Extrusion device for processing polymer flame retardant materials

Abstract

The utility model discloses an extrusion device for processing polymer flame retardant materials, belonging to the field of polymer materials. The device includes an extruder, multiple feeding structures, a double screw feeder, a vacuum filter and a vacuum pump. The feeding structure includes a micro powder feeding structure and at least one non-micro powder feeding structure, and the non-micro powder feeding structure is connected to the first feeding port of the extruder; the double screw feeder is arranged on the left or right side of the extruder, and a discharge port is arranged at its inner end, and a second feed port is arranged on the upper side of its outer end, and a negative pressure port is arranged on it; the discharge port is connected to the left or right side of the plasticizing section, and the second feed port is connected to the micro powder feeding structure; the negative pressure port is arranged near the discharge port, and a filter screen through which the micro powder cannot pass is arranged on it, and it is connected to the vacuum pump through a pipeline with a vacuum filter. The micro powder is fed separately and forced to be fed through the double screw feeder to avoid the micro powder blocking the feed port; other raw materials are fed in the existing way.

Description

Technical Field

[0001] The utility model belongs to the field of polymer materials, and particularly relates to an extrusion device for processing polymer flame retardant materials, which is suitable for the case where a large amount of micro powder is used (such as an addition amount greater than 30%). Background Art

[0002] Wires and cables are wire products used to transmit electrical energy, information and realize electromagnetic energy conversion. Wires and cables in a broad sense are also referred to as cables. Cables in a narrow sense refer to insulated cables, which can be defined as: a collection of the following parts; one or more insulated cores, and their respective coatings, total protective layers and outer sheaths. Cables may also have additional uninsulated conductors. The coating, total protective layer or outer sheath are usually made of polymer materials, which leads to the fact that when a fire occurs, the polymer materials are easily decomposed after being heated to release a large amount of highly toxic and corrosive (such as hydrogen chloride) gases, and produce a large amount of highly toxic smoke, causing significant loss of life and property, and bringing great difficulties to rescue work. In order to avoid and reduce fires and secondary damage caused by fires as much as possible, existing technologies can use flame-retardant cables.

[0003] For example, the patent with application number CN202310141266.7 discloses a flame retardant masterbatch for high CTI flame retardant PC products, which comprises the following components: SAN resin: 10-20%, aluminum hydroxide: 77-83.8%, silicon-based additive: 1-5%, antioxidant: 0.1-0.3%, and lubricant: 1-2%. For example, the patent with application number CN201911088055.1 discloses a thermoplastic radiation-resistant halogen-free low-smoke flame-retardant sheath material for nuclear power plant cables. The sheath material includes the following components in parts by weight: base material: 100, the base material contains at least a high temperature resistant polyolefin elastomer; high temperature resistant radiation resistant modified masterbatch: 30-40, the high temperature resistant radiation resistant modified masterbatch contains at least a condensed polycyclic polynuclear aromatic resin and a high temperature resistant radiation resistant resin; flame retardant: 100-200, the flame retardant contains at least aluminum hydroxide; antioxidant: 4.0-12, the antioxidant contains at least an asymmetric hindered phenol-type calixarene as the main antioxidant; anti-radiation agent: 1.0-12.

[0004] In the prior art, the flame retardancy is usually improved by adding inorganic powders (with very small particle size) such as aluminum hydroxide and magnesium hydroxide. The existing production process of flame retardant materials is as follows: after each feeding device feeds the material, it is sent to each feeding structure through negative pressure, the feeding structure weighs the raw material, and then feeds it into the feed port of the extruder according to the ratio, and the extruder extrude and granulate it.

