Inflation molding apparatus and inflation molding method
The inflation molding apparatus and method address the issue of air pockets in folded films by using a degassing roll and inclination changing roll to create holes or cuts, ensuring automatic suppression and elimination of air pockets, stabilizing the molding process.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- SUMITOMO HEAVY INDS MODERN
- Filing Date
- 2024-12-10
- Publication Date
- 2026-06-22
AI Technical Summary
Inflation-molded cylindrical films often form air pockets when folded between pinch rolls, necessitating manual intervention to eliminate them, which is undesirable in automated processes.
An inflation molding apparatus and method that incorporates a degassing roll positioned near pinch rolls to create holes or cuts in the film, allowing trapped air to escape, and an inclination changing roll to further process the film, ensuring air pockets are automatically suppressed or eliminated.
Automatically prevents and eliminates air pockets in folded films, stabilizing the molding process and eliminating the need for manual intervention.
Smart Images
Figure 2026100906000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an inflation molding apparatus and an inflation molding method.
Background Art
[0002] There is known a technique of inflation molding in which air is sent toward a molten resin extruded in a cylindrical shape to form a film as a product (for example, Patent Document 1). In inflation molding, air is sent into the inner surface side of the molten resin extruded in a cylindrical shape, and it is made into a state called a bubble by expanding it into a thin film cylinder shape, and a cylindrical film is formed by blowing air against the outer surface of the bubble to cool it. The cylindrical film is conveyed and wound up while being folded by being sandwiched between a pair of pinch rolls.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] When folding an inflation-molded cylindrical film by sandwiching it between a pair of pinch rolls, unintended air may enter between the films, and a portion called an air pocket may be formed. Air pockets are likely to occur at the setup stage when the cylindrical film is first sandwiched between a pair of pinch rolls. Conventionally, when an air pocket occurs, an operator has performed operations such as making a cut in the film using a cutting tool such as a cutter. On the other hand, with the automation of inflation molding, there is a desire to automate the operation of suppressing the generation of air pockets or eliminating the generated air pockets.
[0005] The object of the present invention is to enable the automatic suppression or elimination of air pockets that may occur when an inflation-molded cylindrical film is folded. [Means for solving the problem]
[0006] The inflation molding apparatus of the present invention, completed with this objective in mind, is characterized in that, at a position where a cylindrical film formed by sending air toward a cylindrically extruded molten resin is being folded by a pair of pinch rolls and thus narrowing in width, and at a position closer to the pinch rolls than the position where the film begins to narrow in width, the apparatus has a degassing roll that rotates in accordance with the movement of the film to create holes or cuts in the film as a pre-treatment to allow air taken inside the film to escape to the outside. Here, the distance between the degassing roll and the pinch roll may be characterized by being 500 mm or less. Furthermore, the inflation molding apparatus of the present invention, completed for the above purpose, is an inflation molding apparatus characterized by having a roll positioned downstream of a pair of pinch rolls, which changes the inclination of a cylindrical film that has been conveyed in a folded state by the pinch rolls and further conveys it downstream, having an inclination changing roll that first changes the inclination of the film that has been folded by the pinch rolls, and having a degassing roll between the pinch rolls and the inclination changing roll that, as a process to remove air taken inside the film, makes holes or cuts in the film while rotating in accordance with the movement of the film. Furthermore, the inflation molding apparatus of the present invention, completed for the above purpose, is an inflation molding apparatus characterized in that it has a roll positioned downstream of a pair of pinch rolls, which changes the inclination of a cylindrical film that has been conveyed in a folded state by the pinch rolls and conveys it further downstream, and has an inclination changing roll that first changes the inclination of the film that has been folded by the pinch rolls, and the inclination changing roll functions as a degassing roll that makes holes or cuts in the film as a process to remove air that has been taken inside the film. Here, the degassing roll may be a roll having protrusions on its surface, and may be characterized by being pressed against the film and rotating in accordance with the movement of the film while creating holes in the film. Furthermore, the degassing