Extrusion equipment and material extrusion method

Abstract

The invention provides extrusion equipment and a material extrusion method. The extrusion equipment comprises a barrel and a screw. The barrel comprises a main material section, a feeding section and an extrusion section. The main material section comprises a first feeding hole for feeding a main material into the barrel body to form a main melt; the feeding section comprises a second feeding hole for adding the auxiliary material into the barrel so as to be mixed with the main melt to form a mixed material; the extrusion section comprises a discharge port so that mixed melt formed by the mixed materials can be extruded out of the barrel. The screw comprises a first section, a second section and a third section. The first section comprises a first screw groove, a first material space is formed by the first screw groove and the inner wall of the main material section, and first pressure is generated on main materials when the screw rotates. The second section comprises a second spiral groove, a second material space is formed by the second spiral groove and the inner wall of the feeding section, second pressure is generated on the main melt and the auxiliary materials when the screw rotates, and the second pressure is smaller than the first pressure. According to the extrusion equipment provided by the invention, the auxiliary materials can be smoothly added into the barrel body, and the reliability of material switching can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of material extrusion molding, and in particular to extrusion equipment and material extrusion methods. Background Art

[0002] Extrusion equipment can melt materials and extrude the molten materials to obtain wires or other shapes of extruded products. In order to meet application requirements, some extruded products need to have different material compositions in different parts, so it is necessary to add material components of a multiphase system to the extrusion equipment. This often involves switching materials, and the composition of the materials needs to be changed during the extrusion process. For example, in the process of preparing rainbow-colored wires with multiple colors switching in sequence, materials of different colors are switched in sequence, so that the colors on the wires extruded by the extrusion equipment are switched accordingly.

[0003] However, when switching materials, the switched materials will have a lot of residues in the extrusion equipment and will be mixed into the new materials, which will have an adverse effect on the performance of the new materials. For example, in the process of preparing rainbow-colored wires, there are a lot of residues of materials in various places in the extrusion equipment, resulting in the previous color appearing intermittently in the later color when switching colors. The solution in the prior art is to increase the feeding interval between the two colors, and add the material of the later color after the previous color is basically emptied, but this solution will cause the extrusion process to be discontinuous and the size of the extruded product to fluctuate greatly.

[0004] Therefore, it is necessary to provide a new extrusion equipment that can reduce the residue of the previous material and improve the reliability and stability of the material switching process.

[0005] The content of the background technology section is only the information known to the inventor personally, and does not mean that the above information has entered the public domain before the application date of this disclosure, nor does it mean that it can become the prior art of the present disclosure. Summary of the invention

[0006] This specification provides an extrusion device and a material extrusion method, which can solve the problems existing in the related technology.

[0007] In a first aspect, the specification provides an extrusion device, which includes a barrel and a screw. The barrel includes a main material section, a feeding section and an extrusion section. The main material section is at one end of the barrel and includes a first feeding port for adding the main material into the barrel to form a main melt. The feeding section is adjacent to the main material section along the axis direction of the barrel and includes a second feeding port for adding the auxiliary material into the barrel to mix with the main melt to form a mixed material. The extrusion section is adjacent to the feeding section along the axis direction and includes a discharge port so as to extrude the mixed melt formed by the mixed material out of the barrel. The screw is rotatably located in the barrel. The screw includes a first section, a second section and a third section. The first section is located in the main material section and includes a first screw groove, the first screw groove and the inner wall of the main material section form a spiral first material space and generate a first pressure on the main material when the screw rotates. The second section is located in the feeding section and includes a second screw groove, the second screw groove and the inner wall of the feeding section form a spiral second material space and generate a second pressure on the main melt and the auxiliary material when the screw rotates, and the second pressure is less than the first pressure. The third section is located in the extrusion section and includes a third screw groove. The third screw groove and the inner wall of the extrusion section form a spiral third material space to convert the mixed material into a mixed melt.

[0008] In some embodiments, the depth of the first screw groove is less than the depth of the second screw groove, so as to facilitate adding auxiliary materials into the barrel through the second feeding port.

[0009] In some embodiments, the lead of the second thread groove is less than the lead of the first thread groove.

[0010] In some embodiments, the screw further comprises a flow control section. The flow control section is located between the first section and the second section and is configured to limit the flow of the main material so that the flow of the main material passing through the flow control section is less than or equal to a preset flow threshold.

[0011] In some embodiments, the flow control section includes a flow-limiting screw rib, a first flow-limiting screw groove, and a second flow-limiting screw groove. The first flow-limiting screw groove and the second flow-limiting screw groove are respectively located on both sides of the flow-limiting screw rib, the first flow-limiting screw groove is connected to the first screw groove, and the second flow-limiting screw groove is connected to the second screw groove. The diameter of the inner wall of the barrel is larger than the outer diameter of the flow-limiting screw rib, so as to form a gap between the inner wall of the barrel and the flow-limiting screw rib.

[0012] In some embodiments, the extrusion device includes a pressure sensor. The pressure sensor is disposed on the barrel and adjacent to the front end of the second section to measure the material pressure at the front end of the second section. The front end is located at one end of the second section adjacent to the first section.

[0013] In some embodiments, when the screw rotates at the working speed, the material pressure at one end of the first section adjacent to the front end is greater than 2 MPa. At the front end, the material pressure is less than or equal to 2 MPa.

[0014] In some embodiments, in the axial direction, the second feed port and the first feed port have a first spacing distance, the second feed port and the discharge port have a second spacing distance, and the first spacing distance is greater than or equal to the second spacing distance.

[0015] In some embodiments, the ratio of the length of the screw thread segment to the outer diameter is in the range of 20 to 35. The first spacing distance is greater than 10 times the outer diameter of the screw, and the second spacing distance is greater than 4 times the outer diameter of the screw.

[0016] In some embodiments, the operating speed of the screw is configured so that the material transmission speed generated in the first material space is greater than the feeding speed of the main material at the first feeding port.

[0017] In a second aspect, the present specification provides a material extrusion method, which is applied to the extrusion equipment of the first aspect, and the extrusion method includes: controlling the rotation of the screw; adding the main material into the main material section through a first feeding port, so that the main material forms a main melt in the main material section; adding the first auxiliary material into the feeding section through a second feeding port, thereby forming a first mixed melt mixed with the main melt and the first auxiliary material in the extrusion section.

[0018] In some embodiments, after adding the first auxiliary material into the feeding section through the second feeding port, the extrusion method includes: stopping adding the first auxiliary material at the second feeding port, and adding the second auxiliary material into the feeding section through the second feeding port, thereby forming a second mixed melt mixed with the main melt and the second auxiliary material in the extrusion section.

[0019] In some embodiments, after adding the second auxiliary material into the feeding section through the second feeding port, the extrusion method further comprises:

[0020] The second auxiliary material is stopped from being added at the second feeding port, and at least the third auxiliary material is added into the feeding section through the second feeding port, so as to form at least a third mixed melt in the extrusion section. The third mixed melt is formed by mixing the main melt and the third auxiliary material under the drive of the screw.

[0021] In some embodiments, in the first mixed melt, the weight proportion of the main material is greater than 80%. And / or in the second mixed melt, the weight proportion of the main material is greater than 80%.

[0022] In some embodiments, the main material has different colors from the first auxiliary material and the second auxiliary material.

[0023] In some embodiments, the first auxiliary material includes at least one of masterbatch, color oil, color powder, fiber or foaming agent.

[0024] In some embodiments, the second auxiliary material includes at least one of masterbatch, color oil, color powder, fiber or foaming agent.

[0025] It can be seen from the above technical solutions that the extrusion equipment and material extrusion method provided in this specification can make the distance between the first feeding port and the discharge port greater than the distance between the second feeding port and the discharge port. In this way, after the main material is added to the cylinder from the first feeding port, it will take a longer path and time to reach the discharge port, and after the auxiliary material is added to the cylinder from the second feeding port, it will take a shorter path and time to reach the discharge port. In this way, the main material can obtain a more sufficient melting and dispersion effect. When switching from the first auxiliary material to the second auxiliary material at the second feeding port, the first auxiliary material has less residue and can be quickly washed clean during the extrusion process, thereby reducing the risk of the second mixed melt being contaminated by the first auxiliary material and improving the reliability and stability of the material switching process. A pressure difference will be generated between the first material space and the second material space, which can reduce the risk of the material in the second material space overflowing from the second feeding port, and is also conducive to the auxiliary material being smoothly added to the cylinder.

