Pre-die, die structure and compound extruder

Abstract

This invention provides a pre-die, a die structure, and a composite extruder. The pre-die includes a pre-die body and a damping block. The pre-die body has a base adhesive guiding channel for communicating with the base adhesive output end of the extruder and the composite channel of the die plate. The damping block is disposed within the base adhesive guiding channel and protrudes from the bottom wall of the channel. The damping block divides the base adhesive guiding channel into a first flow channel and a second flow channel. The first flow channel extends along a first preset direction, and the second flow channel extends along a second preset direction, forming a preset angle between the extension directions of the first and second flow channels. This pre-die effectively solves the technical problem in the prior art where poor bonding between the upper and lower adhesive layers often occurs in the shoulder area of ​​tire treads formed by traditional pre-die molding, leading to bubble formation.

Description

Technical Field

[0001] This utility model relates to the technical field of extruders, specifically to a pre-die, die structure, and compound extruder. Background Technology

[0002] The tire tread, also known as the tire crown, is a key component that directly contacts the ground. Its structural design and the properties of the rubber compounds used directly affect the overall performance and safety of the tire. Especially for current all-steel radial tires, the main structure of the tread includes the crown and a through-layer composite rubber layer (see...). Figure 1 ), as detailed below: Tread rubber layer: The upper layer of the tread is tread rubber 61, which is usually made of rubber compounds that are wear-resistant, puncture-resistant, have strong grip, and excellent anti-slip properties. These characteristics ensure the stability and safety of the tire under complex road conditions.

[0003] Base layer: The lower layer of the tread is a through-layer composite layer, namely base rubber 62, which combines puncture resistance and low heat generation. The low heat generation compound helps reduce the heat generated by the tire during driving, avoiding shoulder gap problems caused by high tread temperature, thereby ensuring driving safety.

[0004] The production process of tire treads typically involves extrusion, where different layers of rubber are extruded through an extruder and flow through a pre-die to a die plate for compounding. However, in actual production, the rubber flowing from the commonly used pre-die, after being formed into the tire tread, often exhibits poor bonding between the upper layer (crown rubber) 61 and the lower layer (base rubber) 62 in the shoulder area 63 (e.g., Figure 1 The tread layer is delaminated at location 64, leading to air bubble formation. This defect can be clearly observed as a gap on the cross-section after the tread is cut.

[0005] When air bubbles appear between the upper and lower rubber layers of a tire, it not only increases the rework rate and reduces production efficiency, but also causes crown bubble problems in the finished tire, seriously affecting the quality and safety of the finished tire. Specifically, the presence of air bubbles can cause localized stress concentration during tire use, increasing the risk of tire blowout, reducing tire lifespan, and potentially endangering driving safety.

[0006] Therefore, existing technologies still need further development. Utility Model Content

[0007] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a pre-die, die structure, and composite extruder to solve the technical problem that in the existing technology, the tread formed by the traditional pre-die often has poor bonding between the upper layer rubber (crown rubber) and the lower layer rubber (base rubber) in the shoulder area, which leads to the formation of air bubbles.

[0008] To achieve the above-mentioned technical objectives, according to one aspect of this utility model: a pre-die is provided, comprising: a pre-die body and a damping block; the pre-die body is provided with a base adhesive guiding channel for communicating with a composite channel of the base adhesive output end of an extruder and a die plate; the damping block is disposed within the base adhesive guiding channel and protrudes from the bottom wall of the base adhesive guiding channel; the damping block divides the base adhesive guiding channel into a first flow channel and a second flow channel; the first flow channel extends along a first preset direction, and the second flow channel extends along a second preset direction; the extension directions of the first flow channel and the extension directions of the second flow channel form a preset angle, the preset angle being greater than 90° and less than 180°.

[0009] Furthermore, the depth of the first flow channel gradually decreases along the flow direction of the base adhesive; the depth of the second flow channel gradually decreases along the flow direction of the base adhesive.

