Multi-petal double-color co-extrusion machine head
By designing a multi-lobed two-color co-extrusion die head, and adopting a shell, mandrel, and die sleeve structure with an internal and external split core design, the problem that existing cable extrusion die heads cannot produce more than two-lobed two-color strips has been solved, achieving efficient production and low-cost manufacturing of multi-lobed two-color wire cores.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-01
- Publication Date
- 2026-03-24
AI Technical Summary
Existing cable extrusion heads cannot effectively produce two-color stripe products with more than two segments, and have problems such as numerous welding marks, uneven material flow, complex structure, high processing difficulty, and unsuitability for processing heat-sensitive plastics.
Design a multi-lobed two-color co-extrusion die head, which adopts a shell, mandrel and die sleeve structure, and an internal and external flow core design. It connects the main and auxiliary material channels and the branch discharge end through the main and auxiliary feed ports to realize the production of multi-lobed two-color wire cores.
It enables the production of multi-lobed, two-color wire cores, with a simple structure, low processing difficulty, improved production efficiency, and reduced manufacturing costs.
Smart Images
Figure CN224028325U_ABST
Abstract
Description
Technical Field
[0001] This technical solution pertains to extrusion equipment, specifically a multi-lobed, two-color co-extrusion die head. Background Technology
[0002] The main types of die heads in existing cable extruders include cross-shaped die heads, mandrel-type die heads, and spiral mandrel-type die heads.
[0003] The working principle of a cross-shaped die head is as follows: the material is melted and plasticized in the extruder, and then extruded into the die head by the extruder screw. Under the action of the flow dividers, the melt is divided into multiple streams. As the streams flow, they merge evenly in the converging section and continue to flow in the extrusion direction. In the shaping section, the melt is shaped and finally extruded from the die core gap. The disadvantages of a cross-shaped die head are: a relatively large number of weld marks, and a longer residence time of the material in the die head, which can easily cause material blockage.
[0004] The working principle of a mandrel-type die head is as follows: After the melt is extruded, it enters the die head, where a mandrel shaft with flow channels is installed. As the melt flows, it is evenly distributed circumferentially at the top of the mandrel shaft, and then enters the annular flow channel at the top of the die head. In the shaping section, the melt gradually expands to a pre-set size and finally is extruded from the annular gap of the die core. The disadvantages of a mandrel-type die head are: the side-feeding method can easily cause the mandrel shaft to become off-center; the uneven flow rate inside the die head can easily lead to uneven finished product thickness; and the lack of adjusting screws or other devices makes gap adjustment inconvenient.
[0005] The working principle of the spiral mandrel die head is as follows: After the melt is extruded from the extruder, it enters the melt distributor, which distributes the melt evenly in the circumferential direction. A diversion hole is located at the connection between the upper end of the melt distributor and the die head. The melt is divided into a certain number of streams by the diversion hole, and these streams flow directly into the spiral groove. When the melt enters the spiral groove, it flows forward along it. Due to the gap between the mandrel and the die head, a portion of the melt flows out of the spiral groove and into the spiral gap. At this point, the melt has two flow patterns within the die head: one is circumferential flow along the spiral groove, and the other is axial flow along the spiral gap. As the melt flows, the spiral groove gradually disappears, the spiral gap gradually widens, and the melt gradually changes from circumferential movement along the spiral groove to axial movement along the spiral gap, eventually completely switching to axial movement. After buffering in the buffer section, compression in the compression section, and shaping in the shaping section, the final product is formed. Disadvantages of spiral mandrel die heads: complex structure and difficult processing; long material residence time inside the die head, making it unsuitable for processing heat-sensitive plastics.
[0006] Existing die heads can only produce two-color extruded two-color stripes (such as...) Figure 1The two-lobed two-color core of the die head only has two flow channels, which can only produce two-lobed two-color products (for example, the main color material accounts for 70% and the auxiliary color material accounts for 30%), and cannot meet the requirements of four-lobed two-color extrusion products (such as...). Figure 2 The demand for more "petal" products (four-petal bicolor core) is increasing. Summary of the Invention
[0007] To address the problems existing in the prior art, this invention proposes a multi-lobed dual-color co-extrusion die head, which includes a housing, a mandrel, and a die sleeve; the housing has a through hole with the axis of the through hole being a straight line L; the mandrel is inserted into the through hole, and the outer wall of the mandrel is in contact with the inner wall of the through hole; the mandrel is connected to the housing through a connecting mechanism; the die sleeve is connected to the housing through a die sleeve seat.
