A geomembrane with flame retardant efficacy and its preparation method

Abstract

The present invention relates to the technical field of geomembranes, and discloses a geomembrane with flame retardant efficacy and a preparation method thereof. The preparation method of the geomembrane with flame retardant efficacy comprises the following steps: adding high-density polyethylene and a red phosphorus flame retardant into a two-roll mixer for mixing, discharging to obtain a mixed material, granulating the mixed material by a twin-screw granulator to obtain a flame-retardant material; mixing the flame-retardant material with a color masterbatch to obtain a mixture; adding the mixture into extruder A, extruder B, extruder C, and extruder D respectively, and blowing and forming the mixture by a four-layer co-extrusion blown film machine to obtain a geomembrane with flame retardant efficacy. Compared with traditional geomembranes, the red phosphorus flame retardant is added to the geomembrane of the present invention, which not only greatly improves the flame retardant performance of the geomembrane, but also greatly improves the dripping phenomenon during combustion.

Description

Technical Field

[0001] The present invention relates to the technical field of geomembranes, and specifically to a geomembrane with flame retardant effect and a preparation method thereof. Background Art

[0002] Geomembrane is one of the new geotechnical materials emerging in the late 1990s. Geomembrane is a good anti-seepage material mainly made of high-density polyethylene, and is an indispensable material in municipal engineering, mines, landfills, aquaculture, etc.

[0003] For example, Chinese Patent CN103214717B discloses a high-flexibility geomembrane and a preparation method thereof. The raw materials and their weight percentages are: HDPE: 20 - 60; LLDPE: 10 - 55; elastomer: 20 - 65; carbon black masterbatch: 5 - 10, with a total of 100 parts of raw materials. The preparation steps are as follows: Weigh and mix the above raw materials evenly according to the formula, put them into an extruder, melt and mix them evenly in the extruder, then enter a three-layer co-extrusion die head, extrude from a circular die orifice, form a tubular film through air inflation and cooling, and then cut, flatten and wind it into a product. However, the high-flexibility geomembrane of Chinese Patent CN103214717B uses HDPE and LLDPE, which have the disadvantages of being flammable and having a low melting point. When encountering a fire, there is a dripping phenomenon, which is likely to expand the fire. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a preparation method of a geomembrane with flame retardant effect, including the following steps:

[0005] Step (1): Add high-density polyethylene and red phosphorus flame retardant into a two-roll mixer for mixing, discharge the material to obtain a mixed material, and granulate the mixed material through a twin-screw granulator to obtain a flame-retardant material;

[0006] Step (2): Mix the flame-retardant material with a color masterbatch to obtain a mixture; add the mixture into extruder A, extruder B, extruder C, and extruder D respectively, and blow and mold the mixture through a four-layer co-extrusion blown film machine to obtain a geomembrane with flame retardant effect;

[0007] The geomembrane with flame retardant effect has a four-layer structure. One layer extruded from extruder A is layer A, one layer extruded from extruder B is layer B, one layer extruded from extruder C is layer C, and one layer extruded from extruder D is layer D.

[0008] Preferably, in step (1), the mass ratio of high-density polyethylene to red phosphorus flame retardant is 85:15; high-density polyethylene and red phosphorus flame retardant are mixed in a two-roll mixer at 120 - 150 °C for 4 - 10 min; the mixed material is granulated through a twin-screw granulator at 140 - 170 °C.

[0009] Preferably, in the step (2), the mass ratio of the flame retardant to the masterbatch is 95:5; the barrel temperature of extruder A is 170 - 200 °C, the barrel temperature of extruder B is 170 - 205 °C, the barrel temperature of extruder C is 170 - 205 °C, and the barrel temperature of extruder D is 170 - 200 °C.

[0010] Preferably, in the step (2), the die head temperature of the extruder is 160 - 210 °C, the screw speed is 5 - 65 rpm; the blow-up ratio is 1.08 - 1.2.

[0011] Preferably, in the step (2), the thickness of the geomembrane with flame retardant effect prepared is 0.3 - 2 mm.

[0012] The present invention also provides a four-layer co-extrusion blown film machine, which is used for four-layer co-extrusion blown film forming of the mixture in the preparation method of the above-mentioned geomembrane with flame retardant effect:

[0013] The four-layer co-extrusion blown film machine includes a frame body. A cross-cutting machine is arranged on the frame body. A plurality of clamping and conveying clips are arranged on the frame body. A pulling and feeding roller is arranged on the frame body. The cross-cutting machine is located above the clamping and conveying clips. The geomembrane passes through the clamping parts of the clamping and conveying clips. The cross-cutting machine cuts the geomembrane. The clamping and conveying clips clamp the cut-off part of the geomembrane and convey it. The pulling and feeding roller re-pulls the geomembrane conveyed by the clamping and conveying clips to continue winding the geomembrane; ensure that one side of the clamping and conveying clips clamps the head end of the cut geomembrane, one side of the clamping and conveying clips conveys the head end of the geomembrane to the clamping and conveying clips on the other side, and the clamping and conveying clips on the other side convey the head end of the geomembrane to the pulling and feeding roller.

[0014] Preferably, a turning roller is rotationally matched on the frame body. A driving motor is fixedly installed on the frame body. The shaft of the driving motor penetrates the frame body. The turning roller is power-connected to the driving motor. The cross-cutting machine is located on one side of the turning roller. The cross-cutting machine is located above the geomembrane. A plurality of belt pulleys are arranged on the frame body. The belt pulleys are all located below the cross-cutting machine. A toothed belt is tensioned on the belt pulleys. The toothed belt faces the cutter on the cross-cutting machine.