[0010] Furthermore, on the side of the damping block near the base glue output end of the extruder, the height from the top of the damping block to the bottom wall of the base glue guide channel is 5mm-25mm; on the side of the damping block near the composite channel of the die plate, the height from the top of the damping block to the bottom wall of the base glue guide channel is 0mm-3mm.

[0011] Furthermore, the shape of the damping block is an isosceles triangle or an isosceles trapezoid.

[0012] Furthermore, a crown guide channel is also provided on the pre-die body, which is located on the side of the pre-die body away from the base glue guide channel; the crown guide channel is used to communicate with the crown output end of the extruder and the composite channel of the die plate.

[0013] According to another aspect of the present invention, a mouth shape structure is provided, comprising: the pre-mouth shape described above.

[0014] Furthermore, the die structure also includes: a die plate, which is located on the side of the pre-die away from the extruder; the die plate is provided with a composite channel; a base glue guide channel and a crown glue guide channel are provided on the pre-die at intervals, and the output ends of the base glue guide channel and the crown glue guide channel are both connected to the composite channel.

[0015] Furthermore, the die structure also includes: a runner plate assembly, which is disposed between the pre-die and the extruder. The runner plate assembly is provided with a base glue flow channel and a crown glue flow channel at intervals. The base glue flow channel is connected to the base glue output end and the base glue guide channel of the extruder, respectively. The crown glue flow channel is connected to the crown glue output end and the crown glue guide channel of the extruder, respectively.

[0016] According to another aspect of the present invention, a composite extruder is provided, comprising: a die structure, wherein the die structure is the die structure described above.

[0017] Beneficial effects: Applying the technical solution of this utility model, the pre-die provided by this utility model includes a pre-die body and a damping block. The pre-die body is provided with a base adhesive guiding channel for the flow of base adhesive. This base adhesive guiding channel is connected to the base adhesive output end of the extruder and the composite channel of the die plate. The base adhesive guiding channel is located between the base adhesive output end of the extruder and the composite channel of the die plate, serving as a guide path for the base adhesive to transition from the extruder to the forming area. The base adhesive enters the composite channel of the die plate through the output end of the base adhesive guiding channel, forming a composite tread structure together with the crown adhesive. The damping block is disposed within the base adhesive guiding channel and protrudes from the bottom wall of the base adhesive guiding channel, thereby dividing the base adhesive guiding channel into a first flow channel and a second flow channel. The first flow channel extends along a first preset direction, and the second flow channel extends along a second preset direction. The extension directions of the first and second flow channels form a preset angle, which is greater than 90° and less than 180°.

[0018] Therefore, by incorporating damping blocks within the base rubber guide channel, effective control of the base rubber flow path is achieved. When the base rubber enters the pre-form body, it is diverted to the first and second flow channels under the action of the damping blocks. Due to the asymmetrical inclined arrangement of the two channels with a suitable angle, the flow rate of the rubber towards both sides of the damping blocks significantly increases during the diversion process, while simultaneously increasing flow resistance, thereby enhancing the pressure of the rubber in the diversion area. This structural design results in a more uniform and rational pressure distribution of the base rubber after diversion, and enables good pressure matching with the crown rubber in the composite area. This reduces problems such as poor adhesion and interface delamination caused by pressure differences between the upper and lower rubber layers. Especially in the tread shoulder area—a high-incidence area for air bubbles and missing rubber defects in traditional processes—this structure significantly improves the composite quality of the base rubber and crown rubber. Furthermore, the optimized flow and pressure distribution promotes more thorough contact and fusion of the two rubber layers upon entering the composite channel, effectively suppressing air bubble formation. During the tread extrusion molding process, the cross-sectional integrity of the shoulder area is significantly improved, and the phenomenon of gaps in the cross-section after cutting is greatly reduced. This pre-die effectively solves the technical problem in existing treads formed by traditional pre-die molding, where poor bonding between the upper layer rubber (crown rubber) and the lower layer rubber (base rubber) in the shoulder area often leads to air bubble formation. Attached Figure Description

[0019] Figure 1 This diagram illustrates the structural schematic of the tread layering problem in the prior art. Figure 2 A first-view structural schematic diagram of an embodiment of the pre-form according to the present invention is shown; Figure 3 A second-view structural schematic diagram of an embodiment of the pre-form according to the present invention is shown; Figure 4 A schematic diagram of an embodiment of the composite extruder according to the present invention is shown.

