Extruding machine head device for polypropylene foamed beads

Abstract

The invention discloses an extrusion head device for polypropylene foamed beads, the extrusion head device comprises a head body, the head body is provided with a core layer runner and a skin layer runner which are mutually independent, the core layer runner and the skin layer runner respectively comprise a feed port and a discharge port, the feed ports of the core layer runner and the skin layer runner are respectively used for receiving melts, and the discharge port of the skin layer runner is used for discharging the melts. Discharging ports of the core layer flow channel and the skin layer flow channel penetrate through the machine head body, and a discharging port of the skin layer flow channel is annularly arranged outside a discharging port of the core layer flow channel. A core layer molten material body is extruded through a discharging port of the core layer flow channel, and due to the fact that a discharging port of the skin layer flow channel is annularly formed outside the discharging port of the core layer flow channel, after the skin layer molten material body is extruded through the skin layer flow channel, the skin layer molten material body annularly wraps the core layer molten material body, and tows of an interlayer structure are formed. The tows are subjected to kettle type foaming after being cut into particles, and the polypropylene foaming beads of the sandwich structure are obtained.

Description

Technical Field

[0001] This application relates to the molding or joining of plastics; general molding of substances in a plastic state; and post-processing of molded products, specifically to an extruder head device for polypropylene foam beads. Background Technology

[0002] In the granulation process of energy-saving polypropylene foam beads, plastic granules are first heated and melted, then extruded through a mold to continuously produce filaments with specific cross-sectional shapes and functional properties. The resulting filaments are then uniformly stretched and cut into micro-granules. Subsequently, these micro-granules undergo a carbon dioxide autoclave foaming process to obtain polypropylene foam beads with a sandwich structure. Its unique core-skin structure (a core layer consisting of a high melt strength matrix and a skin layer consisting of a rapid softening layer) significantly reduces the energy consumption of foam bead molding, shortens the molding time required for a single mold, and reduces the post-molding baking cycle.

[0003] How to achieve the extrusion molding of polypropylene foam beads with this sandwich structure remains a key technical problem that needs to be solved in this field. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes: An extruder head device for polypropylene foam beads includes a die head body, on which independent core layer channels and skin layer channels are provided. The core layer channels and skin layer channels each include an inlet and an outlet. The inlets of the core layer channels and skin layer channels are used to receive melt. The outlets of the core layer channels and skin layer channels both penetrate the die head body, and the outlet of the skin layer channels is arranged around the outlet of the core layer channels.

[0005] One embodiment of the present invention employs a technical solution to solve its technical problem as follows: the inlets of the core layer flow channel and the skin layer flow channel are respectively connected to metering pumps, and the melt is fed into the core layer flow channel and the skin layer flow channel through the metering pumps.

[0006] One embodiment of the present invention adopts a technical solution to solve its technical problem as follows: the weight ratio of the outer layer material to the core layer material is 1:99~50:50.

[0007] One embodiment of the present invention adopts a technical solution to solve its technical problem as follows: the discharge ports of the core layer flow channel and the skin layer flow channel are flush with the end face of the head body.

[0008] One embodiment of the present invention adopts a technical solution to solve its technical problem as follows: the discharge port of the core layer flow channel is distributed inside the skin layer flow channel and is spaced apart from the end face of the head body.

[0009] One embodiment of the present invention adopts a technical solution to solve its technical problem as follows: the distance between the discharge port of the core layer flow channel and the end face of the head body is 10-120mm.

[0010] An embodiment of the present invention provides a technical solution to solve its technical problem as follows: the die head body includes a first body and a second body. The first body has a cavity and an opening and a co-extrusion channel respectively communicating with the cavity. The second body is disposed in the cavity and has a gap between it and the first body. The opening, the gap, and the co-extrusion channel combine to form the skin flow channel. The second body has a material flow channel. The second body has a feed pipe communicating with the material flow channel and extending out of the opening. The second body has a co-extrusion tube communicating with the material flow channel and inserted into the co-extrusion channel. The feed pipe, the material flow channel, and the co-extrusion tube combine to form the core flow channel.

[0011] One embodiment of the present invention adopts a technical solution to solve its technical problem as follows: the thickness of the first body at the co-extrusion channel is 20-100mm.

[0012] One embodiment of the present invention adopts a technical solution to solve its technical problem as follows: the inner diameter of the co-extrusion channel is 1.3-7mm, and the inner diameter of the co-extrusion tube is 1-4mm.

[0013] One embodiment of the present invention employs a technical solution to solve its technical problem as follows: the side of the second body near the opening is tapered.

