JP4749810B2 - Polymer material temperature controller - Google Patents

Description

  The present invention relates to a temperature control device for a polymer material when the polymer material is melted and extruded.

  As a technique for melting and extruding a polymer material, a technique for extruding with a screw extruder and a forming die and a technique for further providing a gear pump are known. FIG. 7 shows the configuration of an extruder conventionally used. As shown in FIG. 1, the conventional extruder includes a hopper 25, an extruder 11, a screw 12 of the extruder 11, a screw drive source 5 of the screw 12, and a molding die 3. Moreover, FIG. 8 is a figure which shows the structure of the extruder provided with the gear pump conventionally used.

In molding a polymer material, the polymer material is subjected to a crosslinking reaction for the purpose of improving the heat resistance and the like of the molded product. As a method for causing a polymer material to undergo a crosslinking reaction, various methods such as a method of applying light and heat to the polymer material and a method of adding a crosslinking agent are known. As an example of a technique for crosslinking a polymer material with heat, a technique for continuously adding rubber or elastomer by shearing heat generation or raising the temperature near a crosslinking temperature is known (for example, see Patent Document 1). .
Japanese Patent Publication No.62-58895

  When extruding a polymer material using a device having a screw extruder and a forming die, it is necessary to apply heat from the outside in order to raise the temperature to the reaction region of the polymer material and cause the polymer material to undergo a crosslinking reaction. . However, in the configuration in which heat is applied from the outside, the cross-linking reaction is efficiently performed in a portion close to heat, whereas the polymer material does not flow smoothly because the cross-linking reaction is delayed in a portion far from heat. Cause problems. In other words, the viscosity of the polymer material increases as the temperature rises. However, in the configuration in which heat is applied from the outside, the viscosity also varies due to the temperature difference, and a layer with high and low viscosity is formed. This causes a problem that the polymer material does not flow smoothly (the polymer material stagnates on the channel wall surface).

  In addition, in order to improve the heat resistance by crosslinking reaction of the polymer material, it is necessary to perform molding while reacting at a predetermined temperature. This is because when the polymer material exceeds the predetermined temperature, the molecular structure itself of the polymer material is destroyed rather than improving the heat resistance. In order to avoid such a problem, when extruding a polymer material with an apparatus including a screw extruder and a forming die, a method of heating from the outside after the extruding is taken. However, this method has a problem that it takes a long time for heating because the thermal conductivity of the polymer material is small.

On the other hand, with the technique of continuously raising the temperature near the crosslinking temperature by shearing heat generation, it is possible to raise the temperature of the polymer material without applying heat from the outside. However, it cannot be said that the above technique uniformly applies a shearing force to the entire polymer material, and the following problems also occur. That is, in the above technique, two propulsive forces are used to propel the polymer material, ie, the propulsive force of the extruder and the propulsive force generated by the screw feeding portion included in the shear heating cylinder. Here, since the screw feed section adjusts the number of rotations according to the heat applied to the polymer material, the number of rotations changes depending on the temperature applied, and a constant propulsion is applied to the polymer material extruded from the molding die. It is difficult to apply force, in other words, constant pressure. When molding a molded product from a polymer material, it is desirable that a uniform pressure be applied when it is extruded from a molding die. However, the above-described technique has a problem that a certain pressure cannot be applied to the polymer material.

  In the present invention, in view of the above-described problems, when a polymer material is subjected to a crosslinking reaction and molded, the polymer material does not stagnate in the flow path, and the temperature at which the crosslinking reaction time is not affected by the thermal conductivity of the polymer material. An object of the present invention is to provide a control device that can control temperature by applying a constant pressure and a uniform shearing force to a polymer material.

  The present invention employs the following means in order to solve the above-described problems. That is, an apparatus connected to an extruder that melts and extrudes a polymer material and controls the temperature of the polymer material extruded from the extruder, the cylinder member connected to the extruder, and the cylinder member An inner member that is encapsulated through a gap through which the polymer material flows and rotates relative to the cylindrical member, and at least one of the inner surface of the cylindrical member and the outer surface of the inner member An uneven portion for applying a shearing force to the polymer material flowing between the inner surface of the cylindrical member and the outer surface of the inner member is provided, and the uneven portion is twisted so as not to generate a propulsive force in the longitudinal direction. It is configured.