[0020] The above figures include the following reference numerals: 1. Pre-drilled body; 2. Base rubber guide channel; 21. First flow channel; 22. Second flow channel; 3. Damping block; 4. Crown rubber guide channel; 61. Crown rubber; 62. Base rubber; 63. Shoulder area; 64. Tread layering position; 100. Base rubber extruder; 200. Crown rubber extruder; 300. Die head. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0022] Please see Figures 2 to 3 According to an embodiment of the present invention, a pre-die is provided, comprising: a pre-die body 1 and a damping block 3. The pre-die body 1 is provided with a base adhesive guiding channel 2, which is used to communicate with the base adhesive output end of the extruder and the composite channel of the die plate. The damping block 3 is disposed in the base adhesive guiding channel 2 and protrudes from the bottom wall of the base adhesive guiding channel 2. The damping block 3 divides the base adhesive guiding channel 2 into a first flow channel 21 and a second flow channel 22. The first flow channel 21 extends along a first preset direction, and the second flow channel 22 extends along a second preset direction. The extension direction of the first flow channel 21 and the extension direction of the second flow channel 22 form a preset angle, which is greater than 90° and less than 180°.

[0023] As can be seen, the pre-die provided by this utility model includes a pre-die body 1 and a damping block 3. The pre-die body 1 is provided with a base adhesive guiding channel 2 for the flow of base adhesive. The base adhesive guiding channel 2 is connected to the base adhesive output end of the extruder and the composite channel of the die plate. The base adhesive guiding channel 2 is located between the base adhesive output end of the extruder and the composite channel of the die plate, and serves as a guide path for the base adhesive to transition from the extruder to the forming area. The base adhesive enters the composite channel of the die plate through the output end of the base adhesive guiding channel 2, forming a composite tread structure together with the crown adhesive. The damping block 3 is disposed within the base adhesive guiding channel 2 and protrudes from the bottom wall of the base adhesive guiding channel 2, so as to divide the base adhesive guiding channel 2 into a first flow channel 21 and a second flow channel 22 by the damping block 3. The first flow channel 21 extends along a first preset direction, and the second flow channel 22 extends along a second preset direction. The extension direction of the first flow channel 21 and the extension direction of the second flow channel 22 form a preset angle, which is greater than 90° and less than 180°.

[0024] Therefore, by setting damping blocks 3 within the base rubber guide channel 2, effective control of the base rubber flow path is achieved. When the base rubber enters the pre-form body 1, it is diverted to the first flow channel 21 and the second flow channel 22 under the action of damping blocks 3. Because the two channels are asymmetrically inclined with a suitable angle, the flow rate of the rubber towards both sides of the damping blocks 3 increases significantly during the diversion process, while the flow resistance also increases, thereby increasing the pressure of the rubber in the diversion area. This structural design makes the pressure distribution of the base rubber after diversion more uniform and reasonable, and allows for good pressure matching with the crown rubber in the composite area. This reduces problems such as poor adhesion and interface delamination caused by pressure differences between the upper and lower rubber layers. Especially in the tread shoulder area—a high-incidence area for air bubbles and missing rubber defects in traditional processes—this structure significantly improves the composite quality of the base rubber and the crown rubber. Furthermore, the optimized flow and pressure distribution promotes more complete contact and fusion of the two rubber layers when entering the composite channel, effectively suppressing the formation of air bubbles. During the tread extrusion molding process, the cross-sectional integrity of the shoulder area is significantly improved, and the phenomenon of gaps in the cross-section after cutting is greatly reduced. This pre-die effectively solves the technical problem in existing treads formed by traditional pre-die molding, where poor bonding between the upper layer rubber (crown rubber) and the lower layer rubber (base rubber) in the shoulder area often leads to air bubble formation.

