JP6039845B1 - Inflation film forming die - Google Patents

Abstract

To provide a die for forming an inflation film that can suppress an increase in weight without increasing an outer diameter even when the number of branches of a molten synthetic resin increases. An inflation film forming die 2 includes a plurality of plates 21, 22, 23 that are stacked in the axial direction, and branch portions are internal passages 21 a, 21 b that extend in the axial direction inside the plates 21, 22. , 22c, 22d and a pair of branch passages 72, 75, 82, 85 that are formed on the mating surfaces of the adjacent plates 21, 22, 23 and branch off from the end in the pushing direction of the internal passages 21a, 21b, 22c, 22d, And a plurality of branch portions are provided continuously in the axial direction. [Selection] Figure 2

Description

  The present invention relates to a die which is installed at the tip of an extruder of an inflation film manufacturing apparatus for forming a synthetic resin film and extrudes a molten synthetic resin into a tube shape.

  In the production of the inflation film, first, the molten synthetic resin is supplied from the extruder to the supply port of the die, and the molten synthetic resin is continuously extruded into a tube shape from the annular discharge port of the cylindrical die. And after injecting a certain amount of air into this tube and expanding it to a desired size, the tube is generally cooled and solidified with cooling air from the outside to form a tube-like film ( For example, see Patent Document 1). According to Patent Document 1, the die is formed in a cylindrical shape, and the molten synthetic resin is branched on one plane orthogonal to the axial direction, and the molten synthetic resin is dispersed on another plane. The passages of the branching portions are all formed in the same plane, and are branched in multiples every time one, two, four, or eight branches.

JP-A-11-254503

  However, in the die described in Patent Document 1, since all the passages of the branching portion are in the same plane, the outer diameter of the die increases as the number of branches increases. Since the weight of the die is proportional to the square of the outer diameter, there is a problem that the weight of the die is increased compared to the number of branches.

  The present invention has been made in view of the above problems, and an inflation film molding die that can suppress an increase in weight without increasing the outer diameter even when the number of branches of the molten synthetic resin increases. The purpose is to provide.

  In order to achieve the above object, in the present invention, a molten synthetic resin supply port, a branch portion for branching the molten synthetic resin supplied from the supply port, and the molten synthetic resin branched at the branch portion are provided. A die for forming an inflation film, comprising: a dispersion part that is dispersed in a cylindrical shape; and an annular discharge port that extrudes the molten synthetic resin dispersed in the dispersion part as a tube-like film. A plurality of plates, and the branching portion is formed in an axial passage extending in the axial direction inside the plate and a pair of branches formed from a mating surface of the adjacent plates and branching from an end portion in the extrusion direction of the axial passage. There is provided an inflation film forming die in which a plurality of the branch portions are provided continuously in the axial direction.

  According to the die for forming an inflation film of the present invention, an increase in weight can be suppressed without increasing the outer diameter even when the number of branches of the molten synthetic resin increases.

FIG. 1 is a schematic configuration diagram of an inflation film manufacturing apparatus showing an embodiment of the present invention. FIG. 2 is a schematic cross-sectional explanatory view of an inflation film forming die showing an embodiment of the present invention. FIG. 3 is a cross-sectional view taken along the line AA of FIG. 4 is a cross-sectional view taken along line BB in FIG. FIG. 5 is a CC circumferential development sectional view of FIG. 6 is a cross-sectional view taken along the line DD of FIG.

  1 to 6 show an embodiment of the present invention, FIG. 1 is a schematic configuration diagram of an inflation film manufacturing apparatus, and FIG. 2 is a schematic sectional explanatory view of an inflation film forming die showing an embodiment of the present invention. 3 is a sectional view taken along the line AA in FIG. 2, FIG. 4 is a sectional view taken along the line BB in FIG. 2, FIG. 5 is a sectional view taken along the line CC in FIG. is there. In FIG. 2, the melted synthetic resin supply port and each branch passage are shown in one cross-sectional view for easy understanding, but FIG. 2 is only an explanatory diagram, and each branch passage of the present embodiment is shown in FIG. In the arrangement state, they do not appear in the same cross section.

