Extrusion device for solving tread delaminating problem

Abstract

The utility model discloses an extrusion device for solving the problem of tread delamination, which comprises an upper extruder and a lower extruder, the diameter of a screw rod of an upper computer is phi 250mm, the diameter of a screw rod of a lower computer is phi 150mm, and a machine barrel of the lower computer is sleeved with four layers of thermal insulation cotton; the shoulder thickness of the tread mouth shape is 28 to 33 mm; a chamfer is arranged at the edge of the lower parting surface of the tread mouth shape and corresponds to the base rubber inlet; the actual shoulder breadth size L11 of the through tread mouth shape is equal to the standard shoulder breadth size * (0.92-0.94), and the actual total breadth size L12 of the through tread mouth shape is equal to the standard total breadth size * (0.92-0.94); the actual shoulder width size L21 of the wing rubber tread mouth shape is equal to the standard shoulder width size * (0.88-0.94), and the actual total width size L22 of the wing rubber tread mouth shape is equal to the standard total width size * (0.88-0.94). The problem that the production efficiency is affected due to the fact that the upper layer and the lower layer of an existing thick-specification through tread and a thick-specification wing rubber tread are not tightly attached is solved.

Description

[Technical field]

[0001] The utility model belongs to the technical field of rubber product manufacturing, and in particular relates to an extrusion device for solving the problem of tread delamination. [Background technology]

[0002] During the design of all-steel radial truck tires, different tread structures are required due to different requirements for performance and road conditions. The more commonly used structures are wing rubber and through-type structures, which are made by compounding two rubber materials in different structural forms. If the bonding is not dense during the compounding process, after the tread is pressed, there will be serious delamination between the tread rubber and the base rubber layer. This type of tread will cause great hidden dangers to the tire quality after use.

[0003] At present, the tread production line has two types of composite extruders: hot feed Φ250 / Φ150 and cold feed Φ250 / Φ200. Among them, the hot feed Φ250 / Φ150 model is prone to the phenomenon of poor adhesion between the upper and lower layers when producing thick through treads and thick wing rubber treads, especially in winter, and bubbles appear between the layers after the Thousand Layers are pressed. Due to the quality risks, such bad treads cannot be put into use normally, resulting in the inability to produce the corresponding specifications normally, which has a great impact on production efficiency and causes a large amount of return materials during the debugging process. [Contents of the utility model]

[0004] The utility model aims to provide an extrusion device for solving the problem of tread delamination, so as to solve the problem that the upper and lower layers of the existing thick through tread and thick wing rubber tread are prone to poor adhesion, which affects the production efficiency.

[0005] The utility model adopts the following technical scheme: an extrusion device for solving the problem of tread delamination, comprising two extruders arranged up and down, namely an upper machine and a lower machine, the screw diameter of the upper machine is Φ250mm, the screw diameter of the lower machine is Φ150mm, the extrusion directions of the two extruders are arranged in a V shape, and the barrel of the lower machine is outer-circuited with four layers of thermal insulation cotton;

[0006] The outlets of the flow channels of the two extruders are connected with the tread pre-die and the tread die in sequence, and the shoulder thickness of the tread die is 28mm to 33mm; a chamfer is set at the edge of the lower parting surface of the tread die and at the position corresponding to the base rubber / wing rubber inlet;

[0007] The tread mouth type includes through tread mouth type and wing rubber tread mouth type, among which:

[0008] The actual shoulder width dimension L11 of the through-tread mouth type = its standard shoulder width dimension * (0.92-0.94), the actual total width dimension L12 of the through-tread mouth type = its standard total width dimension * (0.92-0.94);

[0009] The actual shoulder width dimension L21 of the wing rubber tread mouth shape = its standard shoulder width dimension * (0.88-0.94), and the actual total width dimension L22 of the wing rubber tread mouth shape = its standard total width dimension * (0.88-0.94).

[0010] Furthermore, the length of a section of edge with a chamfer on the lower parting surface that passes through the tread mouth is equal to the width of the lower rubber layer, and the chamfer is 30°.