[0025] Specifically, such as Figure 2As shown, the depth of the first flow channel 21 gradually decreases along the flow direction of the base adhesive; the depth of the second flow channel 22 gradually decreases along the flow direction of the base adhesive. That is, the depth of the first flow channel 21 gradually decreases along the direction from its input end to its output end; the depth of the second flow channel 22 gradually decreases along the direction from its input end to its output end.

[0026] With the above structural configuration, the depths of the first flow channel 21 and the second flow channel 22 gradually decrease along the flow direction of the base adhesive. This design allows the flow cross-sectional area of ​​the base adhesive to gradually decrease during flow. According to fluid mechanics principles, when the flow cross-sectional area of ​​the fluid (here, the base adhesive) decreases, its flow velocity increases. This velocity change allows for more precise control of the base adhesive flow, ensuring it flows along the expected path and speed, better adapting to the requirements of subsequent molding processes. Simultaneously, due to the gradual decrease in depth, the flow of the base adhesive in the first and second flow channels becomes more uniform. As the channel depth gradually changes, the distribution of the adhesive within the channels becomes more even, avoiding adhesive accumulation or flow obstruction caused by abrupt changes in channel depth. This helps the base adhesive, after being split, to flow evenly to both sides of the damping block, ensuring that the pressure of the base adhesive during flow gradually changes as the channel depth decreases throughout the pre-form. Furthermore, in deeper sections of the channel, the flow resistance and pressure of the adhesive compound are relatively low; conversely, as the channel depth decreases, the flow resistance gradually increases, and the pressure gradually rises as well. This gradual pressure change process allows for smoother pressure variations in the base adhesive compound, better matching the pressure variation trend of the crown adhesive. When bonding within the composite channel, the pressures of the base adhesive and crown adhesive can be more coordinated, reducing interlayer bonding problems caused by excessive pressure differences. The uniform distribution of the inner base adhesive provides favorable conditions for good bonding with the crown adhesive.

[0027] Furthermore, on the side of the damping block 3 near the base glue output end of the extruder, the height from the top of the damping block 3 to the bottom wall of the base glue guide channel 2 is 5mm-25mm; on the side of the damping block 3 near the composite channel of the die plate, the height from the top of the damping block 3 to the bottom wall of the base glue guide channel 2 is 0mm-3mm.

[0028] With the above structural configuration, the height from the top of the damping block 3 to the bottom wall of the base rubber guide channel 2 on the side near the base rubber output end of the extruder is 5mm-25mm. This design provides a relatively large space for the base rubber material to enter the pre-die. When the base rubber is output from the extruder, it has a certain flow kinetic energy and pressure. The larger space can prevent excessive flow resistance caused by the sudden narrowing of space when the material enters the pre-die body 1, which could lead to material accumulation or poor flow. This height range also ensures that the base rubber material can fully enter the two flow channels (first flow channel 21 and second flow channel 22) separated by the damping block 3, providing sufficient material for the subsequent splitting process. At the same time, the height from the top of the damping block to the bottom wall of the base rubber guide channel on the side near the die plate composite channel is 0mm-3mm. This smaller height design can effectively rectify and compress the base rubber material before it enters the composite channel. When the base rubber material reaches this position after passing through the flow channels with gradually decreasing depth, the smaller height allows its flow to be more stable and uniform.