[0008] The shell has a main feed inlet and an auxiliary feed inlet;
[0009] The mandrel includes a coaxial wire guide tube and a mold core; the mold sleeve is connected to the front end of the mold sleeve base, and the inner cavities of the two are connected; the front part of the mold core is in the cavity of the mold sleeve and mates with the wire-bearing area of the mold sleeve; the rear part of the mold core is in the cavity of the mold sleeve and the mold sleeve base, and the area between the outer wall of the mold core and the cavity of the mold sleeve and the mold sleeve base is the rubber channel.
[0010] The mandrel also includes: an inner shunt core and an outer shunt core;
[0011] The inner distributor core is hollow in the middle, and the conduit passes through the hollow core. The mold core is located at the front end of the conduit. The outer distributor core is hollow in the middle, and the shape of the inner wall of the hollow core corresponds to the shape of the outer wall of the inner distributor core. The shell fits tightly around the outer distributor core. The outer distributor core fits tightly around the inner distributor core.
[0012] An auxiliary material flow channel is formed on the surface of the outer flow core. The auxiliary material inlet is connected to the inlet end of the auxiliary material flow channel, and the outlet end of the auxiliary material flow channel is connected to the adhesive channel.
[0013] The inner distributor core has a main material flow channel on its surface. The main inlet is connected to the inlet end of the main material flow channel, and the outlet end of the main material flow channel is connected to the adhesive channel. The outer distributor core has a perforation on its side wall. The two ends of the perforation are connected to the main inlet and the inlet end of the main material flow channel, respectively.
[0014] Here, although they are called "main material" and "auxiliary material," their effective components are the same; only the color masterbatch differs, ultimately allowing the wire core to be distinguished by its appearance. In engineering applications, there is no substantial difference between the main and auxiliary feed inlets.
[0015] The main material flow channel has multiple branches, and the feed end of each branch is connected to the feed end of the main material flow channel; the discharge end of each branch is called the main material branch discharge end, and they are evenly distributed around the straight line L in the rubber channel.
[0016] The auxiliary material flow channel has multiple branches, and the feed end of each branch is connected to the feed end of the auxiliary material flow channel; the discharge end of each branch is called the auxiliary material branch discharge end, and they are evenly distributed around the straight line L in the rubber channel.
[0017] On the radial cross-section of the rubber channel, a main material branch outlet and an auxiliary material branch outlet are adjacent to each other, and the distance between adjacent main and auxiliary material branch outlets is the same.
[0018] Furthermore, it also includes a conduit bushing, which is located inside the hollow of the inner diverter core; the conduit bushing is fitted over the conduit from back to front and the two are fixedly connected; the mold core is connected to the front end of the conduit bushing; the outer wall of the conduit bushing and the outer wall of the rear part of the mold core are smoothly transitioned.
[0019] Furthermore, the through hole inside the housing is a frustum shape with a larger rear end and a smaller front end; the inner shunt core is a frustum shape with a larger rear end and a smaller front end; and the outer shunt core is a frustum shape with a larger rear end and a smaller front end.
[0020] With this shape, only a flange-like connection structure is needed at the rear of the inner and outer flow dividers to secure them to the housing. Since the adhesive material ultimately collects in the bearing area of the mold sleeve, based on the fluid characteristics, the main and auxiliary material flow channels formed by this structure have a smooth collection trend, avoiding adhesive material deposition in the flow channels.
[0021] Furthermore, the discharge ends of all main material branches and auxiliary material branches are on the same plane, which is perpendicular to the direct L. This structure allows the main material and auxiliary material to enter the rubber channel simultaneously. Under the same pressure, the main material and auxiliary material flow towards the bearing area in the same proportion at all times, ultimately resulting in a consistent proportion of the "color petals" extruded outside the bearing area.