[0015] Preferably, a ratchet tooth is rotationally matched at the bottom end of the cutter of the cross-cutting machine. The ratchet tooth drives the toothed belt to rotate when the cross-cutting machine moves back to its original position. A first bevel gear is rotationally matched on the frame body. A second bevel gear is meshed with the first bevel gear. A linkage belt is tensioned on the rotating shafts of the second bevel gear and the belt pulley. A plurality of toothless gears are fixedly installed on the rotating shaft of the first bevel gear. There are gaps between the toothless gears. The teeth of the toothless gears on one side face the teeth of the toothless gears on the other side.

[0016] Preferably, a first wide gear is rotatably fitted on the frame body. The first wide gear meshes with the toothless gear on one side. A second wide gear is rotatably fitted on the frame body. The second wide gear meshes with the toothless gear on the other side. The first wide gear meshes with the second wide gear. A plurality of guide rails are fixedly installed on the frame body. Rack bars are slidably fitted on the guide rails. The rack bar on one side meshes with the first wide gear, and the rack bar on the other side meshes with the second wide gear. Clamping and conveying clips are fixedly installed on the rack bars. Electric telescopic rods are fixedly installed on the clamping and conveying clips, and the electric telescopic rods control the clamping and conveying clips to perform clamping.

[0017] Preferably, a pulling and feeding motor is fixedly installed on the frame body. The shaft of the pulling and feeding motor penetrates the frame body, and the pulling and feeding motor is power-connected to the pulling and feeding roller. A winding roller is rotatably fitted on the frame body, and the winding roller winds the geomembrane. A limiting roller is rotatably fitted on the frame body, and the limiting roller limits the winding of the geomembrane.

[0018] Preferably, a support frame is also fixedly installed on one side of the frame body.

[0019] A plurality of feeding hoppers are arranged at the bottom of the support frame. An extruder is arranged at the bottom of the support frame. The feeding hoppers communicate with the extruder. A conveying cylinder is fixedly installed on the extruder. The conveying cylinder communicates with the discharge port of the extruder. A die head is fixedly installed on the conveying cylinder, and the die head communicates with the conveying cylinder.

[0020] Preferably, a blower is arranged at the bottom of the frame body. A flow dividing box is arranged at the bottom of the frame body. The flow dividing box communicates with the air outlet of the blower. A plurality of air pipes are arranged on the flow dividing box. One end of the air pipe communicates with the flow dividing box, and the other end of the air pipe communicates with the die head.

[0021] Preferably, a power motor is fixedly installed on the frame body. A plurality of rubber rollers are rotatably fitted on the frame body. The power motor is power-connected to the rubber rollers. The rubber rollers are opposite to the die head. Opposite transmission gears are fixedly installed on the rubber rollers, and the opposite transmission gears mesh with each other. A herringbone plate is fixedly installed on the frame body, and the herringbone plate is opposite to the rubber rollers.

[0022] Preferably, a guide roller is rotatably fitted on the frame body. A belt is tensioned between the shaft of the guide roller and the shaft of the power motor. A plurality of transmission rollers are arranged on the frame body, and the transmission rollers are used for transmitting the geomembrane.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. Compared with traditional geomembranes, the flame-retardant geomembrane of the present invention adds red phosphorus flame retardant, which not only greatly improves the flame-retardant performance of the geomembrane, but also significantly improves the dripping phenomenon during combustion.

[0025] 2. In the four-layer coextrusion blown film machine of the present invention, when the cross cutter is reset, the reset drive of the cross cutter clamps the conveying clamps to move towards each other. The clamping conveying clamps on both sides first come close to each other, the clamping conveying clamp at the other end clamps the head end of the geomembrane, the clamping conveying clamp at one end releases the clamping, the cross cutter continues to reset, the clamping conveying clamps at both ends move in the opposite direction, and after the cross cutter is completely reset, the clamping conveying clamp at the other end moves to the side of the pulling roller, so that the pulling roller rolls up the head end of the geomembrane and continues to wind it, enabling the geomembrane to be stably wound for the next time, avoiding manual alignment for winding again, ensuring that the geomembrane is always wound forward each time, and preventing the geomembrane from becoming increasingly offset and folded during winding.

[0026] 3. In the four-layer coextrusion blown film machine of the present invention, when the cross cutter knife is in the first half of the reset process, the teeth on the toothless gear on one side drive the first wide gear and the second wide gear to rotate in opposite directions. The first wide gear and the second wide gear each drive the rack to move towards each other on the guide rail, and the rack drives the clamping conveying clamp to move, so that the clamping conveying clamp at the other end clamps the head end of the geomembrane through the electric telescopic rod, effectively transferring the head end of the cut geomembrane to the clamping conveying clamp at the other end, ensuring the continuity of the geomembrane winding.

[0027] 4. In the four-layer coextrusion blown film machine of the present invention, when the cross cutter knife is in the second half of the reset process, the teeth on the toothless gear on the other side drive the second wide gear and the first wide gear to rotate in the reverse direction, so that the clamping conveying clamp moves in the reverse direction, transferring the head end of the geomembrane clamped by the clamping conveying clamp at the other end to the pulling roller, so that the rigid cooperation of the mechanical transmission accurately transfers the head end of the geomembrane forward to the pulling roller, ensuring the accuracy and quality of the geomembrane winding and improving the winding efficiency of the geomembrane. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic structural diagram of the flame-retardant geomembrane of the present invention;

[0029] Figure 2 is a synthesis process diagram of the flame-retardant geomembrane of the present invention;

[0030] Figure 3 is a test comparison diagram of the ignition time of the flame-retardant geomembranes prepared in the examples and comparative examples of the present invention;

[0031] Figure 4 is a schematic diagram of the structural distribution at the frame of the four-layer coextrusion blown film machine of the present invention;

[0032] Figure 5Schematic diagram of the structural distribution at the clamping and conveying clamp of the four-layer coextrusion blown film machine in the present invention;

[0033] Figure 6 Schematic diagram of the structural distribution at the toothless gear of the four-layer coextrusion blown film machine in the present invention;

[0034] Figure 7 Schematic diagram of the overall structure of the four-layer coextrusion blown film machine in the present invention;

[0035] Figure 8 Schematic diagram of the structural distribution at the die head of the four-layer coextrusion blown film machine in the present invention;

[0036] Figure 9 Schematic diagram of the structural distribution at the rubber roller of the four-layer coextrusion blown film machine in the present invention.