  This is a temperature control device in which the polymer material does not stagnate in the flow path and the crosslinking reaction time is not affected by the thermal conductivity of the polymer material when the polymer material is molded by crosslinking reaction, The temperature can be controlled by applying a constant pressure and a uniform shear force to the molecular material. That is, a uniform shearing force is applied to the polymer material by the uneven portion. Further, since the concavo-convex portion gives a shearing force to the polymer material but does not give a propulsive force, the propulsive force given to the polymer material is determined by the pressure pushed out by the extruder, The pressure applied to the molecular material becomes constant. That is, the uneven part mainly gives a shearing force to the polymer material and is independent of the propulsion force of the extruder. As described above, according to the temperature control device for a polymer material according to the present invention, it is possible to uniformly cause a crosslinking reaction to the polymer material by shearing heat generation without applying heat from the outside.

  The extruder melts the polymer material and pushes the polymer material to a cylindrical member connected to the extruder. The extruder used conventionally can be used for an extruder, for example, a screw extruder is illustrated. Examples of the polymer material include polyethylene and rubber, and the polymer material and the crosslinking agent can be kneaded in the extruder by introducing a crosslinking agent together with the polymer material into the extruder.

  A cylindrical member is connected to the extruder. The cylindrical member includes the internal member. A gap is provided between the inner surface of the cylindrical member and the outer surface of the inner packaging member for allowing the polymer material to flow, and the polymeric material is sheared by rotating relative to the cylindrical member. A force is applied, and the polymer material can be subjected to a cross-linking reaction by internal frictional heat due to a shearing force. A cylinder can be used as the cylindrical member, and a mandrel can be used as the inclusion member. In the present invention, the inner member rotates relative to the cylindrical member. However, any member may be used as long as at least one of the cylindrical member and the inner member is connected to a driving source to rotate. . In addition, the provision of the concavo-convex portion means that, for example, the cross-sectional shape with respect to the axial direction is relatively deformed between the tubular member and the inner member.

Further, the present invention is an apparatus connected to an extruder that melts and extrudes the polymer material, and controls the temperature of the polymer material extruded from the extruder, the cylinder connected to the extruder, A mandrel included in the cylinder and rotating relative to the cylinder, the mandrel having an uneven surface formed on an outer surface in a cross section perpendicular to the axial direction and twisted in the axial direction, the inner surface of the cylinder and the mandrel A gap through which the polymer material flows is formed between the outer surface of the substrate and the gap is formed by alternately forming a region having a large thickness and a region having a small thickness. It is represented by the gap in a right-angle cross section, and in the axial direction, it is represented by a predetermined twist angle that is an angle that does not generate a propulsive force with respect to the direction perpendicular to the axis.

  As a result, it is possible to uniformly cause a cross-linking reaction to the polymer material by shearing heat generation without applying heat from the outside. Further, since the mandrel does not generate propulsive force, the polymer material can be propelled mainly by the propulsive force of the extruder. Accordingly, the propulsive force is constant, and the pressure at the time of extrusion molding from the molding die can be made constant. As a result, it is possible to form a molded product with excellent heat resistance in a short time due to internal frictional heat due to shearing action, and the molded product has more excellent properties by making the density of the molded product constant by keeping the pressure constant. Can be molded.

  The shape of the concavo-convex portion formed on the outer surface of the mandrel can be represented by the gap in the cross section perpendicular to the axial direction, and represented by a predetermined twist angle that is an angle that does not generate propulsive force in the axial direction in the axial direction. Can do. In other words, the shape of the concavo-convex portion formed on the outer surface of the mandrel can be specified by the direction perpendicular to the axis and the axial direction. The expression by the gap means that the cross-sectional shape of the uneven portion can be specified by specifying the thickness of the gap when the uneven portion is viewed in cross section. The gap is formed by the flow of the polymer material formed between the inner surface of the cylinder and the outer surface of the mandrel, and is formed by alternately forming a region having a large thickness and a region having a small thickness.

  On the other hand, when the concavo-convex portion is viewed in the axial direction, it is formed at a predetermined torsional angle that does not generate propulsive force with respect to the direction perpendicular to the axis. In other words, the cross-sectional shape in the axial direction is a shape that is continuously twisted at a predetermined twist angle in the longitudinal direction, and the predetermined twist angle is a gentle angle that does not generate a propulsive force. Thereby, the propulsive force given to the polymer material is mainly determined by the pressure pushed out by the extruder, and the pressure given to the polymer material becomes constant.

