A production process for modified plastic particles

Abstract

This application relates to a production process of modified plastic particles, comprising the following steps: S1: Raw material preparation: Resins: 100 parts of PVC, 15 parts of CPE; Stabilizer: 13 parts of ZnSt; Flame retardant: 200 parts of iron oxide powder; 10 parts of Sb2O3; S2: Grinding: Grind the resin and the flame retardant respectively through a grinder; S3: Melting and mixing: First, mix and stir PVC, CPE and the stabilizer, and then add them together with the flame retardant into a high-speed mixer; S4: Extrusion molding: Add the uniformly stirred mixture into a twin-screw extruder for extrusion; S5: Cooling and cutting: Cool the extruded melt through a cooling water tank and then cut it through a cutting machine. The following relevant properties can be obtained: the oxygen index is 30% - 37%, the tensile strength is 12 - 18 MPa, and the elongation at break is ≥150%. This material has good flame retardancy and smoke suppression properties, and excellent mechanical properties and sound insulation effect. It is suitable for making halogen-free flame-retardant modified PVC for boards, strips and their products with flame retardancy, smoke suppression and sound insulation functions.

Description

Technical Field

[0001] The invention relates to the field of modified plastics, in particular to a production process of modified plastic particles. Background Art

[0002] Plastic modification is a field of the plastic industry that involves a wide range of areas, has high technological content, and can create huge economic benefits. The application range of modified plastics is very wide, from the production of raw resins to the production of modified plastic masterbatches of various specifications and varieties. Almost all the properties of plastics can be improved through modification methods, such as the mechanical properties, chemical properties, flame retardant properties, electromagnetic properties, anti-aging properties, etc. of plastics. And plastic modification technology is almost deeply involved in the raw materials and molding processes of all plastic products. In order to reduce the cost of plastic products, improve performance, and enhance functions, plastic modification technology is indispensable. Therefore, it can be said that plastic modification technology is an inevitable way for the development of the plastic industry, and it is an innovation point and power source for the sustainable development of new materials.

[0003] Plastics have excellent properties and are used in a wider range of applications, especially in the construction, transportation, furniture, electronic appliances and daily necessities industries. They are used in large quantities, making people's lives and the environment more convenient and beautifying, and have achieved significant economic and social benefits. They have gradually replaced traditional materials. However, most commonly used plastics are flammable or combustible in the air. When burned, they produce a lot of smoke and toxic gases, which can suffocate people and affect firefighting and rescue work. Therefore, the flame retardant modification technology of plastics has attracted great attention from countries around the world. Summary of the invention

[0004] In order to make plastics have certain flame retardancy, the present application provides a production process for modified plastic particles.

[0005] The modified plastic granule production process provided in this application adopts the following technical solution:

[0006] A modified plastic granule production process comprises the following steps:

[0007] S1: Raw material preparation: Resin: 100 parts PVC, 15 parts CPE; Stabilizer: 13 parts ZnSt; Flame retardant: 200 parts iron oxide powder; 10 parts Sb2O3;

[0008] S2: Grinding: Grinding the resin and the flame retardant separately by a grinder;

[0009] The grinding machine comprises a frame with an inner cavity, a grinding seat and a grinding disc, the frame is provided with a feed inlet and a discharge port connected to the inner cavity, the grinding seat is fixedly connected to the inner cavity, the grinding disc is rotatably connected to the inner cavity along a horizontal axis, and the circumferential side surface of the grinding disc abuts against the grinding seat;

[0010] S3: Melt mixing: Weigh the ingredients according to the formula ratio, first mix and stir the PVC, CPE and stabilizer, and then add them into the high-speed mixer together with the flame retardant, and stir at a temperature of 80°C for 5 minutes;

[0011] S4: Extrusion molding: Add the mixed material after being stirred evenly into a twin-screw extruder for extrusion, and the temperature of the extruder is controlled at about 180 degrees Celsius;

[0012] S5: Cooling and cutting: The melt after extrusion molding is cooled by a cooling water tank and then cut by a cutting machine.

[0013] By adopting the above technical solution, the particle size of the raw material is made more uniform after passing through the grinder; the raw material enters the grinding seat from the feed port, and the grinding disc is driven by the servo motor to swing back and forth to grind the raw material on the grinding seat, and then discharged through the discharge port.

[0014] The relevant properties can be obtained: oxygen index is 30% to 37%, tensile strength is 12 to 18 MPa, and elongation at break is ≥ 150%. The material has good flame retardancy and smoke suppression, and excellent mechanical properties and sound insulation effects. It is suitable for making halogen-free flame retardant modified PVC with flame retardant, smoke suppression and sound insulation functions of plates, strips and their products.