  As shown in FIG. 1, in the inflation film manufacturing apparatus 100, the first molten synthetic resin 31 (see FIG. 2) and the second molten synthetic resin 32 supplied to the die 2 from the first extruder 11 and the second extruder 12. (See FIG. 2) is extruded in a tube shape from the annular discharge port 2a (see FIG. 2). The extruded first molten synthetic resin 31 and second molten synthetic resin 32 are cooled and solidified by cooling air supplied from a blower (not shown) and blown out from the air ring 4 to form a synthetic resin tube 33. The synthetic resin tube 33 is taken up by the pinch roll 5 and taken up by the winder 6. The die 2 of the present embodiment is configured such that an increase in weight can be suppressed without increasing the outer diameter even when the number of branches of the first molten synthetic resin 31 and the second molten synthetic resin 32 increases. ing.

  As shown in FIG. 2, the die 2 has a cooling passage 2b formed therein, and is formed in a substantially cylindrical shape with the vertical direction as the central axis. The die 2 has a first plate 21, a second plate 22, and a third plate 23 stacked in the axial direction on the lower end side. The first plate 21, the second plate 22, and the third plate 23 are arranged in this order from the lower end side. The die 2 includes a first mandrel 24, a second mandrel 25, and an outer cylinder 26 that are disposed on the upper side of the third plate 23 at intervals in the radial direction. The first mandrel 24, the second mandrel 25, and the outer cylinder 26 are arranged in this order from the inside. Furthermore, the die 2 has a mandrel tip 27 disposed on the upper side of the first mandrel 24 and an adjustment ring 28 disposed on the upper side of the outer cylinder 26. The mandrel tip 27 and the adjustment ring 28 are spaced apart from each other in the radial direction, and the upper end of these gaps forms the aforementioned discharge port 2a.

  The first plate 21 is formed in a plate shape, the first supply port 70 and the second supply port 80 of the first molten synthetic resin 31 and the second molten synthetic resin 32 formed on the outer peripheral surface, the first supply port 70 and A first outlet 71 and a second outlet 81 formed on the upper surface in communication with the second supply port 80, a first supply port 70 and a second supply port 80, a first outlet 71 and a second outlet 81, And a first internal passage 21a and a second internal passage 21b. The first internal passage 21a and the second internal passage 21b extend inward in the radial direction from the first supply port 70 and the second supply port 80 by a predetermined interval, and then toward the first outlet 71 and the second outlet 81. Turn upward. In the present embodiment, the first supply port 70 and the second supply port 80 are formed on opposite sides with respect to the axial center. Moreover, the 1st outflow port 71 and the 2nd outflow port 81 are formed in the radial direction about the 1st outflow port 71 outside, and the 2nd outflow port 81 is formed inside.

  A plate-like second plate 22 is overlaid on the upper surface of the first plate 21. As shown in FIG. 3, a pair of first outlets 71 and second outlets 81 are formed continuously on the mating surfaces of the first plate 21 and the second plate 22 and extend in opposite directions with respect to the circumferential direction. First branch passage 72 and second branch passage 82 are formed. Thereby, the 1st molten synthetic resin 31 and the 2nd molten synthetic resin 32 which flowed out from the 1st outflow port 71 and the 2nd outflow port 81 are branched in the circumferential direction symmetrically, and in each 1st branch passage 72 and The flow in each second branch passage 82 is symmetric. The first branch passages 72 and the second branch passages 82 are formed on the first upper surface groove 21 c and the second upper surface groove 21 d formed on the upper surface of the first plate 21 and on the lower surface of the second plate 22. It is defined by the first lower surface groove 22a and the second lower surface groove 22b. The first branch passages 72 and the second branch passages 82 are respectively connected to the first inlet 73 and the second second outlet of the second plate 22 from the first outlet 71 and the second outlet 81 of the first plate 21, respectively. Inlet 83 is connected.

  The second plate 22 includes two first inlets 73 and second inlets 83 formed on the lower surface, two third outlets 74 and fourth outlets 84 formed on the upper surface, There are two third internal passages 22c and four internal passages 22d that connect the one inlet 73 and each second inlet 83 to each third outlet 74 and each fourth outlet 84. As shown in FIG. 2, each 3rd internal channel | path 22c and each 4th internal channel | path 22d are each extended in an up-down direction. In the present embodiment, the first inlet 73 and the second inlet 83 are formed such that the first inlet 73 is formed outside and the second inlet 83 is formed inside in the radial direction. In the present embodiment, the third outlet 74 and the fourth outlet 84 are formed such that the third outlet 74 is formed outside and the fourth outlet 84 is formed inside in the radial direction.

