Device for preparing special resin for low-odor high-density polyethylene food-grade bottle cap

Abstract

The utility model discloses a device for preparing special resin for a low-odor high-density polyethylene food-grade bottle cap, which comprises a reactor filled with raw materials, the reactor is sequentially connected with a flash tank, a feeding tank, a centrifugal machine and a fluidized bed through pipelines, an outlet of the fluidized bed is connected with a powder bin for degassing through a pipeline, and the powder bin is connected with a vacuum pump through a pipeline. The powder bin is connected with a granulating and distributing bin through a pipeline, the outlet end of the granulating and distributing bin is connected with a spiral mixer, the spiral mixer is connected with a charging machine used for conveying a compounding agent, the outlet end of the spiral mixer is connected with an extruder through a pipeline, the extruder is connected with a particle mixing bin through a pipeline, and the particle mixing bin is connected with a granulating machine through a pipeline. The device has the technical characteristics of simple structure, strong practicability, realization of long-period production of low-odor high-density polyethylene food-grade bottle cap material resin with high oxidation resistance and stable performance, and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of devices for preparing resin, more specifically, a kind of device for preparing low odor high density polyethylene food grade bottle cap special resin, belong to petrochemical field. BACKGROUND

[0002] High-density polyethylene resin is an important plastic material, in addition to being widely used in packaging, building, electronics, automotive and other fields, it is also deeply developed and used in various fields of people's daily life, among them, polyethylene food grade bottle cap special material has increasing market demand, in addition to the increasing requirements of polyethylene mechanical properties, processing performance and other requirements, its odor requirement is also higher and higher, such as food packaging, beverage packaging, pharmaceutical packaging, cosmetic packaging and other fields all require strict low odor index. The polyethylene bottle cap material produced in the prior art is prone to odor due to solvent and additive, so the polyethylene raw material has the defects of large odor and poor sensory, therefore, a device capable of realizing long-period production of low odor high-density polyethylene food grade bottle cap material resin with high oxidation resistance and stable performance is needed. SUMMARY

[0003] To solve the above technical problems, the utility model provides a kind of device for preparing low odor high density polyethylene food grade bottle cap special resin with the technical features such as simple structure, practicality, long-period production of low odor high-density polyethylene food grade bottle cap material resin with high oxidation resistance and stable performance.

[0004] To achieve the above purpose, the utility model is realized by the following technical scheme:

[0005] A kind of device for preparing low odor high density polyethylene food grade bottle cap special resin, including the reactor that raw material is passed into, the reactor is sequentially connected with flash tank, feed tank, centrifuge, fluidized bed by pipeline, the outlet of the fluidized bed is connected with powder bin for degassing by pipeline, the powder bin is connected with granulation sub-bin by pipeline, the outlet end of the granulation sub-bin is connected with screw mixer, the screw mixer is connected with feeder for conveying compound agent, the outlet end of the screw mixer is connected with extruder by pipeline, the extruder is connected with granular mixing bin by pipeline.

[0006] Preferably, the feeding end of the reactor is sequentially connected with hexane refining recovery unit, preheater, mother liquor recovery tank by pipeline, and the mother liquor recovery tank is connected with centrifuge 4 by pipeline.

[0007] Preferably, powder intermediate bin is connected between the powder bin and the granulation sub-bin by pipeline for secondary degassing.

[0008] Preferably, the extruder is a twin-screw extruder capable of controllable variable speed adjustment.

[0009] Preferably, a material line is connected to the line between the preheater and the mother liquor recovery tank for adding a deactivating agent.

[0010] Preferably, the granulating distribution bin and the feeder both send material into the spiral mixer through a hopper; the spiral mixer sends material into the extruder through a hopper.

[0011] Beneficial effects: The process route of the present application adopts four-stage separation to remove volatile components, and the product is subjected to flash evaporation, preliminary separation by a centrifuge, secondary drying by a fluidized bed, deep treatment by a degassing bin and a powder intermediate bin, which can greatly reduce the volatile content of the product, is beneficial to low residual of hydrocarbon substances in the product, and meets the requirements of food-grade bottle cap material indicators. The device has the advantages of simple structure, strong practicability, and can realize long-period production of low-odor high-density polyethylene food-grade bottle cap material resin with high oxidation resistance and stable performance. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a device structure schematic diagram of the present application. DETAILED DESCRIPTION

[0013] The present application is further described below in conjunction with the drawings of the specification, but the present application is not limited to the following examples.