[0037] In the figure: 1. Frame body; 21. Steering roller; 22. Driving motor; 23. Cross cutter; 24. Belt pulley; 25. Tooth belt; 26. Ratchet tooth; 27. First bevel gear; 28. Second bevel gear; 29. Linkage belt; 210. Toothless gear; 211. First wide gear; 212. Second wide gear; 213. Guide rail; 214. Rack; 215. Clamping and conveying clamp; 216. Electric telescopic rod; 217. Pulling and feeding roller; 218. Pulling and feeding motor; 219. Winding roller; 220. Limiting roller; 3. Support frame; 41. Feed hopper; 42. Extruder; 43. Delivery cylinder; 44. Die head; 45. Blower; 46. Shunt box; 47. Air duct; 51. Power motor; 52. Rubber roller; 53. Opposite transmission gear; 54. Herringbone plate; 55. Guide roller; 56. Belt; 57. Transmission roller; 101. Layer A; 102. Layer B; 103. Layer C; 104. Layer D. Detailed implementation manners

[0038] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0039] Embodiment 1

[0040] This embodiment discloses a preparation method of a geomembrane with flame retardant efficacy, including the following steps:

[0041] Step (1): Mix high-density polyethylene and red phosphorus flame retardant in a mass ratio of 85:15, add them to a two-roll mixer and knead at 120 °C for 10 minutes, and discharge; granulate the mixed material with a twin-screw granulator at 140 °C to obtain a flame-retardant material;

[0042] Step (2) Mix the flame retardant and the masterbatch in a mass ratio of 95:5 to obtain a mixture; add the mixture to Extruder A, Extruder B, Extruder C, and Extruder D respectively. The mixture is blown into a film by a four-layer co-extrusion blown film machine to obtain a geomembrane with a flame retardant effect and a thickness of 0.3 mm. Among them, the barrel temperature of Extruder A is 170 °C, the barrel temperature of Extruder B is 170 °C, the barrel temperature of Extruder C is 170 °C, and the barrel temperature of Extruder D is 170 °C; the die head temperature of the extruder is 160 °C, the screw speed is 5 rpm; the blow-up ratio is 1.08.

[0043] Example 2

[0044] This example discloses a preparation method of a geomembrane with a flame retardant effect, including the following steps:

[0045] Step (1) Mix high-density polyethylene and red phosphorus flame retardant in a mass ratio of 85:15, add them to a two-roll mixer and knead at 150 °C for 4 min, then discharge; granulate the mixture through a twin-screw granulator at 170 °C to obtain a flame retardant.

[0046] Step (2) Mix the flame retardant and the masterbatch in a mass ratio of 95:5 to obtain a mixture; add the mixture to Extruder A, Extruder B, Extruder C, and Extruder D respectively. The mixture is blown into a film by a four-layer co-extrusion blown film machine to obtain a geomembrane with a flame retardant effect and a thickness of 2 mm. Among them, the barrel temperature of Extruder A is 200 °C, the barrel temperature of Extruder B is 205 °C, the barrel temperature of Extruder C is 205 °C, and the barrel temperature of Extruder D is 200 °C; the die head temperature of the extruder is 210 °C, the screw speed is 65 rpm; the blow-up ratio is 1.2.

[0047] Example 3

[0048] This example discloses a preparation method of a geomembrane with a flame retardant effect, including the following steps:

[0049] Step (1) Mix high-density polyethylene and red phosphorus flame retardant in a mass ratio of 85:15, add them to a two-roll mixer and knead at 130 °C for 8 min, then discharge; granulate the mixture through a twin-screw granulator at 150 °C to obtain a flame retardant.

[0050] Step (2) Mix the flame retardant and the color masterbatch in a mass ratio of 95:5 to obtain a mixture; add the mixture into extruders A, B, C, and D respectively, and the mixture is blown into a film by a four-layer coextrusion blown film machine to obtain a geomembrane with a flame retardant effect and a thickness of 0.9 mm; among them, the barrel temperature of extruder A is 180 °C, the barrel temperature of extruder B is 185 °C, the barrel temperature of extruder C is 185 °C, and the barrel temperature of extruder D is 180 °C; the die head temperature of the extruder is 175 °C, and the screw speed is 25 rpm; the blow-up ratio is 1.12.

[0051] Example 4

[0052] This example discloses a preparation method of a geomembrane with a flame retardant effect, including the following steps:

[0053] Step (1) Mix high-density polyethylene and red phosphorus flame retardant in a mass ratio of 85:15, add them to a two-roll mixer and knead at 140 °C for 6 minutes, then discharge; granulate the mixture through a twin-screw granulator at 155 °C to obtain a flame retardant.