  A plate-like third plate 23 is overlaid on the upper surface of the second plate 22. As shown in FIG. 4, on the mating surface of the second plate 22 and the third plate 23, each third outlet 74 and each fourth outlet 84, each third outlet 74 and each fourth outlet 84 are provided. A pair of third branch passages 75 and fourth branch passages 85 that are formed continuously with 84 and extend in the circumferential direction are formed. That is, each of the third branch passages 75 and the fourth branch passages 85 is formed for each of the two third outlets 74 and the fourth outlets 84, that is, a total of four. As a result, the first molten synthetic resin 31 and the second molten synthetic resin 32 that have flowed out from the third outlets 74 and the fourth outlets 84 are branched symmetrically in the circumferential direction, and the third branch passages 75 are separated. The flow in the inner and each fourth branch passage 85 is symmetric. The third branch passages 75 and the fourth branch passages 85 are formed on the lower surface of the third plate 23 and the third upper surface groove 22e and the fourth upper surface groove 22f formed on the upper surface of the second plate 22, respectively. It is defined by the third lower surface groove 23a and the fourth lower surface groove 23b. The third branch passages 75 and the fourth branch passages 85 are respectively connected to the third inlets 76 and the fourth outlets of the third plate 23 from the third outlets 74 and 84 of the second plate 22, respectively. 4 inlet 86 is connected.

  The third plate 23 has four third inlets 76 and fourth inlets 86 formed on the lower surface, and four fifth outlets 77 (see FIG. 5) and sixth outlets formed on the upper surface. (Not shown), a fifth internal passage 23c and a sixth internal passage 23d that connect each third inlet 76 and each fourth inlet 86 to each fifth outlet 77 and each sixth outlet, Have As shown in FIG. 2, each of the fifth internal passages 23c and each of the sixth internal passages 23d extends in the vertical direction. In the present embodiment, the third inlet 76 and the fourth inlet 86 are formed such that the third inlet 76 is formed outside and the fourth inlet 86 is formed inside in the radial direction. In the present embodiment, the fifth outflow port 77 and the sixth outflow port are formed such that the fifth outflow port 77 is formed outside and the sixth outflow port is formed inside in the radial direction. The fifth outlets 77 and the sixth outlets are arranged at equal intervals in the circumferential direction.

  In the present embodiment, the upper side of the first internal passage 21 a and the second internal passage 21 b of the first plate 21 forms an axial passage extending in the axial direction, and is formed on the mating surface of the first plate 21 and the second plate 22. Each of the first branch passages 72 and each of the second branch passages 82 form a pair of branch passages that branch from the end of the axial passage in the extrusion direction, and these are the first melt synthetic resin 31 and the second melt synthetic resin 32. 1 branching portion. Further, the third internal passage 22c and the fourth internal passage 22d of the second plate 22 form an axial passage extending in the axial direction, and each third branch passage formed on the mating surface of the second plate 22 and the third plate 23. 75 and each of the fourth branch passages 85 form a pair of branch passages that branch from the end portion of the axial passage in the extrusion direction, and these form a second branch portion of the first molten synthetic resin 31 and the second molten synthetic resin 32. ing. Since the first molten synthetic resin 31 and the second molten synthetic resin 32 are branched by two at each branch portion, by providing the first branch portion and the second branch portion continuously in the axial direction. Finally, it is branched into four. In addition, when the first molten synthetic resin 31 and the second molten synthetic resin 32 are branched into eight, it is only necessary to stack another plate similar to the second plate 22, and when the first molten synthetic resin 31 and the second molten synthetic resin 32 are branched into 16 You just need to stack. Thus, each time one plate is stacked, the number of branches of the first molten synthetic resin 31 and the second molten synthetic resin 32 increases by two, but since the outer diameter of the plate is the same, the weight of the die 2 increases. Can be minimized. In other words, the outer diameter of the die 2 is increased and the weight does not increase dramatically like the one that repeats branching in the same plane.