[0015] Preferably, a material storage groove is provided on the circumferential side surface of the grinding disc, and when the grinder is in a grinding state, the material storage groove is opposite to the feed inlet.

[0016] By adopting the above technical solution, the raw materials enter the storage trough through the feed port. When the grinding disc rotates, the quality of the raw materials falling on the grinding seat is the same, reducing the possibility of low grinding efficiency caused by too much raw material falling on the grinding seat.

[0017] Preferably, the grinding disc is provided with bristles, and the bristles are fixedly connected to a side close to the material storage trough.

[0018] By adopting the above technical solution, when the grinding disc rotates to the side where the material storage tank faces the grinding disc, the brush on the grinding disc first brushes the ground raw materials on the grinding seat to clean the grinding seat.

[0019] Preferably, it further comprises a screening mechanism, which comprises a screen and a driving assembly, wherein the screen is hingedly connected to the inner cavity, and the driving assembly is used for driving the movement of the screen.

[0020] By adopting the above technical solution, the ground raw materials are screened through the screen, thereby reducing the possibility of uneven raw material particles falling out of the discharge port.

[0021] Preferably, the driving assembly includes a rotating disk, an abutment rod and a spring. The rotating disk is coaxially and fixedly connected to the grinding disk, a plurality of abutment holes are provided on the circumferential side of the rotating disk, the abutment rod is slidably connected to the inner cavity along the vertical direction, one end of the abutment rod is hingedly connected to the screen, and one end of the abutment rod away from the screen abuts on the circumferential side of the rotating disk, and the spring is arranged on the inner cavity, and the spring always drives the abutment rod to move toward one side of the rotating disk.

[0022] By adopting the above technical solution, the turntable moves with the grinding disc, and when the abutment rod abuts against the abutment hole, the screen rises, and when the abutment rod abuts against the surface of the turntable, the screen falls. The reciprocating motion of the turntable causes the screen to continuously rise and fall, and the ground raw materials on the screen are screened and filtered by inertia to reduce the possibility of uneven particle size of the screened raw materials falling out of the discharge port.

[0023] Preferably, it also includes a transmission device, which is used to transmit raw materials that cannot pass through the screen back to the storage tank. The transmission device includes multiple conveying plates and a driving mechanism. A conveying pipe is fixedly connected to the inner cavity, and an inlet and an outlet are respectively opened on the conveying pipe. The inlet faces the screen, and the outlet is located on the rotation path of the storage tank. The multiple conveying plates move along the axis of the conveying pipe respectively, and the driving mechanism is used to drive the movement of the multiple conveying plates.

[0024] By adopting the above technical solution, when the screening is completed, the raw materials that fail to pass through the screen enter the inlet respectively and fall on the conveying plate. Through the movement of the conveying plate, the raw materials are sent to the outlet and fall into the storage trough. When the storage trough rotates to face the grinding seat, the ground raw materials are sent back to the grinding seat for secondary grinding.

[0025] Preferably, a plurality of arc-shaped valve openings are movably connected to the inner cavity, and an air outlet connecting the outside and the inner cavity is opened at the center position of the plurality of arc-shaped valve openings, and the plurality of air outlets are simultaneously connected to the fan.

[0026] By adopting the above technical solution, the direction of the air outlet is adjusted by the arc valve port. When the screen screening is completed, the fan is started to blow the ground raw materials remaining on the screen to the inlet side through multiple air outlets. The screen can also be cleaned by the airflow, thereby reducing the possibility of clogging of the filter holes on the screen and reducing the possibility of large amounts of raw materials after large-scale grinding on the screen.

[0027] Preferably, the driving mechanism includes a plurality of connecting chains, a sprocket and a first motor, the plurality of connecting chains are respectively fixedly connected to two adjacent conveying plates, the sprocket is rotatably connected to the inner cavity along a horizontal axis, the first motor is fixedly connected to the frame, and one end of the output shaft of the first motor is fixedly connected to the sprocket.

[0028] By adopting the above technical solution, the sprocket is driven to rotate by the first motor, and the multiple connecting chains are respectively meshed and connected with the sprocket to move the multiple connecting chains. Because the conveying tube limits the conveying plate, the conveying plate can only move along the axis of the conveying plate. The two ends of the connecting chain are respectively connected to two adjacent conveying plates, so that when the transmission connecting chain moves, the conveying plates move together.