[0011] Furthermore, the lower parting surfaces of the wing rubber tread mouth shape are two located at the two ends of the mouth shape, and chamfers are arranged at the edges of the two lower parting surfaces, and the chamfers are 30 degrees.

[0012] The beneficial effects of the utility model are as follows: the utility model has completely solved the problem of delamination of the through tread in the production of thick specifications by adding thermal insulation materials, optimizing the opening size of the die plate, adding chamfers to the lower plate and other measures. The delamination die that has been repaired has a delamination recurrence rate of zero; it reduces a large amount of defective returned materials caused by tread delamination in the production process and a large amount of waste of working hours and manpower caused in the test plate process; at the same time, it also avoids the serious quality risks to the tire caused by the delaminated tread mistakenly flowing into the next process for use.

Brief Description of the Drawings

[0013] Figure 1 This is a schematic structural diagram of an extrusion device for solving the tread delamination problem of the utility model;

[0014] Figure 2 It is a structural schematic diagram of the tread mouth shape of the utility model;

[0015] Figure 3 for Figure 2 AA section diagram in .

[0016] Among them, 1. upper machine, 2. lower machine, 3. runner, 4. tread pre-mouth shape, 5. tread mouth shape, 51. lower parting surface. [Specific implementation method]

[0017] The utility model is described in detail below with reference to the accompanying drawings and specific implementation modes.

[0018] The utility model provides an extrusion device for solving the problem of tread delamination, such as Figure 1 As shown, it includes two extruders arranged up and down, namely an upper machine and a lower machine, namely an upper machine 1 and a lower machine 2, the screw diameter of the upper machine 1 is Φ250mm, the screw diameter of the lower machine 2 is Φ150mm, the extrusion directions of the two extruders are arranged in a V shape, and the barrel 6 of the lower machine 2 is outer-coated with four layers of thermal insulation cotton, and the outermost layer of the thermal insulation cotton is fixed with iron sheet.

[0019] The outlets of the flow channels 3 of the two extruders are connected to the tread pre-die 4 and the tread die 5 in sequence. The tread die is used to compound and shape the rubber materials extruded by the two extruder heads. The tread die 5 is a thick specification, that is, its shoulder thickness is 28mm to 33mm.

[0020] Since the tread delamination made by thick tread die is greatly affected by the ambient temperature, it is mainly concentrated in winter or when the production starts after a long shutdown time during holidays. At this time, the ambient temperature is low or the equipment is shut down for a long time, and the equipment is not preheated properly, which affects the plasticization effect of the rubber during the production process, thereby affecting the viscosity of the rubber. At the same time, when the temperature is low, it also has a certain impact on the shrinkage of the rubber, resulting in more frequent delamination. Therefore, the utility model takes insulation measures for the lower machine, and increases the insulation effect of the lower machine by installing insulation materials on the outer part of the lower machine barrel as a whole, reducing the problem of excessively low rubber temperature due to inadequate preheating, resulting in a decrease in the plasticization performance and viscosity of the rubber. At the same time, when in use, different winter and summer temperature control requirements for the extruder are set, requiring the winter temperature control temperature to be higher than the summer temperature control. At the same time, when producing in winter, the first specification temperature control is increased by 10°C on the original standard. During the holiday shutdown period, the equipment-related personnel enter the class one shift in advance to start and debug the temperature control to ensure that the extruder temperature control operates normally and the equipment preheating effect is guaranteed.

[0021] A chamfer is provided at the edge of the lower parting surface 51 of the tread mouth 5 and at the position corresponding to the base rubber / wing rubber inlet;

[0022] The tread mouth shape 5 includes a through tread mouth shape and a wing rubber tread mouth shape, and the opening ratio thereof is as follows. The opening ratio is the ratio of the standard size of the tread mouth shape 5 to the actual size.

[0023] like Figure 2 As shown, the actual shoulder width dimension L11 of the through-tread mouth type = the standard shoulder width dimension of the through-tread mouth type * (0.92-0.94), and the actual total width dimension L12 of the through-tread mouth type = the standard total width dimension of the through-tread mouth type * (0.92-0.94). For example, if the standard shoulder width dimension is 184mm, the actual shoulder width dimension is 169.5mm; if the standard total width dimension is 276mm, the actual total width dimension is 264mm.