  In the present embodiment, the first branch passage 72 and the third branch passage 75 of the first molten synthetic resin 31 have the same radial distance from the axial center, and the second branch passage 82 and the second branch passage 82 of the second molten synthetic resin 32 are the same. The four branch passages 85 have the same radial distance from the axial center. As described above, for each of the molten synthetic resins 31 and 32, the fixing bolts for integrating the respective members (not shown) and the molten synthetic resins 31 and 32 are integrated by equalizing the radial distances from the axial centers of the plurality of branch passages. A design that does not interfere with the flow paths can be easily performed, and the outer diameter can be minimized. Here, this effect can be obtained without making the radial distance from the axial center of each branch passage exactly equal. For example, the difference in radial distance is within 30 mm, and 10 mm with respect to the discharge port diameter of the die 2. If it is within%, it can be said that the radial distance is substantially equal.

  As shown in FIG. 2, the upper surface of the third plate 23 extends in the radial direction and contacts the first mandrel 24, the second mandrel 25, and the lower end of the outer cylinder 26. A first concave portion 23e, a second concave portion 23f, and a third concave portion 23g for positioning are formed on the upper surface of the third plate 23. The first convex portion 24d and the second mandrel formed at the lower end of the first mandrel 24, respectively. The second convex portion 25g formed at the lower end of 25 and the third convex portion 26c formed at the lower end of the outer cylinder 26 are received. In this embodiment, each recessed part 23e, 23f, 23g and each convex part 24d, 25g, 26c have comprised the fitting part. Moreover, in this embodiment, each recessed part 23e, 23f, 23g and each convex part 24d, 25g, 26c are each formed in the cyclic | annular form continuous in the circumferential direction. The concave portions 23e, 23f, 23g and the convex portions 24d, 25g, 26c may be formed at predetermined intervals in the circumferential direction, or the first mandrel 24, the second mandrel 25, and the outer cylinder 26 positioning mechanism. Can be configured in other ways. Further, the third plate 23 and at least one of the first mandrel 24, the second mandrel 25, and the outer cylinder 26 can be integrally formed.

  The first mandrel 24, the second mandrel 25, and the outer cylinder 26 are each formed in a cylindrical shape, and a cylindrical first shaft is formed by the second outer peripheral surface 25b of the second mandrel 25 and the second inner peripheral surface 26a of the outer cylinder 26. A directional passage 78 is formed, and a cylindrical second axial passage 88 is formed by the first outer peripheral surface 24 a of the first mandrel 24 and the first inner peripheral surface 25 a of the second mandrel 25. The distance L between the second outer peripheral surface 25b of the second mandrel 25 and the second inner peripheral surface 26a of the outer cylinder 26 is the smallest at the lower end, and the first inner surface 24a of the first mandrel 24 and the first inner surface of the second mandrel 25 are the first. The lower end of the distance from the peripheral surface 25a is the smallest. That is, the lower end of the radial distance between the first axial passage 78 and the second axial passage 88 is the smallest. The upper surface 25c of the second mandrel 25 is inclined upward toward the radially outer side. The upper surface of the third plate 23 closes one end of the first axial passage 78 and the second axial passage 88, but the first molten synthetic resin 31 and the second molten synthetic resin 32 are provided in each fifth flow of the third plate 23. It flows into the first axial passage 78 and the second axial passage 88 through the outlet 77 and the sixth outlets. Here, the 1st mandrel 24, the 2nd mandrel 25, and the outer cylinder 26 do not have a fitting part in the 1st axial direction channel | path 78 and the 2nd axial direction channel | path 88, and those vicinity.

  As shown in FIG. 2, a first end surface extending along the upper surface of the third plate 23 is formed at the lower end of the second inner peripheral surface 26 a of the outer cylinder 26 and the lower end of the first inner peripheral surface 25 a of the second mandrel 25. A groove 26b and a second end face groove 25d are formed. The first end face groove 26b and the second end face groove 25d widen the lower ends of the first axial passage 78 and the second axial passage 88 in the radial direction. As shown in FIG. 6, the first end surface groove 26 b and the second end surface groove 25 d are formed deepest immediately above the fifth outlet port 77 and the sixth outlet port, respectively, in the bottom view. It gradually becomes shallower toward the fifth outlet 77 and the sixth outlet adjacent to the side.

