PVC (polyvinyl chloride) cable material extrusion pretreatment device

Abstract

The utility model relates to a PVC (polyvinyl chloride) cable material extrusion pretreatment device which comprises a mixing tank pivotally arranged on a rack, a rotary driving unit and a stirring unit arranged on the mixing tank. And a conveying pipe communicated with a tank cavity of the mixing tank is arranged on the mixing tank. The rotary driving unit can drive the mixing tank to rotate around an axis extending in the transverse direction relative to the rack. The stirring unit comprises a rotating shaft arranged in the mixing tank, a plurality of arm levers fixed on the rotating shaft, and scraping plates fixedly arranged at the free ends of the arm levers. And in the rotating direction of the rotating shaft, the distance between the upstream end of the scraper and the inner wall of the tank cavity is larger than that between the downstream end of the scraper and the inner wall of the tank cavity. The connecting position of the arm rod and the scraper blade is relatively close to the downstream end. According to the utility model, the working efficiency of mixing plastic master batches in the production process of PVC cable materials can be improved, the time consumed in the extrusion pretreatment process of the PVC cable materials can be saved, and the production efficiency of the PVC cable materials is improved.

Description

Technical Field

[0001] This utility model relates to the field of PVC cable material extrusion technology, and more specifically to a PVC cable material extrusion pretreatment device. Background Technology

[0002] PVC cable material is made from polyvinyl chloride as the base resin, with the addition of stabilizers, plasticizers such as dioctyl phthalate, diisodecyl phthalate, dioctyl terephthalate, and trioctyl trimellitate, as well as inorganic fillers such as calcium carbonate, additives, and lubricants, through mixing, kneading, and extrusion. Therefore, the production process of PVC cable material involves mixing various raw material masterbatches. In the past, conventional mixers were often used to mix the plastic masterbatches. When the total amount of raw material masterbatches was relatively large, the thickness of the masterbatches in the mixing chamber of the mixer would be significant. In this case, the mixing paddle could not easily mix the masterbatches at the bottom and top of the mixing chamber evenly in a short time, requiring a longer mixing time to achieve the required mixing efficiency. Utility Model Content

[0003] To improve the efficiency of mixing various plastic masterbatches during the production of PVC cable materials, this invention provides a PVC cable material extrusion pretreatment device, which helps save time required for the PVC cable material extrusion pretreatment process and improves the production efficiency of PVC cable materials.

[0004] The technical solution adopted by this utility model to solve its technical problem is: a PVC cable material extrusion pretreatment device, including a mixing tank pivotally mounted on a frame, a rotary drive unit fixed on the frame, and a stirring unit mounted on the mixing tank.

[0005] A conveying pipe is installed on the mixing tank and communicates with its cavity. The various plastic masterbatches to be mixed are fed into the cavity of the mixing tank through the conveying pipe, at which point the conveying pipe is positioned at the top of the mixing tank. After mixing is completed, the conveying pipe is moved to a position at the bottom of the mixing tank, and the uniformly mixed plastic masterbatches are discharged from the cavity of the mixing tank through the conveying pipe and sent to the next process.

[0006] The rotary drive unit enables the mixing tank to rotate relative to the frame about an axis extending in the lateral direction.

[0007] The mixing unit includes a rotating shaft located in a mixing tank, multiple arms fixed to the rotating shaft, and scrapers fixed at the free ends of the arms. The scrapers are arc-shaped and positioned in the direction of rotation of the rotating shaft, such that the distance between the upstream end of the scraper and the inner wall of the tank cavity is greater than the distance between the downstream end of the scraper and the inner wall of the tank cavity; the connection between the arms and the scrapers is relatively close to the downstream end.

[0008] Optionally, a gear surface is formed on the outer wall of the mixing tank. The rotary drive unit includes a drive gear matched with a motor, and the drive gear meshes with the gear surface.

[0009] Optionally, a fin assembly is provided on the scraper surface, near the upstream end. The fin assembly includes a pair of inner fins, an arc-shaped intermediate fin, and V-shaped side fins. The inner fins, intermediate fins, and side fins are distributed alternately in the width direction of the scraper.

[0010] One end of each of the two inner fins extends to both ends along the length of the scraper, while the other ends extend obliquely towards the middle fin, forming a gap between them. The convex surface of the middle fin faces the inner fins, and the concave surface of the side fins faces the concave surface of the middle fin. Both ends of the side fins extend to the end faces along the length of the scraper. The two ends of the middle fin form a gap relative to the end faces along the length of the scraper.

[0011] Optionally, the height of the inner fin is less than the height of the middle fin; the height of the middle fin is less than the height of the side fin.

[0012] Optionally, the free ends of the inner fin, the middle fin, and the side fin are all inclined towards the upstream end.