[0054] Step (2) Mix the flame retardant and the color masterbatch in a mass ratio of 95:5 to obtain a mixture; add the mixture into extruders A, B, C, and D respectively, and the mixture is blown into a film by a four-layer coextrusion blown film machine to obtain a geomembrane with a flame retardant effect and a thickness of 1.5 mm; among them, the barrel temperature of extruder A is 190 °C, the barrel temperature of extruder B is 195 °C, the barrel temperature of extruder C is 195 °C, and the barrel temperature of extruder D is 190 °C; the die head temperature of the extruder is 190 °C, and the screw speed is 45 rpm; the blow-up ratio is 1.17.

[0055] Comparative Example 1

[0056] This comparative example discloses a preparation method of a geomembrane with a flame retardant effect, including the following steps:

[0057] Step (1) Mix high-density polyethylene and red phosphorus flame retardant in a mass ratio of 85:15, add them to a two-roll mixer and knead at 130 °C for 8 minutes, then discharge; granulate the mixture through a twin-screw granulator at 150 °C to obtain a flame retardant.

[0058] Step (2) Mix the flame retardant and the masterbatch in a mass ratio of 95:5 to obtain a mixture; add the mixture to Extruder A, Extruder B, and Extruder D respectively, and add the high-density polyethylene and the masterbatch in a mass ratio of 95:5 to Extruder C. Blow and mold through a four-layer co-extrusion blown film machine to obtain a geomembrane with a flame retardant effect and a thickness of 0.9 mm. Among them, the barrel temperature of Extruder A is 180 °C, the barrel temperature of Extruder B is 185 °C, the barrel temperature of Extruder C is 185 °C, and the barrel temperature of Extruder D is 180 °C; the die head temperature of the extruder is 175 °C, the screw speed is 25 rpm; the blow-up ratio is 1.12.

[0059] Comparative Example 2

[0060] This comparative example discloses a method for preparing a geomembrane with a flame retardant effect, including the following steps:

[0061] Step (1) Mix the high-density polyethylene and the red phosphorus flame retardant in a mass ratio of 85:15, add them to a two-roll mixer and knead at 130 °C for 8 minutes, and discharge the material; granulate the mixture through a twin-screw granulator at 150 °C to obtain a flame retardant.

[0062] Step (2) Mix the flame retardant and the masterbatch in a mass ratio of 95:5 to obtain a mixture; add the mixture to Extruder A, Extruder C, and Extruder D respectively, and add the high-density polyethylene and the masterbatch in a mass ratio of 95:5 to Extruder B. Blow and mold through a four-layer co-extrusion blown film machine to obtain a geomembrane with a flame retardant effect and a thickness of 0.9 mm. Among them, the barrel temperature of Extruder A is 180 °C, the barrel temperature of Extruder B is 185 °C, the barrel temperature of Extruder C is 185 °C, and the barrel temperature of Extruder D is 180 °C; the die head temperature of the extruder is 175 °C, the screw speed is 25 rpm; the blow-up ratio is 1.12.

[0063] Comparative Example 3

[0064] This comparative example discloses a method for preparing a geomembrane with a flame retardant effect, including the following steps:

[0065] Mix the high-density polyethylene and the masterbatch in a mass ratio of 95:5 to obtain a mixture; add the mixture to Extruder A, Extruder B, Extruder C, and Extruder D respectively, and blow and mold the mixture through a four-layer co-extrusion blown film machine to obtain a geomembrane with a flame retardant effect and a thickness of 0.9 mm. Among them, the barrel temperature of Extruder A is 180 °C, the barrel temperature of Extruder B is 185 °C, the barrel temperature of Extruder C is 185 °C, and the barrel temperature of Extruder D is 180 °C; the die head temperature of the extruder is 175 °C, the screw speed is 25 rpm; the blow-up ratio is 1.12.

[0066] In all of the above examples and comparative examples, the brand of high-density polyethylene is Qatari Chemicals, the model is TR131, and it is from Beijing Zhonglai Chemical Co., Ltd.; the red phosphorus flame retardant is from Jinqiu Phosphating Processing Factory in Rencheng District, Jining City; the masterbatch, with the brand of Cabot, is from Shanghai Jiuqing International Trade Co., Ltd., and the product number is PE6370.

[0067] Test 1. Determination of the vertical burning UL94 rating: According to the UL94-1996 standard, a vertical burning experiment was carried out on the geotextiles with flame retardant effects prepared in Examples 1-4 and Comparative Examples 1-2 using a vertical and horizontal burning UL-94 tester. Observe whether the composite geotextile burns smoothly during the combustion process and whether there are molten drops falling, etc. The test results are shown in Table 1:

[0068] Table 1

[0069]

[0070] From the test results in Table 1, it can be seen that the flame retardant rating of the geotextiles with flame retardant effects prepared in Examples 1-4 of the present invention reaches the V0 level. After ignition, the flame basically goes out within 2 s, the flame retardant performance is excellent, and there are no molten drops; while the flame retardant ratings of the geotextiles with flame retardant effects prepared in Comparative Examples 1-2 are both at the V1 level. Compared with Example 3, replacing the mixture of the flame retardant and the masterbatch in the B layer or C layer with a mixture of high-density polyethylene and the masterbatch reduces the flame retardant performance of the composite geotextile.

[0071] Example 5

[0072] The present invention provides a four-layer co-extrusion blown film machine, which can realize the four-layer co-extrusion blown film forming of the mixture in step (2) of Examples 1-4.