roll may be characterized by being able to house the projection inside and extending the projection to the outside at a predetermined timing. Furthermore, the degassing roll may be a roll having a circular blade, characterized in that it is pressed against the film and rotates in accordance with the movement of the film while making cuts in the film. Furthermore, the degassing roll may be characterized by enabling separation from and contact with the film. Furthermore, the inflation molding method of the present invention, completed with this objective in mind, is an inflation molding method characterized by, at a position where a cylindrical film formed by sending air toward a cylindrically extruded molten resin is being folded by a pair of pinch rolls and thus narrowing in width, and at a position closer to the pinch rolls than the position where the film began to narrow in width, the air taken inside the film is made to escape to the outside by making holes or cuts in the film while rotating in accordance with the movement of the film. Furthermore, the inflation molding method of the present invention, completed with this objective in mind, is an inflation molding method characterized by having a pair of pinch rolls and a roll positioned downstream of the pinch rolls, which changes the inclination of a cylindrical film that has been conveyed in a folded state by the pinch rolls and conveys it further downstream, and between the inclination changing roll that first changes the inclination of the film that has been folded by the pinch rolls, the rolling roll rotates in accordance with the movement of the film and makes holes or cuts in the film as a process to release the air taken inside the film to the outside. Furthermore, the inflation molding method of the present invention, completed with this objective in mind, is an inflation molding method characterized in that a roll is positioned downstream of a pair of pinch rolls and changes the inclination of a cylindrical film that has been conveyed in a folded state by the pinch rolls and then conveys it further downstream, and the inclination changing roll that first changes the inclination of the film that has been folded by the pinch rolls makes holes or cuts in the film as a process to release the air that has been taken inside the film. [Effects of the Invention]
[0007] According to the present invention, air pockets that may occur when an inflation-molded cylindrical film is folded can be automatically suppressed or eliminated. [Brief explanation of the drawing]
[0008] [Figure 1] This figure illustrates a part of the configuration of an inflation molding apparatus according to the first embodiment. [Figure 2] (A) and (B) are diagrams showing specific examples of perforating rolls. [Figure 3] (A) and (B) are diagrams showing variations of the degassing roll. [Figure 4] This figure illustrates a part of the configuration of an inflation molding apparatus according to the second embodiment. [Modes for carrying out the invention]
[0009] Embodiments of the present invention will be described in detail below with reference to the attached drawings. <First Embodiment> [Configuration of inflation molding apparatus 1] Figure 1 is a diagram illustrating a part of the configuration of the inflation molding apparatus 1 according to the first embodiment. The inflation molding apparatus 1 shown in Figure 1 is a device that forms a resin film 200 as a product by inflation molding. The inflation molding apparatus 1 heats the resin that will be the material for the film 200 to a molten state, extrudes the molten resin from an annular die which is a nozzle, and blows air into the inner surface of the cylindrical molten resin. As a result, the molten resin expands and a thin cylindrical molten resin is formed. The inflation molding apparatus 1 then applies cooling air to the outer surface of the formed thin cylindrical molten resin to solidify it. This forms the cylindrical film 200 shown in Figure 1. The formed film 200 is transported in the direction of the thick arrow shown in Figure 1. Hereinafter, the direction in which the film 200 is transported may be called the "upstream side," and the direction in which the film 200 is transported may be called the "downstream side." Also, the vertical direction in the drawing of Figure 1 indicates the up and down directions.
[0010] As shown in Figure 1, the inflation molding apparatus 1 includes a pair of guide sections 110 that guide the transport of the film 200, and a pair of pinch rolls 100 that fold the film 200. The inflation molding apparatus 1 also includes a transport roll positioned downstream of the pair of pinch rolls 100, which changes the inclination of the film 200 that has been transported in a folded state by the pair of pinch rolls 100 and transports it further downstream. This transport roll (hereinafter referred to as the "inclination changing roll") 101 is the first to change the inclination of the film 200 that has been folded by the pair of pinch rolls 100. In this invention, "roll" refers to a member that is in contact with the film 200 and rotates in accordance with the movement of the film 200.