[0013] Optionally, the fin assembly also includes a pair of side plates. The side plates connect the end of the inner fin extending to the end face of the scraper along its length to the end face of the side fin extending to the end face of the scraper along its length.

[0014] Optionally, multiple sets of protruding ribs are distributed on the scraper surface near the downstream end, and these rib sets are alternately distributed along the length of the scraper. Each set of ribs includes side ribs and inner ribs. A lengthwise spacing is formed between the opposite ends of the side ribs and inner ribs. Both the side ribs and inner ribs extend obliquely relative to the width of the scraper, so that the inner extension lines of the side ribs can intersect near the middle of the inner ribs. The oblique extension directions of both allow the side ribs to guide the raw material masterbatch to converge and flow from the scraper's length towards both ends towards the middle, while the inner ribs guide the raw material masterbatch to disperse and flow from the scraper's length towards both ends.

[0015] Optionally, an elastic rubber strip is fixedly provided at the downstream edge of the scraper, the elastic rubber strip extending through the entire length of the scraper, and the free end of the elastic rubber strip contacting the inner wall of the mixing tank cavity.

[0016] The beneficial effects of this utility model are: it can improve the efficiency of mixing plastic masterbatch in the production process of PVC cable material, help save the time required for the extrusion pretreatment process of PVC cable material, and improve the production efficiency of PVC cable material. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model.

[0018] Figure 2 This is a top view of the scraper's structure.

[0019] In the diagram: 10 Frame; 20 Mixing tank; 21 Conveying pipe; 22 Gear surface; 30 Rotary drive unit; 31 Drive gear; 32 Drive motor; 40 Stirring unit; 41 Arm; 42 Scraper; 421 Upstream end; 422 Downstream end; 43 Fin assembly; 431 Inner fin; 432 Middle fin; 433 Side fin; 434 Side plate; 44 Rib assembly; 441 Side rib; 442 Inner rib. Detailed Implementation

[0020] The structures, proportions, and sizes shown in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art. They are not intended to limit the scope of this invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of this invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, terms such as "upper," "lower," "front," "rear," and "middle" used in this specification are merely for clarity and not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

[0021] like Figure 1 , Figure 2 The PVC cable material extrusion pretreatment device shown includes a mixing tank 20 pivotally mounted on a frame 10, a rotary drive unit 30 fixedly mounted on the frame 10, and a stirring unit 40 mounted on the mixing tank 20.

[0022] A conveying pipe 21 communicating with the cavity of the mixing tank 20 is provided on the tank wall. Various raw material masterbatches that need to be mixed are loaded into the cavity of the mixing tank 20 via the conveying pipe 21, and the uniformly mixed raw material masterbatches are also discharged out of the mixing tank 20 via the same conveying pipe 21. During the loading and unloading of the raw material masterbatches, the conveying pipe 21 is moved to a higher position synchronously with the mixing tank 20 (see [link to documentation]). Figure 1 (As shown in the image) and the lower position are sufficient.

[0023] The rotary drive unit 30 includes a drive gear 31 and a drive motor 32, with the drive motor 32 driving the drive gear 31 to rotate. The drive gear 31 meshes with a gear surface 22 fixed on the outer wall of the mixing tank 20, so the rotation of the drive gear 31 can drive the mixing tank 20 relative to the frame 10 around a direction extending in the lateral direction (i.e., Figure 1 Rotate along the axis extending in the front-to-back direction.

[0024] The stirring unit 40 includes a rotating shaft matched with a motor, two arms 41 fixed on the rotating shaft, and scrapers 42 respectively fixed at the free ends of the two arms 41. The rotating shaft, the arms 41, and the scrapers 42 are all disposed within the cavity of the mixing tank 20, with the axis of the rotating shaft approximately coinciding with the axis of the cavity. The arms 41 extend radially along the cavity, and the scrapers 42 are positioned close to the inner wall of the cavity. The length of the scrapers 42 extends in the same direction as the axis of the rotating shaft, and the length of the scrapers 42 is approximately equal to the internal length of the cavity, so that the scrapers 42 can agitate the raw material masterbatch deposited along the entire length of the bottom of the cavity. Two or more arms 41 can be configured for each scraper 42; the specific number depends on the length of the scraper 42. Figure 1 , Figure 2 As shown, if there are two arms 41 configured for each scraper 42, the two arms 41 are fixedly connected to the front end and the rear end of the scraper 42, respectively.