[0073] As Figure 4 shown, a four-layer co-extrusion blown film machine includes a frame body 1. A cross cutter 23 is arranged on the frame body 1. A plurality of clamping and conveying clips 215 are arranged on the frame body 1. A pulling and feeding roller 217 is arranged on the frame body 1. The cross cutter 23 is located above the clamping and conveying clips 215. The geotextile passes through the clamping part of the clamping and conveying clips 215. The cross cutter 23 cuts the geotextile. The clamping and conveying clips 215 clamp the cut-off part of the geotextile and convey it. The pulling and feeding roller 217 re-pulls the geotextile conveyed by the clamping and conveying clips 215 to continue winding the geotextile;

[0074] Ensure that one side of the clamping and conveying clips 215 clamps the head end of the cut geotextile, one side of the clamping and conveying clips 215 conveys the head end of the geotextile to the clamping and conveying clips 215 on the other side, and the clamping and conveying clips 215 on the other side convey the head end of the geotextile to the pulling and feeding roller 217.

[0075] When the present invention is used: after the blown film machine processes the geomembrane, the geomembrane is transmitted to the winding position for winding through transmission. When the geomembrane is transmitted, it passes under the cross-cutting machine 23, through the clamping position of the clamping transmission clamp 215, and between the pulling rollers 217. After this winding is completed, the cross-cutting machine 23 is started, and the cross-cutting machine 23 cuts the geomembrane once. Since the geomembrane passes through the clamping position of the clamping transmission clamp 215, after cutting, the geomembrane falls onto the clamping transmission clamp 215. At the same time, one end of the clamping transmission clamp 215 clamps, and the geomembrane on the other end of the clamping transmission clamp 215 continues to be wound until all winding is completed. Then, when the cross-cutting machine 23 resets, the reset of the cross-cutting machine 23 drives the clamping transmission clamps 215 to move towards each other. When the cross-cutting machine 23 resets to half, the clamping transmission clamps 215 on both sides come close to each other, and the clamping transmission clamp 215 on the other end clamps the head end of the geomembrane, while the clamping transmission clamp 215 at one end releases the clamping. As the cross-cutting machine 23 continues to reset, at this time, the clamping transmission clamps 215 at both ends move in the opposite direction. After the cross-cutting machine 23 is completely reset, the clamping transmission clamp 215 at the other end moves beside the pulling roller 217 so that the pulling roller 217 winds the head end of the geomembrane and continues to wind. At the same time, the clamping transmission clamp 215 at the other end releases. At this time, the head end of the geomembrane is transmitted through the clamping transmission clamp 215, enabling the geomembrane to be stably wound for the next time, avoiding manual re-aligning and winding again, ensuring that the geomembrane is always wound forward each time, and preventing the geomembrane from becoming increasingly offset and folded as it is wound.

[0076] Taking the four-layer coextrusion blown film machine of the present invention as an example for four-layer coextrusion blown film forming of the mixture in steps (2) of Embodiments 1-4 of the present invention, the working principle thereof will be introduced.

[0077] Working principle: First, put the mixture into the feeding hopper 41. When the mixture enters the four extruders 42 through the four feeding hoppers 41, it is heated. Among them, the barrel temperature of extruder A is 170 - 200 °C, the barrel temperature of extruder B is 170 - 205 °C, the barrel temperature of extruder C is 170 - 205 °C, the barrel temperature of extruder D is 170 - 200 °C, the die head temperature of the extruder is 160 - 210 °C, and the screw speed of the extruder is 5 - 65 rpm. The mixed material enters the conveying cylinder 43 through the four extruders 42 and then enters the die head 44 through the conveying cylinder 43. At the same time, the air generated by the blower 45 enters the shunt box 46, passes through the shunt box 46 and enters the air duct 47, and then enters the die head 44 through the air duct 47 to enable the die head 44 to process and produce a geomembrane cylinder, and the blow-up ratio is set to 1.08 - 1.2. The geomembrane cylinder is limited by the chevron plate 54 and enters between the rubber rollers 52 driven by the power motor 51, and is processed into a geomembrane with a thickness of 0.3 - 2 mm by the rubber rollers 52. The geomembrane is transmitted to the turning roller 21 through the guiding roller 55 and the transmission roller 57. The driving motor 22 drives the turning roller 21 to guide the geomembrane to the winding place. When the first winding is completed, the cross-cutting machine 23 drives the cutter to perform the first cutting on the geomembrane. After the cutting is completed, the geomembrane falls onto the clamping and conveying clamp 215. At the same time, one end of the clamping and conveying clamp 215 clamps, and the geomembrane on the other end of the clamping and conveying clamp 215 continues to be wound until all winding is completed. Then when the cross-cutting machine 23 resets, the reset of the cross-cutting machine 23 drives the clamping and conveying clamp 215 to move towards each other first and then move in the opposite direction. After the cross-cutting machine 23 is completely reset, the clamping and conveying clamp 215 at the other end moves to the side of the pulling roller 217 so that the pulling roller 217 winds the head end of the geomembrane and continues to wind, and at the same time the clamping and conveying clamp 215 at the other end loosens.

[0078] Further, as Figure 4-5 shown, a turning roller 21 is rotationally fitted on the frame body 1, a driving motor 22 is fixedly installed on the frame body 1, the shaft of the driving motor 22 penetrates through the frame body 1, and the turning roller 21 is power-connected to the driving motor 22. The cross-cutting machine 23 is located on one side of the turning roller 21, the cross-cutting machine 23 is located above the geomembrane, and a plurality of belt pulleys 24 are arranged on the frame body 1. The belt pulleys 24 are all located below the cross-cutting machine 23, and a toothed belt 25 is tensioned on the belt pulleys 24, and the toothed belt 25 faces the cutter on the cross-cutting machine 23.

[0079] Further, the outer ring of the toothed belt 25 is a toothed ring surface.

[0080] Further, the moving range of the cutter of the cross-cutting machine 23 is opposite to the toothed belt 25.

