Polymer slicing system

Abstract

The utility model relates to a polymer slicing system which comprises a flow guide unit, a slicing unit, a storage stirring unit and a separation unit, wherein the flow guide unit is used for conveying a mixture of a polymer melt and a cooling medium to the slicing unit; the slicing unit is used for cutting the polymer melt to obtain polymer slices; the storing and stirring unit is used for storing a mixture of the polymer slices and the cooling medium under the action of stirring; and the separating unit is used for separating the mixture of the polymer slices and the cooling medium discharged by the storing and stirring unit to obtain the polymer slices and the cooling medium. According to the polymer slicing system provided by the embodiment of the utility model, low-melting-point polymer slices can be fully cooled through the arrangement of the storage stirring unit, and meanwhile, adhesion and caking of the slices are reduced, so that the polymer slices in a better state can be obtained.

Description

Technical Field

[0001] This invention relates to the cutting of polymer melts, and more particularly to a slicing system for low-melting-point polymers. Background Technology

[0002] In the production of some polymer products, after the polymer meets the production quality standards, its melt will pass through pipelines and valves to the casting strip head to form a strip melt. Under the action of cooling water, it will be sent through a guide channel to a pelletizer to be cut into flakes (or granules). The mixture of water and polymer flakes will then be separated by a centrifugal dryer. The separated polymer flakes will be sent to a silo for temporary storage and will be used in subsequent processes.

[0003] In the aforementioned slicing (or pelletizing) process, the polymer melt is sufficiently cooled by passing through the flow channel under the action of the cooling water. If it is necessary to extend the cooling time, this is usually achieved by extending the flow channel or lowering the temperature of the pelletizing cooling water. For polymers with very slow crystallization rates (such as low-melting-point polymers used in engineering plastics), prolonged cooling in the cooling water is required; otherwise, agglomerates will form at room temperature during slicing, making subsequent processes impossible. However, for the slicing of this low-melting-point polymer, neither of the above two measures can extend the cooling time. Utility Model Content

[0004] To overcome at least one of the defects of the prior art, in a first aspect, one embodiment of the present invention provides a polymer slicing system, including a flow guiding unit, a slicing unit, a storage and stirring unit, and a separation unit; wherein, the flow guiding unit is used to transport a mixture of polymer melt and cooling medium to the slicing unit; the slicing unit is used to cut the polymer melt to obtain polymer slices; the storage and stirring unit is used to store the mixture of polymer slices and cooling medium under stirring; the separation unit is used to separate the mixture of polymer slices and cooling medium discharged from the storage and stirring unit to obtain polymer slices and cooling medium.

[0005] According to one embodiment of the present invention, the flow guiding unit includes a flow guiding groove; and / or, the slicing unit includes an underwater pelletizer.

[0006] According to one embodiment of the present invention, the guide channel is connected to the slicing unit; and / or,

[0007] The storage and stirring unit includes a storage tank and a stirring device. The storage tank is used to hold the mixture of the polymer chips and the cooling medium, and the stirring device is used to stir the mixture.

[0008] According to one embodiment of the present invention, the storage tank includes a bottom and a side, and a cooling medium outlet is provided on the side of the storage tank, and a filter screen is provided at the cooling medium outlet; and / or,

[0009] A circulation path is provided outside the storage tank, through which the mixture discharged from the storage tank can return to the storage tank.

[0010] According to one embodiment of the present invention, the circulation path includes a first pipeline and a second pipeline, wherein the first pipeline is connected to the storage tank and the second pipeline respectively.

[0011] According to one embodiment of this utility model, a first valve is provided on the second pipeline for controlling the connection and disconnection of the circulation path; and / or,

[0012] The polymer slicing system includes a third pipeline, which is connected to the first pipeline and the separation unit respectively; a second valve is provided on the third pipeline for controlling the connection and disconnection of the passage between the storage tank and the separation unit.

[0013] According to one embodiment of the present invention, the polymer slicing system includes a cooling medium circulation unit for providing the cooling medium to one or more of the flow guiding unit, the slicing unit, and the storage and stirring unit; and / or,

[0014] The separation unit includes a centrifugal dryer; and / or,

[0015] The polymer slicing system also includes a spinneret for providing strips of polymer melt to the flow guiding unit.

