JP7583520B2 - Stretching Equipment - Google Patents

Description

The present invention can be suitably used in a stretching device that stretches a film in the longitudinal and transverse directions.

In a stretching device, both longitudinal and transverse stretching can be performed; performing these in sequence is called sequential biaxial stretching, and performing them all at once is called simultaneous biaxial stretching. Compared to sequential stretching, simultaneous biaxial stretching has the advantages of being less prone to scratches, being compatible with a wider range of raw materials, being able to stretch even with fast crystallization rates, and having high longitudinal and transverse uniformity of physical properties.

For example, Patent Document 1 (JP Patent Publication 2004-155138 A) discloses a sheet-like material stretching machine in which endless link devices arranged on both sides of a sheet-like material using multiple equal-length link devices formed in a folded ruler shape are driven by sprockets on the inlet and outlet sides of the sheet-like material, and the sheet-like material is guided by guide rollers formed by guides arranged in a diverging shape in the traveling direction, stretching the sheet-like material in the lateral direction.

JP 2004-155138 A

In the case of simultaneous biaxial stretching, the membrane is stretched simultaneously in the direction of membrane movement and in a direction intersecting the direction of membrane movement. When the membrane is stretched in a direction intersecting the direction of membrane movement, a contraction force is generated in the membrane in the direction of membrane movement, and this contraction force causes the membrane to be pulled downstream in the direction of membrane movement. In order to prevent the membrane from being pulled downstream, it is preferable to apply an external force acting on the membrane in the opposite direction to the contraction force. However, when a membrane containing oil is stretched, the oil seeps onto the surface of the membrane, making it difficult for the external force to be transmitted to the membrane.

Other objects and novel features will become apparent from the description of this specification and the accompanying drawings.

The stretching device disclosed in this application includes:
a stretching treatment section for stretching the oil-containing resin film;
a tension applying mechanism that applies tension to the resin film and supplies the resin film to the stretching processing unit;
The tension applying mechanism includes:
a first roller, a second roller and a third roller for transporting the resin film and supplying it to the stretching processing section;
the resin film is transported in a first direction from the first roller to the second roller and in a second direction from the second roller to the third roller;
The first direction and the second direction are different directions.

The stretching device disclosed in this application allows for stable stretching of a film containing oil.

1 is a schematic diagram showing a configuration of a thin film manufacturing system according to an embodiment; FIG. 2 is a plan view showing a structural example of the stretching device shown in FIG. 1 . 3 is an enlarged plan view showing one of the links shown in FIG. 2; FIG. 4 is a cross-sectional view taken along line AA of the link shown in FIG. 3. 4 is a cross-sectional view taken along line AB of the link shown in FIG. 3. FIG. 3 is an enlarged plan view of the periphery of the inlet portion shown in FIG. 2 . FIG. 7 is a side view of the periphery of the inlet portion shown in FIG. 6 . FIG. 8 is a side view showing a study example for FIG. 7 . FIG. 8 is a side view showing a modification of FIG. 7 . FIG. 10 is a side view showing a modification of FIG. 9 . FIG. 8 is a side view showing another modified example of FIG. 7 . FIG. 8 is a side view showing another modified example of FIG. 7 . FIG. 13 is a side view showing a modification of FIG. 12 .

The following describes the embodiments in detail with reference to examples and drawings. In all drawings used to explain the embodiments, the same reference numerals are used for components having the same functions, and repeated explanations will be omitted.

<Overall structure>
FIG. 1 is a schematic diagram showing the configuration of the thin film manufacturing system of this embodiment. The thin film manufacturing system 1 of this embodiment shown in FIG. 1 has a kneading extrusion device (twin-screw kneading extrusion device) 2, a T-die 3, a raw web cooling device 4, a stretching device (simultaneous biaxial stretching device) 5, a take-up device 6, and a winding device 7. In the example shown in FIG. 1, first, a resin material (pellets) and additives are supplied to the raw material supply section 2A of the kneading extrusion device 2. The twin-screw kneading extrusion device 2 transports (conveys) the supplied resin material while mixing it. The T-die 3 extrudes the kneaded material (molten resin) kneaded by the twin-screw kneading extrusion device 2 from a slit. The kneaded material extruded from the T-die 3 is cooled in the raw web cooling device 4 and becomes a film (sheet, resin film) 8. The film formed by the T-die 3 is continuously supplied to the stretching device 5. For the stretching device 5, the film 8 corresponds to the raw material to be stretched. In this specification, the description will be centered on the stretching device 5, and therefore the sheet-like material fed to the stretching device 5 and the membrane 8 before the stretching process are sometimes called the original roll. On the other hand, the membrane 8 after the stretching process is completed and discharged from the stretching device 5 is sometimes called the thin film.

The film 8 formed by cooling in the raw material cooling device 4 is stretched in the MD and TD directions by the stretching device 5 to become a thin film. The stretched film 8 is taken up by the winding device 7 via the take-up device 6.

In the case of the thin film manufacturing system 1 shown as an example in FIG. 1, a thin film is manufactured as described above. Note that the thin film manufacturing system 1 shown in FIG. 1 can be modified in various ways depending on the characteristics of the thin film to be formed. For example, in addition to the configuration shown in FIG. 1, an extraction tank (not shown) may be provided near the take-up device 6 shown in FIG. 1, and the plasticizer (e.g., paraffin, etc.) in the film 8 may be removed in the extraction tank.