  The predetermined torsional angle that does not generate a propulsive force means that it is inclined at a predetermined angle with respect to the direction perpendicular to the axial direction. That is, in the range of 0 to 90 degrees, if the angle is small, the twist is strong and the propulsive force is large, and if the angle is large, the twist is weak and the propulsive force is small.

  Even in the case where the mandrel is rotated by forming the region having the large thickness and the region having the small thickness in this manner in a spiral shape with a predetermined width and a predetermined twist angle that does not generate a propulsive force in the axial direction. Depending on the rotation of the mandrel, a shearing force can be applied to the polymer material without generating a driving force. That is, it is possible to propel the polymer material mainly by the propulsion force of the extruder. As a result, the polymer material can be extruded under a certain pressure, and the above-described shearing action can be applied to the polymer material. It becomes possible to give internal frictional heat.

  Further, according to the present invention, the region where the thickness is large is a displacement thickness portion in which the distance from the inner surface of the cylinder is displaced in a cross section perpendicular to the axial direction, and the region where the thickness is small is a cross section perpendicular to the axial direction. It is good also as what is a constant thickness part from which the distance from the inner surface of the said cylinder is constant.

The constant thickness portion means that the distance between the inner surface of the cylinder and the outer surface of the mandrel is constant, for example, by forming a part of the cross section of the mandrel by an arc. The displacement thickness portion means that the distance between the inner surface of the cylinder, which is an arc, and the outer surface of the mandrel is displaced, for example, by forming a part of the cross section of the mandrel by a straight line.

  The displacement thickness portion is a portion represented by a straight line in a cross section perpendicular to the axial direction of the mandrel. In this way, in the cross section, the linear portion that is the displacement thickness portion and the arc portion that is the constant thickness portion are alternately formed, and the mandrel is rotated relative to the cylinder so that the gap flows. The polymer material sequentially promotes channels having different thicknesses (depths). As a result, a uniform shearing force can be applied to the polymer material, and internal frictional heat can be generated to cause a crosslinking reaction. In addition, when the straight portions and the circular arc portions are alternately formed in the cross section, it is possible to apply a shearing force to the polymer material more efficiently and uniformly by making the arrangement thereof regular. It becomes.

  In the present invention, the predetermined twist angle may be a value larger than 40 degrees and smaller than 90 degrees.

  By setting the predetermined twist angle to a value larger than 40 degrees and smaller than 90 degrees, it is possible to mainly apply a shearing force without applying a driving force to the polymer material. Therefore, the polymer material is mainly driven by the propulsion force of the above-described extruder, and the polymer material can be extruded under a constant pressure.

  In the present invention, the length of the cylinder in the longitudinal direction is not more than four times the inner diameter of the cylinder, and the minimum value of the gap thickness is not more than 1/5 of the inner diameter of the cylinder. it can.

  By adopting such a configuration, it becomes possible to cause a cross-linking reaction uniformly to the polymer material by shearing heat generation, most effectively without applying heat from the outside. The length in the longitudinal direction of the cylinder is 2 to 4 times the inner diameter of the cylinder, and the minimum value of the thickness of the gap is 1/5 to 1/20 of the inner diameter of the cylinder. A crosslinking reaction can be effectively produced. More preferably, the length of the cylinder in the longitudinal direction is approximately three times the inner diameter of the cylinder, and the minimum value of the gap thickness is approximately 1/10 of the inner diameter of the cylinder. The cross-linking reaction can be caused most effectively.

  The polymer material temperature control device according to the present invention may further include an external heating / cooling device on the outer periphery of the cylinder.

  Thereby, it becomes possible to more effectively maintain the predetermined temperature optimum for the crosslinking reaction temperature of the polymer material. That is, for example, when the temperature exceeds the optimum temperature at which the polymer material is subjected to a crosslinking reaction, it is possible to maintain the optimum temperature by causing the external heating and cooling device to function as a cooling device.

  The polymer material temperature control device according to the present invention may further include an internal heating / cooling device inside the mandrel.