[0029] Furthermore, the damping block 3 is shaped like an isosceles triangle or an isosceles trapezoid. This structural arrangement, with the damping block 3 designed as an isosceles triangle or isosceles trapezoid, allows the base adhesive material to be evenly distributed along both sides (the first flow channel 21 and the second flow channel 22) after entering the pre-form. This symmetrical shape ensures that the resistance encountered by the base adhesive during distribution is symmetrical and balanced, preventing the adhesive material from flowing to one side due to asymmetry, thus ensuring a more uniform flow distribution of the base adhesive in the two flow channels. Moreover, this symmetrical shape of the damping block 3 reduces turbulence and disturbances in the base adhesive material during flow. Because the shape of the isosceles triangle or isosceles trapezoid is relatively regular, the flow path of the adhesive material is relatively smooth when passing through the damping block 3, reducing the instability of the adhesive flow. Furthermore, from a fluid dynamics perspective, the symmetrical shape helps reduce flow separation phenomena. When the adhesive material encounters damping block 3, its symmetrical shape allows the adhesive to form a symmetrical flow boundary layer on both sides of the damping block 3, reducing eddies or flow separation caused by irregular shapes. This ensures a smoother flow of the base adhesive, which is beneficial for subsequent molding processes. Furthermore, the isosceles triangular or isosceles trapezoidal shape of the damping block helps to make the pressure distribution of the base adhesive more uniform in the two flow channels. Due to the symmetrical shape, after the base adhesive is split, the pressure change trends of the adhesive in the two flow channels are similar, and the pressure gradient is relatively consistent. This uniform pressure distribution allows for a better match between the pressure of the base adhesive and the crown adhesive at the interlayer bonding point. During the lamination process, the base adhesive and the crown adhesive can bond with more coordinated pressure, reducing local stress concentration caused by pressure differences, thereby improving lamination quality and reducing the risk of bubble formation. Moreover, the symmetrical shape of the damping block 3 allows the base adhesive to have a more precise flow direction and position when entering the lamination channel. The apex of the isosceles triangle or the upper base of the isosceles trapezoid can serve as a relatively clear splitting point, guiding the base adhesive to flow along a predetermined path.

[0030] Furthermore, when the damping block 3 is an isosceles triangle, its vertex angle is located at the input end of the base adhesive guiding channel 2, that is, at the end of the base adhesive guiding channel 2 closest to the base adhesive output end of the extruder. The two base angles are located at the output end of the base adhesive guiding channel 2. The vertex angle of the isosceles triangle is obtuse, and the two base angles are acute. Preferably, the vertex angle of the isosceles triangle is 120°, and the two base angles are 30° each.

[0031] Furthermore, when the damping block 3 is an isosceles triangle, the width of the base of the damping block 3 is between 130mm and 200mm.

[0032] Furthermore, when the damping block 3 is an isosceles trapezoid, its upper base (the shorter base) is located at the input end of the base adhesive guiding channel 2, that is, at the end of the base adhesive guiding channel 2 closest to the base adhesive output end of the extruder. Its lower base (the longer base) has two corners located at the output end of the base adhesive guiding channel 2. These two corners are acute angles. Preferably, the two corners of the lower base are 30°.

[0033] Furthermore, when the damping block 3 is an isosceles trapezoid, the width of the lower base of the damping block 3 is between 130mm and 200mm.

[0034] Preferably, such as Figure 2 As shown, damping block 3 is an isosceles triangle.

[0035] Specifically, such as Figure 2 and Figure 3 As shown, the pre-die body 1 also has a crown rubber guiding channel 4, which is located on the side of the pre-die body 1 away from the base rubber guiding channel 2. The crown rubber guiding channel 4 is used to communicate with the crown rubber output end of the extruder and the composite channel of the die plate. With this structural arrangement, the pre-die body 1 also has a crown rubber guiding channel 4, which is located on the side of the pre-die body 1 away from the base rubber guiding channel 2. The crown rubber guiding channel 4 is used to communicate with the crown rubber output end of the extruder and the composite channel of the die plate. The pre-die body 1 also has a crown rubber guiding channel 4, which is located on the side of the pre-die body 1 away from the base rubber guiding channel 2. The crown rubber guiding channel 4 is used to communicate with the crown rubber output end of the extruder and the composite channel of the die plate.

[0036] This utility model also provides a mouth shape structure, including: the pre-mouth shape of the above embodiment.

[0037] Specifically, the die structure also includes: a die plate located on the side of the pre-die away from the extruder; the die plate is provided with a composite channel; a base glue guide channel 2 and a crown glue guide channel 4 are provided on the pre-die at intervals, and the output ends of the base glue guide channel 2 and the crown glue guide channel 4 are both connected to the composite channel.