  On the other hand, as shown in FIG. 5, the first upper and lower grooves 25e extending upward from the lower end by a predetermined distance on the second outer peripheral surface 25b of the second mandrel 25 and the first outer peripheral surface 24a of the first mandrel 24, respectively. The second upper and lower grooves 24b and the first spiral grooves 25f and the second spiral grooves 24c that spirally extend from the upper ends of the first upper and lower grooves 25e and 24b to the other circumferential side while being inclined upward are formed. . In the present embodiment, a total of four first vertical grooves 25e and second vertical grooves 24b are formed immediately above the fifth outlets 77 and the sixth outlets. Also, a total of four first spiral grooves 25f and second spiral grooves 24c that are continuous with the first upper and lower grooves 25e and the second upper and lower grooves 24b are formed. Each first upper and lower groove 25e and each second upper and lower groove 24b are formed with a constant depth in the vertical direction. Further, as shown in FIGS. 5 and 6, the first spiral groove 25f and the second spiral groove 24c are deepest directly above the first upper and lower grooves 25e and the second upper and lower grooves 24b, respectively, in the bottom view. Formed and gradually shallower toward the other side in the circumferential direction.

  As shown in FIG. 2, the mandrel tip 27 has a cylindrical bottom axial direction together with a lower inclined surface 27 a that defines a communication passage 89 together with an upper surface 25 c of the second mandrel 25 and a third inner peripheral surface 28 a of the adjustment ring 28. And a third outer peripheral surface 27b forming the passage 2c. The communication passage 89 is formed continuously with the second axial passage 88, and the communication passage 89 and the first axial passage 78 merge below the final axial passage 2c. The upper end of the final axial passage 2c forms the aforementioned discharge port 2a.

The flow of the first molten synthetic resin 31 and the second molten synthetic resin 32 in the die 2 configured as described above will be described.
The first molten synthetic resin 31 and the second molten synthetic resin 32 are supplied from the first extruder 11 and the second extruder 12 to the first supply port 70 and the second supply port 80 of the first plate 21. The first molten synthetic resin 31 and the second molten synthetic resin 32 supplied to the first supply port 70 and the second supply port 80 flow radially inward through the first internal passage 21a and the second internal passage 21b. After that, it flows upward and reaches the first outlet 71 and the second outlet 81 of the first plate 21.

  The first molten synthetic resin 31 and the second molten synthetic resin 32 that have reached the first outlet 71 and the second outlet 81 of the first plate 21 are respectively a pair of first branch passages 72 and a pair of second branch passages. 82 is shunted. Here, the first branch passages 72 and the second branch passages 82 are symmetrical with respect to the flow directions of the first molten synthetic resin 31 and the second molten synthetic resin 32 flowing out from the first outlet 71 and the second outlet 81. Therefore, the flow in each first branch passage 72 and each second branch passage 82 is symmetrical. The divided first molten synthetic resin 31 and second molten synthetic resin 32 flow in the circumferential direction through the first branch passages 72 and the second branch passages 82, and each of the two first outlets 73 of the second plate 22. And reaches the second outlet 83. Thereafter, the first molten synthetic resin 31 and the second molten synthetic resin 32 flow upward through the third internal passages 22c and the fourth internal passages 22d of the second plate 22, respectively. The third outlet 74 and the fourth outlet 84 are reached.