[0022] Furthermore, both the main material branch outlet and the auxiliary material branch outlet are long and narrow slits, with the edges of adjacent main and auxiliary material branch outlets connected. This structure restricts the outlet edge position of the main and auxiliary materials from the start of the discharge process, which is beneficial for ensuring a consistent proportion of the final extruded "color petals".
[0023] The structure of this design is applicable to extrusion, semi-extrusion, or tube extrusion mold cores and sleeves.
[0024] In engineering applications, the cross-sectional areas of the main feed inlet, main material flow channel, and main material branch discharge end, as well as the cross-sectional areas of the auxiliary feed inlet, auxiliary material flow channel, and auxiliary material branch discharge end, are determined based on the proportion of the "lobes" in the wire core product.
[0025] Advantages of this invention: Compared with ordinary spiral mandrel type heads, this machine head can achieve multi-lobed two-color wire cores.
[0026] With a simple yet complex structure, it is easy to process and operate. Using this machine head, two materials or colors can be injection molded using the same mold, saving manufacturing time and improving production efficiency; reducing the manufacturing cost of two materials or colors to half that of manufacturing each part separately. Attached Figure Description
[0027] Figure 1 This is a schematic diagram of a cross-section of a two-lobed, two-color wire core;
[0028] Figure 2 This is a schematic diagram of a cross-section of a four-lobed, two-color wire core;
[0029] Figure 1 and Figure 2 In the middle, conductor 101, main color portion 102 of insulating layer, and auxiliary color portion 103 of insulating layer;
[0030] Figure 3 This is a schematic diagram (top view) of the axial cross-section of the die head applied to four-petal two-color co-extrusion in this embodiment;
[0031] Figure 4 This is an assembly diagram (exploded view) of the mandrel in this embodiment.
[0032] Figure 5(a) is a schematic diagram of the external shape when assembled from the inside out into the inner shunt core state;
[0033] Figure 5(b) is a schematic diagram of the axial cross section when assembled from the inside out to the inner shunt core state;
[0034] Figure 6(a) is a schematic diagram of the external shape when assembled from the inside to the outside of the shunt core.
[0035] Figure 6(b) is a schematic diagram of the axial cross section when assembled from the inside to the outside of the shunt core.
[0036] Figure 7(a) is a schematic diagram of the external shunt core.
[0037] Figure 7(b) is a schematic diagram of the axial cross-section of the external shunt core;
[0038] In the diagram: 1. Locking nut; 2. Disc spring; 3. Spherical pad; 4. Cable guide tube; 5. First adjusting screw; 6. Cable guide tube bushing; 7. Adjusting sleeve; 8. M12×80 screw; 9. Upper cover plate; 10. Inner diverter core; 11. Inner diverter core adjusting pad; 12. Outer diverter core adjusting pad; 13. Outer diverter core; 14. Housing; 15. Mold sleeve base; 16. Second adjusting screw; 17. Adjusting screw; 18. Lower end cover; 19. Sealing gasket; 20. Telescopic sleeve; 21. Mold core; 22. Mold sleeve; 23. Through hole; 24. Main feed port; 25. Auxiliary feed port; 26. Main material flow channel; 27. Auxiliary material flow channel; 28. Main material branch discharge end; 29. Auxiliary material branch discharge end. Detailed Implementation
[0039] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.
[0040] refer to Figure 3 Figure 7(b) shows a multi-lobed two-color co-extrusion die head, which includes a housing, a mandrel, and a die sleeve; the housing 14 has a through hole with the axis of the through hole being a straight line L; the mandrel is inserted into the through hole, and the outer wall of the mandrel is in contact with the inner wall of the through hole; the mandrel is connected to the housing 14 through a connecting mechanism; the die sleeve 21 is connected to the housing 14 through a die sleeve seat 15.
[0041] The housing has a main feed inlet 23 and an auxiliary feed inlet 24.