[0026] Other features of the extrusion equipment and material extrusion method provided by this specification will be partially listed in the following description. Based on the description, the content introduced by the following figures and examples will be obvious to those of ordinary skill in the art. The creative aspects of the extrusion equipment and material extrusion method provided by this specification can be fully explained by practicing or using the methods, devices and combinations described in the detailed examples below. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of this specification, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A schematic diagram of the structure of an extrusion device provided according to some embodiments of this specification is shown;

[0029] Figure 2 A schematic diagram of an exploded structure of an extrusion device provided according to some embodiments of this specification is shown;

[0030] Figure 3 A schematic diagram showing an extruded product of an extrusion device provided according to some embodiments of the present specification;

[0031] Figure 4 A schematic diagram showing a flow control section of an extrusion device provided according to some embodiments of the present specification; and

[0032] Figure 5 A flow chart of an extrusion method provided according to some embodiments of the present specification is shown. DETAILED DESCRIPTION

[0033] The following description provides specific application scenarios and requirements of this specification, with the purpose of enabling those skilled in the art to make and use the contents of this specification. Various local modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of this specification. Therefore, this specification is not limited to the embodiments shown, but to the widest scope consistent with the claims.

[0034] The terms used herein are only used for the purpose of describing specific example embodiments and are not restrictive. For example, unless the context clearly indicates otherwise, as used herein, the singular forms "a", "an" and "the" may also include plural forms. When used in this specification, the terms "include", "comprise" and / or "contain" mean that the associated features, integers, steps, operations, elements and / or components exist, but do not exclude the existence of one or more other features, integers, steps, operations, elements, components and / or groups or that other features, integers, steps, operations, elements, components and / or groups may be added in the system / method.

[0035] In view of the following description, these and other features of the present specification, as well as the operation and function of the related elements of the structure, and the economy of the combination and manufacture of the parts can be significantly improved. Reference is made to the accompanying drawings, all of which form a part of this specification. However, it should be clearly understood that the drawings are for illustration and description purposes only and are not intended to limit the scope of this specification. It should also be understood that the drawings are not drawn to scale.

[0036] The flowcharts used in this specification illustrate the operations implemented by the system according to some embodiments in this specification. It should be clearly understood that the operations of the flowcharts may not be implemented in sequence. On the contrary, the operations may be implemented in reverse order or simultaneously. In addition, one or more other operations may be added to the flowchart. One or more operations may be removed from the flowchart.

[0037] In this specification, "X includes at least one of A, B or C" means that X includes at least A, or X includes at least B, or X includes at least C. That is, X may include only any one of A, B, and C, or may include any combination of A, B, and C and other possible contents / elements at the same time. The any combination of A, B, and C may be A, B, C, AB, AC, BC, or ABC.

[0038] In this specification, unless explicitly stated otherwise, the association relationship between structures can be a direct association relationship or an indirect association relationship. For example, when describing "A is adjacent to B", unless it is explicitly stated that A and B are directly adjacent to each other, it should be understood that A can be directly adjacent to B or indirectly adjacent to B, that is, there are other elements between A and B; for another example, when describing "A is above B", unless it is explicitly stated that A is directly above B (AB is adjacent and A is above B), it should be understood that A can be directly above B or indirectly above B (there are other elements between AB and A is above B). And so on.

[0039] Extrusion equipment can melt materials and extrude the molten materials to obtain wires or other shapes of extruded products. In order to meet application requirements, some extruded products need to have different material compositions in different parts, so it is necessary to add material components of a multiphase system to the extrusion equipment. This often involves switching materials, and the material composition needs to be changed during the extrusion process. For example, in the process of preparing rainbow-colored wires with multiple colors switching in sequence, materials of different colors are switched in sequence, so that the colors on the wires extruded by the extrusion equipment are switched accordingly.

[0040] However, after the material is replaced, there will still be a lot of residues of the replaced material in the barrel, so the extruder will continue to extrude wire with the replaced material for a period of time. At the same time, before the replaced material is completely discharged from the extruder, the new material will mix with the replaced material after entering the extruder, which may have an adverse effect on the performance of the wire or cause the wire quality to fail to meet the standards. For example, in the process of preparing rainbow-colored wire, there are a lot of residues of material in various parts of the screw, resulting in the previous color appearing intermittently in the later color when switching colors.

[0041] One solution in the prior art is to increase the feeding interval between the two materials. For example, in the case of changing the color of the extruded wire, the existing method is to stop adding the material of the previous color, and then add the material of the new color after the material with the previous color is discharged from the extruder. However, this solution will cause the extrusion process to be discontinuous and the size of the extruded product to fluctuate greatly.

[0042] In view of this, when feeding, the materials can be divided into main materials and auxiliary materials, and the feed port of the auxiliary materials can be separated from the feed port of the main materials, and the feed port of the auxiliary materials can be designed to be closer to the discharge port. After the main material is added to the cylinder, it needs to go through a longer path and time to reach the discharge port. In this way, the main material can be fully melted and dispersed. After the auxiliary material is added to the cylinder, it needs to go through a shorter path to reach the discharge port, and the distribution area of ​​the auxiliary material is smaller.

[0043] During the extrusion process, the main material can be used as the base material and remain unchanged, while the auxiliary materials can be switched and added. In this way, when replacing the new auxiliary materials, the residue of the old auxiliary materials in the barrel can be reduced and can be quickly flushed clean, which can reduce the risk of the residual old auxiliary materials affecting the performance of the subsequent extruded products. Taking the extruded product as wire as an example, the wire segment where the new and old auxiliary materials are mixed in the extruded wire can be shortened, and the extruded wire segment can be switched from the wire segment with the old auxiliary material to the wire segment with the new auxiliary material more quickly.

[0044] Accordingly, it is necessary to provide an extrusion device, which includes a barrel and a screw. The screw is rotatably located in the barrel. The barrel includes a main material section, a feeding section and an extrusion section. The main material section is at one end of the barrel and includes a first feeding port for feeding the main material into the barrel to form a main melt. The feeding section is adjacent to the main material section along the axial direction of the barrel and includes a second feeding port for feeding the auxiliary material into the barrel to mix with the main melt to form a mixed material. The extrusion section is adjacent to the feeding section along the axial direction and includes a discharge port so as to extrude the mixed melt formed by the mixed material out of the barrel.

[0045] The extrusion equipment can be used to switch and add different auxiliary materials. When switching from the first auxiliary material to the second auxiliary material at the second feeding port, the first auxiliary material has a smaller distribution area and less residue, and can be quickly washed away during the extrusion process, thereby reducing the risk of the subsequent second mixed melt being contaminated by the first auxiliary material.

[0046] For example, in the process of preparing rainbow-colored wire, the materials can be divided into a base material (main material) and a variety of color-enhancing materials (first auxiliary material, second auxiliary material, third auxiliary material and other auxiliary materials with other colors). When the base material remains unchanged, the color change of the wire is completed by adding different color-enhancing materials. Especially when the main material and the first auxiliary material and the second auxiliary material are different in color, when the first auxiliary material and the second auxiliary material are switched, the residue of the first auxiliary material is small and can be quickly washed away. This can reduce the risk of the color of the first auxiliary material mixing into the second mixed melt, so that the color of each section of the extruded product has a higher purity and will not be intermittently mixed with different colors.

[0047] Therefore, the extrusion equipment can reduce the residue of the previous material and improve the reliability and stability of the auxiliary material replacement process.

[0048] In addition, when the main material is transported in the barrel, the main melt formed by the main material will be subjected to a large pressure caused by the rotation of the screw, affecting the smooth addition of the auxiliary material. Therefore, when adding the auxiliary material at the second feeding port, it is also necessary to overcome the problem of the main melt being subjected to a large pressure.