[0025] The scraper 42 is arc-shaped and is located in the direction of rotation of the rotating shaft (i.e., along...). Figure 1 In the direction of ω, the distance between the upstream end 421 of the scraper 42 and the inner wall of the tank cavity is greater than the distance between the downstream end 422 of the scraper 42 and the inner wall of the tank cavity. See [reference needed]. Figure 1The arm 41 is connected to the scraper 42 at a position relatively close to the downstream end 422. Thus, when the scraper 42 rotates within the tank cavity along the rotating shaft, it alternately agitates the raw material masterbatch deposited at the bottom of the tank cavity. This causes the raw material masterbatch to flow from the downstream end 422 of each scraper 42 towards the surface of the scraper 42, then towards the upstream end 421, and finally fall back into the tank cavity from the scraper 42. Because the scraper 42 is arc-shaped and its connection to the arm 41 is close to the downstream end 422, the raw material masterbatch flowing onto the upper surface of the scraper 42 can rotate with the scraper 42 at a certain angle before falling off, resulting in a certain lifting height and facilitating thorough mixing of the raw material masterbatch. Furthermore, the downstream end 422 of the scraper 42 is driven by the lower part of the raw material masterbatch deposited at the bottom of the tank cavity, pushing the raw material masterbatch to move in a circumferential direction and gradually flow onto the scraper 42. Therefore, the scraper 42 can fully agitate the raw material masterbatch deposited to a certain thickness, promoting the full flow of the raw material masterbatch at the bottom of the tank cavity and its full participation in the mixing process. Therefore, the technical solution of this utility model helps to improve the efficiency of mixing raw material masterbatch in the production process of PVC cable materials, helps to save the time required for the extrusion pretreatment process of PVC cable materials, and improves the production efficiency of PVC cable materials.

[0026] like Figures 1 to 2 As shown, on the surface of the scraper 42, a fin assembly 43 is distributed on one side near the upstream end 421. The fin assembly 43 includes a pair of inner fins 431, an arc-shaped middle fin 432, and a V-shaped side fin 433. The inner fins 431, the middle fin 432, and the side fins 433 are located in the width direction of the scraper 42 (i.e.,...). Figure 2 The side fins 433 are distributed alternately in the left and right directions (the same below). The size of the middle fold angle of the side fins 433 is controlled between 160 degrees and 175 degrees.

[0027] One end of each of the two inner fins 431 extends along the length of the scraper 42 (i.e., Figure 2 The two ends of the scraper 42 extend obliquely toward the middle fin 432 (the length extension lines of the two middle fins 432 can intersect on the surface of the scraper 42) and a gap is formed between the opposite ends (along the length direction of the scraper 42).

[0028] The convex surface of the intermediate fin 432 faces the inner fin 431, and the top of the convex surface corresponds to the distance between the opposite ends of the two inner fins 431. The recess of the side fin 433 is opposite to the concave surface of the intermediate fin 432. Both ends of the side fin 433 extend to the longitudinal end faces of the scraper 42. The two ends of the intermediate fin 432 are spaced apart from the longitudinal end faces of the scraper 42.

[0029] The height of the inner wing plate 431 protruding relative to the scraper 42 is less than the height of the middle wing plate 432 protruding relative to the scraper 42. The height of the middle wing plate 432 protruding relative to the scraper 42 is less than the height of the side wing plate 433 protruding relative to the scraper 42. Furthermore, the free ends of the inner wing plate 431, the middle wing plate 432, and the side wing plate 433 all extend obliquely towards the upstream end 421.

[0030] The fin assembly 43 further includes a pair of side plates 434. The side plate 434 connects one end of the inner fin 431 extending to the longitudinal end face (front and rear faces) of the scraper 42 and one end of the side fin 433 extending to the longitudinal end face (front and rear faces) of the scraper 42. Specifically, one side plate 434 is positioned opposite each other at the front edge of the scraper 42, with its two ends connected to the ends of the inner fin 431 (located on the front side) and the side fin 433 (located on the rear side) respectively. The other side plate 434 is positioned opposite each other at the rear edge of the scraper 42, with its two ends connected to the ends of the inner fin 431 (located on the rear side) and the side fin 433 (located on the rear side) respectively.

[0031] like Figure 2 As shown, on the surface of the scraper 42, a plurality of protruding rib groups 44 are distributed on one side near the downstream end 422, and the protruding rib groups 44 are distributed alternately in the length direction of the scraper 42.

[0032] Each of the rib groups 44 includes a side rib 441 and an inner rib 442. A lengthwise spacing is formed between the opposite ends of the side rib 441 and the inner rib 442, and the two ribs extend obliquely in opposite directions. Both the side rib 441 and the inner rib 442 extend obliquely relative to the width direction (i.e., left-right direction) of the scraper 42, so that the side rib 441 can guide the raw material masterbatch to converge and flow from the length of the scraper 42 towards both ends and towards the middle, and the inner rib 442 can guide the raw material masterbatch to disperse and flow from the length of the scraper 42 towards both ends. See [reference needed].Figure 2 .

[0033] An elastic rubber strip is fixedly provided at the edge of the downstream end 422 of the scraper 42. The elastic rubber strip runs through the entire length of the scraper 42 and the free end of the elastic rubber strip contacts the inner wall of the mixing tank 20.