[0016] According to one embodiment of the present invention, the cooling medium circulation unit includes a first storage tank and a first heat exchanger, wherein the first heat exchanger is connected to the first storage tank, the flow guiding unit, and the slicing unit respectively; and / or

[0017] The separation unit also includes a vibrating screen.

[0018] According to one embodiment of the present invention, the separation unit is connected to the first storage tank, and the cooling medium separated from the separation unit can be returned to the first storage tank; and / or,

[0019] The cooling medium circulation unit includes a second storage tank and a second heat exchanger connected to the second storage tank. The cooling medium in the first storage tank can overflow into the second storage tank, and the second storage tank can provide cooling medium for the storage and stirring unit.

[0020] According to one embodiment of the present invention, a first filter and a second filter are provided between the second storage tank and the second heat exchanger; and / or,

[0021] The second heat exchanger is connected to the storage and stirring unit.

[0022] The polymer slicing system of one embodiment of this utility model, by setting up a stirring unit, enables low-melting-point polymer slices to be fully cooled while reducing the adhesion and clumping of the slices, thereby obtaining polymer slices in better condition. Attached Figure Description

[0023] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this invention.

[0024] in:

[0025] Figure 1 This is a schematic diagram of the structure of a polymer slicing system according to one embodiment of the present invention;

[0026] The annotations in the attached figures are explained as follows:

[0027] 10. Spinneret; 20. Flow guide channel; 30. Underwater pelletizer; 41. Storage tank; 42. Mixing device; 43. Slicing pump; 44. First valve; 45. Second valve; 51. Centrifugal dryer; 52. Vibrating screen; 60. Slicing hopper; 70. First storage tank; 71. First circulating pump; 80. First heat exchanger; 90. Second storage tank; 91. First filter; 92. Second circulating pump; 93. Second filter; 100. Second heat exchanger. Detailed Implementation

[0028] Typical embodiments embodying the features and advantages of this utility model will be described in detail in the following description. It should be understood that this utility model can have various variations in different embodiments, all of which do not depart from the scope of this utility model, and the description herein is for illustrative purposes only and not intended to limit this utility model.

[0029] One embodiment of this utility model provides a polymer slicing system, including a flow guiding unit, a slicing unit, a storage and stirring unit, and a separation unit; wherein, the flow guiding unit is used to transport a mixture of polymer melt and cooling medium to the slicing unit; the slicing unit (or pelletizing unit) is used to cut the polymer melt to obtain polymer slices; the storage and stirring unit is used to store the polymer slices and cooling medium under stirring; the separation unit is used to separate the mixture of polymer slices and cooling medium discharged from the storage and stirring unit to obtain polymer slices and cooling medium.

[0030] The polymer slicing system of one embodiment of this utility model is particularly suitable for cutting polymer melts such as low-melting-point polymers, which have very slow crystallization rates and require long-term cooling.

[0031] Reference Figure 1 As shown, in one embodiment, the polymer slicing system includes a spinneret 10 for providing strips of polymer melt to a flow guiding unit. The spinneret 10 may be connected to the flow guiding unit. Further, the spinneret 10 may be a casting head.

[0032] In one embodiment, the flow guiding unit includes a flow guiding channel 20 in which the polymer melt is mixed with a cooling medium, the introduction of which cools the melt. The cooling medium can be water (cooling water or cold-cutting water).

[0033] In one embodiment, the flow channel 20 may be connected to a slicing unit. Further, the slicing unit includes an underwater pelletizer 30. A mixture of polymer melt and cooling medium enters the underwater pelletizer 30 from the flow channel 20. Under the action of the cooling medium, the underwater pelletizer 30 cuts the polymer melt to form polymer slices (or polymer particles).

[0034] In one embodiment, the mixture of polymer chips and cooling medium is discharged from the slicing unit and then enters a storage and stirring unit. The storage and stirring unit includes a storage tank 41 and a stirring device 42. The storage tank 41 holds the mixture of polymer chips and cooling medium to prolong the contact time between the polymer chips and the cooling medium. The stirring device 42 is used to stir the mixture; the stirring device 42 may be, for example, a stirring impeller. The storage tank 41 allows the low-melting-point polymer chips, which are prone to clumping at room temperature, to be sufficiently cooled by the cooling medium. Simultaneously, the stirring device 42 breaks up any clumped chips, reducing the occurrence of agglomeration within the polymer chips.