[0049] In view of this, the embodiments of this specification provide an extrusion device and a material extrusion method. The extrusion device includes a barrel and a screw. A main material section, a feeding section and an extrusion section are sequentially arranged on the barrel along its extension direction (that is, the axial direction of the barrel). In addition, the barrel is also provided with a first feeding port, a second feeding port and a discharge port. The first feeding port is located on the main material section; the second feeding port is located on the feeding section; and the discharge port is located at one end of the extrusion section, that is, the extrusion end of the barrel. In the axial direction of the barrel, the second feeding port is located between the first feeding port and the discharge port. Among them, the first feeding port is for the main material to be added to the barrel, and the second feeding port is for at least the first auxiliary material and the second auxiliary material to be added to the barrel in sequence. The screw is located in the barrel, and the first section, the second section and the third section are respectively arranged corresponding to the main material section, the feeding section and the extrusion section. Through the design of the screw ribs and the screw grooves, a first material space is formed between the first section of the screw and the barrel in the first section, a second material space is formed between the second section of the screw and the barrel, and a third material space is formed between the third section of the screw and the barrel. Because the screw fins in the first section, the second section and the third section are all spiral, the first material space, the second material space and the third material space are all spiral.

[0050] When the screw rotates, the main material melts into the main melt in the first material space and is transported by the first material space toward the discharge port, thereby generating a relatively high pressure at the main melt. When the main melt enters the second material space from the first material space, the space is wider and its pressure will decrease. Since the pressure in the second material space is lower than that in the first material space, the auxiliary material can be added from the second feeding port by overcoming a lower pressure.

[0051] The technical solutions of the embodiments of this specification will be described in detail below with reference to the accompanying drawings.

[0052] Figure 1 A schematic structural diagram of an extrusion device provided according to some embodiments of the present specification is shown. Figure 2 FIG. 2 shows a schematic diagram of an exploded structure of an extrusion device provided according to some embodiments of the present specification. Figure 1 and Figure 2 As shown, the extrusion device 100 may include a drive motor 160, a screw 140, a barrel 110 and an outlet flow channel 170. The screw 140 is rotatably located in the barrel 110. The drive motor 160 is connected to the screw 140 and can drive the screw 140 to rotate relative to the barrel 110.

[0053] The screw 140 includes a screw fin 145 and an axial structure 146, and the screw fin 145 is located on the outer peripheral surface of the axial structure 146. A screw groove is formed between the two screw fins 145. Through the screw groove, a material space can be formed between the barrel 110 and the screw 140 to accommodate the material. When the screw 140 rotates relative to the barrel 110, the material in the material space can be driven to move toward the discharge port 113 through the screw fin 145. The barrel 110 is connected to the outlet channel 170 through the discharge port 113. After the material flows into the outlet channel 170 from the discharge port 113, it is extruded through the outlet channel 170 to form an extruded product 150 such as a wire.

[0054] The material added to the barrel 110 may be in the form of particles, powder, liquid, fiber or a combination thereof. Further, the extrusion device 100 includes a heating device. The heating device is used to heat the screw 140 or the barrel 110, thereby heating the material in the barrel 110. The material can enter the barrel 110 in a solid state and can be converted into a molten state after being heated. In addition, the shearing effect on the material when the screw 140 rotates is also helpful to help the material fully melt and homogenize.

[0055] The barrel 110 may include a main material section 1110, a feeding section 1120, and an extrusion section 1130. The main material section 1110 is at one end of the barrel 110, and includes a first feeding port 111 for feeding the main material 120 into the barrel 110 to form a main melt. The feeding section 1120 is adjacent to the main material section 1110 along the axial direction D1 of the barrel 110, and includes a second feeding port 112 for feeding the auxiliary material into the barrel 110 to mix with the main melt to form a mixed material. The extrusion section 1130 is adjacent to the feeding section 1120 along the axial direction D1, and includes a discharge port 113 so as to extrude the mixed melt formed by the mixed material out of the barrel 110.

[0056] That is, the main material section 1110, the feeding section 1120 and the extrusion section 1130 are sequentially arranged on the cylinder 110 along its extension direction (that is, the axial direction D1 of the cylinder). The main material section 1110 is located at one end of the cylinder 110, and the extrusion section 1130 is located at the other end of the cylinder 110. The discharge port 113 can be arranged at the end of the extrusion section 1130 so as to extrude the mixed melt from the cylinder 110. In some embodiments, the number of the second feeding ports 112 is 1. In other embodiments, the number of the second feeding ports 112 can be two or more.

[0057] The structure of the screw 140 may correspond to the structure of the barrel 110. For example, the screw 140 includes a first section 141, a second section 142 and a third section 143. The second section 142 is located between the first section 141 and the third section 143. These three sections correspond in position to the main material section, the feeding section 1120 and the extrusion section 1130 of the barrel 100, respectively. Each section of the screw includes screw fins 145 and screw grooves arranged at intervals. The screw 140 has an outer diameter D2. The screw outer diameter D2 is also the outer diameter of the screw fin, and its size may be approximately equal to the inner diameter size of the barrel 110. For example, the outer diameter size of the screw fin 145 is 45 mm, and the inner diameter size of the barrel 110 is also 45 mm, and the screw 140 is tightly fitted with the barrel 110.

[0058] The first section 141 of the screw 140 is located in the main material section 1110 and includes a spiral first screw fin 1451 and a first screw groove 1411. The first screw groove 1411 and the inner wall of the main material section 1110 form a spiral first material space 1412. The main function of the first material space 1412 is to melt the solid main material 120 into a first melt. Therefore, the length of the first section 141 is designed to be relatively long so that there is enough time to melt the main material 120. For example, in some embodiments, the length of the first section 141 is 11 to 22 times the outer diameter D2 of the screw 140.

[0059] The second section 142 of the screw 140 is located in the feeding section 1120 and includes a spiral second screw fin 1452 and a second screw groove 1421. The second screw groove 1421 and the inner wall of the feeding section 1120 form a spiral second material space 1423. The main function of the second material space 1423 is to contain the auxiliary material and mix the auxiliary material with the main material 120. Therefore, the length of the second section 142 is designed to be shorter than the first section 141. For example, in some embodiments, the length of the second section 142 is 6 to 12 times the outer diameter D2 of the screw.

[0060] The third section 143 of the screw 140 is located in the extrusion section 1130 and includes a spiral third screw fin 1453 and a third screw groove 1431. The third screw groove 1431 and the inner wall of the extrusion section 1130 form a spiral third material space 1432 to convert the mixed material into a mixed melt. In the third section 143, the auxiliary material and the main material 120 are fully mixed to form a mixed melt, which is finally extruded at the discharge port. The length of this section is the shortest. For example, in some embodiments, the length of the third section 143 is 3 to 7 times the outer diameter D2 of the screw.

[0061] The main material 120 is added to the first material space 1412 from the first feeding port 111; the auxiliary material is added to the second material space 1423 from the second feeding port 112. The first feeding port 111 is opposite to the first section 141. The second feeding port 112 is opposite to the second section 142. Further, along the axial direction D1 of the cylinder 110, the length dimension of the first feeding port 111 is smaller than the length dimension of the first section 141, and the length dimension of the second feeding port 112 is smaller than the length dimension of the second section 142.

[0062] Since the first material space 1412 and the second material space 1423 are both spiral-shaped, when the screw 140 rotates, the materials therein are squeezed in the first material space 1412 and the second material space 1423. Accordingly, when the screw 140 rotates, a first pressure can be generated in the first material space 1412 on the main material 120, and a second pressure can be generated in the second material space 1423 on the main melt and the auxiliary material formed by the main material 120.

[0063] However, if the pressure at the second feeding port 112 is greater than or equal to the first pressure, the material in the second material space 1423 is at risk of overflowing from the second feeding port 112, which is not conducive to the addition of auxiliary materials. Therefore, in the present disclosure, the screw 140 has a special structure so that the second pressure is less than the first pressure. A pressure difference is generated between the first material space 1412 and the second material space 1423, which can reduce the risk of the material in the second material space 1423 overflowing from the second feeding port 112, and is conducive to the smooth addition of auxiliary materials to the second material space 1423.