[0024] The actual shoulder width dimension L21 of the wing rubber tread mouth shape = the standard shoulder width dimension of the wing rubber tread mouth shape * (0.88-0.94), and the actual total width dimension L22 of the wing rubber tread mouth shape = the standard total width dimension of the wing rubber tread mouth shape * (0.88-0.94).

[0025] The tread rubber and the base rubber or the wing rubber are extruded by pressure compounding through the tread die 5. At a certain temperature, when the opening ratio of the tread die 5 is large, when producing thick treads, the compounding pressure of the tread rubber and the base rubber or the wing rubber is small when compounding through the tread die 5, resulting in poor lamination effect between the tread rubber and the base rubber or the wing rubber, and bubbles will appear between the layers of the tread after being pressed by the lasagna.

[0026] The standard size of tread mouth shape 5 is determined according to the national standard design specifications. However, in order to increase the composite pressure of the tread rubber and the base rubber or wing rubber when passing through the tread mouth shape 5, the compression and expansion characteristics of the rubber will be considered on the actual production line. The opening size of the tread mouth shape 5 is proportionally reduced according to the standard size, which increases the feeding pressure and ensures the composite strength of the two layers of rubber. At the same time, due to the characteristic that the extruded rubber will expand in the opposite direction after extrusion, it can be ensured that the size of the extruded product will be restored to the same as the standard size. There are two different options for the reduction ratio depending on whether the tread mouth shape 5 is a through tread mouth shape or a wing rubber tread mouth shape. The specific ratio values ​​are shown above. After reducing the opening ratio of the tread mouth shape, the composite pressure of the two rubbers is significantly increased, and the stratification phenomenon is effectively improved.

[0027] The opening ratio cannot be infinitely small, because the width of the base rubber after extrusion will be infinitely close to or exceed the full width, resulting in the base rubber size failing to meet the design requirements. If the opening ratio is too small, the extrusion pressure will be large, and after long-term use, deformation will easily occur at the parting surface, resulting in poor tread thickness stability. Therefore, the minimum opening ratio of the wing rubber tread mouth is 0.88 of the standard size, and the minimum opening ratio of the tread mouth that passes through the tread is 0.92 of the standard size.

[0028] The utility model tests the tread mouth shape 5 with different opening ratios respectively, and obtains the comparison results as shown in Table 1 below.

[0029] Table 1 Comparison of the speed of the extruders corresponding to the two opening ratios

[0030]

[0031] As shown in Table 1, the speed of the extruder with a tread die with a smaller opening ratio is significantly greater than the extrusion speed of the extruder with a tread die with a larger opening ratio. And compared from the same specification section, the tread die with a smaller opening ratio has a more obvious delamination improvement effect due to the increased extrusion pressure. The meter weight in Table 1 means the weight of each meter of the tread after extrusion during operation, which is continuously detected online. It can be seen from the meter weight data in Table 1 that after the opening ratio of the same tread die is reduced, the speed of the extruder is increased, and the composite pressure is increased, but it has little effect on the meter weight data of the extruded tread.

[0032] After optimizing the opening ratio, the utility model also sets a chamfer at the edge of the lower parting surface 51 of the tread mouth 5 and at the position corresponding to the base rubber / wing rubber inlet.

[0033] During the production process, affected by different batches of rubber materials, some employees increase the speed of the lower machine to ensure that the weight and thickness are qualified. Continuously increasing the speed of the lower machine will eventually cause the extrusion pressure of the lower machine to not match the extrusion pressure of the upper machine, resulting in delamination of the tread after the die is extruded. Therefore, the utility model reduces the speed of the lower machine, and according to the experience of adjusting the ratio of the tread die plate, increases the pressure of the upper machine, which can effectively improve the tread delamination problem. In order to ensure that the base rubber thickness can still meet the technical design requirements when the speed of the lower machine is reduced, the edge of the lower parting surface 51 of the tread die 5 is chamfered to increase the amount of base rubber at the die plate inlet, thereby achieving the purpose of reducing the speed of the lower machine. At the same time, after the tread die 5 is qualified, the die room records the qualified extruder speed and puts it on record, and the machine shall not change the speed of the lower machine at will. At the same time, the machine strengthens the inspection of the size of the tread base rubber. When the thickness is abnormal, it is adjusted and repaired in time to prevent the phenomenon of artificial enlargement of the lower machine.