  The first molten synthetic resin 31 and the second molten synthetic resin 32 that have reached the third outlets 74 and the fourth outlets 84 of the second plate 22 are further divided into a pair of third branch passages 75 and a pair of second outlets, respectively. The current is diverted to the four branch passages 85. Also here, each 3rd branch passage 75 and each 4th branch passage 85 are about the flow direction of the 1st molten synthetic resin 31 and the 2nd molten synthetic resin 32 which flow out from each 3rd outflow port 74 and the 4th outflow port 84. Since it is formed symmetrically, the flow in each third branch passage 75 and each fourth branch passage 85 is symmetrical. The divided first molten synthetic resin 31 and second molten synthetic resin 32 flow in the circumferential direction through each third branch passage 75 and each fourth branch passage 85, and each of the four third inflow ports 76 of the third plate 23. And the fourth inlet 86 is reached. Thereafter, the first molten synthetic resin 31 and the second molten synthetic resin 32 flow upward through the fifth internal passages 23 c and the sixth internal passages 23 d of the third plate 23, Reach the fifth outlet 77 and the sixth outlet. The flow rates of the first molten synthetic resin 31 and the second molten synthetic resin 32 at the four fifth outlets 77 and the sixth outlets are the same because they have been branched symmetrically at the respective branch portions.

  The first molten synthetic resin 31 and the second molten synthetic resin 32 that have reached the fifth outlet 77 and the sixth outlet 87 of the third plate 23 are respectively a first axial passage 78 and a second axial passage 88. Enter. The first molten synthetic resin 31 and the second molten synthetic resin 32 that have entered the first axial passage 78 and the second axial passage 88 are divided into the first end surface groove 26b side and the second end surface groove 25d side, and the first upper and lower grooves. The current is divided into the 25e side and the second vertical groove 24b side.

  As shown in FIG. 5, the first molten synthetic resin 31 and the second molten synthetic resin 32 that are divided into the first end face groove 26b side and the second end face groove 25d side further flow in the circumferential direction in the groove. The first end face groove main flow 78a and the second end face groove main flow (not shown) leak from the groove toward the second inner peripheral surface 26a side of the outer cylinder 26 and the first inner peripheral surface 25a side of the second mandrel 25. The first end face groove leakage flow 78b and the second end face groove leakage flow (not shown) are divided. Since the first end face groove 26b and the second end face groove 25d are formed deepest immediately above the fifth outlets 77 and the sixth outlets, they flow out from the fifth outlets 77 and the sixth outlets. Immediately after that, most of the first molten synthetic resin 31 and the second molten synthetic resin 32 are the first end face groove main flow 78a and the second end face groove main flow. However, since the first end face groove 26b and the second end face groove 25d gradually become shallower in the circumferential direction, the first end face groove leakage flow becomes closer to the adjacent fifth outlets 77 and sixth outlets. 78b and the second end face groove leakage flow gradually leak from the first end face groove 26b and the second end face groove 25d, and finally almost become the first end face groove leakage flow 78b and the second end face groove leakage flow. .

  The first molten synthetic resin 31 and the second molten synthetic resin 32 that are divided into the first vertical groove 25e side and the second vertical groove 24b side flow upward in the groove, and then the first spiral groove 25f and It enters the second spiral groove 24c. The first molten synthetic resin 31 and the second molten synthetic resin 32 that have entered the first spiral groove 25f and the second spiral groove 24c flow through the groove toward the other circumferential direction in the first spiral groove main flow 78c and the second spiral groove main flow. (Not shown) and the first spiral groove leakage flow 78d and the second spiral groove leakage leaking from the groove to the second outer peripheral surface 25b side of the second mandrel 25 and the first outer peripheral surface 24a side of the first mandrel 24. A stream (not shown) is split. Since the first spiral groove 25f and the second spiral groove 24c are formed deepest on the first upper and lower grooves 25e side and the second upper and lower groove 24b side, the first spiral groove 25f and the second spiral groove 24c are immediately after entering the first spiral groove 25f and the second spiral groove 24c. Most of the first molten synthetic resin 31 and the second molten synthetic resin 32 are the first spiral groove main stream 78c and the second spiral groove main stream. However, since the first spiral groove 25f and the second spiral groove 24c gradually become shallower in the other circumferential direction, the first spiral groove leakage flow 78d and the second spiral groove leakage flow gradually become first as they move upward. It leaks out from the spiral groove 25f and the second spiral groove 24c, and finally all become the first spiral groove leakage flow 78d and the second spiral groove leakage flow.