[0029] The technical effects of the present invention are mainly reflected in the following aspects:

[0030] 1. The present invention provides a material storage tank, and the raw materials enter the material storage tank through the feed port. When the grinding disc rotates, the raw materials falling on the grinding seat are of the same quality, thereby reducing the possibility of low grinding efficiency caused by too much raw materials falling on the grinding seat;

[0031] 2. The present invention provides a screening mechanism to screen the ground raw materials through a screen, thereby reducing the possibility of uneven raw material particles falling out of the discharge port;

[0032] 3. The present invention sets a transmission device. When the screen is screened, the raw materials that fail to pass through the screen enter the inlet and fall on the conveying plate. The conveying plate moves to send the raw materials to the outlet and fall into the storage tank. When the storage tank rotates to face the grinding seat, the ground raw materials are sent back to the grinding seat for secondary grinding. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a process flow chart of an embodiment of the present application.

[0034] Figure 2 It is a schematic diagram of the overall structure of the grinding machine according to the embodiment of the present application.

[0035] Figure 3 It is a schematic diagram of the inner cavity structure of an embodiment of the present application.

[0036] Figure 4 It is a schematic diagram of the structure of the transmission device of an embodiment of the present application.

[0037] Figure 5 yes Figure 4 Enlarged view of point A in the middle.

[0038] Explanation of the reference numerals: 1. frame; 11. inner cavity; 111. feed port; 112. discharge port; 12. grinding seat; 13. grinding disc; 131. storage tank; 14. servo motor; 2. screening mechanism; 21. screen; 22. drive assembly; 221. turntable; 2211. abutment hole; 222. abutment rod; 223. spring; 3. transmission device; 31. conveying plate; 32. conveying pipe; 321. inlet; 322. outlet; 33. drive mechanism; 331. connecting chain; 332. sprocket; 333. first motor; 34. arc valve port; 341. air outlet; 342. fan. DETAILED DESCRIPTION

[0039] The following is combined with Figure 1-5 The present application is further described in detail to make the technical solution of the present application easier to understand and grasp.

[0040] The embodiments of the present application disclose a process for producing modified plastic particles.

[0041] Reference Figure 1 A modified plastic particle production process of this embodiment includes the following steps:

[0042] S1: Raw material preparation: Resin: 100 parts PVC, 15 parts CPE; Stabilizer: 13 parts ZnSt; Flame retardant: 200 parts iron oxide powder; 10 parts Sb2O3;

[0043] S2: Grinding: Grinding the resin and the flame retardant separately by a grinder;

[0044] S3: Melt mixing: Weigh the ingredients according to the formula ratio, first mix and stir the PVC, CPE and stabilizer, and then add them into the high-speed mixer together with the flame retardant, and stir at a temperature of 80°C for 5 minutes;

[0045] S4: Extrusion molding: Add the mixed material after being stirred evenly into a twin-screw extruder for extrusion, and the temperature of the extruder is controlled at about 180 degrees Celsius;

[0046] S5: Cooling and cutting: The melt after extrusion molding is cooled by a cooling water tank and then cut by a cutting machine.

[0047] The above process can obtain the following properties: oxygen index of 30% to 37%, tensile strength of 12 to 18 MPa, elongation at break ≥ 150%. The material has good flame retardancy and smoke suppression, and excellent mechanical properties and sound insulation effect. It is suitable for making halogen-free flame retardant modified PVC with flame retardant, smoke suppression and sound insulation functions of plates, strips and their products.

[0048] Reference Figure 2-Figure 4The grinding machine comprises a frame 1 with an inner cavity 11, a grinding seat 12 and a grinding disc 13. The frame 1 is provided with a feed port 111 and a discharge port 112 connected to the inner cavity 11. The grinding seat 12 is fixedly connected to the inner cavity 11. The grinding disc 13 is connected to the inner cavity 11 by rotation along the horizontal axis. The circumferential side of the grinding disc 13 abuts against the grinding seat 12. After passing through the grinding machine, the particle size of the raw material is made more uniform; the raw material enters the grinding seat 12 from the feed port 111, and the grinding disc 13 is driven to swing back and forth by the servo motor 14 to grind the raw material on the grinding seat 12, and then the material is discharged through the discharge port 112.

[0049] Reference Figure 2-Figure 4 A material storage groove 131 is provided on the circumferential side of the grinding disc 13. When the grinder is in the grinding state, the material storage groove 131 faces the feed port 111. The raw materials enter the material storage groove 131 through the feed port 111. When the grinding disc 13 rotates, the raw materials falling on the grinding seat 12 are of the same quality, which reduces the possibility of low grinding efficiency caused by too much raw materials falling on the grinding seat 12.