[0011] The pair of guide sections 110 are plate-shaped or fence-shaped members that guide the outer surface of the molded cylindrical film 200 so that the film width w of the film 200 gradually decreases, and guide it toward the pair of pinch rolls 100. The pair of pinch rolls 100 are positioned above the pair of guide sections 110 in the vertical direction. The pair of pinch rolls 100 are driven by a motor (not shown) or the like to rotate, pulling up the film 200 guided by the pair of guide sections 110, folding it flat, and then feeding it toward the tilt-changing roll 101 on the downstream side.
[0012] The tilt-changing roll 101 changes the tilt of the film 200, which has been transported from the upstream side in a folded state by a pair of pinch rolls 100, and then transports it further downstream. Specifically, the tilt-changing roll 101 is a roll that changes the angle of the film 200's path when it is 180 degrees or less. Downstream of the tilt-changing roll 101, the film 200 transported from the tilt-changing roll 101 is wound up by a winding machine (not shown).
[0013] (Hole-punching roll 10) The inflation molding apparatus 1 has a perforating roll 10 that functions as a degassing roll. The perforating roll 10 is rotatable in accordance with the transport of the film 200 and has protrusions on its surface composed of needles or the like for making holes in the film 200. A specific example of the configuration of the perforating roll 10 will be described later with reference to Figure 2.
[0014] The perforating roll 10 is installed on a pair of guide sections 110. The perforating roll 10 performs pretreatment at a position where the cylindrical film 200 is narrowing in width to be folded by the pair of pinch rolls 100, and at a position closer to the pair of pinch rolls 100 than the position where the film 200 begins to narrow in width, in order to allow air trapped inside the film 200 when it is folded to escape to the outside. Specifically, as pretreatment, the perforating roll 10 punches holes in the film 200.
[0015] The punching roll 10 is preferably arranged so that the distance d1 from the pair of pinch rolls 100 does not become too long. If the distance d1 is too long, the timing for the punching roll 10 to punch holes in the cylindrical film 200 becomes early, and the air inside the cylindrical film 200 easily escapes to the outside. In this case, it takes time to secure a sufficient film width w. Also, the molding is likely to become unstable. Therefore, the distance d1 is preferably 500 mm or less. By setting the distance d1 to 500 mm or less, the air inside the folded film 200 does not easily escape, and the molding does not become unstable.
[0016] 〔Specific Example of Punching Roll 10〕 Figs. 2(A) and (B) are diagrams showing a specific example of the punching roll 10. The punching roll 10 is a rotating body that conveys the film 200 downstream while rotating in accordance with the movement of the film 200 in a state of being pressed against the film 200. The punching roll 10 has a cylindrical outer rotating member 11 that can rotate in a state of being pressed against the film 200, and a cylindrical inner rotating member 12 that is rotatably arranged inside the outer rotating member 11 and has a plurality of protrusions 121 in the circumferential direction. Further, the punching roll 10 has a cylindrical shaft body 13 that serves as the rotation axis of the outer rotating member 11 and the inner rotating member 12. The shaft body 13 is fixed to a part of a pair of guide parts 110 via support members and fixing members (not shown).
[0017] As shown in Fig. 2(A), the punching roll 10 projects the protrusions 121 to the outside and can punch holes in the film 200 while rotating in accordance with the movement of the film 200 in a state of being pressed against the film 200. Also, as shown in Fig. 2(B), the punching roll 10 can convey the film 200 while rotating in accordance with the movement of the film 200 in a state of being pressed against the film 200 with the protrusions 121 housed inside.
[0018] Figure 2(A) shows how the perforating roll 10, with its projection 121 protruding outwards, rotates in accordance with the movement of the film 200, thereby punching holes in the film 200. In other words, when the projection 121 is protruding outwards, the perforating roll 10 can function as a degassing roll that punches holes in the film 200.
[0019] Figure 2(B) shows how the perforating roll 10 rotates in accordance with the movement of the film 200 with the projection 121 retracted inside. In other words, when the projection 121 is retracted inside, the perforating roll 10 functions as a transport roller that carries the film 200.