  As described above, the first molten synthetic resin 31 and the second molten synthetic resin 32 that have entered the first axial passage 78 and the second axial passage 88 have the first end face groove leakage flow 78b and the second end face in the passage. The groove leakage flow, the first spiral groove leakage flow 78d, and the second spiral groove leakage flow are evenly dispersed. The second molten synthetic resin 32 in the second axial passage 88 enters the final axial passage 2c and joins the first molten synthetic resin 31 in the first axial passage 78 directly via the communication passage 89. . The first molten synthetic resin 31 and the second molten synthetic resin 32 that are evenly distributed in the circumferential direction in the final axial passage 2 c are extruded from the discharge port 2 a of the die 2 in a tube shape.

  According to the die 2 configured as described above, the first mandrel 24, the second mandrel 25 and the outer cylinder 26 forming the first axial passage 78 and the second axial passage 88 are not fitted to each other. The first molten synthetic resin 31 and the second molten synthetic resin 32 do not stay in the fitting portion, and deteriorated components are mixed in the first molten synthetic resin 31 and the second molten synthetic resin 32 pushed out from the discharge port 2a. There is nothing. In addition, since the first end surface groove 26b and the second end surface groove 25d are formed on the inner peripheral surface 26a of the outer cylinder 26 and the inner peripheral surface 25a of the second mandrel 25, the first molten synthetic resin 31 and the second molten synthetic resin are formed. Therefore, the stagnation of the first molten synthetic resin 31 and the second molten synthetic resin 32 on the inflow side of the first axial passage 78 and the second axial passage 88 that are relatively likely to be retained can be accurately suppressed. The formation of the first end face groove 26b and the second end face groove 25d is extremely effective when the inflow side of the first axial passage 78 and the second axial passage 88 is narrow as in this embodiment.

  Further, since each end face groove main flow 78a and each spiral groove main flow 78c are directed to opposite sides in the circumferential direction, the first molten synthetic resin 31 and the second molten synthetic resin 32 can be effectively dispersed. Further, since the spiral grooves 24c and 25f are formed via the upper and lower grooves 24b and 25e, the flow of the first molten synthetic resin 31 and the second molten synthetic resin 32 at the lower ends of the axial passages 78 and 88 is caused. Become stable.

  Further, the branched portions of the first molten synthetic resin 31 and the second molten synthetic resin 32 are divided into respective internal passages 21a, 21b, 22c, 22d extending in the axial direction, and a pair of branched passages 72, 75, branched in the radial direction. 82 and 85, and the branch portion is continuously provided in the axial direction, so that the first molten synthetic resin 31 and the second molten synthetic resin 32 can be branched without increasing the outer diameter of the die 2. The die 2 does not increase in weight. Further, since each branch passage 72, 75, 82, 85 is formed on the mating surface of each plate 21, 22, 23, each branch passage 72, 75, 82, 85 can be formed easily and easily. Can do. Moreover, what is necessary is just to change the number of plates according to the number of branches of the 1st molten synthetic resin 31 and the 2nd molten synthetic resin 32, and the design freedom of a branch part improves.

  In the above embodiment, the two axial passages of the first axial passage 78 and the second axial passage 88 are formed. However, the number of the axial passages may be one, or 3 It may be the above. That is, in the above-described embodiment, the three members of the first mandrel 24, the second mandrel 25, and the outer cylinder 26 are arranged as cylindrical members, but the number of cylindrical members can be arbitrarily changed.

  Moreover, in the said embodiment, although each end surface groove | channel 25d, 26b was formed in the internal peripheral surface 25a, 26a of the member of the outer side of each axial direction passage 78, 88, the member of the inner side of an axial direction passage was shown. It may be formed on the outer peripheral surface, or may be formed on both the inner peripheral surface of the outer member and the outer peripheral surface of the inner member.

  On the other hand, in the above embodiment, the spiral grooves 24c and 25f are formed in the first outer peripheral surface 24a and the second outer peripheral surface 25b of the members inside the axial passages 78 and 88, respectively. It may be formed on the inner peripheral surface of the outer member, or may be formed on both the inner peripheral surface of the outer member and the outer peripheral surface of the inner member. Moreover, in the said embodiment, although the lower end of each spiral groove 24c, 25f showed what was continued with the upper end of each upper and lower groove 24b, 25e, for example, it forms a spiral groove continuously with the circumferential groove | channel. Alternatively, the spiral groove may be formed directly from the lower end of the axial passage without being continuous with other grooves such as upper and lower grooves and circumferential grooves.