[0005] Common extruders can refer to the following patents. For example, the patent with application number CN201520412165.X discloses a twin-screw extruder screw assembly for manufacturing anti-adhesion masterbatch, including: a shell, two screws with the same structure are arranged in the shell, and the two screws are meshed and rotated with each other; the screw includes: a conveying section, a melt mixing section, a venting section and a homogenizing compression section; a conveying element is arranged in the conveying section; a meshing element and a ZME mixing element are arranged in the melt mixing section. For example, the patent with application number CN201920680594.3 discloses a screw for a conical twin-screw extruder, including a screw body, and the screw body is composed of a feeding section, a plasticizing section, a venting section and a homogenizing extrusion section; for example, the patent with application number CN201821368436.6 discloses a screw combination of an extruder, and the screw combination includes two mutually meshing screws, which are divided into a feeding section, a plasticizing section, a venting section, a mixing section, a first vacuum devolatilization section, a homogenizing section, a second vacuum devolatilization section, and a metering section from one end of the screw combination to the other end of the screw combination.

[0006] In the prior art, polymer base materials, auxiliary materials and micropowders are all added at the feed port of the extruder (freely falling by gravity). Micropowders are special compared to other raw materials. For example, aluminum hydroxide or magnesium hydroxide is easy to absorb moisture (especially on rainy days. In addition, at the feed port, the polymer is heated and will emit a little water vapor). Micropowders that have absorbed moisture tend to adhere to the feed port of the extruder, slowing down the feed speed of the extruder (the feed port becomes smaller, especially when the amount of micropowder is large), or even clogging, reducing production efficiency. Summary of the invention

[0007] In order to solve the above problems, the embodiment of the utility model provides an extrusion device for processing polymer flame retardant materials. The micro powder is fed separately and forced to feed through a double screw feeder to avoid the micro powder blocking the feed port and affecting the feeding of other raw materials; other raw materials are fed in the existing way to ensure production efficiency. A vacuum filter and a vacuum pump are used to force the exhaust of hot air to avoid clogging of the discharge port of the double screw feeder. The technical solution is as follows:

[0008] The utility model provides an extrusion device for processing polymer flame retardant materials, the device comprising an extruder 1 and a plurality of feeding structures 2 arranged in a front-to-back direction, the extruder 1 comprising a feeding section 11, a plasticizing section 12, an exhaust section 13 and a homogenizing extrusion section 14 arranged in sequence from front to back, the top of the feeding section 11 is provided with a first feeding port 15, the top of the exhaust section 13 is provided with an exhaust port 16, the feeding structure 2 is located above the extruder 1 and comprises a micro powder feeding structure 21 and at least one non-micro powder feeding structure 22, the non-micro powder feeding structure The structure 22 is connected to the first feed port 15; the extrusion device also includes a double-screw feeder 3, a vacuum filter 4 and a vacuum pump 5; the double-screw feeder 3 is arranged on the left or right side of the extruder 1, and a discharge port is arranged at its inner end, and a second feed port 31 is arranged on the upper side of its outer end, and a negative pressure port 32 is arranged on it; the discharge port is connected to the left or right side of the plasticizing section 12, and the second feed port 31 is connected to the micro-powder feeding structure 21; the negative pressure port 32 is arranged close to the extruder 1, and a filter screen through which the micro-powder cannot pass is arranged on it, and it is connected to the vacuum pump 5 through a pipeline with a vacuum filter 4.

[0009] Specifically, the extruder 1 in the embodiment of the utility model includes 7-12 barrel segments arranged side by side in front and back, a first feed port 15 is provided at the top of the first barrel segment, an exhaust port 16 is provided at the top of the fourth barrel segment, and the discharge port of the double-screw feeder 3 is connected to the left or right side of the third barrel segment.

[0010] Specifically, the double-screw feeder 3 in the embodiment of the utility model is arranged in the left-right direction, and two screws are arranged side by side in the front and back, and negative pressure ports 32 are provided on the upper and lower sides; the negative pressure port 32 is located between the two screws.

[0011] Among them, the non-micropowder feeding structure 22 in the embodiment of the utility model is located directly above the first feed port 15; the micropowder feeding structure 21 is located next to the non-micropowder feeding structure 22, and a screw conveyor 6 is horizontally provided at the discharge port at the bottom thereof; the discharge port of the screw conveyor 6 is arranged downward and is connected to the second feed port 31 through a vertical straight pipe 7.