The stretching device 5 of this embodiment stretches the thin film in the MD and TD directions while transporting the film 8 in the MD direction. The MD (Machine Direction) direction is the direction along the transport direction of the thin film, and is also called the vertical direction. The TD (Transverse Direction) direction is the direction intersecting the transport direction of the thin film (the direction perpendicular to the transport direction in the example shown in FIG. 1), and is also called the horizontal direction. The stretching device 5 capable of simultaneously stretching in two mutually intersecting directions is called a simultaneous biaxial stretching device.

The structure of the stretching device 5 and the principle by which the stretching device 5 stretches the film 8 in the MD and TD directions are described below. FIG. 2 is a plan view showing an example of the structure of the stretching device shown in FIG. 1. In the oven shown in FIG. 2, a plurality of links 20 arranged on rails 13A and 13B are arranged, but in FIG. 2, only the rails 13A and 13B and the contours of the film 8 are shown by dotted lines. FIG. 3 is an enlarged plan view showing one of the plurality of links shown in FIG. 2. FIG. 4 is a cross-sectional view taken along line A-A of the link shown in FIG. 3. FIG. 5 is a cross-sectional view taken along line A-B of the link shown in FIG. 3. In FIG. 4 and FIG. 5, in order to make it easier to see the support structure of the clip 21, members that are in positions different from those in the cross sections taken along lines A-A and A-B shown in FIG. 3 are shown in white.

As shown in FIG. 2, the stretching device 5 has a pair of link devices 10A and 10B that are spaced apart from each other in a plan view. The film 8 is disposed between the link device 10A and the link device 10B and transported in the MD direction. In other words, the pair of link devices 10A and 10B are disposed on both sides of the film 8. The portion between the link device 10A and the link device 10B functions as a transport section for transporting the film 8. The stretching device 5 includes a stretching processing section 11 for stretching the film 8, which is a resin film containing oil. The stretching processing section 11 can simultaneously stretch the film 8 in the MD direction along the transport direction of the film 8 and in the TD direction intersecting the MD direction while holding both ends of the film 8. The stretching device 5 also has a heat processing section 12 that covers the stretching processing section 11 and performs heat treatment on the film 8. In the example shown in FIG. 2, an example of heat treatment using an oven is shown as a heat treatment method. A portion of each of the link devices 10A and 10B (stretching processing section 11) is disposed within the heat treatment section 12. In the following description, the portion of each of the link devices 10A and 10B that is disposed so as to pass through the oven that is the heat treatment section 12 and that is disposed within the heat treatment section 12 will be described as the stretching processing section 11. The film 8 passes through the heat treatment section 12 while being held by the link devices 10A and 10B.

Each of the link devices 10A and 10B has a plurality of links 20 connected to form an endless chain. A clip 21 (see FIG. 3), which is a jig for holding the membrane 8, is attached to each of the links 20. The membrane 8 is held by the links 20 via the clips 21.

The multiple links 20 connected to each other are placed on the rails 13A and 13B in a state in which they can run along the rails 13A and 13B. Each of the link devices 10A and 10B has a pair of rails 13A and 13B. Of the pair of rails 13A and 13B, rail 13A is disposed on the inner circumference side, and rail 13B is disposed on the outer circumference side. Note that rail 13A may be called the inner rail, and rail 13B may be called the outer rail.

As shown in FIG. 2, a pair of rails 13A and 13B provided on each of the link devices 10A and 10B are formed in a ring shape extending from the inlet section (inlet side) 14, which is located on the inlet side through which the film 8 before stretching is supplied, to the heat treatment section 12, and the outlet section (outlet side) 15.

The endless chain composed of the multiple links 20 is driven by a link drive mechanism arranged outside the heat treatment section 12. In the example shown in FIG. 2, the stretching device 5 has a link drive mechanism at each of the inlet section 14 and outlet section 15 of the film 8. A sprocket 31, which is a link drive mechanism, is arranged at the inlet section 14 of the film 8. A sprocket 32, which is a link drive mechanism, is arranged at the outlet section 15 of the film 8. The sprockets 31 and 32 are each engaged with the multiple links 20 and rotate to send out the multiple links 20 in the MD direction. Each of the multiple links 20 moves on the rails 13A and 13B by the driving force of the rotational movement of the sprockets 31 and 32.

The pitch between adjacent links 20 (sometimes called link pitch) among the multiple links 20 can be changed according to the distance between rails 13A and 13B. In other words, the pitch between adjacent links 20 can be adjusted by adjusting the distance between rails 13A and 13B. In more detail, in areas where the distance between rails 13A and 13B is large, the pitch between adjacent links 20 is smaller than in areas where the distance between rails 13A and 13B is small.

The links 20 are arranged on the rails such that the pitch between adjacent links 20 is changeable. Clips 21 (see FIG. 3) are attached to one end of each of the links such that the pitch (center distance) between adjacent clips 21 is changeable. In the heat treatment section 12, the membrane 8 is stretched in the TD direction in a region where the separation distance between the rail 13B of the link device 10A and the rail 13B of the link device 10B gradually increases. The stretching section 11 includes a region where the separation distance between the rail 13A of the link device 10A and the rail 13A of the link device 10B gradually increases. In the region where the separation distance between the two rails 13A facing each other via the membrane 8 increases, the membrane 8 held by the clips 21 is stretched in the TD direction.

The stretching device 5 has a region (MD stretching region) in which the link pitch of the multiple links 20 of the link device 10A and the link pitch of the multiple links 20 of the link device 10B become larger in the heat treatment section 12. The film 8 is stretched in the MD direction in this region where the link pitch becomes larger. In the region where the link pitch becomes larger, the distance between the rail 13A and the rail 13B becomes smaller in each of the link devices 10A and 10B. The region where the distance between the rail 13B of the link device 10A and the rail 13B of the link device 10B gradually becomes larger is the same region as the region where the link pitch becomes larger, so in this region, the film 8 is stretched in the TD direction and the MD direction simultaneously.

