Polyethylene plastic bag blow molding equipment

Abstract

The utility model relates to the technical field of polyethylene plastic bag production, in particular to polyethylene plastic bag blow molding equipment. Comprising a melting part, a blow molding part is arranged at the outlet end of the melting part, a cooling assembly is arranged in a support above the blow molding part, two clamping rollers are rotationally connected in the upper end of the support, an upper guide roller is rotationally connected to one side of the upper end of the support, a lower guide roller is rotationally connected to the outer side of the support below the upper guide roller, and a winding roller is rotationally connected to the support below the lower guide roller. And by arranging the cup cylinder, after the film body discharged from the annular groove is stretched, the film body part close to the die head can be effectively prevented from being adhered under the blocking effect of the cup cylinder, and the quality of the plastic bag can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of polyethylene plastic bag production, in particular to polyethylene plastic bag blow molding equipment. Background Art

[0002] High barrier low-density polyethylene plastic bags are manufactured by film blowing machines, which heat and melt plastic particles and then blow them into thin films. The film blowing machine heats the raw materials into a molten state and extrude them through an extrusion mechanism, blows out film bubbles through the film blowing mechanism, and the film bubbles are stretched and cooled in the traction mechanism to obtain a film, which is finally rolled up through a winding mechanism.

[0003] The patent document with application number CN202322501656.9 discloses a film blowing machine for plastic bag production. When in use, plastic particles enter the melting part and are melted. The melted plastic particles are blown into a film body by the blowing part. After the film body is cooled by the air ring, it is pressed by the bubble pressing roller, and then guided by the guide roller to enter between the first cleaning rollers. After being stretched and cleaned by the first cleaning roller, it enters the cleaning frame and is finally rolled up by the film collection roller. However, after the film body is discharged from the blowing part, due to the high temperature and low strength of the film body, the air ring is directly used to cool the film body. The wind discharged from the air ring is likely to cause perforation of the film body, which is likely to increase the defective rate of plastic bags.

[0004] The patent document with application number 202220263185.5 discloses a blow molding machine used in the production of plastic bags. When working, the spiral feeding mechanism uses a gradually narrowing cavity to extrude the material, and uses the friction generated during the material conveying process to generate a certain amount of heat. When the material is input into the hot melt film blowing unit, the material is melted by the hot melt mechanism inside the hot melt film blowing unit at high temperature, and the film is blown through the film blowing mechanism. The blown film is cylindrical under the action of inflation, passes through the limit frame under the traction of the staff, and is flattened by the flattening guide roller group, and then passes around the guide roller on the guide roller mounting frame and is rolled up by the reel roller. After the film body is discharged from the film blowing mechanism, the film body part above the film blowing mechanism will shrink during the process of stretching the film body. When the film body above the film blowing mechanism shrinks, due to the high temperature of the film body, part of the film body is prone to adhesion. Under the action of the wind entering the film body, the adhesion of the film body part will cause the adhesion of the film body part to deform during the separation process, resulting in uneven film thickness and affecting the quality of the plastic bag. At the same time, the film body after adhesion may cause uneven air volume entering the film body, which in turn causes deformation of the film body. When producing small-diameter plastic bags, the film body is particularly prone to adhesion due to the small diameter of the film blowing mechanism. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a polyethylene plastic bag blow molding device which can prevent the film body from sticking and can avoid the film body from being perforated during the production process.

[0006] The polyethylene plastic bag blow molding equipment comprises a melting part, a blowing part is arranged at the outlet end of the melting part, the blowing part is located in a bracket, a cooling component is arranged in the bracket above the blowing part, two clamping rollers are rotatably connected in the upper end of the bracket, an upper guide roller is rotatably connected to one side of the upper end of the bracket, a lower guide roller is rotatably connected to the outer side of the bracket below the upper guide roller, and a winding roller is rotatably connected to the bracket below the lower guide roller, and is characterized in that the blowing part comprises a fixed cylinder fixed on the melting part, a through hole connected to the outlet end of the melting part is opened on the side wall of the fixed cylinder, an overflow hole connected to the outside is opened on the side wall of the fixed cylinder, an annular die head is fixed on the upper end of the fixed cylinder, an annular cavity is opened in the die head, the annular cavity is connected to the through hole, an annular groove is opened on the inner side of the die head, the annular groove is connected to the annular cavity, a blowing component is concentrically arranged on the inner side of the die head, a cup cylinder is detachably and fixedly connected to the upper end of the blowing component, and the cup cylinder is concentric with the die head.