[0020] The functions of extending and retracting the projection 121 of the perforating roll 10 can be realized, for example, with the following configuration. Specifically, a space 14 is formed between the outer rotating member 11 and the inner rotating member 12. In addition, a space 15 is formed between the inner rotating member 12 and the shaft 13. The inner rotating member 12 is made of an elastic material such as rubber, and when air is sent into the space 15, it expands in the direction that widens the diameter (indicated by the white arrow), and when air is removed from the space 15, it contracts in the direction that narrows the diameter.
[0021] In Figure 2(B), the perforating roll 10 is in a state where the air has been removed from the space 15, causing the inner rotating member 12 to contract and the projection 121 to be retracted inside. When air is introduced into the space 15 shown in Figure 2(B), the inner rotating member 12 expands in the direction of the white arrow. Then, as shown in Figure 2(A), the projection 121 penetrates the outer rotating member 11 and protrudes to the outside. The dashed line in Figure 2(A) shows the position of the inner rotating member 12 before air is introduced into the space 15.
[0022] Here, the method for supplying air to space 15 in Figure 2(B) and the method for removing air from space 15 in Figure 2(A) are not particularly limited. For example, the shaft 13 may be provided with an air duct connected to the outside, which has the function of supplying high-pressure air towards space 15 and the function of sucking in and exhausting the air from space 15.
[0023] [Variation 1] The perforating roll 10 shown in Figures 2(A) and (B) allows for the protrusion and retraction of the projection 121, enabling the perforation of the film 200 at the required timing. However, it is not limited to this. The degassing roll of the present invention may, for example, be a perforating roll that always has a plurality of projections on its surface and is movable in a direction away from and towards the film 200. In this case, the roll can be brought closer to the film 200 at a predetermined timing (for example, the setup timing) to create holes, and at other times it can be moved away from the film 200 to prevent perforation.
[0024] [Variation 2] Figures 3(A) and (B) show modified examples of the degassing roll. Figures 3(A) and (B) show a cutting roll 20 as a modified example of a degassing roll. The cutting roll 20 is a roll that is pressed against the film 200 and rotates in accordance with the movement of the film 200, making cuts in the film 200.
[0025] The cutting roll 20 is equipped with a circular blade 21 in the circumferential direction and has a disc-shaped rotating member 22 that can rotate while the circular blade 21 is pressed against the film 200, and a cylindrical shaft 23 that serves as the axis of rotation of the rotating member 22. The cutting roll 20 is positioned in the same location as the punching roll 10 in Figures 2(A) and (B) above, but is movable in the direction toward and away from the film 200. Therefore, at predetermined timings (for example, setup timings), the cutting roll 20 makes cuts by contacting the film 200, as shown in Figure 3(A). At other times, it moves away from the film 200 and does not make cuts, as shown in Figure 3(B).
[0026] The number of cutting rolls 20 may be one, but multiple cutting rolls 20 may be arranged in a line along the width direction of the film 200. This allows for cutting over a wide area of the film 200, which can suppress the formation of air pockets even if the location where air pockets occur is not constant, and can also suppress leakage of any air pockets that do occur.
[0027] In summary, the inflation molding apparatus 1 according to the first embodiment only needs to have the following configuration, and various different embodiments can be adopted. In other words, the inflation molding apparatus 1 is characterized in that, at a position where the cylindrical film 200 formed by sending air toward the molten resin extruded into a cylindrical shape is narrowed in width to be folded by a pair of pinch rolls 100, and at a position closer to the pair of pinch rolls 100 than the position where the film 200 began to narrow in width, the apparatus has a hole-punching roll 10 or a cut-in roll 20 that rotates in accordance with the movement of the film 200 to make holes or cuts in the film 200 as a pre-treatment to allow air taken inside the film 200 to escape to the outside.
[0028] This automatically creates holes or cuts in the cylindrical film 200 before the pair of pinch rolls 100 fold it. As a result, the air inside the folded film 200 is removed, automatically preventing the formation of air pockets.