In addition, since the stretching device 5 increases the link pitch in the heat treatment section 12, it is necessary to keep the link pitch small at the entrance section 14 to the heat treatment section 12. For this reason, the stretching device 5 is provided with a sprocket 33 arranged outside the heat treatment section 12 and at the entrance section 14 of the film 8. The sprocket 33 rotates at a slower rotational speed than the rotational speed of the sprocket 31. The sprocket 33 engages with the multiple links 20. By arranging the sprocket 33, which rotates slower than the rotational speed of the sprocket 31, at the entrance section 14 of the film 8, the link pitch of the multiple links 20 becomes small in the area engaged with the sprocket 33. The sprocket 33 functions as a link adjustment mechanism for reducing the link pitch of the multiple links 20.

At the entrance 14 to the heat treatment section 12, the membrane 8 is held by a clip 21 attached to a link 20 provided in each of the link devices 10A and 10B. The clip 21 is configured to open and close by the up and down movement of the holding part 21B (see Figs. 4 and 5) by the force of the spring 21A or the like described in Figs. 3 to 5. The clip 21 is transported in the MD direction together with the link 20 while holding an end of the membrane 8. The membrane 8 is heated in the heat treatment section 12, and is stretched in the MD direction and the TD direction with the movement of the clip 21. After being stretched, the membrane 8 is transported toward the exit 15 of the heat treatment section 12 while being held by the clip 21. Outside the heat treatment section 12 and at the exit 15 of the membrane 8, the membrane 8 is released from the clip 21. The take-up device 6 and winding device 7 shown in FIG. 1 are arranged at the exit side of the membrane 8, and the stretched membrane 8 is wound up by the winding device 7 and collected.

The stretching device 5 also has a tensioning mechanism 40A that applies tension to the film 8 while supplying the film 8 to the stretching processing section 11. The tensioning mechanism 40A is disposed upstream of the inlet section 14 in the transport direction of the film 8, and includes a mechanism for applying tension to the film 8. The detailed structure and operation of the tensioning mechanism 40A will be described later.

Next, the structure of the link 20 will be described. As shown in FIG. 3, the link 20 includes an upper link plate 22, a lower link plate 23, and rail holders 24 and 25. Each of the upper link plate 22 and the lower link plate 23 is a plate-shaped member that extends linearly in a plan view. A shaft 26 is inserted into one end of the upper link plate 22. As shown in FIG. 4 and FIG. 5, the shaft 26 is also inserted into the lower link plate 23, and the upper link plate 22 and the lower link plate 23 are connected via the shaft 26 in a freely rotatable state with the center of the shaft 26 as the rotation axis. A clip 21 is attached to one end of the lower link plate 23. As shown in FIG. 4, the shaft 26 is inserted into the lower link plate 23 between one end to which the clip 21 is attached and the other end. In FIG. 3, the state in which the upper link plate 22 and the lower link plate 23 rotate around the shaft 26 is shown diagrammatically using a two-dot chain line. When the upper link plate 22 and the lower link plate 23 rotate around the shaft 26 as the rotation axis, the angle θ1 formed between the upper link plate 22 and the lower link plate 23 changes.

In this specification, the increase in angle θ1 shown in FIG. 3 may be referred to as "opening the link," and the decrease in angle θ1 may be referred to as "closing the link." The action of increasing or decreasing the angle θ1 may be referred to as the "opening and closing of the link."

As shown by the two-dot chain lines in Figs. 4 and 5, a shaft 27 is inserted into the upper link plate 22. The shaft 27 is a connecting member that connects adjacent links 20. The shaft 27 is inserted into the upper link plate 22 of one link 20 and the lower link plate 23 of the other link 20 of the adjacent links 20. The upper link plate 22 of one link 20 and the lower link plate 23 of the other link 20 are connected via the shaft 27 in a state in which they can rotate freely around the center of the shaft 27 as a rotation axis. As shown in Fig. 5, an engagement portion 29 that engages with the sprockets 31, 32, and 33 shown in Fig. 2 is attached to the other end of the upper link plate 22. In the upper link plate 22, the shaft 27 is inserted between the engagement portion 29 and the shaft 26. When the upper link plate 22 and the lower link plate 23 rotate around the shaft 27 as a rotation axis, the angle (not shown) between the upper link plate 22 of one link 20 and the lower link plate 23 of the other link 20 changes.

As shown in Figures 4 and 5, rail holder 25 is attached to the lower end of shaft 26. Rail holder 25 is attached in a rotatable state with the center of shaft 26 as the rotation axis. As shown in Figure 4, rail holder 24 is attached to the lower end of shaft 27. Rail holder 24 is attached in a rotatable state with the center of shaft 27 as the rotation axis. Rail holder 24 is arranged to cover rail 13A, and rail holder 25 is arranged to cover rail 13B. Each of rail holders 24 and 25 is a member that includes a flanged roller that is arranged to sandwich rail 13A or 13B, and a holder that holds the flanged roller.

Since the link 20 has the above structure, when the distance between rail 13A and rail 13B changes, the upper link plate 22 and the lower link plate 23 rotate in response to the change. As a result, the pitch of adjacent links 20 changes in response to the distance between rail 13A and rail 13B. The pitch of adjacent links 20 can be determined based on the apex of the rotatable portion, in other words, the center of shaft 26.