[0007] Specifically, the blowing assembly includes an air inlet pipe fixed in a fixed cylinder, an air inlet end of the air inlet pipe is fixedly connected to a bell mouth, a fixing rod is fixed in the bell mouth, and the fixing rod is detachably fixedly connected to the cup cylinder.

[0008] Specifically, the cup tube includes a straight tube portion at the upper end, a conical tube portion is coaxially fixedly connected below the straight tube portion, the lower end of the straight tube portion and the upper end of the conical tube portion are in an arc transition, a support rod is coaxially fixed to the lower end of the conical tube portion, and the support rod is threadedly connected to the fixing rod.

[0009] Specifically, the cooling assembly includes a cylinder body, which is fixed in the bracket. The cylinder body is concentric with the blow molding part. An annular cavity is opened in the cylinder wall of the cylinder body. A spacer ring is fixed in the annular cavity. The annular cavity above the spacer ring is an air cavity, and the annular cavity below the spacer ring is a liquid cavity. A plurality of air holes are opened on the inner wall of the cylinder above the spacer ring, and the air holes are connected with the air cavity. An air inlet pipe is fixed on the outside of the cylinder, and the air inlet pipe is connected with the air cavity. A water inlet pipe and a water outlet pipe are fixed on the outside of the cylinder, and the water inlet pipe and the water outlet pipe are connected with the liquid cavity. An inner ring is fixed on the inner wall of the cylinder below the spacer ring.

[0010] 1. By setting the cup barrel, after the film discharged from the ring groove is stretched, the film part close to the die head can be effectively prevented from sticking under the blocking effect of the cup barrel, which can improve the quality of the plastic bag.

[0011] 2. By setting air holes on the conical part of the cup tube, the amount of air entering the film body can be guaranteed, ensuring the normal progress of the blow molding process.

[0012] 3. The cup barrel is detachable, which is convenient for cleaning the die head.

[0013] 4. When the membrane penetrates the cylinder, it contacts the inner ring in advance. The water flowing in the liquid cavity can cool the membrane in advance, which can prevent the wind from being discharged from the air hole from causing perforation of the membrane, thereby ensuring the quality of the plastic bag and reducing the defective rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the utility model.

[0015] Figure 2 for Figure 1 Magnified view of area A.

[0016] Figure 3 It is a front view of the cup tube.

[0017] Figure 4 for Figure 3 Middle BB section view.

[0018] Figure 5 A schematic diagram of the cylinder.

[0019] Figure 6 A top view of the cylinder.

[0020] Figure 7 for Figure 4 CC section view.

[0021] The names of the parts in the attached figure are: 1 melt part; 2 fixed cylinder; 3 cup cylinder; 4 bracket; 5 clamping roller; 6 upper guide roller; 7 lower guide roller; 8 wind-up roller; 9 through hole; 10 die head; 11 ring cavity; 12 ring groove; 13 air inlet pipe; 14 bell mouth; 15 fixed rod; 16 support rod; 17 straight cylinder part; 18 conical cylinder part; 19 air hole; 20 cylinder body; 21 air inlet pipe; 22 water inlet pipe; 23 water outlet pipe; 24 air hole; 25 inner ring; 26 spacer ring. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0023] Example 1: Reference Figure 1-Figure 4 As shown, the polyethylene plastic bag blow molding equipment includes a melting part 1, and the melting part 1 is a screw extruder.

[0024] A blow molding section is provided at the outlet end of the molten material section 1, and the blow molding section is located in a bracket 4. A cooling assembly is provided in the bracket 4 above the blow molding section. Two clamping rollers 5 are rotatably connected to the upper end of the bracket 4, an upper guide roller 6 is rotatably connected to one side of the upper end of the bracket 4, a lower guide roller 7 is rotatably connected to the outer side of the bracket 4 below the upper guide roller 6, and a winding roller 8 is rotatably connected to the bracket 4 below the lower guide roller 7.

[0025] The melting section 1 heat-melts the plastic particles into a molten state and then inputs them into the blow molding section. The blow molding section blows the molten plastic into a film body, which passes through the cooling assembly and two clamping rollers 5 and successively passes around the upper guide roller 6 and the lower guide roller 7 before being wound up by the winding roller 8.