[0014] The beneficial effects of this invention are as follows: The core layer molten material is fed into the core layer flow channel and extruded through the outlet of the core layer flow channel; at the same time, the skin layer molten material is fed into the skin layer flow channel. Since the outlet of the skin layer flow channel is arranged around the outlet of the core layer flow channel, after the skin layer molten material is extruded through the skin layer flow channel, the skin layer molten material will form a ring-shaped coating around the core layer molten material, forming a filament bundle with a sandwich structure. After the filament bundle is pelletized, it is foamed in a kettle to obtain polypropylene foam beads with a sandwich structure. Attached Figure Description

[0015] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a cross-sectional view of polypropylene foam beads. Figure 2 This is a cross-sectional view of a polyolefin filament bundle. Figure 3 This is one of the structural schematic diagrams of the extruder head assembly; Figure 4 for Figure 3 Cross-sectional view of the extruder head assembly shown Figure 5 This is the second schematic diagram of the extruder head assembly; Figure 6 for Figure 5 A cross-sectional view of the extruder head assembly shown; Figure 7 for Figure 6 Enlarged view of point A in the middle. Detailed Implementation

[0016] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0017] In the description of this invention, "multiple" means two or more; "greater than," "less than," and "exceeding" are understood to exclude the stated number; "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0018] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0019] In this invention, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to a fixed connection, a detachable connection, or an integrally formed connection; they can refer to a mechanical connection; they can refer to the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0020] Reference Figure 1-7This application proposes an embodiment of the extrusion head device for polypropylene foamed beads, which includes a die head body. The die head body is provided with independent core layer flow channels 20 and skin layer flow channels 30. The core layer flow channels 20 and skin layer flow channels 30 respectively include an inlet and an outlet. The inlets of the core layer flow channels 20 and skin layer flow channels 30 are used to receive melt. The outlets of the core layer flow channels 20 and skin layer flow channels 30 both penetrate the die head body, and the outlet of the skin layer flow channel 30 is arranged around the outlet of the core layer flow channel 20.

[0021] See attached document Figure 1 As shown, the polypropylene foam beads 10 with a sandwich structure includes a core layer 11 and a skin layer 12. When the extruder head device is working, the raw material particles of the core layer 11 and the skin layer 12 are fed into two melt extruders. The two melt extruders heat and melt the raw material particles of the core layer and the skin layer and extrude them to the core layer flow channel 20 and the skin layer flow channel 30 respectively. Specifically, the core layer molten material is fed into the core layer flow channel 20 and extruded through the outlet of the core layer flow channel 20; simultaneously, the skin layer molten material is fed into the skin layer flow channel 30. Since the outlet of the skin layer flow channel 30 is located outside the outlet of the core layer flow channel 20, after the skin layer molten material is extruded through the skin layer flow channel 30, it forms a ring-shaped coating around the core layer molten material, creating a filament bundle 70 with a sandwich structure. The filament bundle 70 has an inner core 71 and an outer skin 72 distributed outside the inner core. The cross-sectional view of the filament bundle 70 is shown below. Figure 2 As shown, the fiber bundle 70 with a sandwich structure is pelletized and then foamed in a batch to obtain the following... Figure 1 The polypropylene foam beads 10 shown have a sandwich structure.

[0022] Specifically, the weight ratio of the skin layer material to the core layer material in the polypropylene foamed beads is 1:99 to 50:50. By adjusting the weight ratio of the skin layer material to the core layer material, the thickness ratio of the core layer and the skin layer in the sandwich structure can be adjusted. Therefore, in this embodiment, metering pumps 40 are respectively provided at the inlets of the core layer flow channel 20 and the skin layer flow channel 30. The melt is fed into the core layer flow channel 20 or the skin layer flow channel 30 after passing through the metering pumps 40. The flow rate ratio of the melt flowing into the core layer flow channel 20 and the skin layer flow channel 30 can be controlled by the metering pumps 40 to produce filaments with different thickness ratios of sandwich structures, further controlling the thickness ratio of the sandwich structure of the core layer 11 and the skin layer 12 in the foamed beads.

[0023] The meaning of the discharge port of the skin layer flow channel 30 being arranged outside the discharge port of the core layer flow channel 20 can be that the discharge port of the core layer flow channel 20 is distributed outside the discharge port of the skin layer flow channel. Or refer to the appendix Figure 3-4As shown, in one embodiment, the outlets of the core layer channel 20 and the skin layer channel 30 are flush with the end face of the die head body. When the core layer molten material and the skin layer molten material are extruded respectively, co-extrusion coating is generated at the outlet of the corresponding channel. As a preferred option, please refer to the appendix. Figure 5-7 As shown, in this example, the outlet of the core layer flow channel 20 is distributed inside the skin layer flow channel 30 and is spaced apart from the end face of the die head body. This allows the core layer molten material to be extruded within the skin layer flow channel 30 and then flow synchronously with the skin layer molten material within the skin layer flow channel 30, and be extruded synchronously through the outlet of the skin layer flow channel 30. This fully utilizes the stretchability of polypropylene, ensures the stability of the melt flow, and maintains uniform thickness of the core and skin layers. This is beneficial for improving interlayer adhesion strength and enhancing the uniformity of the skin layer molten material's coating of the core layer molten material. Specifically, the distance between the outlet of the core layer flow channel 20 and the end face of the die head body is 10-120 mm.