[0012] Furthermore, the two negative pressure ports 32 in the embodiment of the utility model are connected by a C-shaped hard tube 33, and the C-shaped hard tube 33 is located in front of or behind the double-screw feeder 3 and is connected to an L-shaped hard tube 34 in the middle thereof; the L-shaped hard tube 34 is arranged in the left-right direction, and is located directly in front of or behind the double-screw feeder 3, and the inner end of its horizontal tube is connected to the middle part of the outer side of the C-shaped hard tube 33, and its vertical tube is located at the lower side of the outer end of the horizontal tube; the vertical tube is provided with a first valve 35 and its lower end is connected to the vacuum filter 4 through a steel wire braided hose.

[0013] Furthermore, an upper bypass pipe 36 and a lower bypass pipe 37 are respectively provided on the upper and lower sides of the horizontal pipe in the embodiment of the utility model. The upper bypass pipe 36 and the lower bypass pipe 37 are relatively arranged and are both arranged vertically. The upper end of the upper bypass pipe 36 is provided with a pressure gauge 38 and is closed by the pressure gauge 38, and the lower bypass pipe 37 is provided with a second valve 39 and its lower end is open.

[0014] Specifically, the L-shaped hard tube 34 in the embodiment of the utility model is located at the rear side of the double screw feeder 3 , and the vacuum filter 4 and the vacuum pump 5 are located at the front and lower side of the double screw feeder 3 .

[0015] Among them, the vacuum filter 4 in the embodiment of the utility model includes a vertically arranged sealing tank, a filter element in the sealing tank and a head hinged on the top of the sealing tank, and the head can be screwed open upward; the upper part of the sealing tank is connected to the L-shaped hard tube 34 through a steel wire braided hose, and the bottom thereof is connected to the vacuum pump 5 through a steel wire braided hose.

[0016] Specifically, the number of the non-micro powder feeding structures 22 in the embodiment of the utility model is two, and the feeding structure 2 includes a feeding module and a weighing bin arranged in sequence from top to bottom.

[0017] This patent has the following beneficial effects: The embodiment of the utility model provides an extrusion device for processing polymer flame retardant materials. The micro powder is fed separately and forced to be fed through a double screw feeder to avoid the micro powder blocking the feed port and affecting the feeding of other raw materials; other raw materials are fed in the existing way; production efficiency is guaranteed. In addition, by pumping negative pressure on the double screw feeder (it can work intermittently, regularly or when the double screw feeder may be blocked), the hot air (and possibly water vapor) at the discharge port of the double screw feeder is discharged in time to avoid the discharge port of the double screw feeder being blocked. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of an extrusion device for processing polymer flame retardant materials in an embodiment of the utility model;

[0019] Figure 2 It is a top view of an extrusion device used for processing polymer flame retardant materials;

[0020] Figure 3 It is a structural diagram of a double screw feeder.

[0021] In the figure: 1 extruder, 2 feeding structure, 3 double screw feeder, 4 vacuum filter, 5 vacuum pump, 6 screw conveyor, 7 straight pipe;

[0022] 21 micro powder feeding structure, 22 non-micro powder feeding structure;

[0023] 11 feeding section, 12 plasticizing section, 13 exhaust section, 14 homogenizing extrusion section, 15 first feeding port, 16 exhaust port;

[0024] 31 second feed port, 32 negative pressure port, 33 C-shaped hard pipe, 34 L-shaped hard pipe, 35 first valve, 36 upper bypass pipe, 37 lower bypass pipe, 38 pressure gauge, 39 second valve. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the utility model clearer, the utility model will be further described in detail below with reference to the accompanying drawings.