[0029] Here, the distance d1 between the punching roll 10 or cutting roll 20 and the pair of pinch rolls 100 may be characterized by being 500 mm or less. If the distance between the perforating roll 10 or cutting roll 20 and the pair of pinch rolls 100 exceeds 500 mm, the timing at which the perforating roll 10 or cutting roll 20 punches holes or cuts in the cylindrical film 200 becomes earlier. As a result, air inside the cylindrical film 200 escapes more easily, and it takes more time to secure a sufficient film width w. Also, the molding process tends to become unstable. In contrast, by setting the distance d1 to 500 mm or less, air inside the folded film 200 does not escape easily, and the molding process does not become unstable.
[0030] Furthermore, the perforating roll 10 may be a roll having protrusions 121 on its surface, and may be characterized by rotating in accordance with the movement of the film 200 while being pressed against the film 200, thereby punching holes in the film 200. As a result, the perforating roll 10, which has protrusions 121 on its surface, rotates in accordance with the flow of the film 200 while pressing the protrusions 121 against the film 200. Consequently, holes can be automatically punched in the film 200.
[0031] Furthermore, the punching roll 10 may be characterized by being able to store the projection 121 internally and extending the projection 121 externally at a predetermined timing. This allows the projection 121 to protrude outward at the necessary time (for example, during setup) to create a hole in the film 200, and to retract the projection 121 inward at the unnecessary time to prevent it from creating a hole in the film 200.
[0032] Furthermore, the perforating roll 10 or the cutting roll 20 may be characterized by enabling separation from and contact with the film 200. By bringing the perforating roll 10 or the cutting roll 20 into contact with the film 200 at the necessary timing (for example, during setup), holes can be made in the film 200. Furthermore, the perforating roll 10 or the cutting roll 20 can be separated from the film 200 at times when it is not needed.
[0033] Furthermore, the inflation molding method of the present invention, completed with this objective in mind, is an inflation molding method characterized in that, at a position where a cylindrical film 200 formed by sending air toward a cylindrically extruded molten resin is narrowed in width for folding by a pair of pinch rolls 100, and at a position closer to the pinch rolls than the position where the film began to narrow in width, holes or cuts are made in the film 200 while rotating in accordance with the movement of the film 200 as a pretreatment to allow air taken inside the film 200 to escape to the outside.
[0034] <Second Embodiment> [Configuration of inflation molding apparatus 2] Figure 4 is a diagram illustrating a part of the configuration of the inflation molding apparatus 2 according to the second embodiment. The configuration of the inflation molding apparatus 2 shown in Figure 4 is basically the same as the configuration of the inflation molding apparatus 1 according to the first embodiment described above. That is, the inflation molding apparatus 2 has a pair of guide sections 110, a pair of pinch rolls 100 for folding the film 200, and an inclination changing roll 101 for changing the inclination of the film 200 and transporting it downstream.
[0035] The inflation molding apparatus 2 has a perforating roll 10 that serves as a degassing roll. The perforating roll 10 of the inflation molding apparatus 2 has the same function as the perforating roll 10 of the inflation molding apparatus 1, but its location is different. Specifically, the perforating roll 10 of the inflation molding apparatus 2 is positioned between a pair of pinch rolls 100 and a tilt-changing roll 101. As a result, the perforating roll 10 of the inflation molding apparatus 2 punches holes in the film 200 as a process to remove air trapped inside the film 200, between the pair of pinch rolls 100 and the tilt-changing roll 101.
[0036] It is preferable that the perforating roll 10 of the inflation molding apparatus 2 be positioned so that the distance d2 between it and the pair of pinch rolls 100 does not become too long. If the distance d2 becomes too long, the timing at which the perforating roll 10 punches holes in the film 200 will be delayed. If the timing at which holes are punched in the film 200 is delayed, air pockets are more likely to form in the film 200 as it is conveyed between the pair of pinch rolls 100 and the tilt-changing roll 101. Furthermore, it becomes more difficult to eliminate the air pockets that have formed.
[0037] Therefore, it is preferable that the perforating roll 10 of the inflation molding apparatus 2 is not positioned downstream of the tilt-changing roll 101. In other words, it is preferable that the perforating roll 10 be positioned between the pair of pinch rolls 100 and the tilt-changing roll 101. Furthermore, it is preferable that the perforating roll 10 be positioned such that the distance d2 is 500 mm or less.