[0081] Further, as Figure 5-6As shown in the figure, the bottom end of the cutting knife of the cross-cutting machine 23 is rotationally fitted with a ratchet 26. When the ratchet 26 moves with the cross-cutting machine 23 during reset, it drives the toothed belt 25 to rotate. A first bevel gear 27 is rotationally fitted on the frame 1. A second bevel gear 28 is engaged with the first bevel gear 27. A linkage belt 29 is tensioned on the rotating shafts of the second bevel gear 28 and the pulley 24. A plurality of toothless gears 210 are fixedly installed on the rotating shaft of the first bevel gear 27. There are gaps between the toothless gears 210. The teeth of the toothless gears 210 on one side are opposite to the teeth of the toothless gears 210 on the other side.

[0082] Further, when the ratchet 26 moves with the cutting knife of the cross-cutting machine 23 during cutting, the ratchet 26 contacts the tooth ring surface of the toothed belt 25 and deflects, that is, the ratchet 26 does not push the toothed belt 25 to rotate at this time. When the ratchet 26 moves with the cutting knife of the cross-cutting machine 23 during reset, the ratchet 26 contacts the tooth ring surface of the toothed belt 25 and does not deflect, that is, the ratchet 26 pushes the toothed belt 25 to rotate at this time.

[0083] Further, through the transmission of the linkage belt 29, the second bevel gear 28, and the first bevel gear 27, every time the toothed belt 25 rotates once when it is driven by the reset movement of the cutting knife of the cross-cutting machine 23, and when the toothed belt 25 drives the toothless gear 210 to rotate, after each complete reset of the cutting knife of the cross-cutting machine 23, the toothless gear 210 rotates one circle.

[0084] Among them, the driving motor 22 drives the steering roller 21 to guide the geomembrane to the winding place. When one winding is completed, the cross-cutting machine 23 drives the cutting knife to cut the geomembrane once. When the cutting knife of the cross-cutting machine 23 moves during reset, the cutting knife drives the ratchet 26 to move. The ratchet 26 abuts against the tooth grooves on the tooth ring surface of the toothed belt 25 to drive the toothed belt 25 to rotate on the pulley 24. The pulley 24 drives the linkage belt 29 to rotate. The linkage belt 29 drives the second bevel gear 28 to rotate. The second bevel gear 28 drives the first bevel gear 27 to rotate. The first bevel gear 27 drives the toothless gear 210 to rotate.

[0085] Further, as Figure 4-6 shown in the figure, a first wide gear 211 is rotationally fitted on the frame 1. The first wide gear 211 is engaged with the toothless gear 210 on one side. A second wide gear 212 is rotationally fitted on the frame 1. The second wide gear 212 is engaged with the toothless gear 210 on the other side. The first wide gear 211 is engaged with the second wide gear 212. A plurality of guide rails 213 are fixedly installed on the frame 1. Rack bars 214 are slidably fitted on the guide rails 213. The rack bar 214 on one side is engaged with the first wide gear 211. The rack bar 214 on the other side is engaged with the second wide gear 212. Clamping and conveying clips 215 are fixedly installed on the rack bars 214. Electric telescopic rods 216 are fixedly installed on the clamping and conveying clips 215. The electric telescopic rods 216 control the clamping and conveying clips 215 to perform clamping.

[0086] Among them, when the cutting knife of the cross-cutting machine 23 is in the first half of the reset process, the teeth on the toothless gear 210 on one side drive the first wide gear 211 to rotate, the first wide gear 211 drives the second wide gear 212 to rotate, the first wide gear 211 and the second wide gear 212 respectively drive the rack 214 to move towards each other on the guide rail 213, the rack 214 drives the clamping and conveying clamp 215 to move, so that the clamping and conveying clamp 215 at the other end clamps the head end of the geomembrane through the electric telescopic rod 216. And when the cutting knife of the cross-cutting machine 23 is in the second half of the reset process, the teeth on the toothless gear 210 on the other side drive the second wide gear 212 to rotate, the second wide gear 212 drives the first wide gear 211 to rotate, so that the clamping and conveying clamp 215 moves in the reverse direction, so as to convey the head end of the geomembrane clamped by the clamping and conveying clamp 215 at the other end to the pulling and feeding roller 217.

[0087] Further, as Figure 4 shown, a pulling and feeding motor 218 is fixedly installed on the frame body 1, the shaft of the pulling and feeding motor 218 penetrates through the frame body 1, the pulling and feeding motor 218 is power-connected to the pulling and feeding roller 217, a winding roller 219 is rotatably matched on the frame body 1, the winding roller 219 winds the geomembrane, and a limiting roller 220 is rotatably matched on the frame body 1, and the limiting roller 220 limits the winding of the geomembrane.

[0088] Among them, the pulling and feeding motor 218 drives the pulling and feeding roller 217 to pull and feed the geomembrane, so as to send the geomembrane to the winding roller 219 for winding, and at the same time, the limiting roller 220 limits the geomembrane.

[0089] Further, as Figure 7-8 shown, a support frame 3 is also fixedly installed on one side of the frame body 1.

[0090] A plurality of feed hoppers 41 are arranged at the bottom of the support frame 3, an extruder 42 is arranged at the bottom of the support frame 3, the feed hoppers 41 communicate with the extruder 42, a conveying cylinder 43 is fixedly installed on the extruder 42, the conveying cylinder 43 communicates with the discharge port of the extruder 42, and a die head 44 is fixedly installed on the conveying cylinder 43, and the die head 44 communicates with the conveying cylinder 43.