[0034] In some embodiments, Figure 3 As shown, the length of a section of edge with a chamfer on the lower parting surface 51 that passes through the tread mouth is equal to the width of the lower layer of rubber, and the chamfer is 30°.

[0035] In some embodiments, the lower parting surfaces 51 of the wing rubber tread mouth shape are two located at two ends of the mouth shape, and chamfers are provided at the edges of the two lower parting surfaces 51, and the chamfers are 30 degrees.

[0036] The utility model tests the rubber inlet of the base of the lower parting surface of the through tread mouth shape without chamfer and with chamfer respectively, and obtains the comparative results as shown in Table 2 below.

[0037] Table 2 Comparison of the glue inlet without chamfer and with chamfer at the base of the parting surface

[0038]

[0039] From the comparison of the speeds of the glue inlet at the base of the lower parting surface without chamfer and with a chamfer of 30° in Table 2, it can be seen that after adding a chamfer to the edge of the lower parting surface and reducing the rotation speed of the lower machine, there is no delamination between the thick tread layers, and the improvement effect is significant.

[0040] The utility model is suitable for Φ250 / Φ150 extruder models, and the tread shoulder thickness is 28mm-33mm, or the tread rubber area ratio is greater than 4000mm 2The large through-tread can completely solve the delamination problem of large-size through-tread in production, and the delamination recurrence rate is zero. It reduces the large amount of defective returned materials caused by tread delamination in the production process and the large amount of man-hours and manpower waste caused in the test process. At the same time, it also avoids the serious quality risks of tires caused by delaminated treads mistakenly flowing into the next process, providing a basic guarantee for the company's tires to be more competitive.

Claims

1. An extrusion device for solving the problem of tread delamination, comprising two extruders arranged in an upper and lower position, namely an upper machine (1) and a lower machine (2), wherein the screw diameter of the upper machine (1) is Φ250 mm, and the screw diameter of the lower machine (2) is Φ150 mm, It is characterized in that The extrusion directions of the two extruders are arranged in a V shape, and the barrel outer shell of the lower machine (2) is provided with four layers of thermal insulation cotton; The outlets of the flow channels (3) of the two extruders are connected to the tread pre-die (4) and the tread die (5) in sequence, and the shoulder thickness of the tread die (5) is 28 mm to 33 mm; a chamfer is provided at the edge of the lower parting surface (51) of the tread die (5) and at the position corresponding to the base rubber / wing rubber inlet; The tread mouth shape (5) includes a through tread mouth shape and a wing tread mouth shape, wherein: The actual shoulder width dimension L11 of the through-tread mouth shape = its standard shoulder width dimension * (0.92-0.94), and the actual total width dimension L12 of the through-tread mouth shape = its standard total width dimension * (0.92-0.94); The actual shoulder width dimension L21 of the wing rubber tread mouth shape = its standard shoulder width dimension*(0.88-0.94), and the actual total width dimension L22 of the wing rubber tread mouth shape = its standard total width dimension*(0.88-0.94).

2. An extrusion device for solving the tread delamination problem as claimed in claim 1, It is characterized in that The length of a section of edge with a chamfer on the lower parting surface (51) that passes through the tread mouth is equal to the width of the lower rubber layer, and the chamfer is 30 degrees.

3. An extrusion device for solving the tread delamination problem as claimed in claim 1, It is characterized in that The lower parting surfaces (51) of the wing rubber tread mouth shape are two located at the two ends of the mouth shape, and chamfers are arranged at the edges of the two lower parting surfaces (51), and the chamfers are 30 degrees.

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