CN212194148U - plastic extruder - Google Patents

Abstract

The utility model discloses a plastic extruder, which belongs to the field of plastic processing machinery. Mainly, there is a control system on the host, the screen changer is equipped with a pressure sensor, the pressure sensor communicates with the control system and transmits pressure data. , A metering pump is connected between the rear tee and the die head. The metering pump communicates with the control system and transmits flow data. The control system controls the speed of the host according to the flow data of the metering pump. After the data drops to the predetermined flow threshold, the screen changer is controlled to start the screen change. The utility model is mainly used for reducing the pressure difference between the front and the back of the filter screen when the filter screen is replaced, the extrusion plastic is more coherent and smooth, and the product quality is guaranteed.

Description

plastic extruder

technical field

The utility model relates to a plastic processing machine, in particular to a plastic extruder.

Background technique

At present, there are many enterprises using recycled plastics to make plastic products in the domestic market, and recycled plastics are characterized by more impurities, so filters must be installed on plastic extruders, and filters must be replaced frequently. In order to improve the efficiency of filter replacement, an automatic screen changer is generally used. When the automatic screen changer is replacing the filter screen, it is easy to generate a large pressure difference between the front and the back of the screen, so that the qualified product cannot be squeezed out immediately after the screen is changed.

Utility model content

The purpose to be achieved by the utility model is to provide a plastic extruder, which reduces the pressure difference between the front and the back of the filter when the filter is replaced, extrudes the plastic more coherently and smoothly, and ensures product quality.

In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a plastic extruder, including a main machine, an extrusion cylinder, a front tee, a screen changer, a rear tee and a die head, the main machine is provided with a control system, the extrusion cylinder is Set on the main machine, the extrusion end of the extrusion cylinder is connected with the inlet of the front tee, the two outlets of the front tee are respectively connected with two screen changers, and the two screen changers are respectively connected with the two screen changers of the rear tee. The inlet is connected, the outlet of the rear tee is connected with the die head, the screen changer is equipped with a pressure sensor, the pressure sensor communicates with the control system and transmits pressure data, the two screen changers are controlled by the control system to work and choose one to open the front connection. There is a metering pump connected between the tee and the rear tee, and the rear tee and the die head. The metering pump communicates with the control system and transmits flow data. The control system controls the speed of the host according to the flow data of the metering pump, and the control system increases when the pressure data After the predetermined pressure threshold and the flow data drop to the predetermined flow threshold, the screen changer is controlled to start the screen change.

Further, the predetermined flow threshold is set at 5% to 10% of the normal flow value.

Further, the front tee and/or the rear tee are of steel pipe structure.

Further, the front tee and/or the rear tee are castings, and a tee channel is provided in the casting.

Further, the casting is in the shape of a cuboid.

Further, the three-way channel is made of steel.

Further, the screen changer is a belt filter screen changer.

After adopting the above-mentioned technical scheme, the utility model has the following advantages: firstly, through the real-time flow data obtained by the metering pump, the control system can judge the blockage of the filter screen currently in use, and as impurities accumulate on the filter screen, the When the flow rate drops, the flow data will naturally gradually decrease, and the pressure data of the pressure sensor will also increase. When the pressure data rises to the predetermined pressure threshold and the flow data drops to the predetermined flow threshold, the screen changer can automatically change the screen, intelligent The high degree of automation can reduce manual duty and reduce the cost of enterprise employment; secondly, because the pressure data of the pressure sensor and the metering pump are real-time data, and through the threshold comparison, the control system can control the start of the screen changer in advance, instead of waiting until The screen changer that is turned off is only activated after the filter screen in use is basically or even completely blocked. The new filter screen can allow the plastic to pass through and fill the space behind the screen more quickly, so that the pressure behind the screen quickly rises and is close to the pressure in front of the screen. Effectively reduce the pressure difference between the front and back of the filter when the filter is replaced, and extrude the plastic more coherently and smoothly to ensure product quality. The control system controls the speed of the host according to the flow data of the metering pump, and can ensure normal extrusion processing when the flow data drops but the pressure data does not reach the threshold. Misjudgments will occur, reducing unnecessary waste of filters and reducing usage costs.

Description of drawings

Below in conjunction with accompanying drawing, the utility model is further described:

Fig. 1 is the structural representation (1) of the first embodiment of the present utility model;

Fig. 2 is the structural representation (two) of the first embodiment of the present utility model;

Fig. 3 is the schematic diagram of the front tee in the second embodiment of the present utility model;

4 is a schematic diagram of the rear tee in the second embodiment of the present invention.