[0026] The blow molding part includes a fixed cylinder 2 fixed on the melt part 1, and a through hole 9 connected to the outlet end of the melt part 1 is provided on the side wall of the fixed cylinder 2, and an overflow hole connected to the outside is provided on the side wall of the fixed cylinder 2. An annular die head 10 is fixed on the upper end of the fixed cylinder 2, and an annular cavity 11 is provided in the die head 10, and the annular cavity 11 is connected to the through hole 9. An annular groove 12 is provided on the inner side of the die head 10, and the annular groove 12 is connected to the annular cavity 11, and the end of the annular groove 12 facing the center of the die head 10 is inclined upward. A blowing assembly is concentrically arranged on the inner side of the die head 10, and a cup barrel 3 is detachably fixedly connected to the upper end of the blowing assembly, and the cup barrel 3 is concentric with the die head 10.

[0027] The blowing assembly includes an air inlet pipe 13 fixed in the fixed tube 2 , the air inlet end of the air inlet pipe 13 is fixedly connected to a bell mouth 14 , a fixing rod 15 is fixed in the bell mouth 14 , and the fixing rod 15 is detachably fixedly connected to the cup tube 3 .

[0028] The cup tube 3 comprises a straight tube portion 17 at the upper end, a conical tube portion 18 is fixedly connected concentrically below the straight tube portion 17, the lower end of the straight tube portion 17 and the upper end of the conical tube portion 18 are in arc transition, and a plurality of air holes 19 are evenly distributed on the circumference of the conical tube portion 18. A support rod 16 is fixedly connected concentrically to the lower end of the conical tube portion 18, and the support rod 16 is threadedly connected to the fixing rod 15.

[0029] During operation, the air inlet pipe 13 is connected to the fan. The molten plastic is discharged from the annular groove 12 to form a film body. The film body is pulled upward, and the cup tube 3 is located in the film body. The film body passes through the cooling assembly and the two clamping rollers 5 and successively bypasses the upper guide roller 6 and the lower guide roller 7 before being wound up by the winding roller 8. During the upward movement of the film body, the fan blows air into the film body through the air inlet pipe 21 and the bell mouth 14, and part of the air flows out through the overflow hole, while there is always air in the film body below the two clamping rollers 5. After the fan is started, the film body is blown into shape.

[0030] After the film is formed, it is wound up by the winding roller 8. During the process of winding up the film by the winding roller 8, the film is always stretched. After the film is stretched, the part of the film above the die head 10 will shrink. When the part of the film above the die head 10 shrinks, the part of the film near the die head 10 is prone to adhesion due to the higher temperature of the film near the die head 10. By providing the cup barrel 3, after the film discharged from the annular groove 12 of the die head 10 is stretched, the part of the film near the die head 10 can be effectively prevented from adhesion under the blocking effect of the cup barrel 3. By providing the air hole 19 on the conical cylinder part 18 of the cup barrel 3, the air volume entering the film can be guaranteed, and the normal progress of the blow molding process can be guaranteed. At the same time, the cup barrel 3 is detachable, which is convenient for cleaning the die head 10.

[0031] Embodiment 2: Based on Embodiment 1, refer to Figure 1 , Figure 5 , Figure 6 and Figure 7 As shown, the cooling assembly includes a cylinder 20, which is fixed in the bracket 4. The cylinder 20 is concentric with the blow molding part, and an annular cavity is opened in the cylinder wall of the cylinder 20. A spacer ring 26 is fixed in the annular cavity. The annular cavity above the spacer ring 26 is a wind cavity, and the annular cavity below the spacer ring 26 is a liquid cavity. A plurality of wind holes 24 are opened on the inner wall of the cylinder 20 above the spacer ring 26, and the wind holes 24 are connected to the wind cavity. An air inlet pipe 21 is fixed on the outside of the cylinder 20, and the air inlet pipe 21 is connected to the wind cavity. A water inlet pipe 22 and a water outlet pipe 23 are fixed on the outside of the cylinder 20, and the water inlet pipe 22 and the water outlet pipe 23 are connected to the liquid cavity. An inner ring 25 is fixed on the inner wall of the cylinder 20 below the spacer ring 26.

[0032] The inner ring 25 has chamfers at both ends. The inner ring 25 has chamfers at both ends to prevent the membrane from being scratched when the membrane moves upward in the inner ring 25.