[0038] [Variation 1] In the example shown in Figure 4, a perforating roll 10 is positioned between the pair of pinch rolls 100 and the tilt-changing roll 101 to function as a degassing roll. However, the tilt-changing roll 101 may also function as a degassing roll. That is, multiple protrusions may be provided on the surface of the tilt-changing roll 101 so that when the film 200 comes into contact with the tilt-changing roll 101, the multiple protrusions punch holes in the film 200. In this case, since the tilt-changing roll 101 functions as a degassing roll, there is no need to secure a position for the perforating roll 10.
[0039] [Variation 2] In the inflation molding apparatus 2 according to the second embodiment, similar to the inflation molding apparatus 1 according to the first embodiment, the cutting rolls 20 shown in Figures 3(A) and (B) may be placed in place of the perforating rolls 10 shown in Figures 2(A) and (B).
[0040] In summary, the inflation molding apparatus 2 according to the second embodiment only needs to have the following configuration, and various different embodiments can be adopted. In other words, the inflation molding apparatus 2 is an inflation molding apparatus characterized by having a roll positioned downstream of a pair of pinch rolls 100, which changes the inclination of the film 200 that has been conveyed in a folded state by the pair of pinch rolls 100 and conveys it further downstream, having an inclination changing roll 101 that first changes the inclination of the film 200 that has been folded by the pair of pinch rolls 100, and having a hole-punching roll 10 or cut-in roll 20 that rotates in accordance with the movement of the film 200 to make holes or cuts in the film 200 as a process to remove air that has been taken inside the film 200 between the pair of pinch rolls 100 and the inclination changing roll 101.
[0041] As a result, after the pair of pinch rolls 100 fold the cylindrical film 200, holes are automatically punched or cuts are automatically made in the folded film 200. Consequently, any resulting air pockets are automatically eliminated. Furthermore, if the perforating roll 10 or cutting roll 20 is positioned downstream of the tilt-changing roll 101, the timing at which the perforating roll 10 or cutting roll 20 punches holes or cuts in the film 200 is delayed. In this case, air pockets are more likely to form in the film 200 being transported between the pair of pinch rolls 100 and the tilt-changing roll 101, and it becomes more difficult to eliminate them. Conversely, by positioning the perforating roll 10 or cutting roll 20 upstream of the tilt-changing roll 101, air pockets are less likely to form in the film 200 being transported between the pair of pinch rolls 100 and the tilt-changing roll 101. Also, any air pockets that do form are easier to eliminate.
[0042] Furthermore, the tilt-changing roll 101 may also be characterized by functioning as a hole-punching roll 10 or a cutting roll 20. As a result, the tilt-changing roll 101 functions as either a punching roll 10 or a cutting roll 20, eliminating the need to secure a new position for the punching roll 10 or cutting roll 20. Consequently, the configuration of the inflation molding apparatus 2 can be simplified.
[0043] Furthermore, the inflation molding method of the present invention, completed with this objective in mind, is an inflation molding method characterized in that, between a pair of pinch rolls 100 and a roll positioned downstream of the pair of pinch rolls 100, which changes the inclination of a cylindrical film 200 that has been conveyed in a folded state by the pair of pinch rolls 100 and conveys it further downstream, the roll rotates in accordance with the movement of the film 200 to make holes or cuts in the film 200 as a process to release air trapped inside the film 200 to the outside.
[0044] Furthermore, the inflation molding method of the present invention, completed with this objective in mind, is an inflation molding method characterized in that a roll positioned downstream of a pair of pinch rolls 100 changes the inclination of a cylindrical film 200 that has been conveyed in a folded state by the pair of pinch rolls 100 and conveys it further downstream, and the inclination changing roll 101 that first changes the inclination of the film 200 folded by the pair of pinch rolls 100 causes the film 200 to make holes or cuts as a process to release the air trapped inside the film 200.