[0014] As Figure 1 shown is a specific embodiment of a device for preparing low-odor high-density polyethylene food-grade bottle cap special resin, the embodiment is a device for preparing low-odor high-density polyethylene food-grade bottle cap special resin, which comprises a reactor 1 into which raw materials are fed, the reactor 1 is sequentially connected with a flash tank 2, a feed tank 3, a centrifuge 4, and a fluidized bed 5 through pipelines, the outlet of the fluidized bed 5 is connected with a powder bin 6 for degassing through a pipeline, the powder bin 6 is connected with a granulating distribution bin 7 through a pipeline, the outlet end of the granulating distribution bin 7 is connected with a spiral mixer 8, the spiral mixer 8 is connected with a feeder 9 for conveying a compounded agent, the outlet end of the spiral mixer 8 is connected with an extruder 10 through a pipeline, the extruder 10 is connected with a granular material mixing bin 11 through a pipeline, the feed end of the reactor 1 is sequentially connected with a hexane refining recovery unit 14, a preheater 12, and a mother liquor recovery tank 13 through pipelines, a material line 16 is connected to the pipeline between the preheater 12 and the mother liquor recovery tank 13 for adding a deactivating agent. The mother liquor recovery tank 13 is connected with the centrifuge 4 through a pipeline, and the powder bin 6 and the granulating distribution bin 7 are connected with a powder intermediate bin 15 through a pipeline for secondary degassing.

[0015] The preheater 12 is used to preliminarily heat the material entering the hexane refining system to 60-80 DEG C, so as to reduce the heat load of the subsequent evaporator; the mother liquor recovery tank is used to collect the solvent (hexane) preliminarily separated by the centrifuge 4. The hexane refining recovery unit (i.e. the hexane refining system) is prior art, which mainly comprises an evaporator for removing heavy components, a rectifying tower for removing light components, and a cooler and an adsorption tower, and is used to purify the refined solvent (hexane).

[0016] The application adopts a four-stage separation process to remove volatile components, and the product is subjected to flash evaporation, centrifuge preliminary separation, fluidized bed secondary drying, degassing bin and powder intermediate bin deep treatment, so that the volatile component content of the product can be greatly reduced, the low residual of hydrocarbon substances in the product is beneficial, and the food-grade bottle cap material index requirement is achieved.

[0017] After the polyethylene slurry is subjected to flash evaporation tank, centrifuge separation, fluidized bed drying and devolatilization, the secondary gas-solid separation is additionally added and solidified, so that the gas-phase volatile components and oligomers contained in the resin are reduced, the solvent and the residual catalyst and co-catalyst in the resin are inactivated by increasing the injection of a quantitative (according to the actual needs) deactivator in the hexane refining recovery unit, and the long-period production of the low-odor high-density polyethylene food-grade bottle cap material resin with high oxidation resistance and stable performance is realized.

[0018] Embodiment of the device for production according to the application:

[0019] Embodiment 1:

[0020] Polyethylene powder, polymerization load 38 t / h, polymerization temperature 83 °C, one reverse ethylene partial pressure 239 kPa, one reverse reaction total pressure 524 kPa, H2 / C2 concentration ratio 0.696 mol / mol, C6 / C2 concentration ratio 0.006 mol / mol; two reverse ethylene partial pressure 251 kPa, two reverse reaction total pressure 533 kPa, H2 / C2 concentration ratio 0.684 mol / mol, C6 / C2 concentration ratio 0.0060 mol / mol. Mixer speed 850 rpm, solvent recovery unit deactivator 8 kg / h, secondary degassing powder bin 200 tons, degassing time 5 h, catalyst activity 20 tPE / kg, complex agent HDPE 2-8 (main components are 37.5% composite antioxidant, 62.5% thermal stabilizer). The above polyethylene powder, complex agent are measured and mixed according to a certain ratio, and then the double screw mixer is rotated at a speed of 850 rpm, and the temperatures of the four extruder zones are 201 °C, 197 °C, 242 °C and 216 °C, respectively. The density of the obtained polyethylene resin product is 0.9583 g / cm 3 , the melt mass flow rate is 3.40 g / 10 min, the tensile yield stress is 24.4 MPa, the nominal strain at break is 801%, and the notched Charpy impact strength is 10 kJ / m 2 .