[0091] Among them, the mixture is put into the feed hopper 41, the mixture enters the extruder 42 through the feed hopper 41, enters the conveying cylinder 43 through the extruder 42, and enters the die head 44 through the conveying cylinder 43.

[0092] Further, as Figure 7 shown, a blower 45 is arranged at the bottom of the frame body 1, a flow dividing box 46 is arranged at the bottom of the frame body 1, the flow dividing box 46 communicates with the air outlet of the blower 45, a plurality of air pipes 47 are arranged on the flow dividing box 46, one end of the air pipe 47 communicates with the flow dividing box 46, and the other end of the air pipe 47 communicates with the die head 44.

[0093] Among them, the air generated by the blower 45 enters the shunt box 46, passes through the shunt box 46 and enters the air duct 47, and then passes through the air duct 47 and enters the die head 44, so that the die head 44 processes and produces a geotextile film tube.

[0094] Further, as Figure 7 、 Figure 9 shown, a power motor 51 is fixedly installed on the frame body 1, a plurality of rubber rollers 52 are rotatably fitted on the frame body 1, the power motor 51 is power-connected to the rubber rollers 52, the rubber rollers 52 are opposite to the die head 44, oppositely rotating transmission gears 53 are fixedly installed on the rubber rollers 52, the oppositely rotating transmission gears 53 are meshed with each other, a herringbone plate 54 is fixedly installed on the frame body 1, and the herringbone plate 54 is opposite to the rubber rollers 52.

[0095] Among them, the geotextile film tube is limited by the herringbone plate 54, enters between the rubber rollers 52 driven by the power motor 51, and is processed into a geotextile film by the rubber rollers 52.

[0096] Further, as Figure 7 、 Figure 9 shown, a guide roller 55 is rotatably fitted on the frame body 1, a belt 56 is tensioned between the shaft of the guide roller 55 and the shaft of the power motor 51, and a plurality of transmission rollers 57 are arranged on the frame body 1, and the transmission rollers 57 are used for transmitting the geotextile film.

[0097] Among them, the power motor 51 drives the belt 56 to rotate, the belt 56 drives the guide roller 55 to rotate, the guide roller 55 guides and transmits the geotextile film, and the geotextile film is transmitted to the winding place through the transmission rollers 57.

[0098] Working principle:

[0099] When the blown film machine processes the geotextile film, the geotextile film is transmitted to the winding place for winding through transmission. When the geotextile film is transmitted, it passes under the cross-cutting machine 23, through the clamping place of the clamping transmission clamp 215, and between the pulling rollers 217. After this winding is completed, the cross-cutting machine 23 is started, and the cross-cutting machine 23 makes a primary cut on the geotextile film. Because the geotextile film passes through the clamping place of the clamping transmission clamp 215, after the cutting is completed, the geotextile film falls onto the clamping transmission clamp 215. At the same time, one end of the clamping transmission clamp 215 clamps, and the geotextile film on the other end of the clamping transmission clamp 215 continues to be wound until all winding is completed. Then when the cross-cutting machine 23 resets, the reset of the cross-cutting machine 23 drives the clamping transmission clamps 215 to move towards each other. When the cross-cutting machine 23 resets to half, the clamping transmission clamps 215 on both sides lean against each other, and the clamping transmission clamp 215 on the other end clamps the head end of the geotextile film, and the clamping transmission clamp 215 on one end releases the clamping. As the cross-cutting machine 23 continues to reset, at this time, the clamping transmission clamps 215 at both ends move in the opposite direction, and after the cross-cutting machine 23 is completely reset, the clamping transmission clamp 215 on the other end moves to the side of the pulling roller 217, so that the pulling roller 217 winds the head end of the geotextile film and continues to wind, and at the same time, the clamping transmission clamp 215 on the other end releases;

[0100] Among them, first, the mixture is put into the feeding hopper 41. The mixture enters the extruder 42 through the feeding hopper 41, enters the conveying cylinder 43 through the extruder 42, enters the die head 44 through the conveying cylinder 43. At the same time, the air generated by the blower 45 enters the shunt box 46, enters the air duct 47 through the shunt box 46, and enters the die head 44 through the air duct 47, so that the die head 44 processes and produces a geomembrane cylinder.

[0101] Then, the geomembrane cylinder is limited by the chevron plate 54 and enters between the rubber rollers 52 driven by the power motor 51. It is processed into a geomembrane through the rubber rollers 52. The power motor 51 drives the belt 56 to rotate, the belt 56 drives the guide roller 55 to rotate, the guide roller 55 guides and transmits the geomembrane, and the geomembrane is transmitted to the turning roller 21 through the transmission roller 57.

[0102] Then, the drive motor 22 drives the turning roller 21 to guide the geomembrane to the winding place. When the first winding is completed, the cross-cutting machine 23 drives the cutter to perform a first cutting on the geomembrane. When the cutter of the cross-cutting machine 23 moves back to its original position, the cutter drives the ratchet 26 to move. The ratchet 26 abuts against the tooth grooves on the tooth surface of the toothed belt 25 to drive the toothed belt 25 to rotate on the pulley 24. The pulley 24 drives the linkage belt 29 to rotate, the linkage belt 29 drives the second bevel gear 28 to rotate, the second bevel gear 28 drives the first bevel gear 27 to rotate, and the first bevel gear 27 drives the toothless gear 210 to rotate.