[0042] The mandrel includes a coaxial wire guide tube 4 and a mold core 20; the mold sleeve 21 is connected to the front end of the mold sleeve base 15, and the inner cavities of the two are connected; the front part of the mold core is in the cavity of the mold sleeve and mates with the wire-bearing area of the mold sleeve; the rear part of the mold core is in the cavity of the mold sleeve and the mold sleeve base, and the area between the outer wall of the mold core and the cavity of the mold sleeve and the mold sleeve base is the material channel;
[0043] Its characteristic is that the mandrel also includes: an inner shunt core 10 and an outer shunt core 13;
[0044] The inner diverter core 10 is hollow in the middle, and the conduit 4 passes through the hollow. The mold core is located at the front end of the conduit 4. The outer diverter core 13 is hollow in the middle, and the shape of the hollow inner wall corresponds to the shape of the outer wall of the inner diverter core 10. The shell fits tightly around the outer diverter core 13. The outer diverter core 13 fits tightly around the inner diverter core 10.
[0045] An auxiliary material flow channel 26 is formed on the surface of the outer flow core 13. The auxiliary material inlet 24 is connected to the inlet end of the auxiliary material flow channel 26, and the outlet end of the auxiliary material flow channel 26 is connected to the adhesive channel.
[0046] A main material flow channel 25 is formed on the surface of the inner flow core 10. The main feed port 23 is connected to the feed end of the main material flow channel 25, and the discharge end of the main material flow channel 25 is connected to the adhesive channel. A through hole 22 is formed on the side wall of the outer flow core 13. The two ends of the through hole are respectively connected to the main feed port and the feed end of the main material flow channel.
[0047] The main material flow channel 25 has multiple branches, and the feed end of each branch is connected to the feed end of the main material flow channel; the discharge end of each branch is called the main material branch discharge end 27, and they are evenly distributed around the straight line L in the rubber channel.
[0048] The auxiliary material flow channel 26 has multiple branches, and the feed end of each branch is connected to the feed end of the auxiliary material flow channel; the discharge end of each branch is called the auxiliary material branch discharge end 28, and they are evenly distributed around the straight line L in the rubber channel.
[0049] In the radial section of the rubber channel, a main material branch outlet 27 and an auxiliary material branch outlet 28 are adjacent to each other, and the distance between adjacent main and auxiliary material branch outlets is the same.
[0050] Further reference Figure 4 Figures 5(b) and 6(b) show that the conduit bushing 6 is located inside the hollow of the inner diverter core 10; the conduit bushing 6 is fitted over the conduit 4 from back to front and the two are fixedly connected; the mold core is connected to the front end of the conduit bushing; the outer wall of the conduit bushing and the outer wall of the rear part of the mold core are smoothly transitioned.
[0051] The through hole inside the housing 14 is a frustum shape with a larger rear end and a smaller front end; the inner shunt core 10 is a frustum shape with a larger rear end and a smaller front end; the outer shunt core 13 is a frustum shape with a larger rear end and a smaller front end.
[0052] The discharge ends of all main material branches and auxiliary material branches are on the same plane, which is perpendicular to the direct L.
[0053] Both the main material branch outlet and the auxiliary material branch outlet are long and narrow slits, and the edges of adjacent main and auxiliary material branch outlets are connected.
[0054] The structure of the mold core and mold sleeve can be extrusion type, semi-extrusion type or extrusion tube type; in this example, it is extrusion type.
[0055] In this example, there are two main material branch discharge ends and two auxiliary material branch discharge ends, corresponding to a four-lobed two-color co-extrusion die head. (See also...) Figure 3 The four-lobed dual-color co-extrusion die head is equipped with two extruders. The rubber material channels of the two extruders are respectively connected to the two feed ports of the die head (main feed port 23 and auxiliary feed port 24). The two parts of the material are combined into a rubber material channel in the die head and then extruded into shape.
[0056] The main extrusion equipment supplies the primary color in the two-color process of the product, while the auxiliary extrusion equipment supplies the secondary color. The primary and secondary materials flow through the four branch outlets of the inner and outer flow dividers to the die core and die sleeve, thus achieving a four-petal two-color process.