<Tensioning mechanism>
Next, the details of the tensioning mechanism shown in Figures 1 and 2 will be described. As shown in Figure 2, the stretching device 5 has a tensioning mechanism 40A that is arranged upstream of the inlet 14 in the conveying direction of the film 8 and has a mechanism for applying tension to the film 8. In the region where the film 8 is stretched in the TD direction, a contraction force 8F is generated in the MD direction as the film 8 is stretched in the TD direction. In Figure 2, the contraction force 8F is shown diagrammatically by an arrow. The contraction force 8F is generated toward a neutral point in the region where the film 8 is stretched in the TD direction. When the contraction force 8F is generated around the inlet 14, the film 8 is pulled toward the downstream side of the MD direction (the outlet 15 side shown in Figure 2), which is the traveling direction.

As described above, at the inlet 14, the membrane 8 is gripped by the clip 21 of the link 20 (see FIG. 3). Therefore, if the position of the membrane 8 is shifted due to the contraction force 8F, the position gripped by the clip 21 may shift. If the position gripped by the link 20 of the link device 10A shifts from the position gripped by the link 20 of the link device 10B, the membrane 8 is transported with the gripping position shifted, and is stretched diagonally when stretched in the MD and TD directions, resulting in variation in the quality of the stretched thin film.

Therefore, in order to prevent the membrane 8 from being pulled by the contraction force 8F at the inlet section 14, it is preferable to apply tension 8T as an external force acting in the opposite direction to the contraction force 8F. By applying tension 8T, it is possible to prevent the membrane 8 from shifting in position due to the contraction force 8F. Tension 8T is applied by the tension applying mechanism 40A. The membrane 8 is transported by the link 20 holding the membrane 8 moving from the inlet section 14 toward the outlet section 15 due to the driving force of sprockets 31 and 32. The tension applying mechanism 40A applies tension 8T to the membrane 8 by applying a resistance force to the force transporting the membrane 8.

Figure 6 is an enlarged plan view of the vicinity of the entrance shown in Figure 2. The link devices 10A and 10B shown in Figure 6 are covered by the cover 16, but in Figure 6, the link devices 10A and 10B arranged inside the cover 16 are shown by solid lines. Figure 7 is a side view of the vicinity of the entrance shown in Figure 6. Figure 8 is a side view showing a study example for Figure 7. First, using Figure 8, a tension applying mechanism unit 40Z, which is a study example for this embodiment, will be described. Each of the multiple rollers (drive roller 41, guide roller 42, etc.) shown in Figures 6 to 8 is covered by the housing 47, but in Figures 6 to 8, the multiple rollers arranged inside the housing 47 are shown by solid lines.

The tensioning mechanism 40Z shown in FIG. 8 has a drive roller 41 that contacts the membrane 8 and sends out the membrane 8, and a guide roller 42 that contacts the membrane 8 and rotates according to the movement of the membrane 8. In the example shown in FIG. 8, the tensioning mechanism 40Z has a guide roller 42A that contacts the membrane 8 after the drive roller 41, and a guide roller 42B that contacts the membrane 8 before the drive roller 41. The tensioning mechanism 40Z also has a nip roller 43 that contacts the membrane 8 and presses the membrane 8 against the drive roller 41. The tensioning mechanism 40Z applies a resistance force that resists the force that transports the membrane 8 (the driving force of the drive roller 41 and the driving force of the sprockets 31 and 32 shown in FIG. 2) by pressing the membrane 8 against the drive roller 41 with the nip roller 43. The membrane 8 is pulled toward the upstream side of the inlet 14 by this resistance force, so that the tension 8T shown in FIG. 2 is generated in the membrane 8. This tension 8T acts to cancel the contraction force 8F shown in FIG. 2, so the effect of the contraction force 8F generated at the inlet 14 can be reduced.

However, according to the study of the present inventors, it was found that if the film 8 contains oil (oil components), the tensioning mechanism 40Z cannot provide sufficient tension. As an example of a film 8 that contains oil, a separator built into a lithium ion secondary battery will be taken as an example and explained.

In a lithium-ion secondary battery, the separator is an insulating film that is sandwiched between a positive electrode plate and a negative electrode plate. The insulating film used for the separator is required to have the function of passing an electrolyte, lithium ions, etc., in addition to the insulating function between the electrodes. For this reason, the separator has many holes. For example, the following method is used to form a resin insulating film with many holes. That is, a plasticizer is added to a solvent mixed with a resin material (hereinafter referred to as raw resin) that is the raw material of the separator. This plasticizer is a non-volatile solvent that can form a uniform solution at a temperature equal to or higher than the melting point of the raw resin, and is made of a material that can be extracted and removed after thinning. As such a plasticizer, for example, oil such as liquid paraffin or paraffin wax can be used. The raw resin is kneaded with a solvent containing the plasticizer, and then formed into a sheet using, for example, a T-die 3 shown in FIG. 1, and then thinned using a stretching device 5. Thereafter, the plasticizer contained in the thin film is extracted and removed by a washing process, and then a porous resin thin film is formed by performing a drying process and a stabilization process.

When a separator is formed by the above process, the film 8 fed to the stretching device 5 contains a plasticizer, which is an oil. When the film 8 containing oil is fed to the tensioning mechanism 40Z shown in FIG. 8, the oil seeps onto the surface of the film 8, reducing the frictional resistance between the film 8 and the nip roller 43. The surface of the nip roller 43 is covered with a polymeric resin, such as silicone, which comes into contact with the film 8. However, when the oil seeps onto the surface of the film 8, the frictional resistance between the film 8 and the nip roller 43 is small, and it has been found that the nip roller 43 cannot apply sufficient resistance.