Detailed ways

Example 1:

As shown in Figure 1 and Figure 2, the present utility model provides a plastic extruder, including a main machine, an extrusion cylinder 1, a front three-way 2, a screen changer 3, a rear three-way 4 and a die head 5. The main machine is provided with There is a control system, the extrusion cylinder 1 is set in the main engine, the extrusion end of the extrusion cylinder 1 is connected with the inlet of the front three-way 2, and the two outlets of the front three-way 2 are respectively connected with the two screen changers 3, and the two The screen changer 3 is connected with the two inlets of the rear tee 4 respectively, and the outlet of the rear tee 4 is connected with the die head 5. The screen changer is equipped with a pressure sensor, and the pressure sensor communicates with the control system and transmits pressure data. The two screen changers 3 are controlled by the control system, and one of them is opened to communicate with the front tee 2 and the rear tee 4. A metering pump 6 is connected between the rear tee 4 and the die head 5, and the metering pump 6 communicates with the control system. The flow data is transmitted, the control system controls the rotation speed of the host according to the flow data of the metering pump 6, and the control system controls the screen changer 3 to start screen changing after the pressure data rises to the predetermined pressure threshold and the flow data drops to the predetermined flow threshold.

First, through the real-time flow data obtained by the metering pump 6, the control system can judge the blockage of the filter screen currently in use. The pressure data of the sensor will also rise. When the pressure data rises to the predetermined pressure threshold and the flow data drops to the predetermined flow threshold, the screen changer can automatically change the screen. The cost of employment; secondly, since the pressure data of the pressure sensor and the metering pump 6 are real-time data, and through the threshold comparison, the control system can control the screen changer 3 to start in advance, instead of waiting until the filter in use is basically or even completely blocked. The screen changer 3 that has just been turned off, the new filter can allow the plastic to pass through and fill the space behind the screen more quickly, so that the pressure behind the screen rises rapidly and is close to the pressure in front of the screen, which can effectively reduce the pressure in front of the screen when the filter is replaced. Compared with the pressure difference after the net, the extruded plastic is more coherent and smooth, and the product quality is guaranteed. The control system controls the rotation speed of the main engine according to the flow data of the metering pump 6, and can ensure normal extrusion processing when the flow data drops but the pressure data does not reach the threshold value. There will be no misjudgment, unnecessary waste of the filter screen will be reduced, and the use cost will be reduced. The process of starting the closed screen changer can be heated to a predetermined temperature first, and then the valve is opened to connect the front three-way and the rear three-way. The so-called front of the screen refers to the upstream side of the filter screen, and the rear of the screen refers to the downstream side of the filter screen.

Generally, the predetermined flow threshold can be set at 5% to 10% of the normal flow value.

The front tee 2 can be made of steel pipe structure, which is welded by steel pipe to ensure smooth internal passage, which is conducive to the flow of plastics. In the same way, the rear tee 4 can also adopt the steel pipe structure.

As a feasible solution, the screen changer 3 is a belt filter screen changer, which has high efficiency and reliability in automatically replacing the filter screen. Of course, the common filter screen changer in the prior art can also be used.

Embodiment 2:

In order to improve the heating and heat preservation effect, as shown in FIG. 3 , the front tee 2 can be a casting, and the casting is provided with a tee channel 7 . And in order to make the plastic flow smoothly, the tee channel can be made of steel. In order to facilitate processing and assembly, the casting can be selected as a cuboid. For the same reason, as shown in Figure 4, the rear tee 4 can also be cast.

For other content not described in this embodiment, reference may be made to Embodiment 1.

In addition to the above-mentioned preferred embodiments, the present utility model has other embodiments, and those skilled in the art can make various changes and deformations according to the present utility model, as long as they do not depart from the spirit of the present utility model, they shall belong to the claims of the present utility model. the range defined in .

Claims (7)

1. Plastic extruder, including main machine, extrusion barrel, front tee, screen changer, rear tee and die head, the main machine is equipped with a control system, the extrusion barrel is located in the main machine, and the extrusion end of the extrusion barrel is It is connected to the entrance of the front three-way, the two outlets of the front three-way are connected to the two screen changers respectively, and the two screen changers are connected to the two inlets of the rear three-way respectively. The head is connected, the screen changer is equipped with a pressure sensor, the pressure sensor communicates with the control system and transmits pressure data, and the two screen changers are controlled by the control system to work and choose one to open to connect the front three-way and the rear three-way, which is characterized in that, A metering pump is connected between the rear tee and the die head. The metering pump communicates with the control system and transmits flow data. The control system controls the speed of the host according to the flow data of the metering pump. After the flow data drops to the predetermined flow threshold, the screen changer is controlled to start the screen change. 2 . The plastic extruder according to claim 1 , wherein the predetermined flow rate threshold is set at 5% to 10% of the normal flow rate value. 3 . 3 . The plastic extruder according to claim 1 , wherein the front tee and/or the rear tee are of steel pipe structure. 4 . 4 . The plastic extruder according to claim 1 , wherein the front tee and/or the rear tee are castings, and a tee channel is provided in the casting. 5 . 5. The plastic extruder according to claim 4, wherein the casting is in the shape of a rectangular parallelepiped. 6. The plastic extruder according to claim 4, wherein the three-way channel is made of steel. 7 . The plastic extruder according to claim 1 , wherein the screen changer is a belt filter screen changer. 8 .

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