  Moreover, in the said embodiment, what formed two branch parts with three plates, the 1st plate 21, the 2nd plate 22, and the 3rd plate 23 was shown, However, Three or more branch parts are formed with four or more plates. May be formed.

  While the embodiments of the present invention have been described above, the embodiments described above do not limit the invention according to the claims. In addition, it should be noted that not all the combinations of features described in the embodiments are essential to the means for solving the problems of the invention.

2 Die 2a Discharge port 2b Cooling passage 2c Final axial passage 4 Air ring 5 Pinch roll 6 Winder 11 First extruder 12 Second extruder 21 First plate 21a First internal passage 21b Second internal passage 21c First 1 upper surface groove 21d second upper surface groove 22 second plate 22a first lower surface groove 22b second lower surface groove 22c third internal passage 22d fourth internal passage 22e third upper surface groove 22f fourth upper surface groove 23 third plate 23a third lower surface Groove 23b Fourth lower surface groove 23c Fifth internal passage 23d Sixth internal passage 24 First mandrel 24a First outer peripheral surface 24b First upper and lower groove 24c First spiral groove 25 Second mandrel 25a First inner peripheral surface 25b Second outer peripheral surface 25c upper surface 25d second Tanmenmizo 25e second vertical groove 25f second helical groove 26 the outer cylinder 26a second inner peripheral surface 26b first Tanmenmizo 2 Mandrel tip 27a Lower inclined surface 28 Adjustment ring 28a Third inner peripheral surface 31 First molten synthetic resin 32 Second molten synthetic resin 33 Synthetic resin 70 First supply port 71 First outlet port 72 First branch passage 73 First inlet port 74 Third outlet 75 Third branch passage 76 Third inlet 77 Fifth outlet 78 First axial passage 78a First end groove main flow 78b First end groove leakage flow 78c First spiral groove main flow 78d First spiral groove Leakage flow 89 Connecting passage 80 Second supply port 81 Second outlet 82 Second branch passage 83 Second inlet 84 Fourth outlet 85 Fourth branch passage 86 Fourth inlet 88 Second axial passage 100 Inflation film production Device L Distance

Claims (3)

A molten synthetic resin supply port;
A branch part for branching the molten synthetic resin supplied from the supply port;
A dispersion part for dispersing the molten synthetic resin branched at the branch part in a cylindrical shape with the vertical direction as an axial direction ;
An inflation film forming die comprising: an annular discharge port for extruding the molten synthetic resin dispersed in the dispersion part as a tubular film,
It has a plurality of plates stacked in the vertical direction ,
The branch portion includes a plate axial passage extending in the vertical direction in the interior of the plate, it is formed on the mating surface of the adjacent said plate pair of branch passages branching from the extrusion direction end portion of the plate axial passage And having
A plurality of the branch portions are provided continuously in the vertical direction ,
The dispersion portion has at least one cylindrical axial passage in a cylindrical shape through which the molten synthetic resin flows,
The cylindrical axial passage is formed between the outer peripheral surface of the inner member and the inner peripheral surface of the outer member,
The lower ends of the inner member and the outer member are in contact with the upper surface of the uppermost plate of the plurality of plates,
On the upper surface of the uppermost plate, an outlet for allowing the molten synthetic resin branched at the branching portion to flow into the cylindrical axial passage is formed,
The dispersion portion has an end surface groove formed along the upper surface at the lower end of at least one of the outer peripheral surface of the inner member and the inner peripheral surface of the outer member;
The end face groove is a die for forming an inflation film that is deepest directly above the outlet and shallows from immediately above the outlet toward one circumferential direction . The dispersion portion has a spiral groove formed in a spiral shape on at least one of the outer peripheral surface of the inner member and the inner peripheral surface of the outer member,
The inflation film forming die according to claim 1, wherein the spiral groove extends in the other circumferential direction. The dispersing portion has an upper and lower groove extending upward by a predetermined distance from at least one lower end of the outer peripheral surface of the inner member and the inner peripheral surface of the outer member,
The inflation film forming die according to claim 2, wherein the spiral groove extends from the upper end of the upper and lower grooves to the other circumferential direction.

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