[0045] <Other> Although this embodiment has been described above, the present invention is not limited to the embodiment described above. Furthermore, the effects of the present invention are not limited to those described in this embodiment.
[0046] For example, in the example shown in Figure 4, only a perforating roll 10, which serves as a degassing roll, is placed between the pair of pinch rolls 100 and the tilt-changing roll 101, but the system is not limited to this. In addition to the perforating roll 10, for example, a conveying roll that does not change the tilt of the film 200 may be placed. [Explanation of Symbols]
[0047] 1...Inflation molding apparatus, 10...Perforation roll, 11...Outer rotating member, 12...Inner rotating member, 13, 23...Shaft body, 20...Cutting roll, 21...Circular blade, 22...Rotating member, 100...Pair of pinch rolls, 110...Pair of guide parts, 121...Protrusion, 200...Film
Claims
1. The cylindrical film, formed by blowing air towards a cylindrically extruded molten resin, is narrowed in width by being folded by a pair of pinch rolls. At a position closer to the pinch rolls than the position where the film begins to narrow in width, the degassing roll is provided, which rotates in accordance with the movement of the film to create holes or cuts in the film as a pre-treatment to allow air trapped inside the film to escape to the outside. Inflation molding machine.
2. The distance between the degassing roll and the pinch roll is 500 mm or less. The inflation molding apparatus according to claim 1.
3. A roll positioned downstream of a pair of pinch rolls, which changes the inclination of a cylindrical film that has been conveyed in a folded state by the pinch rolls and further conveys it downstream, having an inclination changing roll that first changes the inclination of the film that has been folded by the pinch rolls, The pinch roll and the tilt-changing roll are provided with a degassing roll that rotates in accordance with the movement of the film to make holes or cuts in the film, as a process to remove air trapped inside the film. Inflation molding machine.
4. A roll positioned downstream of a pair of pinch rolls, which changes the inclination of a cylindrical film that has been conveyed in a folded state by the pinch rolls and further conveys it downstream, having an inclination changing roll that first changes the inclination of the film that has been folded by the pinch rolls, The tilt-changing roll is characterized in that it functions as a degassing roll that makes holes or cuts in the film as a process to remove air trapped inside the film. Inflation molding machine.
5. The degassing roll is a roll having protrusions on its surface, and is characterized by being pressed against the film and rotating in accordance with the movement of the film while creating holes in the film. An inflation molding apparatus according to any one of claims 1, 3, or 4.
6. The degassing roll is characterized in that the projection can be stored inside and the projection is made to protrude to the outside at a predetermined timing. The inflation molding apparatus according to claim 5.
7. The degassing roll is a roll having a circular blade, and is characterized by making cuts in the film while rotating in accordance with the movement of the film while being pressed against the film. An inflation molding apparatus according to any one of claims 1, 3, or 4.
8. The degassing roll is characterized by enabling separation from and contact with the film. An inflation molding apparatus according to any one of claims 1, 3, or 4.
9. A cylindrical film, formed by blowing air towards a cylindrically extruded molten resin, is being folded by a pair of pinch rolls, narrowing its width at a position closer to the pinch rolls than the position where the film begins to narrow. This pretreatment involves making holes or cuts in the film while rotating in accordance with its movement, in order to allow air trapped inside the film to escape to the outside. Inflation molding method.
10. A pair of pinch rolls and a roll positioned downstream of the pinch rolls, which changes the inclination of a cylindrical film that has been conveyed in a folded state by the pinch rolls and further conveys it downstream, characterized in that, between the inclination-changing roll that initially changes the inclination of the film folded by the pinch rolls, the roll rotates in accordance with the movement of the film and makes holes or cuts in the film as a process to release air trapped inside the film to the outside, Inflation molding method.
11. A roll positioned downstream of a pair of pinch rolls, which changes the inclination of a cylindrical film that has been conveyed in a folded state by the pinch rolls and further conveys it downstream, characterized in that the inclination changing roll that first changes the inclination of the film folded by the pinch rolls causes holes or cuts in the film as a process to release air trapped inside the film. Inflation molding method.