[0034] In this invention, the mixing effect of the raw material masterbatch flowing on the scraper 42 is enhanced by setting the fin assembly 43 and the rib assembly 44. Specifically, the rib assembly 44 helps to enhance the flow capacity of the raw material masterbatch in the length direction of the scraper 42, promoting the mixing and flowability of the raw material masterbatch in the length direction; the fin assembly 43 can agitate the raw material masterbatch on the scraper 42, further promoting the mixing degree of the raw material masterbatch in the length direction, causing the raw material masterbatch to converge towards the middle of the length and then disperse towards the ends of the length, finally converging towards the middle again and finally sliding off the outside of the scraper 42. In particular, the side plates 434 can increase the height of the raw material masterbatch carried and lifted by the scraper 42, so that the raw material masterbatch can be fully lifted to a higher position, and improve the flow capacity of the raw material masterbatch on the scraper 42 surface during this period, which helps the fins and ribs to fully exert their disturbance effect.

[0035] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit it. Many aspects of this utility model can be improved without departing from the overall concept. Those skilled in the art can modify or change the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A pretreatment device for extrusion of PVC cable material, characterized in that: It includes a mixing tank (20) pivotally mounted on a frame (10), a rotary drive unit (30), and a stirring unit (40) mounted on the mixing tank (20); A conveying pipe (21) communicating with the tank cavity is provided on the mixing tank (20); The rotary drive unit (30) enables the mixing tank (20) to rotate relative to the frame (10) about an axis extending in the lateral direction; The stirring unit (40) includes a rotating shaft in the mixing tank (20), multiple arms (41) fixed on the rotating shaft, and a scraper (42) fixed at the free end of the arm (41). The scraper (42) is arc-shaped and in the rotation direction of the rotating shaft, the distance between the upstream end (421) of the scraper (42) and the inner wall of the tank cavity is greater than the distance between the downstream end (422) and the inner wall of the tank cavity. The position where the arm (41) and the scraper (42) are connected is relatively close to the downstream end (422).

2. The PVC cable material extrusion pretreatment device according to claim 1, characterized in that: A gear surface (22) is formed on the outer wall of the mixing tank (20); the rotary drive unit (30) includes a drive gear (31) matched with the motor, and the drive gear (31) meshes with the gear surface (22).

3. The PVC cable material extrusion pretreatment device according to claim 1, characterized in that: On the surface of the scraper (42), a fin assembly (43) is provided on one side near the upstream end (421); the fin assembly (43) includes a pair of inner fins (431), an arc-shaped middle fin (432), and a V-shaped side fin (433); the inner fins (431), the middle fin (432) and the side fin (433) are distributed alternately in the width direction of the scraper (42); One end of each of the two inner fins (431) extends to both ends of the scraper (42) along its length, and the other end extends obliquely toward the middle fin (432) with a gap between the opposite ends; the convex surface of the middle fin (432) faces the inner fin (431), and the concave opening of the side fin (433) is opposite to the concave surface of the middle fin (432); both ends of the side fin (433) extend to the two end faces of the scraper (42) along its length; the two ends of the middle fin (432) are respectively spaced apart from the end faces of the scraper (42) along its length.

4. The PVC cable material extrusion pretreatment device according to claim 3, characterized in that: The height of the inner fin (431) is less than the height of the middle fin (432); the height of the middle fin (432) is less than the height of the side fin (433).

5. The PVC cable material extrusion pretreatment device according to claim 4, characterized in that: The free ends of the inner fin (431), the middle fin (432), and the side fin (433) all tilt towards the upstream end (421).

6. The PVC cable material extrusion pretreatment device according to claim 3, characterized in that: The fin assembly (43) also includes a pair of side plates (434); the side plates (434) connect the end of the inner fin (431) extending to the end face of the scraper (42) and the end of the side fin (433) extending to the end face of the scraper (42).

7. The PVC cable material extrusion pretreatment device according to claim 1, characterized in that: On the surface of the scraper (42), a plurality of rib groups (44) are provided on one side near the downstream end (422) and are distributed alternately in the length direction of the scraper (42); the rib group (44) includes a side rib (441) and an inner rib (442); a length-direction spacing is formed between the opposite ends of the side rib (441) and the inner rib (442); Both the side protrusions (441) and the inner protrusions (442) extend obliquely relative to the width direction of the scraper (42). The side protrusions (441) can guide the raw material masterbatch to flow from the length of the scraper (42) towards both ends and towards the middle. The inner protrusions (442) can guide the raw material masterbatch to flow disperse towards both ends along the length of the scraper (42).

8. The PVC cable material extrusion pretreatment device according to claim 1, characterized in that: An elastic rubber strip is fixedly provided at the edge of the downstream end (422) of the scraper (42), so that the free end of the elastic rubber strip contacts the inner wall of the mixing tank (20).

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