[0035] In one embodiment, the storage tank 41 includes a receiving cavity, and a bottom and sides surrounding the receiving cavity. The mixture of polymer chips and cooling medium is contained in the receiving cavity. A cooling medium outlet is provided on the side of the storage tank 41, and a filter screen is provided at the cooling medium outlet. The cooling medium in the stirring device 42 can overflow from the storage tank 41 through the cooling medium outlet, and the polymer chips are blocked inside the storage tank 41 by the filter screen. Further, the pore size of the filter screen provided at the cooling medium outlet can be 0.8 to 1.2 mm, for example, 0.9 mm, 1 mm, or 1.1 mm.

[0036] In one embodiment, a circulation passage is provided outside the storage tank 41, through which the mixture of polymer chips and cooling medium discharged from the storage tank 41 can return to the storage tank 41. The circulation of materials in the storage tank 41 can act as agitation, preventing the polymer chips from settling to the bottom.

[0037] In one embodiment, the circulation path includes a first pipeline and a second pipeline, with the first pipeline connected to the storage tank 41 and the second pipeline respectively. Furthermore, a slicing pump 43 is installed on the first pipeline, allowing material in the storage tank 41 to flow out of the storage tank 41 under the action of the slicing pump 43.

[0038] In one embodiment, a material outlet is provided at the bottom of the storage tank 41, through which the mixture of polymer chips and cooling medium flows out of the storage tank 41 and into the first pipeline. Furthermore, the opening and closing of the material outlet can be controlled by a bottom valve of the storage tank.

[0039] In one embodiment, the second pipeline is connected to the storage tank 41 and the first pipeline respectively, and a first valve 44 is provided on the second pipeline to control the connection and disconnection of the circulation path.

[0040] In one embodiment, the polymer slicing system further includes a third pipeline, which is connected to the first pipeline and the separation unit respectively; a second valve 45 is provided on the third pipeline for controlling the connection and disconnection of the passage between the storage tank 41 and the separation unit.

[0041] In one embodiment, the separation unit includes a centrifugal dryer 51. The mixture of polymer chips and cooling medium, discharged from the storage tank 41 containing the stirring unit, enters the centrifugal dryer 51 of the separation unit for separation and drying to obtain polymer chips and cooling medium. Further, the polymer chips are discharged from the top of the centrifugal dryer 51, and the cooling medium is discharged from the bottom of the centrifugal dryer 51.

[0042] In one embodiment, the separation unit further includes a vibrating screen 52, through which polymer chips discharged from the centrifugal dryer 51 are fed for processing to remove elongated pieces and fine particles. Further, the chips processed by the vibrating screen 52 can be sent to a chip hopper 60 for subsequent drying and packaging.

[0043] In one embodiment, the polymer slicing system further includes a cooling medium circulation unit for providing a cooling medium to one or more of the flow guiding unit, slicing unit, and storage and stirring unit.

[0044] In one embodiment, the cooling medium circulation unit includes a first storage tank 70 and a first heat exchanger 80. The first storage tank 70 is used to store the cooling medium; the first heat exchanger 80 is connected to the first storage tank 70 and is used to perform heat exchange treatment on the cooling medium discharged from the first storage tank 70. Further, the first heat exchanger 80 is connected to a flow guiding unit and a slicing unit respectively, and is used to provide cooling medium to the flow guiding unit and the slicing unit.

[0045] In one embodiment, a first circulating pump 71 is provided between the first storage tank 70 and the first heat exchanger 80 to transport the cooling medium from the first storage tank 70 to the first heat exchanger 80.

[0046] In one embodiment, the flow channel 20 includes a cooling medium inlet connected to a first heat exchanger 80 to introduce cooling medium into the flow channel 20. Simultaneously, the flowing cooling medium from the inlet propels the polymer melt within the flow channel 20 into the downstream slicing unit.

[0047] In one embodiment, the flow guiding unit includes a spraying device disposed above the flow guiding channel 20. The spraying device can be connected to the first heat exchanger 80 to spray a cooling medium onto the polymer melt located in the flow guiding channel 20 to promote its cooling.