[0038] Furthermore, a base adhesive guide channel 2 and a crown adhesive guide channel 4 are provided at intervals on the pre-die body 1 of the pre-die.

[0039] Specifically, the die structure also includes: a runner plate assembly, which is disposed between the pre-die and the extruder. The runner plate assembly is provided with a base glue flow channel and a crown glue flow channel at intervals. The base glue flow channel is connected to the base glue output end and the base glue guide channel 2 of the extruder, respectively. The crown glue flow channel is connected to the crown glue output end and the crown glue guide channel 4 of the extruder, respectively.

[0040] This utility model also provides a composite extruder, including: a die structure, wherein the die structure is the die structure of the above embodiment.

[0041] Specifically, such as Figure 4 As shown, the compound extruder also includes: a base rubber extruder 100, a crown rubber extruder 200, and a die head 300. The die head 300 is equipped with a die-shaped structure. The output ends of the base rubber extruder 100 and the crown rubber extruder 200 are both connected to the die-shaped structure inside the die head 300.

[0042] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0043] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments, and will not be repeated here.

[0044] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0045] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0046] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A pre-gauge, characterized in that, include: A pre-die body (1) is provided with a base glue guiding channel (2), which is used to communicate with the base glue output end of the extruder and the composite channel of the die plate; A damping block (3) is disposed within the base adhesive guiding channel (2), and the damping block (3) protrudes from the bottom wall of the base adhesive guiding channel (2); the damping block (3) divides the base adhesive guiding channel (2) into a first flow channel (21) and a second flow channel (22), the first flow channel (21) extends along a first preset direction, the second flow channel (22) extends along a second preset direction, and the extension direction of the first flow channel (21) and the extension direction of the second flow channel (22) form a preset angle, the preset angle being greater than 90° and less than 180°.

2. The pre-flute pattern according to claim 1, characterized in that, The first flow channel (21) is along the flow direction of the base adhesive, and the depth of the first flow channel (21) gradually decreases; the second flow channel (22) is along the flow direction of the base adhesive, and the depth of the second flow channel (22) gradually decreases.

3. The pre-flute pattern according to claim 2, characterized in that, The damping block (3) is located on the side near the base glue output end of the extruder, and the height from the top of the damping block (3) to the bottom wall of the base glue guide channel (2) is 5mm-25mm; the damping block (3) is located on the side near the composite channel of the die plate, and the height from the top of the damping block (3) to the bottom wall of the base glue guide channel (2) is 0mm-3mm.

4. The pre-flute pattern according to claim 1, characterized in that, The shape of the damping block (3) is an isosceles triangle or an isosceles trapezoid.

5. The pre-flute pattern according to claim 1, characterized in that, The pre-die body (1) is also provided with a crown glue guide channel (4), which is located on the side of the pre-die body (1) away from the base glue guide channel (2); the crown glue guide channel (4) is used to communicate with the crown glue output end of the extruder and the composite channel of the die plate.

6. A mouth-shaped structure, characterized in that, include: The pre-form according to any one of claims 1 to 5.

7. The mouth structure according to claim 6, characterized in that, The die structure also includes: a die plate, which is located on the side of the pre-die away from the extruder; the die plate is provided with a composite channel; the pre-die is provided with a base glue guiding channel (2) and a crown glue guiding channel (4) spaced apart, and the output end of the base glue guiding channel (2) and the output end of the crown glue guiding channel (4) are both connected to the composite channel.

8. The mouth structure according to claim 7, characterized in that, The die structure also includes: a flow channel plate assembly, which is disposed between the pre-die and the extruder. The flow channel plate assembly is provided with a base glue flow channel and a crown glue flow channel at intervals. The base glue flow channel is connected to the base glue output end of the extruder and the base glue guide channel (2) respectively. The crown glue flow channel is connected to the crown glue output end of the extruder and the crown glue guide channel (4) respectively.

9. A composite extruder, characterized in that, include: The mouth shape structure is the mouth shape structure according to any one of claims 6 to 8.

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