  As a result, for example, when the temperature required for the crosslinking reaction of the polymer material is exceeded, it becomes possible to maintain the internal heating / cooling device as a cooling device at a predetermined temperature optimum for the crosslinking reaction temperature. . Moreover, the temperature adjustment of the polymer material can be performed more accurately by using the above-described external heating / cooling device in combination.

According to the present invention, when molding is performed by cross-linking a polymer material, the polymer material does not stagnate in the flow path, and the temperature control device does not affect the cross-linking reaction time due to the thermal conductivity of the polymer material. The temperature can be controlled by applying a constant pressure and a uniform shearing force to the polymer material.

  Next, an embodiment of a temperature control device for a polymer material according to the present invention will be described based on the drawings.

  FIG. 1 is a side view showing a configuration of a temperature control device for a polymer material according to the present embodiment, and FIG. 2 is a cross-sectional view taken along line AA in FIG. As shown in FIG. 1, the temperature control device for a polymer material includes an extruder 11 having a screw 12, a cylinder 13 connected to the extruder 11, a cylinder 13, and a relative rotation with the cylinder 13. The configuration includes a mandrel 14, a non-rotating die mandrel 16, and a molding die 3. The non-rotating die mandrel 16 is connected and fixed to a support lot 23 penetrating the mandrel 14. As shown in FIG. 2, the cylinder 13 has a cylindrical cross section, and the included mandrel 14 has a cross section composed of a flat plane portion 30 and a circular arc surface portion 31 formed of a circular arc surface.

  The polymer material 7 extruded from the extruder 11 flows through a gap 32 formed between the inner surface of the cylinder 13 and the outer surface of the mandrel 14. At that time, since the mandrel 14 rotates relative to the cylinder 13, a shearing force is applied to the polymer material 7, thereby generating internal frictional heat and causing a crosslinking reaction.

  Here, the gap 32 is constant in the arcuate surface portion 31 as shown in FIG. That is, as shown in the figure, the value of the gap 32 is the smallest in the arcuate surface portion 31, and is the largest value at the center P in the axial width direction of the plane portion 30. As shown in FIG. 2, the arcuate surface portion 31 and the flat surface portion 30 are regularly configured, so that the polymer material 7 can be effectively kneaded, and as a result, a uniform shearing force is applied to achieve uniform properties. The formed product 7a can be formed. In this embodiment, a 6-plane configuration having 6 plane portions 30 and 6 arc surface portions 31 is used. However, the present invention is not limited to this. For example, 8 rows having 8 plane surfaces 30 and 8 arc surface portions 31 are provided. A planar configuration may be adopted.

  When the planar portion 30 and the arcuate surface portion 31 are viewed in the axial direction of the mandrel 13, they are each formed with a predetermined width and a predetermined twist angle α. The constant width means that the flat portion 30 and the arcuate surface portion 31 are regularly formed at a predetermined twist angle α not only in the cross section but also in the axial direction, as shown in FIG. α indicates a predetermined twist angle that does not generate a propulsive force in the present invention, and is set to 50 degrees in this embodiment. Even when the mandrel 14 is rotated by having such an uneven portion formed on the outer surface of the mandrel 14, no propulsive force is generated in the polymer material 7 by the rotating action of the mandrel 14, and the extruder is mainly used. The polymer material 7 can be pushed out by the driving force from 11. Therefore, the propulsive force to the polymer material 7 can be given without depending on the rotation speed of the mandrel 14, and the pressure in the cylinder 13 can be kept constant. The polymer material 7 subjected to the crosslinking reaction is extruded by the molding die 3 to become a molded product 7a.

  In this embodiment, the length L of the cylinder 13 in the longitudinal direction is three times the inner diameter D of the cylinder 13, and the minimum value of the gap 32 is 1/10 of the inner diameter D of the cylinder 13. By adopting such a configuration, it becomes possible to cause a cross-linking reaction uniformly to the polymer material by shearing heat generation, most effectively without applying heat from the outside.

  Next, an overall configuration of a polymer material molding apparatus including a polymer material temperature control apparatus according to the present invention will be described with reference to the drawings.