[0024] In this embodiment, in order to achieve independent distribution of the core layer flow channel 20 and the skin layer flow channel 30 on the die head body, the die head body includes a first body 50 and a second body 60. The first body 50 is provided with a cavity 51 and an opening 52 and a co-extrusion channel 53 respectively communicating with the cavity 51. The second body 60 is disposed in the cavity 51 and has a gap between it and the first body 50. The opening 52, the gap and the co-extrusion channel 53 are combined to form the skin layer flow channel 30. The second body 60 is provided with a material flow channel 61. The second body 60 is provided with a feed pipe 62 communicating with the material flow channel 61 and passing through the opening 52. The second body 60 is provided with a co-extrusion tube 63 communicating with the material flow channel 61 and inserted into the co-extrusion channel 53. The feed pipe 62, the material flow channel 61 and the co-extrusion tube 63 are combined to form the core layer flow channel 20.

[0025] The opening 52 constitutes the inlet of the skin flow channel 30, and the co-extrusion channel 53 constitutes the outlet of the skin flow channel 30. The feed pipe 62 forms the feed port of the core layer flow channel 20, and the co-extrusion pipe 63 forms the discharge port of the core layer flow channel 20.

[0026] Based on the above, the first body 50 is provided with a plurality of co-extrusion channels 53 arranged in a ring to realize the extrusion of multiple filament bundles with sandwich structures.

[0027] The second body 60 is tapered on the side near the opening 52 to uniformly guide the molten skin material flowing into the skin channel 30.

[0028] In this embodiment, the thickness of the first body 50 at the co-extrusion channel 53 is designed to be 20-100mm to ensure the structural strength of the first body 50.

[0029] Preferably, the inner diameter of the co-extrusion channel 53 is 1.3-7 mm, and the inner diameter of the co-extrusion tube 63 is 1-4 mm, to ensure the tensile balance performance of the core layer and the skin layer after extrusion.

[0030] Of course, the present invention is not limited to the above-described embodiments. Those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications and substitutions are included within the scope defined by the claims of this application.

Claims

1. An extruder head device for polypropylene foam beads, characterized in that, The polypropylene foam beads (10) include a core layer (11) and a skin layer (12) covering the core layer (11). The extrusion head device includes a head body, on which independent core layer channels (20) and skin layer channels (30) are provided. The core layer channels (20) and skin layer channels (30) include an inlet and an outlet, respectively. The inlets of the core layer channels (20) and skin layer channels (30) are used to receive melt. The outlets of the core layer channels (20) and skin layer channels (30) both penetrate the head body, and the outlet of the skin layer channel (30) is arranged around the outlet of the core layer channel (20).

2. The extruder head device for polypropylene foam beads according to claim 1, characterized in that, The inlets of the core layer channel (20) and the skin layer channel (30) are respectively connected to metering pumps (40), and the melt is fed into the core layer channel (20) and the skin layer channel (30) through the metering pumps (40).

3. The extruder head device for polypropylene foam beads according to claim 2, characterized in that, The weight ratio of the outer layer material to the core layer material is 1:99~50:

50.

4. The extruder head device for polypropylene foam beads according to claim 1, characterized in that, The discharge ports of the core layer flow channel (20) and the skin layer flow channel (30) are flush with the end face of the head body.

5. The extruder head device for polypropylene foam beads according to claim 1, characterized in that, The discharge port of the core layer flow channel (20) is distributed inside the skin layer flow channel (30) and is spaced apart from the end face of the head body.

6. The extruder head device for polypropylene foam beads according to claim 5, characterized in that, The distance between the discharge port of the core layer flow channel (20) and the end face of the head body is 10-120mm.

7. The extruder head device for polypropylene foamed beads according to any one of claims 1-6, characterized in that, The die head body includes a first body (50) and a second body (60). The first body (50) is provided with a cavity (51) and an opening (52) and a co-extrusion channel (53) respectively communicating with the cavity (51). The second body (60) is disposed in the cavity (51) and has a gap between it and the first body (50). The opening (52), the gap and the co-extrusion channel (53) are combined to form the skin flow channel (30). The second body (60) is provided with a material flow channel (61). The second body (60) is provided with a feed pipe (62) communicating with the material flow channel (61) and passing through the opening (52). The second body (60) is provided with a co-extrusion tube (63) communicating with the material flow channel (61) and inserted into the co-extrusion channel (53). The feed pipe (62), the material flow channel (61) and the co-extrusion tube (63) are combined to form the core flow channel (20).

8. The extruder head device for polypropylene foam beads according to claim 7, characterized in that, The thickness of the first body (50) at the co-extrusion channel (53) is 20-100 mm.

9. The extruder head device for polypropylene foam beads according to claim 7, characterized in that, The inner diameter of the co-extrusion channel (53) is 1.3-7 mm, and the inner diameter of the co-extrusion tube (63) is 1-4 mm.

10. The extruder head device for polypropylene foam beads according to claim 7, characterized in that, The second body (60) is tapered on the side near the opening (52).

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