 15. Stop bar, 16. Bolt bar, 17. Identification card, 18. Ball bearing, 19. Placement box, 20. Magnet. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Example: A printing machine for producing plastic bags, such as Figures 1-4 As shown, the system includes a support base 1, a printing machine 2, a fixed frame 4, a first motor 5, a rotating shaft 6, a movable frame 7, and an adjustment assembly. The printing machine 2 is installed in the middle of the support base 1. Guide plates are provided on both the left and right sides of the top of the support base 1. Slide grooves 3 are opened on the front and back parts of both sides of the support base 1. The four fixed frames 4 are slidably connected to the support base 1 through the slide grooves 3. Between two fixed frames 4 on the same side, one is equipped with the first motor 5, and the other is slidably connected to the movable frame 7. The output shaft of the first motor 5 passes through the fixed frame 4 and is welded to the rotating shaft 6. The rotating shaft 6 is slidably connected to the movable frame 7. An adjustment assembly for adjusting the height of the fixed frames 4 on both sides is provided on the front side of the support base 1.

[0023] like Figure 1 and Figure 2As shown, the adjustment assembly includes a mounting plate 8, a gear 9, a connecting plate 10, a rack 11, and a second motor 12. The mounting plate 8 is fixedly connected to the center of the front side of the support base 1 by screws. The second motor 12 is mounted on the front side of the mounting plate 8. The rotational speed of the second motor 12 is much lower than that of the first motor 5, and the rotation direction of the second motor 12 is related to the unwinding and take-up directions. Connecting plates 10 are connected to adjacent ends of the two fixing frames 4 on the front of the left and right sides of the support base 1. The connecting plates 10 fit snugly against the support base 1, ensuring stable movement of the fixing frames 4. A rack 11 is connected to an adjacent end of each of the two connecting plates 10. A gear 9 is rotatably connected to the rear end of the mounting plate 8. The gear 9 is connected to the output shaft of the second motor 12, and meshes with the rack 11. With the gear 9 meshing with the racks 11 on both sides, the fixing frames 4 at the unwinding and take-up ends are at their initial height, with the unwinding end higher and the take-up end lower. After printing starts, when the diameter of the take-up roller increases, causing a change in film tension, the second motor 12 starts, driving the gear 9 to rotate. Gear 9 drives the racks 11 on both sides to move in opposite directions, one side rises and the other side falls. The linkage fixing frame 4 slides along the slide groove 3 through the connecting plate 10. The unwinding end fixing frame 4 slowly moves up to compensate for the decrease in roll diameter, and the winding end fixing frame 4 moves down synchronously to adapt to the increase in roll diameter.

[0024] like Figure 1 and Figure 4 As shown, it also includes a base plate 13, a stop bar 15, and a bolt 16. The bottom of the left and right fixed frames 4 on the same side are connected to the base plate 13. The base plate 13 has several limiting holes 14. The left and right ends of the stop bar 15 are slidably connected to the bolt 16. The bolt 16 is interference-fitted with the limiting holes 14. The stop bar 15 is engaged with the base plate 13 through the bolt 16. The top of the stop bar 15 contacts the rotating shaft 6. The worker takes out the bolt 16, pulls the stop bar 15 outward, puts in a plastic bag roll containing a cardboard tube, and inserts the bolt 16 into the corresponding limiting hole 14 according to the width of the cardboard tube. After the bolt 16 is inserted into the limiting hole 14, the stop bar 15 is locked onto the base plate 13 through the interference fit between the bolt 16 and the limiting hole 14, restricting the axial displacement of the cardboard tube. After printing is completed, the bolt 16 is pulled out and the finished roll is taken out.

[0025] like Figure 4 As shown, it also includes identification cards 17. Several identification cards 17 are set on the base plate 13, and the positions of the identification cards 17 correspond to the limiting holes 14. The identification cards 17 indicate the standard width of the cardboard tube corresponding to different limiting holes 14. The staff can quickly match the position of the stop bar 15 without measurement to ensure that the cardboard tube is installed in the center and to prevent the plastic bag roll from swinging off-center.

[0026] like Figure 4As shown, it also includes ball bearings 18. Several ball bearings 18 are rotatably connected to the top of the stop bar 15, and the ball bearings 18 are in contact with the rotating shaft 6. When the rotating shaft 6 drives the cardboard tube to rotate, the ball bearings 18 roll freely on the top of the stop bar 15, converting sliding friction into rolling friction, reducing wear on the end face of the rotating shaft 6, and reducing the motor load.

[0027] like Figure 1 As shown, it also includes a placement box 19. The placement box 19 is connected to the base plate 13 and is used to temporarily store small parts such as bolts 16 and tools to prevent parts from being lost. The box is located at the edge of the base plate 13 and does not affect the operation of the equipment when it is put in or taken out.

[0028] like Figure 3 As shown, it also includes a magnet 20. The fixed frame 4, to which the movable frame 7 is connected, is equipped with a magnet 20. The movable frame 7 is made of magnetic metal, and the magnet 20 is used to magnetically attract the movable frame 7. After the movable frame 7 is removed from the fixed frame 4, the plastic bag roll / cardboard tube is inserted into the rotating shaft 6. When the movable frame 7 returns to its original position, its metal part is attracted by the magnet 20 on the fixed frame 4, quickly positioning and fixing the other end of the rotating shaft 6. The magnetic attraction ensures that the movable frame 7 does not loosen during high-speed winding, while also facilitating one-handed operation and disassembly, improving roll changing efficiency.