[0033] The fan is connected to the air inlet pipe 21, so that water circulates in the water inlet pipe 22, the liquid cavity and the water outlet pipe 23. When the membrane body passes through the cylinder 20, it contacts the inner ring 25 in advance. The water flowing in the liquid cavity can pre-cool the membrane body, and then the wind discharged from the air hole 24 performs secondary cooling on the membrane body, which can prevent the wind discharged from the air hole 24 from causing perforation of the membrane body, thereby ensuring the quality of the plastic bag and reducing the defective rate.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A polyethylene plastic bag blow molding device, comprising a melting part (1), a blowing part being arranged at the outlet end of the melting part (1), the blowing part being located in a bracket (4), a cooling assembly being arranged in the bracket (4) above the blowing part, two clamping rollers (5) being rotatably connected in the upper end of the bracket (4), an upper guide roller (6) being rotatably connected on one side of the upper end of the bracket (4), a lower guide roller (7) being rotatably connected on the outer side of the bracket (4) below the upper guide roller (6), a winding roller (8) being rotatably connected on the bracket (4) below the lower guide roller (7), and the winding roller (8) being rotatably connected on the bracket (4), characterized in that: The blow molding part comprises a fixed cylinder (2) fixed on the molten material part (1), a through hole (9) connected to the outlet end of the molten material part (1) is provided on the side wall of the fixed cylinder (2), an overflow hole connected to the outside is provided on the side wall of the fixed cylinder (2), an annular die head (10) is fixed on the upper end of the fixed cylinder (2), an annular cavity (11) is provided in the die head (10), the annular cavity (11) is connected to the through hole (9), an annular groove (12) is provided on the inner side of the die head (10), the annular groove (12) is connected to the annular cavity (11), a blowing assembly is concentrically arranged on the inner side of the die head (10), a cup cylinder (3) is detachably fixedly connected to the upper end of the blowing assembly, and the cup cylinder (3) is concentric with the die head (10).

2. The polyethylene plastic bag blow molding equipment according to claim 1, characterized in that: The melting part (1) is a screw extruder.

3. The polyethylene plastic bag blow molding equipment according to claim 1, characterized in that: One end of the annular groove (12) facing the center of the die head (10) is inclined upward.

4. The polyethylene plastic bag blow molding equipment according to claim 1, characterized in that: The blowing assembly comprises an air inlet pipe (13) fixed in a fixed cylinder (2); an air inlet end of the air inlet pipe (13) is fixedly connected to a bell mouth (14); a fixing rod (15) is fixed in the bell mouth (14); and the fixing rod (15) is detachably fixedly connected to the cup cylinder (3).

5. The polyethylene plastic bag blow molding equipment according to claim 4, characterized in that: The cup tube (3) comprises a straight tube portion (17) at the upper end, a conical tube portion (18) is coaxially fixedly connected below the straight tube portion (17), the lower end of the straight tube portion (17) and the upper end of the conical tube portion (18) are in an arc transition, a support rod (16) is coaxially fixed at the lower end of the conical tube portion (18), and the support rod (16) is threadedly connected to the fixing rod (15).

6. The polyethylene plastic bag blow molding equipment according to claim 5, characterized in that: The conical cylinder portion (18) is evenly distributed on its circumference with a plurality of air holes (19).

7. The polyethylene plastic bag blow molding equipment according to claim 1, characterized in that: The cooling component comprises a cylinder (20), the cylinder (20) being fixed in a bracket (4), the cylinder (20) being concentric with the blow molding part, an annular cavity being provided in the cylinder wall of the cylinder (20), a spacer ring (26) being fixed in the annular cavity, the annular cavity above the spacer ring (26) being an air cavity, the annular cavity below the spacer ring (26) being a liquid cavity, a plurality of air holes (24) being provided on the inner wall of the cylinder (20) above the spacer ring (26), the air holes (24) being connected to the air cavity, an air inlet pipe (21) being fixed on the outer side of the cylinder (20), the air inlet pipe (21) being connected to the air cavity, a water inlet pipe (22) and a water outlet pipe (23) being fixed on the outer side of the cylinder (20), the water inlet pipe (22) and the water outlet pipe (23) being connected to the liquid cavity, and an inner ring (25) being fixed on the inner wall of the cylinder (20) below the spacer ring (26).

8. The polyethylene plastic bag blow molding equipment according to claim 7, characterized in that: The upper and lower ends of the inner ring (25) are both chamfered.

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