[0057] refer to Figure 3 and Figure 4 The engineering application structure of the four-lobed dual-color co-extrusion die head in this embodiment includes a locking nut 1, a disc spring 2, a spherical pad 3, a cable guide tube 4, a first adjusting screw 5, a cable guide tube bushing 6, a bushing adjusting screw sleeve 7, an upper cover plate 9, an inner diverter core 10, an inner diverter core adjusting pad 11, an outer diverter core adjusting pad 12, an outer diverter core 13, a housing 14, a die sleeve seat 15, a second adjusting screw 16, a lower end cover 17, a sealing gasket 18, a telescopic sleeve 19, a die core 20, and a die sleeve 21.
[0058] In this embodiment, the entire machine is installed vertically, that is, the axis of the housing 14 is perpendicular to the horizontal plane.
[0059] The mold core 20 is screwed to the front end of the cable guide tube 4. The cable guide tube bushing 6 is fitted between the cable guide tube 4 and the hollow space between the cable guide tube 4 and the inner diverter core 10. The tail end of the cable guide tube 4 is screwed with the locking nut 1, the disc spring 2 and the spherical pad 3 from the outside to the inside.
[0060] Four first adjusting screws 5 are screwed through the rear side wall of the conduit bushing 6, and their ends abut against the rear of the conduit 4 radially. The rear of the conduit bushing 6 is screwed onto the bushing adjusting screw sleeve 7; the bushing adjusting screw sleeve 7 is connected to the housing 14 through the upper cover plate 9.
[0061] The inner diverter core 10 and the outer diverter core 13 have flange-like structures at their tail ends. The upper cover plate 9 fixes the inner diverter core 10 and the outer diverter core 13 to the housing 14 with M12×80 screws 8. Adjusting shims (i.e., inner diverter core adjusting shim 11 and outer diverter core adjusting shim 12) are respectively installed between the inner diverter core 10, the outer diverter core 13 and the housing 14.
[0062] The housing 14 has a main feed port 23 and an auxiliary feed port 24 on both radial sides.
[0063] At the front end of the housing 14, the mold base 15 extends into the hollow front end of the housing 14 and is fixed by four second adjustment screws 16 through the front side wall of the housing 14; the lower end cover 17 is connected to the front end face of the housing 14 by screws, and a clamping nut is screwed at the center of the lower end cover 17, and the lower end cover 17 is pressed into the mold hole at the front end of the mold base 15 by the clamping nut.
[0064] In this example, there are two discharge ends for the main material branch and two discharge ends for the auxiliary material branch, and the corresponding multi-lobed two-color co-extrusion die head is a four-lobed two-color co-extrusion die head.
[0065] The machine head is connected to an upper cover plate and a telescopic sleeve at both ends. The upper cover plate is fixed to the machine head by positioning bolts, and the telescopic sleeve is connected to the right side of the machine head by threads.
[0066] Referring further to Figures 5(a), 5(b), 6(a), and 6(b), a U-shaped flow channel (main material flow channel) is milled on the outer surface of the inner flow divider core, with one end open and the other closed. Two flow channels are milled on the outer surface of the outer flow divider core (the starting end of which is connected to the auxiliary feed port), and the two flow channels are distributed at 180 degrees. During installation, the U-shaped flow channel of the inner flow divider core is at a 90-degree angle to any one of the flow channels of the outer flow divider core.
[0067] Referring further to Figures 6(a) and 6(b), the perforations on the outer splitter core 13 are connected to the main extruder material flow channel through the main feed port.
[0068] The following explanation uses a four-lobed two-color co-extrusion die head as an example to illustrate the principle of this die head.
[0069] The machine head features an improved material feeding channel: two U-shaped channels (grooves) are milled on the inner branch core 10 (sidewall), symmetrical about line L. The two U-shaped channels have a total of four discharge ends, with adjacent discharge ends forming a main material branch discharge end. These discharge ends connect directly to the material being extruded between the die core and die sleeve, while the main feed port connects to the U-shaped channels. The main pigment quickly fills the extrusion space.
[0070] Two flow channels (grooves) are milled on the outer flow core 13 (side wall), and their discharge ends serve as one auxiliary material branch discharge end.
[0071] The leading edge of the protruding structure between the two discharge ends of a U-shaped flow channel corresponds to the position of the discharge end of an auxiliary material branch.
[0072] When the main and auxiliary extruders work simultaneously, the main material quickly fills the extrusion space through the inner splitting core. Since the flow channels on the outer splitting core are smaller, the extruded material is also less, thus forming a four-petal two-color structure.