[0026] Example 1

[0027] See also Figure 1-3Embodiment 1 provides an extrusion device for processing polymer flame retardant materials, which includes an extruder 1, a double screw feeder 3, a vacuum filter 4, a vacuum pump 5 and a plurality of feeding structures 2. The extruder 1 is arranged in the front-to-back direction, and a feeding section 11, a plasticizing section 12, an exhaust section 13 and a homogenizing extrusion section 14 are arranged in sequence from front to back. A first feed port 15 (a bucket-shaped structure) is provided at the top of the feed section 11, and an exhaust port 16 is provided at the top of the exhaust section 13. The feeding structure 2 is located above the extruder 1, and includes a micro-powder feeding structure 21 and at least one non-micro-powder feeding structure 22 (usually multiple), which includes a feeding module and a weighing bin arranged in sequence from top to bottom (consistent with the prior art, the weighing bin is connected to the first feed port 15 or the second feed port 31). The micro powder feeding structure 21 is used to quantitatively output micro powder (such as aluminum hydroxide or magnesium hydroxide, etc.), and the non-micro powder feeding structure 22 is used to quantitatively output other raw materials (usually particles or fine powders, including polymer base materials and auxiliary materials, etc.) other than micro powder. The non-micro powder feeding structure 22 is located directly above the first feeding port 15, and is connected to the first feeding port 15 (consistent with conventional technology, using gravity to freely fall). The double-screw feeder 3 is arranged on the left or right side of the extruder 1, and is arranged in the left-right direction. Two screws are arranged side by side in the front and back of the double-screw feeder 3. The inner end (the end close to the extruder 1 is defined as the inner end in this embodiment) is provided with a discharge port (toward the left or right side of the extruder 1). The inner end is fixed on the extruder 1, and is connected to the inner cavity of the extruder 1. The upper side of the outer end is provided with a second feed port 31 (vertically arranged), and the upper and lower sides are provided with negative pressure ports 32 (vertically arranged, connected to the inner cavity of the double-screw feeder 3), which are used to force the extruder 1 to output micro powder. Specifically, it can be bonengK306FG-B56-D201 (parameters are n2: 259RPM, n1: 1450RPM). Preferably, the double-screw feeder 3 is arranged close to the exhaust port 16 to reduce the heat and pressure at the discharge port of the double-screw feeder 3. The discharge port is connected to the left or right side of the plasticizing section 12, and the second feed port 31 is connected to the micro-powder feed structure 21. Specifically, the micro-powder feed structure 21 is located next to the non-micro-powder feed structure 22, and the discharge port at the bottom thereof is horizontally provided with a screw conveyor 6. The discharge port of the screw conveyor 6 (located directly above the second feed port 31) is set downward and connected to the second feed port 31 through a vertical straight pipe 7. The negative pressure port 32 is arranged near the discharge port to discharge the hot air at the discharge port in time. It is located between the two screws and is provided with a filter screen through which the micro-powder cannot pass. The area of ​​the filter screen in this embodiment is large to avoid being completely blocked. Specifically, the double screw feeder 3 is provided with a negative pressure cavity (specifically a rectangular cavity arranged in the left and right directions, the inner cavity cooperates with the screw) at the negative pressure port 32, and the negative pressure ports 32 are provided on both the upper and lower sides of the negative pressure cavity and can be disassembled to replace or clean the filter screen; the filter screen is located adjacently above or adjacently below the upper and lower sides of the negative pressure cavity, and covers the entire cross-section of the negative pressure cavity to increase the area. The filter screen needs to be replaced or cleaned regularly.The two negative pressure ports 32 (which can be connected together first) are connected to the vacuum pump 5 through a pipeline with a vacuum filter 4. The vacuum pump 5 can work intermittently to maintain a slight negative pressure at the negative pressure port 32 (to ensure that the hot air can be discharged in time, and the pressure cannot be too large to avoid suction from the exhaust port 16, and to ensure that the exhaust port 16 is exhausted normally). Specifically, the distance between the negative pressure port 32 and the discharge port of the double screw feeder 3 is 2-6 cm, and the distance between it and the second feed port 31 is greater than 15 cm.