[0064] Next, the decompression structure of the screw 140 will be described in detail.

[0065] In some embodiments, the depth of the first screw groove 1411 is less than the depth of the second screw groove 1421 , so as to facilitate adding auxiliary materials into the barrel 110 through the second feeding port 112 .

[0066] After the main material 120 is added to the barrel 110, it can first enter the first screw groove 1411 (first material space 1412) and move toward the second section 142 driven by the first screw rib 1451. Then the main material 120 can enter the second screw groove 1421 (second material space 1423). At this time, the auxiliary material is added to the main material 120, and the volume becomes larger. The main material 120 and the auxiliary material move toward the discharge port 113 together and driven by the second screw rib 1452. If the depth of the second screw groove 1421 is set to be larger, the ability to accommodate materials is stronger, which can reduce the pressure of the main material 120 when it flows through the second section 142, so as to facilitate the addition of materials into the barrel 110 through the second feeding port 112.

[0067] For example, the upper limit of the conveying capacity of the first section 141 is a material flow rate of 8 kg / h to 9 kg / h, and the upper limit of the conveying capacity of the second section 142 may be a material flow rate of 10 kg / h.

[0068] In the prior art of single-screw extrusion, the depth of the screw groove of the screw 140 tends to gradually decrease along the conveying direction of the material, so that the material pressure gradually increases, which is obviously not conducive to the formation of a low-pressure zone.

[0069] In some embodiments, the outer diameter of the screw flight 145 remains constant along the axial direction D1 of the barrel 110. The outer diameter of the shaft structure 146 in the first section 141 is greater than the outer diameter of the shaft structure 146 in the second section 142, so that the depth of the first screw groove 1411 is less than the depth of the second screw groove 1421.

[0070] In some embodiments, the lead of the second screw groove 1421 is smaller than the lead of the first screw groove 1411. This is beneficial to improving the mixing effect of the materials at the second section 142, improving the separation degree between the mixed melts at different positions of the second screw groove 1421, and reducing the interference between the first mixed melt and the second mixed melt. The lead refers to the axial distance between adjacent corresponding points on the same spiral line.

[0071] In some embodiments, the lead of the third screw groove 1431 is greater than the lead of the second screw groove 1421 , which helps to improve the material conveying capacity of the third screw groove 1431 .

[0072] In some embodiments, Figure 1 and Figure 2 As shown, the screw 140 further includes a flow control section 144. The flow control section 144 can be configured as a barrier structure. The flow control section 144 is located between the first section 141 and the second section 142, and is configured to limit the flow of the main material 120 so that the flow of the main material 120 passing through the flow control section 144 is less than or equal to a preset flow threshold.

[0073] The preset flow rate threshold value allowed to pass through the flow control section 144 is less than the upper limit of the conveying capacity of the first section 141, and is also less than the upper limit of the conveying capacity of the second section 142. For example, the upper limit of the conveying capacity of the first section 141 is a material flow rate of 8kg / h to 9kg / h, and the upper limit of the conveying capacity of the second section 142 is a material flow rate of 10kg / h, and the preset flow rate threshold value allowed to pass through the flow control section 144 is 6kg / h.

[0074] The material conveying process in the cylinder 110 is a dynamic process. Therefore, the conveying flow rate of the material will fluctuate. The flow control section 144 can control the conveying flow rate of the main material 120 so that the conveying flow rate of the main material 120 remains stable. In this way, when the main material 120 passes through the flow control section 144 and reaches the second section 142, the flow rate will not be excessive, which is conducive to maintaining the main material 120 in a low pressure state in the second section 142, and facilitating the addition of new materials in the second section 142.

[0075] Furthermore, the flow control section 144 is adjacent to the front end 1422 of the second section 142, and the material can reach the front end 1422 of the second section 142 after passing through the flow control section 144. This is conducive to improving the flow stabilization effect of the flow control section 144 on the material at the second section 142.

[0076] Figure 4 A schematic diagram of a flow control section of an extrusion device provided according to some embodiments of the present specification is shown.

[0077] In some embodiments, Figure 1 , Figure 2 and Figure 4 As shown, the flow control section 144 includes a flow limiting screw rib 1443, a first flow limiting screw groove 1441 and a second flow limiting screw groove 1442. The flow limiting screw rib 1443, the first flow limiting screw groove 1441 and the second flow limiting screw groove 1442 are all spiral. The first flow limiting screw groove 1441 and the second flow limiting screw groove 1442 are parallel and are respectively located on both sides of the flow limiting screw rib 1443.

[0078] The flow control section 144 is divided into two ends, the first end 144a of which is adjacent to the first section 141 of the screw 140, and the second end 144b of which is adjacent to the second section 142 of the screw 140. The first end 144a and the second end 144b of the flow control section 144 have a diameter D2, and are clearance-matched with the inner wall of the barrel 110, so that the flow control section 144 can rotate freely in the barrel, and can also play a role in sealing the flow of materials.

[0079] The first flow-limiting screw groove 1441 is divided into two ends. The first end starts at the first end 144a of the flow-control section 144 and is connected to the first screw groove 1411, that is, connected to the main material section 1110 of the barrel 110; the second end stops in the flow-control section 144 and is isolated by the second end 144b of the flow-control section 144, so as not to be connected to the feeding section 1120 of the barrel 110.

[0080] The second flow-limiting screw groove 1442 is also divided into two ends. The second end thereof starts at the second end 144b of the flow-controlling section 144 and is connected to the second screw groove 1421, that is, connected to the feeding section 1120 of the barrel 110; the first end thereof stops in the flow-controlling section 144 and is isolated by the first end 144a of the flow-controlling section 144, so as to be disconnected from the main material section 1110 of the barrel 110.

[0081] The flow-limiting spiral rib 1443 is located between the first end 144a and the second end 144b of the flow-control section 144. The diameter of the inner wall of the cylinder 110 is larger than the outer diameter of the flow-limiting spiral rib 1443, so that a gap is formed between the inner wall of the cylinder 110 and the flow-limiting spiral rib 1443. The gap allows the first flow-limiting spiral groove 1411 to communicate with the second flow-limiting spiral groove 1442.

[0082] When the extruder is working, the main material 120 in the first screw groove 1411 can enter the first flow-limiting screw groove 1441 from the first end of the first flow-limiting screw groove 1441, then pass through the gap between the inner wall of the barrel 110 and the flow-limiting screw rib 1443, and then reach the second flow-limiting screw groove 1442, and then enter the second screw groove 1421 through the second end of the second flow-limiting screw groove 1442. In this way, when the main material 120 passes through the flow-control section 144, the flow-limiting screw rib 1443 can limit the flow of the main material 120. At the same time, the structure of the flow-control section 144 can squeeze the main material 120, so that the main material 120 is further dispersed and melted, and the dispersion and melting degree of the main material 120 is improved.

[0083] In some embodiments, the pitch of the flow control section 144 is smaller than that of the first section 141 and the second section 142 , and the lead of the flow control section 144 is larger than that of the first section 141 and the second section 142 .

[0084] The end of the second section 142 adjacent to the first section 141 is its front end 1422. In some embodiments, when the screw 140 rotates at the working speed, the material pressure at the end of the first section 141 adjacent to the front end 1422 of the second section 142 is greater than 2MPa. At the front end 1422 of the second section 142, the material pressure is less than or equal to 2MPa. Further, the material at the front end 1422 of the second section 142 is the main material 120 that has just arrived at the second section 142. For example, the pressure range of the main material 120 at the front end 1422 of the second section 142 may be 1.4MPa to 1.6MPa or 1.6MPa to 2MPa.

[0085] The material pressure at the front end 1422 can be used to measure the material filling degree of the entire second section 142. If the filling degree of the main material 120 when flowing through the second section 142 is too high, internal pressure will be generated, so that there is a risk of the main material 120 overflowing from the second feeding port 112. Therefore, it is necessary to control the pressure of the main material 120 when flowing through the second section 142 so that it does not exceed the preset pressure threshold.