[0050] Reference Figure 2-Figure 4 The grinding disc 13 is fixedly connected with brush bristles, which are fixedly connected to a side close to the material storage tank 131. When the grinding disc 13 rotates to the side where the material storage tank 131 faces the grinding disc 13, the brush on the grinding disc 13 first brushes the ground raw materials on the grinding seat 12, cleans the grinding seat 12, and reduces the possibility of residual raw materials on the grinding seat 12.

[0051] Reference Figure 2-Figure 4 , and also includes a screening mechanism 2, the screening mechanism 2 includes a screen 21 and a driving assembly 22, the screen 21 is movably connected to the inner cavity 11, and the driving assembly 22 is used to drive the movement of the screen 21. The ground raw materials are screened by the screen 21 to reduce the possibility of uneven raw material particles falling out of the discharge port 112.

[0052] Reference Figure 2-Figure 5 The driving assembly 22 includes a rotating disk 221, an abutting rod 222 and a spring 223. The rotating disk 221 is coaxially and fixedly connected to the grinding disk 13. A plurality of abutting holes 2211 are provided on the circumferential side of the rotating disk 221. The abutting rod 222 is slidably connected to the inner cavity 11 along the vertical direction. One end of the abutting rod 222 is fixedly connected to the screen 21. One end of the abutting rod 222 away from the screen 21 abuts on the circumferential side of the rotating disk 221. The spring 223 is sleeved on the inner cavity 11. The two ends of the spring 223 abut on the spring 223 respectively, and the spring 223 always drives the abutting rod 222 to move toward one side of the rotating disk 221.

[0053] Reference Figure 2-Figure 4The turntable 221 moves with the grinding disc 13. When the abutting rod 222 abuts against the abutting hole 2211, the screen 21 rises. When the abutting rod 222 abuts against the surface of the turntable 221, the screen 21 falls. The reciprocating motion of the turntable 221 causes the screen 21 to continuously rise and fall. Through inertia, the ground raw materials on the screen 21 are screened and filtered, so that the raw materials with a particle size smaller than the filter hole diameter fall down, and the raw materials with a particle size larger than the filter hole diameter continue to remain on the screen 21, so as to reduce the possibility of uneven particle size of the screened raw materials falling out of the discharge port 112.

[0054] Reference Figure 2-Figure 4 , and also includes a transmission device 3, which is used to transmit the raw materials that cannot pass through the screen 21 back to the storage tank 131. The transmission device 3 includes multiple conveying plates 31 and a driving mechanism 33. A conveying pipe 32 is fixedly connected to the inner cavity 11, and an inlet 321 and an outlet 322 are respectively opened on the conveying pipe 32. The inlet 321 faces the screen 21, and the outlet 322 is located on the rotation path of the storage tank 131. The multiple conveying plates 31 move along the axis of the conveying pipe 32 respectively, and the driving mechanism 33 is used to drive the movement of the multiple conveying plates 31.

[0055] Reference Figure 2-Figure 4 A plurality of arc-shaped valve ports 34 are movably connected to the inner cavity 11, and an air port 341 connecting the outside and the inner cavity 11 is provided at the center of the arc-shaped valve port 34. The plurality of air ports 341 are simultaneously connected to a fan 342, and the direction of the air port 341 is adjusted by the arc-shaped valve port 34. When the screening of the screen 21 is completed, the fan 342 is started, and the ground raw materials remaining on the screen 21 are blown to the side of the inlet 321 through the plurality of air ports 341. The screen 21 can also be cleaned by the air flow, thereby reducing the possibility of clogging of the filter holes on the screen 21 and reducing the possibility of large amounts of raw materials after grinding on the screen 21.

[0056] Reference Figure 2-Figure 4 After the screening of the screen 21 is completed, the airflow blown out through the air outlet 341 causes the raw materials on the screen 21 that fail to pass through the screen 21 to enter the inlet 321 respectively, and make them fall on the conveying plate 31. Through the movement of the conveying plate 31, the raw materials are sent to the outlet 322 and fall into the storage tank 131. When the storage tank 131 rotates to face the grinding seat 12, the ground raw materials are sent back to the grinding seat 12 for secondary grinding.

[0057] Reference Figure 2-Figure 4 The driving mechanism 33 includes a plurality of connecting chains 331, a sprocket 332 and a first motor 333. The plurality of connecting chains 331 are respectively fixedly connected to two adjacent conveying plates 31. The sprocket 332 is rotatably connected to the inner cavity 11 along the horizontal axis direction. The first motor 333 is fixedly connected to the frame 1. One end of the output shaft of the first motor 333 is fixedly connected to the sprocket 332.