In the case of the tensioning mechanism 40A shown in FIG. 6 and FIG. 7, even when stretching a film 8 containing oil, the tension 8T shown in FIG. 2 can be applied. In detail, as shown in FIG. 7, the tensioning mechanism 40A has a drive roller (roller) 41 that contacts the film 8 and sends out the film 8, and a guide roller (roller) 42 that contacts the film 8 and rotates according to the movement of the film 8. In the example shown in FIG. 7, the tensioning mechanism 40A has multiple rollers (drive roller 41 and multiple guide rollers 42) for supplying the film 8 to the stretching processing section 11 (see FIG. 2). The film 8 is transported in a direction from the guide roller (roller) 42D toward the drive roller 41 (forward direction X1 in FIG. 7) and in a direction from the drive roller 41 toward the guide roller (roller) 42C (reverse direction X2 in FIG. 7). The transport direction from the guide roller 42D to the drive roller 41 is different from the transport direction from the drive roller 41 to the guide roller 42C. In the example shown in FIG. 7, the direction is the opposite. The example shown in FIG. 7 can also be expressed as follows. The tension applying mechanism 40A has guide rollers 42C and 42A that contact the film 8 after the drive roller 41, and guide rollers 42B and 42D that contact the film 8 before the drive roller 41. The film 8 is supplied to the entrance section 14 after contacting the drive roller 41, the guide roller 42C, and the guide roller 42A in order. The guide roller 42C is located at a height different from the height of the drive roller 41 with the installation surface FL of the stretching device 5 as the reference surface, and is located at a position farther from the entrance section 14 than the drive roller 41. In other words, the guide roller 42C is located at a height different from the height of the drive roller 41, and is located at a position farther from the stretching processing section 11 shown in FIG. 2 than the drive roller 41. In the example shown in FIG. 7, the guide roller 42C is located at a position lower than the height of the drive roller 41 with the installation surface FL of the stretching device 5 as the reference surface.

In the following description, when describing the height of various rollers such as the drive roller 41 and the guide roller 42, or the surface of the film 8, the height is described when the installation surface FL of the stretching device 5 is used as the reference surface. In addition, when simply comparing the heights of the rollers, the height of the rotation axis (center of rotation) of the rollers relative to the reference surface is compared. For example, when describing that "the guide roller 42C is located at a different height from the drive roller 41," this means that the height of the rotation axis (center of rotation) of the guide roller 42C and the height of the rotation axis of the drive roller 41 are different from each other. However, when referring to the height of a specific part of the roller, such as the upper end or lower end of the roller, this means the height of that part. Similarly, in the following description, the distance of various rollers such as the drive roller 41 and the guide roller 42 from the inlet portion 14 may be expressed as being far or close. In this case, for example, the surface closest to the tensioning mechanism unit 40A among the side surfaces 16s of the cover 16 provided at the inlet portion 14 shown in FIG. 7 is used as the reference surface. For example, when the expression "guide roller 42C disposed at a position farther from the entrance section 14 than the drive roller 41" is used, it means that the shortest distance from the rotation axis (center of rotation) of the guide roller 42C to the side surface 16s of the cover 16 is longer than the shortest distance from the rotation axis (center of rotation) of the drive roller 41 to the side surface 16s of the cover 16. Similarly, the distance of various rollers such as the drive roller 41 and the guide roller 42 from the stretching processing section 11 may be expressed as being far or close. In this case, the boundary between the heat processing section 12 and the entrance section 14 shown in FIG. 2 is used as a reference position, and the distance from this reference position is used to refer to the distance.

In the case of tensioning mechanism 40A, a guide roller 42C is provided that is positioned lower than drive roller 41 and farther from entrance section 14 (in other words, from stretching processing section 11 in FIG. 2) than drive roller 41, and is configured so that film 8 comes into contact with guide roller 42C after coming into contact with drive roller 41, making the transport path of film 8 more complex than that of tensioning mechanism 40Z shown in FIG. 8. In the example shown in FIG. 7, the upper end of guide roller 42C is at least lower than the rotation axis of drive roller 41.

As shown in FIG. 7 and FIG. 8, the direction from the tensioning mechanism 40A (or 40Z) toward the entrance 14 is the forward direction X1, and the opposite direction of the forward direction X1 is the reverse direction X2. In the case of the tensioning mechanism 40Z shown in FIG. 8, the membrane 8 is transported only in the forward direction X1. On the other hand, in the case of the tensioning mechanism 40A shown in FIG. 7, the transport path of the membrane 8 includes a path (return path) between the drive roller 41 and the guide roller 42C along the reverse direction X2. When the transport path of the membrane 8 includes the return path, the guide roller 42C located at the end of the return path is disposed between the contact interface between the guide roller 42C and the membrane 8 and the entrance 14. In the example shown in FIG. 7, when a strong contraction force 8F (see FIG. 2) occurs in the membrane 8, the membrane 8 in the tensioning mechanism 40A is pulled toward the entrance 14 by the contraction force 8F. At this time, the guide roller 42C is disposed between the contact interface between the guide roller 42C and the film 8 and the inlet 14, so the greater the force pulling the film 8, the stronger the film 8 is pressed against the guide roller 42C. As a result, even if oil seeps out onto the surface of the film 8, the guide roller 42C provides the film 8 with resistance to the force pulling the film 8 in the forward direction X1. In other words, the film 8 is given a tension 8T (see FIG. 2) by the guide roller 42C.