[0086] The operator controls the pressure at the front end 1422 of the second section 142 to be less than or equal to 2 MPa, so that the pressure of the main material 120 when flowing through the second section 142 does not exceed the preset pressure threshold. In this way, a cavity, i.e., a low-pressure area, is formed at the second section 142. At this time, the main material 120 will not overflow from the second feeding port 112, and the second auxiliary material 02 is allowed to be added to the second section 142 through the second feeding port 112.

[0087] For example, the upper limit of the conveying capacity of the second section 142 is a material flow rate of 10 kg / h. If the addition speed of the main material 120 and the flow rate in the cylinder 110 are 6 kg / h, the main material 120 cannot fill the second section 142, so that a low pressure area is formed in the second section 142. If the addition speed of the main material 120 and the flow rate in the cylinder 110 reach or approach 9 kg / h, the pressure in the second section 142 exceeds the preset pressure threshold.

[0088] In some embodiments, Figure 1 As shown, the extrusion device 100 includes a pressure sensor 180 . The pressure sensor 180 is disposed on the barrel 110 and adjacent to the front end of the second section 142 , and measures the material pressure at the front end of the second section 142 .

[0089] Through the pressure sensor 180, the operator can measure the pressure value when the main material 120 reaches the second section 142. Based on the measurement result of the pressure sensor 180, the operator or the controller can accurately control the pressure when the main material 120 flows through the second section 142.

[0090] In some embodiments, the pressure value of the main material 120 when it reaches the second section 142 is affected by the rotation speed of the screw 140 and the feeding speed of the main material 120. When the pressure value of the main material 120 does not meet the requirements, the operator or the controller can adjust the rotation speed of the screw 140 and the feeding speed of the main material 120, so that the pressure value of the main material 120 meets the requirements. For example, when the pressure sensor 180 measures a pressure of 2.3 MPa, the operator or the controller can increase the rotation speed of the screw 140 and reduce the feeding speed of the main material 120, so that the pressure value of the main material 120 is reduced to less than or equal to 2 MPa.

[0091] The material can be transported by a feeder into the barrel 110. For example, the feeder can input the material into the barrel 110 through a pump. For another example, the feeder can push the material into the barrel 110 through its own screw.

[0092] The way in which the feeder adds material to the barrel 110 may include starve feeding and flood feeding. Starve feeding is to set the material supply to be lower than the current theoretical capacity of the extruder so that the inside of the screw is not completely filled with raw materials. In starve feeding of the main material 120, the main material 120 can fall directly into the barrel 110, no material is accumulated in the hopper at the first feeding port 111, and the space between the barrel 110 and the screw 140 is partially filled. In overflow feeding, the material first enters the hopper at the first feeding port 111, and there is material accumulation in the hopper, and the material in the hopper gradually falls into the barrel 110. In this way, the extrusion device 100 sucks in as much material as possible, and the space between the barrel 110 and the screw 140 can be filled.

[0093] In some embodiments, the operating speed of the screw 140 is configured so that the material transmission speed generated in the first material space 1412 is greater than the feeding speed of the main material 120 at the first feeding port 111 .

[0094] By configuring the feeding speed of the main material 120 and the working speed of the screw 140 in this way, the main material 120 can be fed into the barrel 110 in a hungry state. In this way, the feeder can conveniently measure the feeding speed of the material and can effectively control the feeding speed of the material, which is conducive to maintaining a stable material flow in the barrel 110 and also conducive to maintaining a low pressure state of the material at the second feeding port 112 in the barrel 110.

[0095] For example, when the screw 140 rotates at 25 rpm, the barrel 110 has a material flow rate of 12 kg / h in a saturated state. If the feeder provides material at a rate of 8 kg / h, the melt at the first feeding port 111 does not fill the barrel 110 and is in a hungry state.

[0096] Furthermore, the operating speed of the screw 140 is configured so that the material transmission speed generated in the second material space 1423 is greater than the sum of the feeding speeds of the main material 120 and the auxiliary material. By configuring the feeding speeds of the main material 120 and the auxiliary material and the operating speed of the screw 140 in this way, the main material 120 and the auxiliary material can be added to the barrel 110 in a hungry state.

[0097] In the scenario of replacing auxiliary materials, the first feeding port 111 is used to add the main material 120 into the barrel 110, and the second feeding port 112 is used to add at least the first auxiliary material 01 and the second auxiliary material 02 into the barrel 110 in sequence. When the screw 140 rotates, the main material 120 and the first auxiliary material 01 first form a first mixed melt and leave the barrel 110 from the discharge port 113, and then the main material 120 and the second auxiliary material 02 form a second mixed melt and leave the barrel 110 from the discharge port 113.

[0098] In the axial direction D1 of the barrel 110, the second feed port 112 is located between the first feed port 111 and the discharge port 113. That is to say, the distance between the first feed port 111 and the discharge port 113 is greater than the distance between the second feed port 112 and the discharge port 113. In this way, the material added to the barrel 110 from the first feed port 111 will take a longer path and time to reach the discharge port 113, and the material added to the barrel 110 from the second feed port 112 will take a shorter path and time to reach the discharge port 113. Therefore, when the material added to the barrel 110 from the second feed port 112 is switched, less residue of the first mixed melt is left, which is conducive to the first mixed melt being washed clean by the second mixed melt.

[0099] According to the adding process of the first auxiliary material 01 and the second auxiliary material 02, the time period corresponding to the extrusion process may have a first time window and a second time window. The first time window generally corresponds to the time period of adding the first auxiliary material 01; the second time window generally corresponds to the time period of adding the second auxiliary material 01. The first time window is before the second time window.

[0100] In the first time window, the main material 120 can be continuously added to the first feeding port 111, and the first auxiliary material 01 can be continuously added to the second feeding port 112. The rotation of the screw 140 can drive the main material 120 and the first auxiliary material 01 in the barrel 110 to move toward the discharge port 113. After the main material 120 and the first auxiliary material 01 meet, the main material 120 and the first auxiliary material 01 are mixed under the drive of the screw 140. After the main material 120 and the first auxiliary material 01 are mixed and melted, a first mixed melt can be formed, and then leave the barrel 110 from the discharge port 113.

[0101] During the transition period between the first time window and the second time window, the main material 120 can still be continuously added to the first feeding port 111 , while the main material 120 is stopped from being added to the second feeding port 112 .

[0102] In the second time window, the main material 120 can still be continuously added to the first feeding port 111, and the second auxiliary material 02 can be continuously added to the second feeding port 112. The rotation of the screw 140 can drive the main material 120 and the second auxiliary material 02 in the barrel 110 to move toward the discharge port 113. After the main material 120 and the second auxiliary material 02 meet, the main material 120 and the second auxiliary material 02 are mixed under the drive of the screw 140. After the main material 120 and the second auxiliary material 02 are mixed and melted, a second mixed melt can be formed, and then leave the barrel 110 from the discharge port 113.

[0103] Therefore, during the extrusion process, the first feeding port 111 does not involve material switching. When the second feeding port 112 switches from the first auxiliary material 01 to the second auxiliary material 02, the first auxiliary material 01 has a small distribution area and less residue, and can be quickly flushed clean during the extrusion process, thereby reducing the risk of the second mixed melt being contaminated by the first auxiliary material 01.

[0104] In some embodiments, the main material 120 has different colors from the first auxiliary material 01 and the second auxiliary material 02. For example, when the extruded product 150 is a 3D printing wire with a color gradient, the main material 120 can be used as the base material of the extruded product 150, the first color pigment can be used as the first auxiliary material 01, and the second color pigment can be used as the second auxiliary material 02. The base material and the pigment can have a corresponding color after mixing. When the first auxiliary material 01 is switched to the second auxiliary material 02, the color of the mixed melt in the cylinder 110 is also switched accordingly. The residue of the first auxiliary material 01 is small and can be quickly washed away, which can reduce the risk of the color of the first auxiliary material 01 being mixed into the second mixed melt, so that the color of each section of the extruded product 150 has a higher purity and will not be mixed with different colors. In this way, the transition zone of the color switching of the obtained 3D printing wire is narrow, and a single coil of wire can be used to print a model with color change, and the printed model has distinct colors without switching wire coils of different colors during the 3D printing process.