[0029] In the initial stage of operation, the staff first determines the winding and unwinding direction based on the height of the two rotating shafts 6. Then, they remove the movable frame 7 and install the plastic bag roll. This involves pulling out the bolt 16 to disengage it from the limiting hole 14, removing the stop bar 15, and placing the plastic bag roll with the cardboard tube onto the rotating shaft 6. The movable frame 7 is then reset and automatically secured using the magnet 20. Following the instructions on the identification card 17, a suitable limiting hole 14 is selected, and the stop bar 15 is secured using the bolt 16. During the preparation stage, the plastic bag is routed around the printing machine 2 and fixed to the winding end. The position of the stop bar 15 is checked to ensure good contact between the ball bearing 18 and the rotating shaft 6.

[0030] During operation, the take-up motor and printing press 2 are started first. The second motor 12 of the adjustment assembly then begins operation. The second motor 12 drives the rack 11 via gear 9. The rack 11, through the connecting plate 10, drives the two side mounting frames 4 to move in opposite directions. The unwinding end rises as the roll diameter decreases, while the take-up end descends synchronously. This automatic adjustment process maintains the ideal angle for the plastic bag as it passes through the printing press 2. During this process, the stop bar 15 continuously supports the rotating shaft 6 via ball bearings 18 to prevent vibration, and the magnet 20 keeps the movable frame 7 stable. The entire system maintains constant printing tension.

[0031] After printing is completed, the second motor 12 and the first motor 5 are turned off, the bolt 16 is removed, the stop bar 15 is taken off, the finished roll material is removed, and then the take-up and unwind positions are changed, the printing direction of the printing press 2 is adjusted, and continuous printing is completed. By using the up-and-down moving take-up and unwind components, the tension fluctuation and printing offset problems caused by changes in roll diameter in traditional printing press 2 are effectively solved, ensuring both printing accuracy and improving operating efficiency.

[0032] The above embodiments are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Therefore, all equivalent changes made based on the content described in the claims of the present utility model should be included within the scope of the claims of the present utility model.

Claims

1. A printing machine for plastic bag production, characterized in that, The utility model provides a printing machine, including support base (1) and fixed frame (4), the support base (1) middle installation has the printing machine (2), the support base (1) top both sides are provided with the guide material inclined plate, the support base (1) left and right sides both sides are opened the sliding slot (3), four fixed frame (4) are connected through the sliding slot (3) with the support base (1) sliding, and between the same side two fixed frame (4), one is installed first motor (5), and the other sliding connection has movable frame (7), the output shaft of first motor (5) passes through fixed frame (4) and is connected with the pivot (6), the pivot (6) is connected with movable frame (7) sliding, the support base (1) front side is provided with the adjusting assembly of adjusting both sides fixed frame (4) height.

2. A printing machine for the production of plastic bags as claimed in claim 1, characterized in that Adjusting assembly includes mounting plate (8), gear (9), connecting plate (10), rack (11) and second motor (12), the support base (1) front side middle part is connected with mounting plate (8), the mounting plate (8) front side is installed with second motor (12), and the adjacent end of both front fixed frame (4) is connected with connecting plate (10), and the adjacent end of both connecting plate (10) is connected with rack (11), the rear end of mounting plate (8) is rotatably connected with gear (9), the output shaft of second motor (12) is connected with gear (9), and gear (9) is engaged with rack (11).

3. A printing machine for the production of plastic bags as claimed in claim 2, characterized in that It further includes a stop rod (15), and the bottom of the same side of the left and right fixed frame (4) is connected with a bottom plate (13), a plurality of limiting holes (14) are formed in the bottom plate (13), a bolt rod (16) is slidably connected to the left and right ends of the stop rod (15), the bolt rod (16) is in interference fit with the limiting hole (14), the stop rod (15) is clamped and matched with the bottom plate (13) through the bolt rod (16), and the top of the stop rod (15) is in contact with the pivot (6).

4. A printing machine for the production of plastic bags as claimed in claim 3, characterized in that, A plurality of identification cards (17) are arranged on the bottom plate (13), and the positions of the identification cards (17) correspond to the positions of the limiting holes (14).

5. A printing machine for the production of plastic bags as claimed in claim 4, characterized in that A plurality of ball bearings (18) are rotatably connected to the top of the stop rod (15), and the ball bearings (18) are in contact with the pivot (6).

6. A printing machine for the production of plastic bags as claimed in claim 5, characterized in that, A placing box (19) is connected to the bottom plate (13).

7. A printing machine for the production of plastic bags as claimed in claim 6, characterized in that the connection A magnet (20) is arranged on the fixed frame (4) with the movable frame (7), the movable frame (7) is made of a magnetically attracted metal, and the magnet (20) is used for magnetically attracting the movable frame (7). A magnet (20) is arranged on the fixed frame (4) with the movable frame (7), the movable frame (7) is made of a magnetically attracted metal, and the magnet (20) is used for magnetically attracting the movable frame (7).

Images