[0048] In one embodiment, the underwater pelletizer 30 includes a cooling medium inlet pipe and a cooling medium outlet pipe for the entry and exit of the cooling medium. Further, the cooling medium inlet pipe of the underwater pelletizer 30 is connected to a first heat exchanger 80 to provide cooling medium to the underwater pelletizer 30. After the polymer melt is cut, the mixture of polymer chips and cooling medium enters a storage and stirring unit. Further, a portion of the cooling medium in the underwater pelletizer 30 enters the storage and stirring unit, while another portion (excess or excess) of the cooling medium flows through the cooling medium outlet pipe of the underwater pelletizer 30 to the first storage tank 70. Further still, a filter screen is provided in the cooling medium outlet pipe, or the cooling medium outlet pipe is located at the front end of the cutter head of the underwater pelletizer 30, to discharge another portion of the cooling medium before cutting, preventing small polymer chips from flowing out of the cooling medium outlet pipe after cutting; or a filter screen is provided below the guide channel 20.

[0049] In one embodiment, the cooling medium separated by the centrifugal dryer 51 of the separation unit can be returned to the first storage tank 70. Furthermore, cooling medium overflowing from the cooling medium outlet of the storage tank 41 can flow into the first storage tank 70.

[0050] In one embodiment, the cooling medium circulation unit includes a second storage tank 90 and a second heat exchanger 100 connected to the second storage tank 90; when there is too much cooling medium in the first storage tank 70, the excess cooling medium can overflow into the second storage tank 90, and the second heat exchanger 100 is used to perform heat exchange treatment on the cooling medium discharged from the second storage tank 90.

[0051] In one embodiment, the second storage tank 90 can provide a cooling medium for storing the stirring unit. Furthermore, the second heat exchanger 100 is connected to the storage tank 41, and the cooling medium flowing out of the second storage tank 90 can enter the storage tank 41 to replenish its cooling medium after heat exchange through the second heat exchanger 100.

[0052] In one embodiment, a first filter 91, a second circulating pump 92, and a second filter 93 are sequentially arranged between the second storage tank 90 and the second heat exchanger 100. The first filter 91 and the second filter 93 are used to filter the cooling medium discharged from the second storage tank 90. ​​The first filter 91 is a basket filter with a filtration accuracy of 0.8 to 1.2 mm, such as 0.9 mm, 1 mm, or 1.1 mm. The second filter 93 is a candle filter with a filtration accuracy of 140 to 160 μm, such as 145 μm, 150 μm, or 155 μm.

[0053] According to one embodiment of the polymer slicing system of this utility model, during operation, the storage tank 41 is replenished with water to a certain level, and the stirring device 42, the first valve 44, and the slicing pump 43 are started to allow the water in the storage tank 41 to circulate. The first storage tank 70 is replenished with water to a certain level, and the first circulation pump 71 is started to transport the water in the first storage tank 70 to the first heat exchanger 80 for heat exchange and cooling. Then, the water discharged from the first heat exchanger 80 is transported to the guide channel 20 and the underwater pelletizer 30.

[0054] The polymer melt is formed into strip-shaped melt through the spinneret 10, and the strip-shaped melt enters the guide channel 20 to mix with cooling water; then the mixture is passed into the underwater pelletizer 30 for slicing (or pelletizing); then, the mixture of polymer slices and cooling water enters the storage tank 41, where the polymer slices are in full contact with the cooling water and are further cooled. The stirring device 42 reduces the adhesion and clumping of the slices, and the self-circulation of the polymer slices and water mixture prevents the slices from sinking to the bottom; at the same time, excess cooling water in the storage tank 41 overflows from the cooling medium outlet on the side to the first storage tank 70;

[0055] After the polymer chips are fully cooled in the storage tank 41, the first valve 44 is closed to stop the self-circulation of cooling water, and the second valve 45 is opened. Under the action of the chip pump 43, the mixture of polymer chips and cooling water enters the centrifugal dryer 51 of the separation unit. The mixture is separated into polymer chips and cooling water by the centrifugal dryer 51. The cooling water is discharged from the bottom of the centrifugal dryer 51 and flows back to the first storage tank 70. The polymer chips are discharged from the top of the centrifugal dryer 51 and enter the vibrating screen 52 for processing. The processed polymer chips are stored in the chip hopper 60.