  FIG. 3 is a side view showing an overall configuration of a polymer material molding apparatus including a polymer material temperature control apparatus according to the present embodiment, and FIG. 4 is a cross-sectional view taken along line BB in FIG. In addition, the detailed description is abbreviate | omitted by attaching | subjecting the same number about the same component. As shown in FIG. 3, a polymer material molding apparatus including a polymer material temperature control device according to the present invention includes an extruder 11 having a screw 12, a cylinder 13 connected to the extruder 11, a mandrel 14, and a die. The configuration includes a mandrel 16 and a forming die 3.

  In the present embodiment, an outer jacket portion 17a corresponding to the outer heating / cooling device according to the present invention is provided on the outer periphery of the cylinder 13. Further, an inner jacket portion 17 b corresponding to the inner heating / cooling device according to the present invention is provided inside the mandrel 14. The outer jacket portion 17a is connected to the fluid circulation device 8 via the tube 8a, and the fluid circulation device 8 is connected to the inner jacket portion 17b via the tube 8b. The thermometer 19b provided in the cylinder 13 corresponding to the tip position of the mandrel 14 detects the temperature, and circulates a heating medium, a cooling medium, etc. in the outer jacket 17a and / or 17b as necessary, so that the polymer It becomes possible to keep the temperature of the material 7 at a temperature optimized for the crosslinking reaction. In addition, the thermometer can also be arrange | positioned also at the front-end | tip part of the extruder 11 (19a). Thereby, the temperature before and after the crosslinking reaction can be measured for the polymer material 7.

  The mandrel 14 is rotated relative to the cylinder 13 by the driving force of the driving source 10 being transmitted through the driving unit 9. The polymer material temperature control apparatus according to this embodiment can adjust the shearing force applied to the polymer material 7 by the rotational speed of the mandrel 14. When the mandrel 14 is rotated at a high speed, the shearing force applied to the polymer material 7 increases and the heat generation temperature also increases. Conversely, when the mandrel 14 is rotated at a low speed, the shearing force applied to the polymer material 7 is reduced and the heat generation temperature is also lowered. In the temperature control device for the polymer material according to the present embodiment, since the predetermined twist angle α is set to a gentle angle of 50 degrees, no propulsive force is given to the polymer material 7 by the rotation of the mandrel 14. The polymer material 7 can be propelled mainly by the pushing force of the extruder 11.

  The support rod 23 supports the non-rotating mandrel 16 and further has a hollow portion 15. Compressed air sucked from the joint 12 flows into the hollow portion 15 via the rotary joint 11. The compressed air is discharged from the tip of the forming die 3 so that the polymer material 7 is tube-formed. The temperature required for the crosslinking reaction of the polymer material 7 can be adjusted by adjusting the temperature of the compressed air.

  Next, the temperature control device for the polymer material according to the present embodiment will be described in comparison with a conventional extruder.

  7 and 8 are diagrams showing the configuration of an extruder conventionally used. As shown in FIG. 7, the conventional extruder includes a hopper 25, an extruder 11, a screw 12 of the extruder 11, a screw drive source 5 of the screw 12, and a molding die 3. In such a conventional extruder 11, in order to raise the temperature of the polymer material 7 to the reaction region and cause the polymer material 7 to undergo a crosslinking reaction, heat is applied from the outside, or heating after the extrusion is performed from the outside. I had to do it. However, the configuration in which heat is applied from the outside causes a problem that the polymer material 7 is stagnated on the wall surface of the flow path. When heated after extrusion, the polymer material has a low thermal conductivity, which requires a long time. The problem was caused.

FIG. 8 is a view showing the configuration of an extruder conventionally used with a gear pump. Compared with the extruder shown in FIG. 7, the extruder shown in FIG. 8 is different in configuration in that it includes a gear pump 4 at the tip of the extruder 11 and a drive source 6 of the gear pump 4 that drives the gear pump 4. In the extruder provided with the gear pump, the same problem as the extruder shown in FIG. 7 has occurred. In addition, the detailed description is abbreviate | omitted by attaching | subjecting the same number about the same component.

  On the other hand, FIG.5 and FIG.6 is a figure which shows schematic structure of the polymeric material shaping | molding apparatus provided with the temperature control apparatus of the polymeric material which concerns on a present Example. In addition, the detailed description is abbreviate | omitted by attaching | subjecting the same number about the same component. As shown in FIG. 5, a polymer material molding apparatus including a polymer material temperature control device according to this embodiment includes an extruder 11, a screw drive source 5 that drives a screw 12 of the extruder 11, and an extruder. 11 is provided with a temperature control device 2 for the polymer material connected to 11.