[0021] Example 2:

[0022] Polyethylene powder, polymerization load 36 t / h, polymerization temperature 83 °C, one reverse ethylene partial pressure 243 kPa, one reverse reaction total pressure 546 kPa, H2 / C2 concentration ratio 0.772 mol / mol, C6 / C2 concentration ratio 0.0050 mol / mol; two reverse ethylene partial pressure 231 kPa, two reverse reaction total pressure 543 kPa, H2 / C2 concentration ratio 0.796 mol / mol, C6 / C2 concentration ratio 0.0049 mol / mol. Mixer speed 850 rpm, solvent recovery unit deactivator 8 kg / h, powder secondary degassing time 4 h, catalyst activity 19 tPE / kg, complex agent HDPE 2-8 (main components are 37.5% composite antioxidant, 62.5% thermal stabilizer). The above polyethylene powder, complex agent are measured and mixed according to a certain ratio, and then the double screw mixer is rotated at a speed of 840 rpm, and the temperatures of the extruder zones are 208 °C, 196 °C, 212 °C and 242 °C, respectively. The density of the obtained polyethylene resin product is 0.9580 g / cm 3 , the melt mass flow rate is 3.72 g / 10 min, the tensile yield stress is 24.5 MPa, the nominal strain at break is 612%, and the notched Charpy impact strength is 9.8 kJ / m 2 .

[0023] Preferably, the extruder 10 is a controllable variable speed twin screw extruder. The granulating distribution bin 7 and the feeder 9 both feed the material into the spiral mixer 8 through a hopper; the spiral mixer 8 feeds the material into the extruder 10 through a hopper.

[0024] Finally, it should be noted that the present application is not limited to the above embodiments, but can have many variations. All variations that can be directly derived or inferred from the content disclosed in the present application by those of ordinary skill in the art should be considered within the scope of the present application.

Claims

1. An apparatus for preparing a low odor high density polyethylene food grade bottle cap specialty resin, characterized by: The application relates to a production line for producing granular fertilizer, which comprises a reactor (1) into which raw materials are fed, a flash tank (2), a feed tank (3), a centrifuge (4), a fluidized bed (5) connected in sequence through pipelines, a powder bin (6) for degassing connected through a pipeline at the outlet of the fluidized bed (5), a granulation distribution bin (7) connected through a pipeline at the powder bin (6), a spiral mixer (8) connected at the outlet end of the granulation distribution bin (7), a feeder (9) for conveying a compound agent connected on the spiral mixer (8), an extruder (10) connected through a pipeline at the outlet end of the spiral mixer (8), and a granular material mixing bin (11) connected through a pipeline at the extruder (10).

2. A device for preparing a low odor high density polyethylene food grade bottle cap special resin according to claim 1, characterized in that: The feed end of the reactor (1) is connected in sequence through pipelines with a hexane refining recovery unit (14), a preheater (12) and a mother liquor recovery tank (13), and the mother liquor recovery tank (13) is connected through a pipeline with the centrifuge (4).

3. A device for preparing a low odor high density polyethylene food grade bottle cap special resin according to claim 1 or 2, characterized in that: A powder intermediate bin (15) is connected through a pipeline between the powder bin (6) and the granulation distribution bin (7) for secondary degassing.

4. A device for preparing a low odor high density polyethylene food grade bottle cap special purpose resin according to claim 1, characterized in that: The extruder (10) is a controllable variable-speed adjustable double-screw extruder.

5. A device for preparing a low odor high density polyethylene food grade bottle cap special purpose resin according to claim 2, characterized in that: A material pipeline (16) is connected on the pipeline between the preheater (12) and the mother liquor recovery tank (13) for adding an inactivating agent.

6. A device for preparing a low odor high density polyethylene food grade bottle cap special purpose resin according to claim 1, characterized in that: The granulation distribution bin (7) and the feeder (9) both feed materials into the spiral mixer (8) through funnels; the spiral mixer (8) feeds materials into the extruder (10) through a funnel.

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