[0105] For example, Figure 3 Schematic diagram of an extruded product of an extrusion device provided according to some embodiments of this specification is shown. Figure 1 and Figure 3 As shown, the first auxiliary material 01 is black, and accordingly, the first mixed melt is black after extrusion and solidification. The second auxiliary material 02 is white, and accordingly, the second mixed melt is white after extrusion and solidification. In the extruded product obtained by the prior art, when the first auxiliary material is switched to the second auxiliary material, there is a wider transition zone, and some black first mixed melt will be mixed in the second mixed melt, affecting the appearance of the second mixed melt after solidification. In the extruded product 150 obtained in the embodiment of this specification, when the first auxiliary material 01 is switched to the second auxiliary material 02, the transition zone is narrower, and the appearance color of the second mixed melt after solidification is purer.

[0106] In some embodiments, the type of pigment may include at least one of masterbatch, color oil or color powder. Among them, masterbatch is convenient for adding materials and easy to measure. Color oil has bright color effect and is conducive to accurate measurement. Color powder has the most effective ingredients, which is conducive to reducing the amount of material added and is easier to disperse.

[0107] In some embodiments, in the barrel 110, the temperature at the second feed port 112 is higher than the temperature at the first feed port 111. When the temperature is higher, the viscosity of the material will be lower, and it will be easier to be driven by the screw 140 and less likely to remain. In addition, the higher temperature can facilitate the second auxiliary material 02 to form a mixed melt with the first auxiliary material 01. For example, in the barrel 110, the temperature at the first feed port 111 is 150°C to 180°C, and then the temperature at the second feed port 112 is 200°C to 210°C.

[0108] In some embodiments, the main material 120 may be a single substance or a mixture of at least two substances. The first auxiliary material 01 may be a single substance or a mixture of at least two substances. The second auxiliary material 02 may be a single substance or a mixture of at least two substances.

[0109] In some embodiments, the main material 120 can be continuously added to the first feeding port 111, and after the first auxiliary material 01 and the second auxiliary material 02 are added in sequence, at least one material can be added in a preset order at the second feeding port 112.

[0110] For example, when the extruded product 150 is a rainbow-colored wire, the first auxiliary material 01, the second auxiliary material 02, the third auxiliary material and the fourth auxiliary material can be added to the second feeding port 112 in sequence. The main material 120 itself may not have a color, or the main material 120 itself may have a color. For example, the main material 120 is yellow. The first auxiliary material 01, the second auxiliary material 02, the third auxiliary material and the fourth auxiliary material can be pigments of different colors, for example, the colors of the first auxiliary material 01, the second auxiliary material 02, the third auxiliary material and the fourth auxiliary material can be red, green, blue and white, respectively.

[0111] In some embodiments, auxiliary materials may also be added into the cylinder 110 at the second feeding port 112 in a periodic cycle.

[0112] Some examples of the order of adding auxiliary materials at the second feeding port 112 are given below. Among them, the first auxiliary material 01, the second auxiliary material 02, the third auxiliary material and the fourth auxiliary material can be represented by 01, 02, 03 and 04 respectively, and the window period in which the first auxiliary material 01, the second auxiliary material 02, the third auxiliary material and the fourth auxiliary material are not added is represented by 00.

[0113] Example 1: 01→02→01→02.

[0114] Example 2: 01→02→03→04.

[0115] Example 3: [01→02]→00→[01→02]→00→[01→02]→…00→[01→02].

[0116] Example 4: [01→02→03]→[01→02→03]→……[01→02→03].

[0117] Example 5: [01→02→03→04]→[01→02→03→04]→……[01→02→03→04].

[0118] Example 6: [01→02→03→04→03→02]→[01→02→03→04→03→02]→…[01→02→

[0119] 03→04→03→02].

[0120] Example 7: [01→02→01→03→01→04]→[01→02→01→03→01→04]→……[01→02→

[0121] 01→03→01→04].

[0122] In some embodiments, the main material 120 is the sum of the materials added to the barrel 110 at the first feeding port 111. In other embodiments, the main material 120 is part of the materials added at the first feeding port 111.

[0123] In some embodiments, the main material 120 is added continuously at a constant speed. In other embodiments, the main material 120 is added at a variable speed or intermittently.

[0124] The first auxiliary material 01 can be added in the first time window. In some embodiments, in the first time window, the first auxiliary material 01 is the sum of the materials added to the barrel 110 at the second feeding port 112. In other embodiments, in the first time window, the first auxiliary material 01 is part of the materials added at the second feeding port 112.

[0125] In some embodiments, the first auxiliary material 01 is added continuously at a constant speed. In other embodiments, the first auxiliary material 01 is added at a variable speed or intermittently.

[0126] The second auxiliary material 02 can be added in the second time window. In some embodiments, in the second time window, the second auxiliary material 02 is the sum of the materials added to the barrel 110 at the second feeding port 112. In other embodiments, in the second time window, the second auxiliary material 02 is part of the materials added at the second feeding port 112.

[0127] In some embodiments, during the extrusion process, most of the material can be added to the barrel 110 from the first feeding port 111 , and a small portion of the material can be added to the barrel 110 from the second feeding port 112 .

[0128] The material added to the barrel 110 from the first feeding port 111 will take a longer path and time to reach the discharge port 113. Accordingly, the material added to the barrel 110 from the first feeding port 111 is more fully homogenized and melted. Therefore, most of the material is added to the barrel 110 from the first feeding port 111, which is conducive to the full melting and homogenization of the entire material.

[0129] The material added to the barrel 110 from the second feeding port 112 will reach the discharge port 113 after a shorter path and time, and accordingly, the homogenization and melting effect of the material added to the barrel 110 from the second feeding port 112 is weaker. Therefore, adding a small portion of the material to the barrel 110 from the second feeding port 112 is beneficial to fully melt and homogenize the material added to the barrel 110 from the second feeding port 112, and is beneficial to reduce the residue of the previous material when switching materials at the second feeding port 112.

[0130] For example, the first auxiliary material 01 and the second auxiliary material 02 are pigments of different colors, and a small amount of pigment can dye a large amount of main material 120. A small amount of pigment particles are relatively small, and are easily dispersed after being added to the barrel 110. Therefore, a small amount of pigment can fully blend with the main material 120 after a short path and time, thereby dyeing the main material 120. Along the conveying direction of the material, the part of the pigment located after the second feeding port 112 in the barrel 110 will make it easier to discharge the previous pigment when switching pigments.

[0131] In some embodiments, in the first mixed melt, the weight proportion of the main material 120 is greater than 80%. That is, in the first time window, the weight ratio of the main material 120 added to the first auxiliary material 01 in the barrel 110 may be greater than 4:1. Further, in the first time window, the feeding speed (feeding weight per unit time) ratio of the main material 120 to the first auxiliary material 01 is greater than 4:1.

[0132] In some embodiments, within the first time window, the weight of the main material 120 added to the barrel 110 accounts for 90% to 97% of the sum of the weight of the main material 120 and the first auxiliary material 01. In other words, within the first time window, the weight ratio of the main material 120 added to the barrel 110 to the first auxiliary material 01 is 9:1 to 32.3:1.

[0133] In some embodiments, in the first mixed melt, the volume proportion of the main material 120 is greater than 80%. That is, in the first time window, the volume ratio of the main material 120 added to the first auxiliary material 01 in the barrel 110 may be greater than 4:1. Further, in the first time window, the feeding speed (feeding volume per unit time) ratio of the main material 120 to the first auxiliary material 01 is greater than 4:1.

[0134] In some embodiments, in the second mixed melt, the weight proportion of the main material 120 is greater than 80%. That is, in the second time window, the weight ratio of the main material 120 added to the barrel 110 to the second auxiliary material 02 may be greater than 4:1. Further, in the second time window, the feeding speed (feeding weight per unit time) ratio of the main material 120 to the second auxiliary material 02 is greater than 4:1.