[0028] Furthermore, the two negative pressure ports 32 in the embodiment of the utility model are connected by a C-shaped hard tube 33, which is located in front of or behind the double screw feeder 3 and is connected to an L-shaped hard tube 34 in the middle. The L-shaped hard tube 34 is arranged in the left-right direction, and is located directly in front of or directly behind the double screw feeder 3, and includes a horizontal tube and a vertical tube. The horizontal tube is arranged in the left-right direction, and its inner end is connected to the middle of the outer side of the C-shaped hard tube 33, and an upper bypass tube 36 and a lower bypass tube 37 are respectively arranged on its upper and lower sides. The vertical tube is arranged vertically, and is located at the lower side of the outer end of the horizontal tube, and a first valve 35 is arranged on it, and its lower end is connected to the upper part of the vacuum filter 4 through a steel wire braided hose. The upper bypass pipe 36 and the lower bypass pipe 37 are arranged opposite to each other and are arranged vertically. The upper end of the upper bypass pipe 36 is provided with a pressure gauge 38 and is closed by the pressure gauge 38 (to detect air pressure). The lower bypass pipe 37 is provided with a second valve 39 (usually closed) and its lower end is open for pressure relief. The first valve 35, the second valve 39 and the pressure gauge 38 ensure that the discharge port of the double screw feeder 3 is slightly negative pressure.

[0029] The vacuum filter 4 in the embodiment of the utility model includes a vertically arranged sealing tank, a filter element in the sealing tank (tiny dust cannot pass through to avoid affecting the vacuum pump 5), and a hinged head on the top of the sealing tank, etc. The head can be screwed upward to replace the filter element, which is consistent with the structure of the existing vacuum filter. The upper part of the sealing tank is connected to the L-shaped hard pipe 34 through a steel wire braided hose, and the bottom of the sealing tank is connected to the vacuum pump 5 through a steel wire braided hose.

[0030] Example 2

[0031] See also Figure 1-2 Embodiment 2 provides an extrusion device for processing polymer flame retardant materials, and its structure is basically the same as that of Embodiment 1, except that: the extruder 1 in this embodiment includes 7-12 barrel sections arranged side by side in front and back, a first feed port 15 is provided at the top of the first barrel section, an exhaust port 16 is provided at the top of the fourth barrel section, and the discharge port of the double-screw feeder 3 is connected to the left or right side of the third barrel section so as to be arranged close to the exhaust port 16.

[0032] Example 3

[0033] See also Figure 2Example 3 provides an extrusion device for processing polymer flame retardant materials, and its structure is basically the same as that of Example 1, except that: the double screw feeder 3 in this embodiment is arranged on the right side of the extruder 1, the L-shaped hard pipe 34 is located on the rear side of the double screw feeder 3, the C-shaped hard pipe 33 is located on the rear side of the double screw feeder 3 and is open to the front, and the vacuum filter 4 and the vacuum pump 5 are located at the front and lower part of the double screw feeder 3.

[0034] Example 4

[0035] See also Figure 1 Embodiment 4 provides an extrusion device for polymer flame retardant material processing, and its structure is basically the same as that of Embodiment 1, except that the amount of micropowder in this embodiment is 40-50% of the total weight of the raw material. There are two non-micropowder feeding structures 22, one non-micropowder feeding structure 22 is used to output the polymer base material, and the other non-micropowder feeding structure 22 is used to output other raw materials.

[0036] Among them, "first", "second", "third" and "fourth" in this patent only serve to distinguish and have no other special meanings.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An extrusion device for processing polymer flame retardant materials, comprising an extruder (1) and a plurality of feed structures (2) arranged in a front-to-back direction, wherein the extruder (1) comprises a feed section (11), a plasticizing section (12), an exhaust section (13) and a homogenizing extrusion section (14) arranged in sequence from front to back, a first feed port (15) being provided at the top of the feed section (11), an exhaust port (16) being provided at the top of the exhaust section (13), the feed structure (2) being located above the extruder (1) and comprising a micro powder feed structure (21) and at least one non-micro powder feed structure (22), the non-micro powder feed structure (22) being connected to the first feed port (15); characterized in that: The extrusion device further comprises a double-screw feeder (3), a vacuum filter (4) and a vacuum pump (5); the double-screw feeder (3) is arranged on the left side or the right side of the extruder (1), and is provided with a discharge port at its inner end, and is provided with a second feed port (31) on the upper side of its outer end, on which a negative pressure port (32) is provided; the discharge port is connected to the left side or the right side of the plasticizing section (12), and the second feed port (31) is connected to the micro-powder feeding structure (21); the negative pressure port (32) is arranged close to the discharge port, and is provided with a filter screen through which micro-powder cannot pass, and is connected to the vacuum pump (5) via a pipeline with a vacuum filter (4).