[0056] On the other hand, the cooling water overflowing from the first storage tank 70 enters the second storage tank 90, and after being processed by the first filter 91, the second filter 93, and the second heat exchanger 100 in sequence, it enters the storage tank 41 to replenish the storage tank 41.

[0057] The polymer slicing system of this utility model has a storage tank that allows low-melting-point polymer slices that are prone to sticking and clumping at room temperature to be fully cooled. The clumped slices can be broken up by the action of the stirring device, thereby obtaining polymer slices in better condition, and realizing the mass production of polymers with very slow crystallization rates that require long-term cooling.

[0058] Unless otherwise specified, the terms used in this utility model have the meanings commonly understood by those skilled in the art.

[0059] The embodiments described in this utility model are for illustrative purposes only and are not intended to limit the scope of protection of this utility model. Those skilled in the art can make various other substitutions, changes and improvements within the scope of this utility model. Therefore, this utility model is not limited to the above embodiments, but is only defined by the claims.

Claims

1. A polymer slicing system, characterized in that, The system includes a flow guiding unit, a slicing unit, a storage and stirring unit, and a separation unit. The flow guiding unit conveys a mixture of polymer melt and cooling medium to the slicing unit. The slicing unit cuts the polymer melt to obtain polymer slices. The storage and stirring unit stores the mixture of polymer slices and cooling medium under stirring. The separation unit separates the mixture of polymer slices and cooling medium discharged from the storage and stirring unit, obtaining polymer slices and cooling medium.

2. The polymer slicing system according to claim 1, characterized in that, The flow guiding unit includes a flow guiding channel; and / or, The slicing unit includes an underwater pelletizer.

3. The polymer slicing system according to claim 2, characterized in that, The flow guide channel is connected to the slicing unit; and / or, The storage and stirring unit includes a storage tank and a stirring device. The storage tank is used to hold the mixture of the polymer chips and the cooling medium, and the stirring device is used to stir the mixture.

4. The polymer slicing system according to claim 3, characterized in that, The storage tank includes a bottom and a side. A cooling medium outlet is provided on the side of the storage tank, and a filter screen is provided at the cooling medium outlet; and / or, A circulation path is provided outside the storage tank, through which the mixture discharged from the storage tank can return to the storage tank.

5. The polymer slicing system according to claim 4, characterized in that, The circulation path includes a first pipeline and a second pipeline, wherein the first pipeline is connected to the storage tank and the second pipeline, respectively.

6. The polymer slicing system according to claim 5, characterized in that, A first valve is installed on the second pipeline to control the connection and disconnection of the circulation path; and / or, The polymer slicing system includes a third pipeline, which is connected to the first pipeline and the separation unit respectively; a second valve is provided on the third pipeline for controlling the connection and disconnection of the passage between the storage tank and the separation unit.

7. The polymer slicing system according to claim 1, characterized in that, Includes a cooling medium circulation unit for providing the cooling medium to one or more of the flow guiding unit, the slicing unit, and the storage and stirring unit; and / or, The separation unit includes a centrifugal dryer; and / or, The polymer slicing system also includes a spinneret for providing strips of polymer melt to the flow guiding unit.

8. The polymer slicing system according to claim 7, characterized in that, The cooling medium circulation unit includes a first storage tank and a first heat exchanger, wherein the first heat exchanger is connected to the first storage tank, the flow guiding unit, and the slicing unit; and / or The separation unit also includes a vibrating screen.

9. The polymer slicing system according to claim 8, characterized in that, The separation unit is connected to the first storage tank, and the cooling medium separated from the separation unit can be returned to the first storage tank; And / or, The cooling medium circulation unit includes a second storage tank and a second heat exchanger connected to the second storage tank. The cooling medium in the first storage tank can overflow into the second storage tank, and the second storage tank can provide cooling medium for the storage and stirring unit.

10. The polymer slicing system according to claim 9, characterized in that, A first filter and a second filter are provided between the second storage tank and the second heat exchanger; and / or, The second heat exchanger is connected to the storage and stirring unit.

Images