CN203246062U - Plastic extruder - Google Patents

Abstract

The utility model provides a novel plastic extruder, which comprises a head mould, a machine cover, a bushing, a barrel, a heating resistance wire, a screw, an electric control device, a material inlet, a transmission device, and a cooling water channel. , motor and frame; the machine cover is set on the upper end of the frame, the screw is sleeved in a smooth bush, and the bush is fixed in the barrel with a smooth inner wall through a groove, and one end of the screw is connected with the transmission device, and the transmission The device is connected to the motor. This plastic extruder is improved on the basis of the original plastic extruder. It adopts a new extruder screw structure. At the same time, it also changes the fixing method of the bushing and barrel. The previous fixing method is by friction. Secure the bushing to the barrel, now with the grooves. The screw structure of the extruder is novel, simple and cheap, can provide relatively stable extrusion pressure, not only saves cost but also improves production efficiency.

Description

plastic extruder

technical field

The utility model relates to a plastic molding processing device, in particular to a plastic extruder. the

Background technique

Extrusion molding is one of the important molding methods of plastic molding processing. Most thermoplastics can be formed by this method. Extrusion molding is carried out on the extruder, which is one of the main equipment of plastic molding processing machinery. Products produced by extrusion molding are widely used in people's life and agriculture, construction industry, petrochemical industry, machinery manufacturing , Defense and other industrial sectors. the

The good development prospects of the plastic processing industry will still be the source of rapid development of China's plastic machinery manufacturing industry. Relatively moderate models, such as extra-large, precision, special-purpose injection molding machines, low-temperature, high-power single-screw extruders, multi-layer co-extrusion blow molding machines for producing high-impermeability and heat-resistant packaging materials, etc., The production of industrial parts (auto parts, etc.) blow molding machinery, etc., has a good development prospect. the

The extrusion screw used in the traditional extruder is a variable-pitch screw with equal depth, which may cause uneven mixing and crushing of materials and poor extrusion effect, which will seriously affect the quality and quantity of production. When the extruder is working, because the screw and the barrel bushing fit closely, and the bushing and barrel are mostly fixed by friction, the phenomenon of "bore sweeping" often occurs. the

Contents of the invention

Purpose of the invention: This utility model provides a plastic extruder, the purpose of which is to solve the problems of poor extrusion effect and easy "sweeping" of the previous equipment. the

Technical solution: the utility model is realized through the following technical solutions:

A kind of plastic extruder, it is characterized in that: this extruder comprises machine head mould, machine cover, bushing, barrel, heating resistance wire, screw rod, electric control device, material inlet, transmission device, cooling water channel, motor and the frame; the hood is set on the upper end of the frame, the screw is sleeved in a smooth bush, and the bush is fixed in the barrel with a smooth inner wall through a groove, and one end of the screw is connected to the transmission device, and the transmission device is connected to Motor; there is a cooling water channel inside the screw; the heating resistance wire that melts the plastic to be processed can be wound on the barrel, and the heating resistance wire is connected with the electric control device arranged under the machine cover; the feeding port is set in the feeding section of the screw In the upper part, the wall thickness of the bushing corresponding to the feeding section is smaller than that of other parts, so that the bushing at this place forms a bell mouth shape to accommodate more plastic.

The extruder screw is divided into three parts according to the axial direction, which are feeding section, melting section and homogenizing section in turn. The feeding section is the part connected with the transmission device; the cooling water channel extends to its homogenizing section; The melting section and the homogenizing section are provided with threads with helicoids, and the melting section is also provided with secondary threads. the

The diameter of the screw increases sequentially from the feeding section, the melting section and the homogenizing section, and the length of each section also increases sequentially, and the length-to-diameter ratio is 20. the

The groove depth of the screw gradually becomes shallower from the feeding section, the melting section to the homogenizing section, and the helix angle is between 3°-15°. the

The relationship between the compression ratio of screw feeding section, melting section and homogenizing section is 1: 1.6: 2.4. the

The ratio of the flight width of the main and auxiliary threads in the melting section is 4:3, the ratio of the pitch is 1:1.1, and the radial height difference of the single side of the main and auxiliary threads is 0.5mm. the

The bushing is made of low alloy nitrided steel and is grooved at the very front end. the

The transmission device is arranged in the housing at one end of the frame, and an air outlet and an oil cup for dripping lubricating oil to the transmission device are opened above the housing. the

Advantages and effects: the utility model provides a new type of plastic extruder, which is improved on the basis of the original plastic extruder, adopts a new extruder screw structure, and at the same time, changes the bushing and barrel The fixing method used in the past was to fix the bushing and the machine barrel by friction, but now it is fixed by grooves. The screw structure of the extruder is novel, simple and cheap, can provide relatively stable extrusion pressure, not only saves cost but also improves production efficiency .