Claims
1. A multi-lobed two-color co-extrusion die head, comprising a housing, a mandrel, and a die sleeve; the housing has a through hole with the axis of the through hole being a straight line L; the mandrel is inserted into the through hole, and the outer wall of the mandrel is in contact with the inner wall of the through hole; the mandrel is connected to the housing; the die sleeve is connected to the housing via a die sleeve seat; The shell has a main feed inlet and an auxiliary feed inlet; The mandrel includes a coaxial wire guide tube and a mold core; the mold sleeve is connected to the front end of the mold sleeve base, and the inner cavities of the two are connected; the front part of the mold core is in the cavity of the mold sleeve and mates with the wire-bearing area of the mold sleeve; the rear part of the mold core is in the cavity of the mold sleeve and the mold sleeve base, and the area between the outer wall of the mold core and the cavity of the mold sleeve and the mold sleeve base is the rubber channel. Its characteristics are The mandrel also includes: an inner shunt core and an outer shunt core; The inner distributor core is hollow in the middle, and the conduit passes through the hollow core. The mold core is located at the front end of the conduit. The outer distributor core is hollow in the middle, and the shape of the inner wall of the hollow core corresponds to the shape of the outer wall of the inner distributor core. The shell fits tightly around the outer distributor core. The outer distributor core fits tightly around the inner distributor core. An auxiliary material flow channel is formed on the surface of the outer flow core. The auxiliary material inlet is connected to the inlet end of the auxiliary material flow channel, and the outlet end of the auxiliary material flow channel is connected to the adhesive channel. The inner distributor core has a main material flow channel on its surface. The main inlet is connected to the inlet end of the main material flow channel, and the outlet end of the main material flow channel is connected to the adhesive channel. The outer distributor core has a perforation on its side wall. The two ends of the perforation are connected to the main inlet and the inlet end of the main material flow channel, respectively. The main material flow channel has multiple branches, and the feed end of each branch is connected to the feed end of the main material flow channel; the discharge end of each branch is called the main material branch discharge end, and they are evenly distributed around the straight line L in the rubber channel. The auxiliary material flow channel has multiple branches, and the feed end of each branch is connected to the feed end of the auxiliary material flow channel; the discharge end of each branch is called the auxiliary material branch discharge end, and they are evenly distributed around the straight line L in the rubber channel. On the radial cross-section of the rubber channel, a main material branch outlet and an auxiliary material branch outlet are adjacent to each other, and the distance between adjacent main and auxiliary material branch outlets is the same.
2. The multi-lobed dual-color co-extrusion die head according to claim 1, characterized in that: It also includes a conduit bushing, which is located inside the hollow of the inner diverter core; the conduit bushing is fitted over the conduit from back to front and the two are fixedly connected; the mold core is connected to the front end of the conduit bushing; the outer wall of the conduit bushing and the outer wall of the rear part of the mold core are smoothly transitioned.
3. The multi-lobed dual-color co-extrusion die head according to claim 1, characterized in that: The through hole inside the housing is a frustum shape with a larger rear end and a smaller front end; the inner shunt core is a frustum shape with a larger rear end and a smaller front end; the outer shunt core is a frustum shape with a larger rear end and a smaller front end.
4. The multi-lobed dual-color co-extrusion die head according to claim 1, characterized in that: The discharge ends of all main material branches and auxiliary material branches are on the same plane, which is perpendicular to the direct L.
5. The multi-lobed dual-color co-extrusion die head according to claim 1, characterized in that: Both the main material branch outlet and the auxiliary material branch outlet are long and narrow slits, and the edges of adjacent main and auxiliary material branch outlets are connected.
6. The multi-lobed dual-color co-extrusion die head according to claim 1, characterized in that: The structure of the mold core and mold sleeve can be extrusion type, semi-extrusion type, or tube extrusion type.
7. The multi-lobed dual-color co-extrusion die head according to claim 1, characterized in that: The main material branch discharge end and the auxiliary material branch discharge end are each two, and the corresponding multi-lobed two-color co-extrusion die head is a four-lobed two-color co-extrusion die head.