In the configuration of FIG. 7, in addition to the guide roller 42C, the drive roller 41 also applies tension to the film 8. That is, at the drive roller 41, which is the start of the return path, the greater the force with which the film 8 is pulled in the reverse direction X2 in the return path, the stronger the film 8 is pressed against the drive roller 41. As a result, the drive roller 41 applies resistance to the film 8 against the force with which the film 8 is pulled in the reverse direction X2.

As described above, in the case of the tensioning mechanism 40A shown in FIG. 7, even if the oil contained in the membrane 8 seeps out to the surface and the contact interface with the guide roller 42C becomes slippery, tension 8T (see FIG. 2) can be applied to the membrane 8. This tension 8T can offset the force that pulls the membrane 8 near the entrance 14 toward the exit due to the contraction force 8F generated in the membrane 8 as shown in FIG. 2. As a result, it is possible to prevent the link 20 of the link device 10A and the link 20 of the link device 10B from shifting in the position where they grip the membrane 8 at the entrance 14.

In addition, in the present embodiment, when tension is applied to the membrane 8 by providing a return path in the transport path of the membrane 8 within the tension applying mechanism 40A, the increase in the area occupied by the tension applying mechanism 40A can be suppressed.

The embodiment shown in FIG. 7 can be expressed as follows. As shown in FIG. 7, the film 8 has a front surface 8f and a back surface 8b opposite the front surface 8f. The front surface 8f faces upward at the entrance section 14, and the back surface 8b faces the installation surface FL of the stretching device 5 at the entrance section 14. In the case of the tensioning mechanism section 40A, the drive roller 41 contacts the back surface 8b of the film 8, and the guide roller 42C contacts the front surface 8f of the film 8. Note that each of the guide rollers 42A and 42D contacts the back surface 8b of the film 8, and the guide roller 42B contacts the front surface 8f of the film 8. In the transport path of the membrane 8 in the tensioning mechanism 40A, when the drive roller 41 at the beginning of the return path contacts one side of the membrane 8 (back side 8b) and the guide roller 42C at the end contacts the other side of the membrane 8 (front side 8f), the above-mentioned resistance force can be applied to the membrane 8.

Next, of the multiple guide rollers 42 shown in FIG. 7, the guide rollers 42A, 42B, and 42D other than the guide roller 42C will be described. Each of the multiple guide rollers 42, including the guide roller 42C, is a metallic cylindrical member (or columnar member). The surface of each of the multiple guide rollers 42 is covered with a metal film (e.g., a chrome-plated film) that has excellent abrasion resistance and corrosion resistance. The drive roller 41 has a structure similar to the multiple guide rollers 42, except that a motor 44 (see FIG. 6) is connected to its rotating shaft. For example, each of the multiple guide rollers 42 and the drive roller 41 have the same diameter.

The guide roller 42A is provided to adjust the height of the film 8 supplied to the entrance section 14. The guide roller 42A is arranged so that the height of the upper end of the guide roller 42A matches the height of the back surface 8b of the film 8 at the entrance section 14, with the installation surface FL of the stretching device 5 as the reference surface. The lower end of the guide roller 42C is arranged at a position lower than the upper end of the guide roller 42A, with the installation surface FL as the reference surface, so that the height of the film 8 can be controlled by contact between the guide roller 42A and the back surface 8b of the film 8. In addition, the drive roller 41 is arranged at a position higher than the guide roller 42A. In detail, the lower end of the drive roller 41 is arranged at a position higher than the upper end of the guide roller 42A.

The guide roller 42B is provided to prevent wrinkles and slack in the film 8 cooled by the raw fabric cooling device 4 shown in FIG. 1. As shown in FIG. 1, in order to increase the contact area between the raw fabric cooling device 4 and the film 8, the guide roller 4A is provided between the raw fabric cooling device 4 and the tensioning mechanism 40A, and the guide roller 4A is provided at a higher position than the raw fabric cooling device 4. The guide roller 42B shown in FIG. 7 is provided at a lower position than the guide roller 4A (see FIG. 1) in order to prevent wrinkles and slack in the film 8. In addition, it is preferable that the height difference between the guide roller 42B and the guide roller 4A is large. In the example shown in FIG. 7, the installation surface FL is used as the reference surface, and the guide roller 42B is provided at a lower position (closer to the installation surface FL) than the guide rollers 42A and 42C and the drive roller 41.

The guide roller 42D is provided to prevent interference between the film 8 transported between the guide roller 42B and the drive roller 41 and the guide roller 42C. The guide roller 42D is located at a higher position than the guide roller 42C. If the guide roller 42D is not provided, the film 8 is transported linearly from the guide roller 42B shown in FIG. 7 toward the drive roller 41, so there is a possibility that the guide roller 42C and the film 8 may interfere with each other. To avoid this interference, the position of the guide roller 42C is restricted. As shown in FIG. 7, when the guide roller 42D is provided between the drive roller 41 and the guide roller 42B, and the transport path of the film 8 is configured so that the guide rollers 42B, 42D, and the drive roller 41 contact the film 8 in this order, the guide roller 42D can prevent interference between the film 8 and the guide roller 42C. In this case, the design freedom for determining the position of the guide roller 42C increases, so the guide roller 42C can be placed at an optimal position, taking into consideration the above-mentioned resistance force imparting characteristics and the durability of the guide roller 42C.