The beneficial effects of the present invention are:

(1) The separation screw is used to make the material mixing more uniform, promote the complete melting of the material, and make the extrusion process more stable.

(2) Adding secondary threads in the melting section makes the material subject to greater extrusion and shearing in this section. the

(3) Good exhaust performance and less bore sweeping. the

(4) Improve production capacity and reduce power loss. the

(5) The screw is easy to process and the price is moderate. the

Description of drawings:

Fig. 1 is the structural representation of the utility model;

Fig. 2 is a screw structure diagram;

Fig. 3 is a machine barrel structure diagram;

In the figure: machine head mold 1, machine cover 2, bushing 3, machine barrel 4, heating resistance wire 5, screw rod 6, electric control device 7, material inlet 8, oil cup 9, air outlet 10, transmission device 11, Cooling channel 12, water outlet 13, motor 14, frame 15, groove 31.

The specific embodiment: the utility model is further described below in conjunction with the accompanying drawings:

As shown in Figure 1, the utility model provides a plastic extruder, which includes a die 1, a machine cover 2, a bushing 3, a barrel 4, a heating resistance wire 5, a screw 6, an electric control Device 7, material inlet 8, transmission device 11, cooling water channel 12, motor 14 and frame 15; machine cover 2 is arranged on the upper end of frame 15, and screw rod 6 is sleeved in smooth bush 3, and bush 3 passes through concave Groove 31 is fixed in the machine barrel 4 that has smooth inner wall, and one end of screw rod 6 is connected with transmission device 11, and transmission device 11 is connected with motor 14; Inside screw rod 6 is provided with cooling channel 12, and the outlet end of cooling channel 12 is provided with Water outlet 13; the heating resistance wire 5 that can melt the plastics that need to be processed can be wound on the barrel 4, and the plastics that need to be processed can be melted, and the heating resistance wire 5 is connected with the electric control device 7 arranged under the machine cover 2; The feed port 8 is set on the upper part of the feeding section L1 of the screw, and the wall thickness of the bushing 3 corresponding to the feeding section L1 is smaller than that of other parts so that the bushing 3 forms a trumpet shape to accommodate more plastics.

The extruder screw 6 is divided into three parts according to the axial direction, which are the feeding section L1, the melting section L2 and the homogenizing section L3 in turn. The feeding section L1 is the part connected with the transmission device 11; Section L3; there are screw threads with helicoids in the feeding section, melting section and homogenizing section, and a secondary thread is provided in the melting section L2. the

The diameter of the screw 6 increases successively from the feeding section, the melting section and the homogenizing section, and the length of each section also increases sequentially, and the length-to-diameter ratio is 20. the

The groove depth of the screw 6 gradually becomes shallow from the feeding section, the melting section to the homogenizing section, and the helix angle is between 3°-15°. the

The relationship between the compression ratio of screw 6 feeding section L1, melting section L2 and homogenizing section L3 is 1: 1.6: 2.4. the

The ratio of the flight width of the main and auxiliary threads in the melting section L2 is 4:3, the ratio of the pitch is 1:1.1, and the radial height difference of the single side of the main and auxiliary threads is 0.5mm. the

The bushing 3 is made of low-alloy nitrided steel, and has a groove 31 at the front end. the

The transmission device 11 is arranged in a housing at one end of the frame 15, and an air outlet 10 and an oil cup 9 for dripping lubricating oil to the transmission device 11 are provided above the housing. the