[0135] In some embodiments, in the second time window, the weight of the main material 120 added to the barrel 110 accounts for 90% to 97% of the sum of the weight of the main material 120 and the second auxiliary material 02. That is, in the second time window, the weight ratio of the main material 120 added to the barrel 110 to the second auxiliary material 02 is 9:1 to 32.3:1.

[0136] In some embodiments, in the second mixed melt, the volume proportion of the main material 120 is greater than 80%. That is, in the second time window, the volume ratio of the main material 120 added to the second auxiliary material 02 in the barrel 110 may be greater than 4:1. Further, in the second time window, the feeding speed (feeding volume per unit time) ratio of the main material 120 to the second auxiliary material 02 is greater than 4:1.

[0137] In some embodiments, the first auxiliary material 01 includes at least one of fiber or foaming agent. The second auxiliary material 02 includes at least one of fiber or foaming agent.

[0138] The structure of the fiber is easily destroyed when it is sheared. The first auxiliary material 01 and the second auxiliary material 02 will reach the discharge port 113 through a shorter path and time, and will be less sheared. Therefore, the operator adds the fiber to the barrel 110 from the second feed port 112, which is conducive to maintaining a longer length of the fiber and improving the mechanical properties of the extruded product 150.

[0139] In some embodiments, the fibers may include carbon fibers and glass fibers.

[0140] The structure of the foaming agent is easily decomposed when heated. The first auxiliary material 01 and the second auxiliary material 02 will reach the discharge port 113 through a shorter path and time, and will be less heated. Therefore, the foaming agent is added to the cylinder 110 from the second feed port 112, which is conducive to the preservation of the foaming agent and obtains a foamable extruded product 150.

[0141] In some embodiments, Figure 2 As shown, in the axial direction D1 of the cylinder 110, the second feed port 112 and the first feed port 111 have a first spacing distance L1, and the second feed port 112 and the discharge port 113 have a second spacing distance L2, and the first spacing distance L1 is greater than or equal to the second spacing distance L2.

[0142] Further, the first spacing distance L1 is greater than or equal to 2 times of the second spacing distance L2. For example, the first spacing distance L1 may be 3 times of the second spacing distance L2.

[0143] By setting the position of the second feeding port 112 in this way, the travel of the material added to the cylinder 110 from the second feeding port 112 will not be too large, which is conducive to the material added to the cylinder 110 from the second feeding port 112 being quickly flushed clean.

[0144] In some embodiments, the ratio of the length L0 of the thread segment of the screw 140 to the outer diameter D2 of the screw 140 (aspect ratio) ranges from 20 to 35. Along the axial direction D1 of the barrel 110, the thread segment of the screw 140 can be the starting point where the thread begins to appear and the end point where the thread ends completely.

[0145] For example, the aspect ratio of the screw 140 is 30.

[0146] For example, the outer diameter D2 of the screw rod 140 may be 30 mm, and the length L0 of the thread segment may be 600 mm to 1050 mm. For another example, the outer diameter D2 of the screw rod 140 may be 45 mm, and the length L0 of the thread segment may be 900 mm to 1350 mm.

[0147] Furthermore, the outer diameter D2 of the screw 140 may be greater than or equal to 40 mm. For example, the outer diameter D2 of the screw 140 may be equal to 45 mm. This is conducive to the screw 140 obtaining a larger conveying capacity, increasing the conveying amount of the material, and thus increasing the output of the extruded product 150.

[0148] In some embodiments, the first spacing distance L1 is greater than 10 times the outer diameter D2 of the screw 140, and the second spacing distance L2 is greater than 4 times the outer diameter D2 of the screw 140. Further, the first spacing distance L1 is greater than 15 times the outer diameter D2 of the screw 140, and the second spacing distance L2 is greater than 5 times the outer diameter D2 of the screw 140.

[0149] In this way, the main material 120 can be fully dispersed and melted after being added into the cylinder 110 , and the first auxiliary material 01 can be fully mixed with the main material 120 after being added into the cylinder 110 , thereby improving the overall melting and mixing effect of the materials in the cylinder 110 .

[0150] The above is a schematic scheme of the extrusion device 100 of the embodiment of this specification. It should be noted that the schematic scheme of the extrusion device 100 and the technical scheme of the extrusion method described below belong to the same concept. The details of the schematic scheme of the extrusion device 100 and the technical scheme of the extrusion method can be referenced to each other.

[0151] This specification also provides a material extrusion method P100. The extrusion method P100 can be implemented by manual control by an operator, or can be implemented by automatic control by a controller, or can be implemented by both.

[0152] The controller includes at least one storage medium and at least one processor. The at least one storage medium stores at least one instruction set for material extrusion. The at least one processor is in communication with the at least one storage medium. When the extrusion device is running, the at least one processor reads the at least one instruction set and executes the extrusion method P100 described in this specification according to the instructions of the at least one instruction set.

[0153] The storage medium may include one or more of a disk, a read-only storage medium, or a random access storage medium. The storage medium may also include a non-volatile random access memory.

[0154] The processor may be in the form of one or more processors. According to some embodiments of the present specification, the processor may include one or more hardware processors, such as a microcontroller, a microprocessor, a reduced instruction set computer (RISC), an application-specific integrated circuit (ASIC), an application-specific instruction set processor (ASIP), a central processing unit (CPU), a microprocessor (MCU), a graphics processing unit (GPU), a physical processing unit (PPU), a microcontroller unit, a digital signal processor (DSP), a field programmable gate array (FPGA), an advanced RISC machine (ARM), a programmable logic device (PLD), any circuit or processor capable of performing one or more functions, etc., or any combination thereof.

[0155] Figure 5 A flow chart of an extrusion method provided according to some embodiments of the present specification is shown.

[0156] like Figure 5 As shown, the extrusion method P100 is applied to the above-mentioned extrusion device 100, and the extrusion method P100 includes:

[0157] S100: Control the rotation of the screw;

[0158] S200: adding the main material into the main material section through the first feeding port, so that the main material forms a main melt in the main material section;

[0159] S300: adding the first auxiliary material into the feeding section through the second feeding port, so as to form a first mixed melt mixed with the main melt and the first auxiliary material in the extrusion section.

[0160] In some embodiments, after adding the first auxiliary material into the feeding section through the second feeding port, the extrusion method P100 further includes:

[0161] S400: stopping adding the first auxiliary material at the second feeding port, and adding the second auxiliary material into the feeding section through the second feeding port, so as to form a second mixed melt mixed with the main melt and the second auxiliary material in the extrusion section.

[0162] In some embodiments, after adding the second auxiliary material into the feeding section through the second feeding port, the extrusion method P100 further includes:

[0163] S500: Stop adding the second auxiliary material at the second feeding port, and add at least the third auxiliary material into the feeding section through the second feeding port, so as to form at least a third mixed melt in the extrusion section. The third mixed melt is formed by mixing the main melt and the third auxiliary material under the drive of the screw.

[0164] The specific implementation of steps S100, S200, S300, S400 and S500 has been introduced in the aforementioned implementation of the extrusion device and will not be repeated here.

[0165] In summary, the main material 120 and the first auxiliary material 01 form a first mixed melt in the feeding section 1120 and the extrusion section 1130 and leave the barrel 110 from the discharge port 113. When the auxiliary material is replaced, the operator of the extrusion device 100 replaces the first auxiliary material 01 with the second auxiliary material 02 at the second feeding port 112. The main material 120 and the second auxiliary material 02 form a second mixed melt and leave the barrel 110 from the discharge port 113. The main material 120 added to the barrel 110 from the first feeding port 111 will reach the discharge port 113 after a longer path and time, and the auxiliary material added to the barrel 110 from the second feeding port 112 will reach the discharge port 113 after a shorter path and time. When switching from the first auxiliary material 01 to the second auxiliary material 02 at the second feeding port 112, the first auxiliary material 01 has less residue and can be quickly washed clean during the extrusion process, thereby reducing the risk of the second mixed melt being contaminated by the first auxiliary material 01. Especially when the main material 120 is different in color from the first auxiliary material 01 and the second auxiliary material 02, when the first auxiliary material 01 and the second auxiliary material 02 are switched, the first auxiliary material 01 has less residue and can be quickly flushed clean, which can reduce the risk of the color of the first auxiliary material 01 mixing into the second mixed melt, so that the color of each section of the extruded product 150 has a higher purity without discontinuous doping with different colors.