[0103] And when the cutter of the cross-cutting machine 23 is in the first half of its return, the teeth on the toothless gear 210 on one side drive the first wide gear 211 to rotate. The first wide gear 211 drives the second wide gear 212 to rotate. The first wide gear 21 and the second wide gear 212 respectively drive the rack 214 to move towards each other on the guide rail 213. The rack 214 drives the clamping and conveying clamp 215 to move, so that the clamping and conveying clamp 215 at the other end clamps the head end of the geomembrane through the electric telescopic rod 216. And when the cutter of the cross-cutting machine 23 is in the second half of its return, the teeth on the toothless gear 210 on the other side drive the second wide gear 212 to rotate. The second wide gear 212 drives the first wide gear 211 to rotate, so that the clamping and conveying clamp 215 moves in the reverse direction, and the head end of the geomembrane clamped by the clamping and conveying clamp 215 at the other end is conveyed to the pulling and feeding roller 217. The pulling and feeding motor 218 drives the pulling and feeding roller 217 to pull and feed the geomembrane, so as to send the geomembrane to the winding roller 219 for winding, and at the same time, it is limited by the limiting roller 220.

[0104] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirits of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A preparation method of a geomembrane with flame retardant effect, characterized in that, It includes the following steps: Step (1): Add high-density polyethylene and red phosphorus flame retardant into a two-roll mixer for mixing, and discharge the material to obtain a mixed material. The mixed material is granulated by a twin-screw granulator to obtain a flame-retardant material; Step (2): Mix the flame-retardant material with a masterbatch to obtain a mixture; add the mixture into extruder A, extruder B, extruder C, and extruder D respectively. The mixture is blown into a film by a four-layer coextrusion blown film machine to obtain a geomembrane with flame-retardant effect; The four-layer coextrusion blown film machine includes a frame body. A first wide gear is rotatably fitted on the frame body. A first bevel gear is rotatably fitted on the frame body. A plurality of toothless gears are fixedly installed on the rotating shaft of the first bevel gear. The first wide gear meshes with one side of the toothless gears. A second wide gear is rotatably fitted on the frame body. The second wide gear meshes with the toothless gears on the other side. The first wide gear meshes with the second wide gear. A plurality of guide rails are fixedly installed on the frame body. Rack bars are slidably fitted on the guide rails. One side of the rack bars meshes with the first wide gear, and the other side of the rack bars meshes with the second wide gear. Clamping and conveying clips are fixedly installed on the rack bars. Electric telescopic rods are fixedly installed on the clamping and conveying clips. The electric telescopic rods control the clamping and conveying clips to perform clamping.

2. The preparation method of a geomembrane with flame retardant effect according to claim 1, characterized in that, In step (1), the mass ratio of high-density polyethylene to red phosphorus flame retardant is 85:15; high-density polyethylene and red phosphorus flame retardant are mixed in a two-roll mixer at 120 - 150 °C for 4 - 10 min; the mixed material is granulated by a twin-screw granulator at 140 - 170 °C.

3. The preparation method of a geomembrane with flame retardant effect according to claim 1, characterized in that, In step (2), the mass ratio of the flame-retardant material to the masterbatch is 95:5; the barrel temperature of extruder A is 170 - 200 °C, the barrel temperature of extruder B is 170 - 205 °C, the barrel temperature of extruder C is 170 - 205 °C, and the barrel temperature of extruder D is 170 - 200 °C.

4. The preparation method of a geomembrane with flame retardant effect according to claim 1, characterized in that, In step (2), the die head temperature of the extruder is 160 - 210 °C, the screw speed is 5 - 65 rpm; the blow-up ratio is 1.08 - 1.

2.

5. The preparation method of a geomembrane with flame retardant effect according to claim 1, characterized in that, In step (2), the thickness of the geomembrane with flame-retardant effect prepared is 0.3 - 2 mm.

6. A geomembrane with flame retardant effect prepared by the method according to any one of claims 1 - 5.

7. A four - layer co - extrusion blown film machine used in the preparation method of a geomembrane with flame retardant effect according to any one of claims 1 - 5, characterized in that, A cross-cutting machine is arranged on the frame body. A plurality of clamping and conveying clips are arranged on the frame body. Pulling rollers are arranged on the frame body. The cross-cutting machine is located above the clamping and conveying clips. The geomembrane passes through the clamping positions of the clamping and conveying clips. The cross-cutting machine cuts the geomembrane. The clamping and conveying clips clamp the cut-off part of the geomembrane and convey it. The pulling rollers re-pull the geomembrane conveyed by the clamping and conveying clips to continue winding the geomembrane; Ensure that one side of the clamping and conveying clips clamps the head end of the cut geomembrane. One side of the clamping and conveying clips conveys the head end of the geomembrane to the clamping and conveying clips on the other side. The clamping and conveying clips on the other side convey the head end of the geomembrane to the pulling rollers.

8. The four - layer co - extrusion blown film machine according to claim 7, characterized in that, A steering roller is rotationally fitted on the frame body. A driving motor is fixedly installed on the frame body. The shaft of the driving motor penetrates through the frame body. The steering roller is power-connected to the driving motor. The cross-cutting machine is located on one side of the steering roller and above the geomembrane. A plurality of belt pulleys are arranged on the frame body, and the belt pulleys are all located below the cross-cutting machine. A toothed belt is tensioned on the belt pulleys, and the toothed belt faces the cutting knife on the cross-cutting machine.

9. The four - layer co - extrusion blown film machine according to claim 8, characterized in that, A ratchet tooth is rotationally fitted at the bottom end of the cutting knife of the cross-cutting machine. When the ratchet tooth moves with the cross-cutting machine during reset, it drives the toothed belt to rotate. A second bevel gear is engaged with the first bevel gear. A linkage belt is tensioned between the rotating shafts of the second bevel gear and the belt pulley. There is a gap between the toothless gears, and the teeth of the toothless gear on one side face the teeth of the toothless gear on the other side.

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