  As shown in FIG. 5, the polymer material temperature control apparatus according to the present example is connected to a conventional extruder to cause the polymer material 7 to crosslink and react with the channel wall surface. It is possible to solve the above-mentioned problems such as stagnation and a long time required for the crosslinking reaction. In other words, it is possible to use conventional equipment, and it can be said that it is very economical.

  FIG. 6 is a diagram showing a schematic configuration of a polymer material molding apparatus including a gear pump including the polymer material temperature control apparatus according to the present embodiment. As shown in FIG. The molecular material temperature control device can also be connected to an extruder equipped with a gear pump. In addition, the configuration including the gear pump 4 makes it possible to stably supply the polymer material 7 to the temperature controller 2 of the polymer material. As a result, the pressure during molding can be made more uniform, and a molded product 7a having excellent properties can be molded.

  As mentioned above, although preferred embodiment of this invention was described, the temperature control apparatus of the polymeric material which concerns on this invention can contain these combinations as much as possible not only in these.

It is a side view which shows the structure of the temperature control apparatus of the polymeric material which concerns on a present Example. It is AA sectional drawing in FIG. It is a side view which shows the whole polymer material shaping | molding apparatus provided with the temperature control apparatus of the polymeric material which concerns on a present Example. It is BB sectional drawing in FIG. It is a figure which shows schematic structure of the polymeric material shaping | molding apparatus provided with the temperature control apparatus of the polymeric material which concerns on a present Example. It is a figure which shows schematic structure of the polymeric material shaping | molding apparatus provided with the gear pump provided with the temperature control apparatus of the polymeric material which concerns on a present Example. It is a figure which shows the structure of the extruder used conventionally. It is a figure which shows the structure of the extruder provided with the gear pump conventionally used.

Explanation of symbols

2 ... temperature control device 3 of polymer material 3 ... molding die 4 ... gear pump 5, 10 ... drive source 7 ... polymer material 7a ... molded product 8 ... circulation device 8a 8b: tube 9 ... rotating mandrel drive unit 11 ... extruder 12 ... screw 13 ... cylinder 14 ... mandrel 15 ... hollow part 16 ... die mandrel 17a .... Outer jacket 17b ... Inner jacket 23 ... Die mandrel support rod 25 ... Hopper 30 ... Flat part 31 ... Arc surface part 32 ... Gap

Claims (5)

An apparatus connected to an extruder that melts and extrudes the polymer material, and controls the temperature of the polymer material extruded from the extruder,
A cylinder connected to the extruder;
A mandrel enclosed in the cylinder and rotating relative to the cylinder, the mandrel having an uneven surface formed on an outer surface in a cross section perpendicular to the axial direction;
The mandrel has, as the concavo-convex portion, a flat portion made of a flat surface and an arc surface portion made of an arc surface,
A gap through which the polymer material flows is formed between the inner surface of the cylinder and the outer surface of the mandrel,
In the gap, regions having a large thickness formed between the planar portion and the inner surface of the cylinder and regions having a small thickness formed between the arcuate surface portion and the inner surface of the cylinder are alternately formed. And
The shape of the concavo-convex portion is represented by a predetermined twist angle that is a small angle with the direction perpendicular to the axis and the driving force in the axial direction,
The temperature control device for a polymer material, wherein the predetermined twist angle is a value larger than 40 degrees and smaller than 90 degrees. The region where the thickness is large is a displacement thickness portion where the distance from the inner surface of the cylinder is displaced in a cross section perpendicular to the axial direction,
2. The temperature control device for a polymer material according to claim 1, wherein the region having a small thickness is a constant thickness portion having a constant distance from the inner surface of the cylinder in a cross section perpendicular to the axial direction. The length in the longitudinal direction of the cylinder is not more than 4 times the inner diameter of the cylinder,
3. The temperature control device for a polymer material according to claim 1, wherein a minimum value of the thickness of the gap is 1/5 or less of an inner diameter of the cylinder.   The temperature control device for a polymer material according to any one of claims 1 to 3, further comprising an external heating and cooling device on an outer periphery of the cylinder.   The temperature control device for a polymer material according to any one of claims 1 to 4, further comprising an internal heating / cooling device inside the mandrel.

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