[0166] The above is a description of a specific embodiment of the present specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require a specific order or a continuous order to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0167] In summary, after reading this detailed disclosure, those skilled in the art will appreciate that the foregoing detailed disclosure may be presented only by way of example and may not be limiting. Although not explicitly stated herein, those skilled in the art will appreciate that this specification requires various reasonable changes, improvements and modifications to the embodiments. These changes, improvements and modifications are intended to be proposed by this specification and are within the spirit and scope of the exemplary embodiments of this specification.

[0168] In addition, certain terms in this specification have been used to describe embodiments of this specification. For example, "one embodiment", "an embodiment" and / or "some embodiments" mean that a particular feature, structure or characteristic described in conjunction with the embodiment may be included in at least one embodiment of this specification. Therefore, it can be emphasized and should be understood that two or more references to "an embodiment" or "an embodiment" or "an alternative embodiment" in various parts of this specification do not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics may be appropriately combined in one or more embodiments of this specification.

[0169] It should be understood that in the foregoing description of the embodiments of this specification, in order to help understand a feature and for the purpose of simplifying this specification, this specification combines various features in a single embodiment, figure or its description. However, this does not mean that the combination of these features is necessary. When reading this specification, it is entirely possible for a person skilled in the art to mark out some of the devices as separate embodiments. In other words, the embodiments in this specification can also be understood as the integration of multiple secondary embodiments. This is also true when the content of each secondary embodiment is less than all the features of a single aforementioned disclosed embodiment.

[0170] Each patent, patent application, publication of patent application, and other materials, such as articles, books, specifications, publications, documents, documents, etc., cited in this disclosure (excluding any historical review documents related thereto) are hereby incorporated by reference for all purposes related to this disclosure, such as in the specification and claims of this disclosure. However, if there is any inconsistency or conflict between the descriptions, definitions, and / or terminology of the above materials and the descriptions, definitions, and / or terminology used in this disclosure, the descriptions, definitions, and / or terminology used in this disclosure shall prevail.

[0171] Finally, it should be understood that the embodiments of the application disclosed herein are explanations of the principles of the embodiments of this specification. Other modified embodiments are also within the scope of this specification. Therefore, the embodiments disclosed in this specification are only used as examples and not as limitations. Those skilled in the art can adopt alternative configurations according to the embodiments in this specification to implement the applications in this specification. Therefore, the embodiments of this specification are not limited to the embodiments accurately described in the application.

Claims

1. An extrusion device, characterized in that: include: Cylinder, comprising: The main material section is located at one end of the barrel and includes a first feeding port for feeding the main material into the barrel to form a main melt. a feeding section, adjacent to the main material section along the axial direction of the barrel, and comprising a second feeding port for feeding auxiliary materials into the barrel to be mixed with the main melt to form a mixed material, and an extrusion section, adjacent to the feeding section along the axial direction and comprising a discharge port for extruding a mixed melt formed by the mixed material out of the barrel; and The screw is rotatably located in the barrel and comprises: a first section, located in the main material section and comprising a first screw groove, wherein the first screw groove and the inner wall of the main material section form a spiral first material space, wherein the first material space generates a first pressure on the main material when the screw rotates, and a second section, located in the feeding section and comprising a second screw groove, wherein the second screw groove and the inner wall of the feeding section form a spiral second material space, wherein the second material space generates a second pressure on the main melt and the auxiliary material when the screw rotates, and the second pressure is less than the first pressure, and The third section is located in the extrusion section and includes a third screw groove. The third screw groove and the inner wall of the extrusion section form a spiral third material space to convert the mixed material into the mixed melt.

2. The extrusion device according to claim 1, characterized in that The depth of the first screw groove is smaller than the depth of the second screw groove, so as to facilitate adding auxiliary materials into the barrel through the second feeding port.

3. The extrusion device according to claim 1 or 2, characterized in that: The lead of the second screw groove is smaller than the lead of the first screw groove.

4. The extrusion device according to claim 1 or 2, characterized in that: The screw further comprises: The flow control section is located between the first section and the second section, and is configured to limit the flow of the main material so that the flow of the main material passing through the flow control section is less than or equal to a preset flow threshold.

5. The extrusion device according to claim 4, characterized in that The flow control section includes a flow-limiting screw rib, a first flow-limiting screw groove, and a second flow-limiting screw groove. The first flow-limiting screw groove and the second flow-limiting screw groove are respectively located on both sides of the flow-limiting screw rib, the first flow-limiting screw groove is communicated with the first screw groove, and the second flow-limiting screw groove is communicated with the second screw groove; The diameter of the inner wall of the cylinder is larger than the outer diameter of the flow-limiting spiral rib, so as to form a gap between the inner wall of the cylinder and the flow-limiting spiral rib.

6. The extrusion device according to claim 1 or 2, characterized in that: Including pressure sensor, The pressure sensor is disposed on the cylinder and adjacent to the front end of the second section to measure the material pressure at the front end of the second section. The front end is located at an end of the second section adjacent to the first section.

7. The extrusion device according to claim 6, characterized in that When the screw rotates at the working speed, At one end of the first section adjacent to the front end, the material pressure is greater than 2 MPa; At the front end, the material pressure is less than or equal to 2 MPa.

8. The extrusion device according to claim 1 or 2, characterized in that: In the axial direction, the second feed port and the first feed port have a first spacing distance, the second feed port and the discharge port have a second spacing distance, and the first spacing distance is greater than or equal to the second spacing distance.

9. The extrusion device according to claim 8, characterized in that The ratio of the thread length to the outer diameter of the screw is in the range of 20 to 35; The first spacing distance is greater than 10 times the outer diameter of the screw, and the second spacing distance is greater than 4 times the outer diameter of the screw.

10. The extrusion device according to claim 1 or 2, characterized in that: The operating speed of the screw is configured so that the material transmission speed generated in the first material space is greater than the feeding speed of the main material at the first feeding port.

11. A material extrusion method, characterized in that: Applied to the extrusion device according to any one of claims 1 to 10, the extrusion method comprises: Controlling the rotation of the screw; Adding the main material into the main material section through the first feeding port, so that the main material forms the main melt in the main material section; The first auxiliary material is added into the feeding section through the second feeding port, so that a first mixed melt mixed with the main melt and the first auxiliary material is formed in the extrusion section.

12. The extrusion method according to claim 11, characterized in that After the first auxiliary material is added into the feeding section through the second feeding port, the method comprises: The addition of the first auxiliary material is stopped at the second feeding port, and the second auxiliary material is added into the feeding section through the second feeding port, so as to form a second mixed melt mixed with the main melt and the second auxiliary material in the extrusion section.

13. The extrusion method according to claim 12, characterized in that After adding the second auxiliary material into the feeding section through the second feeding port, the method further includes: Stop adding the second auxiliary material at the second feeding port, and add at least the third auxiliary material into the feeding section through the second feeding port, so as to form at least a third mixed melt in the extrusion section; the third mixed melt is formed by mixing the main melt and the third auxiliary material under the drive of the screw.

14. The extrusion method according to claim 12, characterized in that In the first mixed melt, the weight proportion of the main material is greater than 80%; and / or In the second mixed melt, the weight proportion of the main material is greater than 80%.

15. The extrusion method according to claim 12, characterized in that The main material has different colors from the first auxiliary material and the second auxiliary material.

16. The extrusion method according to claim 12, characterized in that The second auxiliary material includes at least one of masterbatch, color oil, color powder, fiber or foaming agent.

17. The extrusion method according to any one of claims 11 to 16, characterized in that The first auxiliary material includes at least one of masterbatch, color oil, color powder, fiber or foaming agent.

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