As shown in Figure 1, the cylinder 4 is first heated to the temperature required by the process. The plastic is poured into the machine barrel 4 from the material inlet 8, and at this moment, the plastic moves forward in the bush 3 under the propelling action of the extruding screw 6. During this process, the material is continuously conveyed forward and compacted. At the end of the feeding section L1, that is, the left end of the L1 section shown in Figure 2, the plastic is gradually heated by the inner wall of the heated barrel and the frictional heat. When the plastic enters the melting section L2 from the feeding section L1, the volume of the screw channel gradually becomes smaller due to the gradual shallowing of the screw channel, and the obstacles of the filter screen, the splitter plate and the machine head As a result, the plastic is further compacted and forms a high pressure. At the same time, the temperature of the plastic continues to rise under the action of external heat from the barrel 4 and the strong stirring, mixing, shearing and friction of the extrusion screw 6 and the bushing 3. High, the amount of melted plastics just keeps increasing like this, and the amount of unmelted plastics keeps decreasing. When the end of the melting section L2 is reached, that is, the left end of the L2 section in Fig. 2, most or all of the solid plastics have been melted. The melted plastic will be further plasticized and homogenized after entering the homogenizing section L3, and it can be extruded from the head die 1 at constant pressure, constant temperature and quantitatively. Then, through auxiliary machines such as the nose die, cooling, shaping, and traction, the required plastic extruded products are finally obtained. the

In the improved plastic proposed by the utility model, the separated screw makes the mixing of materials more uniform, promotes the complete melting of materials, and makes the extrusion process more stable. During the extrusion process of the material, in the melting section, due to the effect of the sub-thread, the material is subjected to greater extrusion and shearing in this section, so that the plastic melt can be fully plasticized, so the extrusion effect is good. the

Claims (8)

1. A plastic extruder, characterized in that: the extruder comprises a die (1), a machine cover (2), a bushing (3), a barrel (4), a heating resistance wire (5), Screw (6), electric control device (7), material inlet (8), transmission device (11), cooling channel (12), motor (14) and frame (15); machine cover (2) is arranged on the machine The upper end of the frame (15), the screw rod (6) is sleeved in the smooth bush (3), the bush (3) is fixed in the barrel (4) with a smooth inner wall through the groove (31), and the screw rod (6) One end of the screw rod (6) is connected to the transmission device (11), and the transmission device (11) is connected to the motor (14); a cooling water channel (12) is arranged inside the screw rod (6); a heating resistance wire (5 ) is wound on the barrel (4), and the heating resistance wire (5) is connected with the electric control device (7) arranged under the cover (2); the feeding port (8) is set on the upper part of the screw feeding section (L1) , the wall thickness of the bushing (3) corresponding to the feeding section (L1) is smaller than that of other parts so that the bushing (3) at this place forms a bell mouth shape to accommodate more plastics. 2. The plastic extruder according to claim 1, characterized in that: the extruder screw (6) is divided into three parts according to the axial direction, which are feeding section (L1), melting section (L2) and homogenizing section in sequence Section (L3), the feeding section (L1) is the part connected with the transmission device (11); the cooling water channel (12) extends to its homogenization section (L3); there are The screw thread with helix has a secondary thread at the melting section (L2). 3. The plastic extruder according to claim 2, characterized in that: the diameter of the screw (6) increases sequentially from the feeding section, the melting section and the homogenizing section, and the length of each section also increases sequentially, and the length-to-diameter ratio thereof is uniform. for 20. 4. The plastic extruder according to claim 2, characterized in that: the depth of the screw groove of the screw (6) gradually becomes shallower from the feeding section, the melting section to the homogenizing section, and the helix angle is between 3°-15° between. 5. The plastic extruder according to claim 2, characterized in that: the relationship between the compression ratio of the screw (6) feeding section (L1), melting section (L2) and homogenizing section (L3) is 1: 1.6:2.4. 6. The plastic extruder according to claim 2, characterized in that: the ratio of the width of the main and auxiliary flight of the melting section (L2) is 4:3, the ratio of the pitch is 1:1.1, and the flight of the main and auxiliary flight is 1:1.1. The radial height difference on one side is 0.5mm. 7. The plastic extruder according to claim 1, characterized in that: the bush (3) is made of low-alloy nitrided steel, and has a groove (31) at the front end. 8. The plastic extruder according to claim 1, characterized in that: the transmission device (11) is set in the casing at one end of the frame (15), and an air outlet (10) is opened above the casing for An oil cup (9) for dripping lubricating oil into the transmission (11).

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