<Modification>
FIG. 9 is a side view showing a modified example of FIG. 7. The tensioning mechanism 40B shown in FIG. 9 differs from the tensioning mechanism 40A shown in FIG. 7 in the height of the guide roller 42B and in the absence of the guide roller 42D shown in FIG. 7. In the case of the tensioning mechanism 40B, the guide roller 42B is disposed at a position higher than the driving roller 41. More specifically, the lower end of the guide roller 42B is at the same height as the upper end of the driving roller 41. The above-mentioned "same height" includes not only the case where the height is strictly the same, but also the case where there is an error of the range of the thickness of the film 8 disposed in the tensioning mechanism 40B. If the error is of this magnitude, the height can be regarded as substantially the same. In the case of the tensioning mechanism 40B, even if the guide roller 42D shown in FIG. 7 is not provided, the guide roller 42C and the film 8 do not interfere with each other. In addition, the design freedom regarding the position of the guide roller 42C is not particularly restricted. However, the height difference between the guide roller 42B and the guide roller 4A (see FIG. 1) is smaller than that of the example shown in FIG. 7.

Although not shown, as a modified example of the embodiment shown in FIG. 7, the guide roller 42A may not be arranged. In this case, the installation surface FL is used as the reference surface, and the height of the lower end of the guide roller 42C must be arranged so that it matches the height of the front surface 8f of the film 8 at the entrance section 14. From the viewpoint of making it easier to control the height of the back surface 8b of the film 8 supplied to the entrance section 14, it is particularly preferable that the guide roller 42A is arranged so that it contacts the back surface 8b of the film 8.

Figure 10 is a side view showing a modified example of Figure 9. The tension applying mechanism 40C shown in Figure 10 differs from the tension applying mechanism 40A shown in Figure 7 and the tension applying mechanism 40B shown in Figure 9 in that the guide roller 42C is positioned higher than the drive roller 41. The structure of the tension applying mechanism 40C is a structure in which the positions of the drive roller 41 and the guide roller 42B are inverted upside down compared to the tension applying mechanism 40B shown in Figure 9.

The tensioning mechanism 40C differs from the tensioning mechanism 40A shown in FIG. 7 and the tensioning mechanism 40B shown in FIG. 9 in that the front surface 8f of the film 8 contacts the drive roller 41 and the back surface 8b of the film 8 contacts the guide roller 42C. The tensioning mechanism 40C is similar to the tensioning mechanism 40A shown in FIG. 7 in that the drive roller 41, which is the start of the return path, contacts one surface (front surface 8f) of the film 8, and the guide roller 42C, which is the end, contacts the other surface (back surface 8b) of the film 8 in the transport path of the film 8 in the tensioning mechanism 40C. Therefore, the tensioning mechanism 40C can also apply the above-mentioned resistance to the film 8 containing oil.

Tensioning mechanism 40C also differs from tensioning mechanism 40B shown in FIG. 9 in that guide roller 42B is positioned higher than guide roller 42A. In this case, the height difference between guide roller 42B and guide roller 4A (see FIG. 1) can be made larger than in the example shown in FIG. 9.

Figure 11 is a side view showing another modified example of Figure 7. The tension applying mechanism 40D shown in Figure 11 differs from the tension applying mechanism 40A shown in Figure 7 in that it further has a nip roller 43. The nip roller 43 operates to pinch the film 8 between itself and the drive roller 41 and press it against the drive roller 41. As shown in Figure 11, the back surface 8b of the film 8 contacts the drive roller 41, and the front surface 8f of the film 8 contacts each of the guide roller 42C and the nip roller 43.

The nip roller 43 has the same structure as the nip roller 43 described with reference to FIG. 8. The nip roller 43 is disposed in a position facing the drive roller 41. For example, the surface of the nip roller 43 is covered with a polymer resin film such as silicone, and this polymer resin film comes into contact with the film 8. However, in the case of this modified example, the purpose of using the nip roller 43 is different from the example shown in FIG. 8. That is, when the nip roller 43 comes into contact with the film 8, oil is seeped onto the surface of the film 8. For this reason, the frictional resistance between the film 8 and the nip roller 43 is small. Therefore, the role of the nip roller 43 is small from the viewpoint of applying resistance to the film 8 by pressing the nip roller 43 against the film 8.

However, the inventor of the present application found that pressing the nip roller 43 against the film 8 can be expected to have the effect of removing or reducing the oil that has seeped out onto the surface of the film 8. As shown in FIG. 11, when the nip roller 43 arranged above the drive roller 41 comes into contact with the front surface 8f of the film 8, at least a part of the oil that has seeped out onto the surface of the front surface 8f is removed by the nip roller 43. As a result, the front surface 8f side of the film 8 becomes less slippery than before it comes into contact with the nip roller 43. In this state, the front surface 8f of the film 8 comes into contact with the guide roller 42C, so that the frictional resistance at the contact interface between the guide roller 42C and the film 8 increases compared to the example shown in FIG. 7. As a result, the guide roller 42C can apply the above-mentioned resistance force to the film 8 more efficiently compared to the example shown in FIG. 7.

In this way, according to this modified example, the frictional resistance between the guide roller 42C and the membrane 8 can be increased by draining the oil from the front surface 8f, which is the contact interface between the membrane 8 and the guide roller 42C, just before the membrane 8 and the guide roller 42C come into contact with each other.

Note that while FIG. 11 shows a representative modified example of FIG. 7, a nip roller 43 shown in FIG. 11 may be added as a modified example of the tensioning mechanism 40B shown in FIG. 9 or the tensioning mechanism 40C shown in FIG. 10. For example, when adding a nip roller 43 (see FIG. 11) to the tensioning mechanism 40C shown in FIG. 10, the nip roller 43 is added below the drive roller 41 in FIG. 10. In this case, the front surface 8f of the film 8 contacts the drive roller 41, and the back surface 8b of the film 8 contacts each of the guide roller 42C and the nip roller 43.