[0058] Reference Figure 2-Figure 4 The sprocket 332 is driven to rotate by the first motor 333, and the multiple connecting chains 331 are respectively engaged with the sprocket 332 to move. Because the conveying tube 32 limits the conveying plate 31, the conveying plate 31 can only move along the axis of the conveying plate 31. The two ends of the connecting chain 331 are respectively connected to two adjacent conveying plates 31, so that when the transmission connecting chain 331 moves, the conveying plate 31 moves together.

[0059] Of course, the above are only typical examples of the present application. In addition, the present application may have many other specific implementation methods. All technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present application.

Claims

1. A modified plastic particle production process, characterized in that: The following steps are involved: S1: Raw material preparation: Resin: 100 parts PVC, 15 parts CPE; Stabilizer: 13 parts ZnSt; Flame retardant: 200 parts of iron oxide powder; 10 parts of Sb2O3; S2: Grinding: Grinding the resin and the flame retardant separately by a grinder; The grinding machine comprises a frame (1) with an inner cavity (11), a grinding seat (12) and a grinding disc (13); the frame (1) is provided with a feed port (111) and a discharge port (112) communicating with the inner cavity (11); the grinding seat (12) is fixedly connected to the inner cavity (11); the grinding disc (13) is rotatably connected to the inner cavity (11) along a horizontal axis; the circumferential side surface of the grinding disc (13) abuts against the grinding seat (12); A material storage groove (131) is provided on the circumferential side surface of the grinding disc (13); when the grinding machine is in a grinding state, the material storage groove (131) faces the feed inlet (111); The grinding disc (13) is provided with bristles, and the bristles are fixedly connected to a side close to the material storage tank (131); The device also comprises a screening mechanism (2), wherein the screening mechanism (2) comprises a screen (21) and a driving assembly (22), wherein the screen (21) is hingedly connected to the inner cavity (11), and the driving assembly (22) is used to drive the movement of the screen (21); The driving assembly (22) comprises a rotating disk (221), an abutting rod (222) and a spring (223); the rotating disk (221) is coaxially and fixedly connected to the grinding disk (13); a plurality of abutting holes (2211) are provided on the circumferential side surface of the rotating disk (221); the abutting rod (222) is slidably connected to the inner cavity (11) along the vertical direction; one end of the abutting rod (222) is hingedly connected to the screen (21); one end of the abutting rod (222) away from the screen (21) abuts against the circumferential side surface of the rotating disk (221); the spring (223) is arranged on the inner cavity (11); and the spring (223) always drives the abutting rod (222) to move toward one side of the rotating disk (221); It also comprises a transmission device (3), the transmission device (3) being used for transmitting raw materials that cannot pass through the screen (21) back to the material storage tank (131), the transmission device (3) comprising a plurality of conveying plates (31) and a driving mechanism (33), a conveying pipe (32) being fixedly connected to the inner cavity (11), an inlet (321) and an outlet (322) being respectively provided on the conveying pipe (32), the inlet (321) being oriented toward the screen (21), the outlet (322) being located on the rotation path of the material storage tank (131), the plurality of conveying plates (31) respectively moving along the axis of the conveying pipe (32), and the driving mechanism (33) being used for driving the movement of the plurality of conveying plates (31); The inner cavity (11) is movably connected with a plurality of arc-shaped valve ports (34), and a vent (341) for connecting the outside and the inner cavity (11) is provided at the center of the plurality of arc-shaped valve ports (34), and the plurality of vents (341) are simultaneously connected to a ventilator (342); The driving mechanism (33) comprises a plurality of connecting chains (331), a sprocket (332) and a first motor (333); the plurality of connecting chains (331) are respectively fixedly connected to two adjacent conveying plates (31); the sprocket (332) is rotatably connected to the inner cavity (11) along a horizontal axis; the first motor (333) is fixedly connected to the frame (1); and one end of an output shaft of the first motor (333) is fixedly connected to the sprocket (332); S3: Melt mixing: Weigh the ingredients according to the formula ratio, first mix and stir the PVC, CPE and stabilizer, and then add them into the high-speed mixer together with the flame retardant, and stir at a temperature of 80°C for 5 minutes; S5: Extrusion molding: Add the mixed material after being stirred evenly into a twin-screw extruder for extrusion, and control the temperature of the extruder at about 180 degrees Celsius; S6: Cooling and cutting: The melt after extrusion molding is cooled by a cooling water tank and then cut by a cutting machine.

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