2. The extrusion device for polymer flame retardant material processing according to claim 1, characterized in that: The extruder (1) comprises 7-12 barrel sections arranged side by side in a front-to-back manner, a first feed port (15) is provided at the top of the first barrel section, an exhaust port (16) is provided at the top of the fourth barrel section, and the discharge port of the double-screw feeder (3) is connected to the left or right side of the third barrel section.

3. The extrusion device for polymer flame retardant material processing according to claim 1, characterized in that: The double-screw feeder (3) is arranged in the left-right direction, and two screws are arranged side by side in the front and back. Negative pressure ports (32) are provided on both the upper and lower sides of the double-screw feeder; the negative pressure port (32) is located between the two screws.

4. The extrusion device for polymer flame retardant material processing according to claim 1, characterized in that: The non-micro powder feeding structure (22) is located directly above the first feeding port (15); the micro powder feeding structure (21) is located next to the non-micro powder feeding structure (22), and a screw conveyor (6) is horizontally provided at the discharge port at the bottom thereof; the discharge port of the screw conveyor (6) is arranged downward and is connected to the second feeding port (31) through a vertical straight pipe (7).

5. The extrusion device for processing polymer flame retardant materials according to claim 3, characterized in that: The two negative pressure ports (32) are connected via a C-shaped hard tube (33), the C-shaped hard tube (33) is located in front of or behind the double screw feeder (3) and is connected to an L-shaped hard tube (34) in the middle thereof; the L-shaped hard tube (34) is arranged in a left-right direction and is located directly in front of or behind the double screw feeder (3), the inner end of the horizontal tube is connected to the middle of the outer side of the C-shaped hard tube (33), and the vertical tube is located at the lower side of the outer end of the horizontal tube; the vertical tube is provided with a first valve (35) and the lower end thereof is connected to a vacuum filter (4) via a steel wire braided hose.

6. The extrusion device for processing polymer flame retardant materials according to claim 5, characterized in that: An upper bypass pipe (36) and a lower bypass pipe (37) are respectively provided on the upper and lower sides of the horizontal pipe. The upper bypass pipe (36) and the lower bypass pipe (37) are arranged opposite to each other and are both arranged vertically. A pressure gauge (38) is provided at the upper end of the upper bypass pipe (36) and is closed by the pressure gauge (38). A second valve (39) is provided on the lower bypass pipe (37) and its lower end is open.

7. The extrusion device for processing polymer flame retardant materials according to claim 5, characterized in that: The L-shaped hard pipe (34) is located at the rear side of the double screw feeder (3), and the vacuum filter (4) and the vacuum pump (5) are located at the front and lower part of the double screw feeder (3).

8. The extrusion device for processing polymer flame retardant materials according to claim 5, characterized in that: The vacuum filter (4) comprises a vertically arranged sealing tank, a filter element in the sealing tank and a sealing head hinged on the top of the sealing tank, wherein the sealing head can be screwed open upwards; the upper part of the sealing tank is connected to an L-shaped hard pipe (34) via a steel wire braided hose, and the bottom part of the sealing tank is connected to a vacuum pump (5) via a steel wire braided hose.

9. The extrusion device for processing polymer flame retardant materials according to claim 1, characterized in that: The number of the non-micro powder feeding structures (22) is two, and the feeding structure (2) comprises a feeding module and a weighing bin which are arranged in sequence from top to bottom.

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