Figure 12 is a side view showing another modified example of Figure 7. Figure 13 is a side view showing a modified example of Figure 12. The tension applying mechanism 40E shown in Figure 12 differs from the tension applying mechanism 40A shown in Figure 7 in that it further includes a tension measuring unit 45 that measures the tension applied to the membrane 8, and a control unit 46 that controls the driving force for transporting the membrane 8 based on the measurement result by the tension measuring unit 45.

When the tension applying mechanism 40E is equipped with a tension measuring unit 45 and a control unit 46, the driving force for transporting the membrane 8 can be automatically adjusted according to the degree of tension 8T (see FIG. 2) applied to the membrane 8. This allows an appropriate tension 8T to be continuously maintained. On the other hand, in the case of each of the tension applying mechanism 40A shown in FIG. 7 to the tension applying mechanism 40D shown in FIG. 11, when the membrane 8 is pulled in the forward direction X1 at the inlet 14, a force that resists the force pulling the membrane 8 is applied with a preset tension 8T. This means that it is necessary to manually adjust the force pulling the membrane 8 in the forward direction X1 to balance the preset tension 8T.

The function of adjusting the driving force for transporting the membrane 8 using the tension measuring unit 45 and the control unit 46 shown in FIG. 12 is effective when the driving force is insufficient to prevent slack in the membrane 8, or when the pulling force in the forward direction X1 becomes excessively large due to a malfunction of the drive system.

There are various variations in the method of measuring the tension of the membrane 8 and the method of controlling the driving force for transporting the membrane 8 based on the measurement results, but the following provides an illustrative explanation of representative and preferred embodiments.

In the example shown in FIG. 12, the tension measuring unit 45 has a dancer roller 45A, a support plate 45B, a fulcrum 45C, and a sensor 45D. The film 8 is transported in a direction from the guide roller 42C toward the dancer roller 45A and from the dancer roller 45A toward the guide roller 42A. The transport direction from the guide roller 42C to the dancer roller 45A is different from the transport direction from the dancer roller 45A to the guide roller 42A. In addition, the transport direction from the guide roller 42C to the dancer roller 45A and the transport direction from the dancer roller 45A to the guide roller 42A are different from the transport direction from the guide roller 42D to the drive roller 41 and the transport direction from the drive roller 41 to the guide roller 42C. The tension measuring unit 45 measures the tension of the film 8 between the guide roller 42C and the dancer roller 45A, and between the guide roller 42A and the dancer roller 45A.

The dancer roller 45A is in contact with the film 8 and supported so as to be movable in the height direction (Z direction shown in FIG. 12) of the tension applying mechanism 40E according to the tension of the film 8. The support plate 45B is attached to the fulcrum 45C fixed to the housing 47 so as to be rotatable about the fulcrum 45C fixed to the housing 47 as the center of rotation, and is structured to support the dancer roller 45A at the end opposite to the connection with the fulcrum 45C. Therefore, the dancer roller 45A moves along an arc trajectory centered on the fulcrum 45C. The sensor 45D is fixed to the housing 47 and detects the movement direction and the degree of movement of the dancer roller 45A. The sensor 45D is, for example, an infrared sensor, and detects the rotation angle of the support plate 45B or the position of the dancer roller 45A to detect the movement direction and the degree of movement of the dancer roller 45A. As shown typically by a solid line in FIG. 12, the sensor 45D is electrically connected to the control unit 46.

The measurement results detected by the sensor 45D are transmitted to the control unit 46 as an electrical signal. The control unit has a processing circuit that processes the data transmitted from the sensor 45D, and an arithmetic processing circuit that generates a drive signal for driving the drive device of the stretching device 5 based on the processing results. The drive device of the stretching device 5 includes, for example, sprockets 31, 32, and 33 shown in FIG. 2, and drive roller 41 shown in FIG. 12. These drive devices are driven based on the drive signal transmitted from the control unit 46.

For example, if the driving force for transporting the film 8 becomes stronger and the strength of pulling the film 8 in the forward direction X1 at the inlet 14 increases, the dancer roller 45A rises along the above-mentioned arcuate track. In this case, the sensor 45D detects the degree of rise of the dancer roller 45A and transmits a data signal to the control unit 46. The extension processing circuit of the control unit 46 compares the measurement result after processing by the data processing circuit with a preset threshold value. For example, if the measurement result is greater than the upper threshold value, a drive signal is generated for the sprockets 31, 32, and 33 shown in FIG. 2 to reduce the rotation speed. Also, if the measurement result is extremely greater than the upper threshold value, a drive signal is generated for the sprockets 31, 32, and 33 to stop rotating. As a result, the strength of pulling the film 8 in the forward direction X1 is appropriately adjusted, and the dancer roller 45A descends to a predetermined position.

For example, when the strength of pulling the film 8 in the forward direction X1 at the inlet 14 is small, the dancer roller 45A descends along the above-mentioned arcuate trajectory due to its own weight. In this case, the sensor 45D detects the degree of descent of the dancer roller 45A, and a data signal is transmitted to the control unit 46. The extension processing circuit of the control unit 46 compares the measurement result after processing by the data processing circuit with a preset threshold value. For example, when the measurement result is smaller than the lower threshold value, a drive signal is generated for the sprockets 31, 32, and 33 shown in FIG. 2 to increase the rotational speed. As a result, the strength of pulling the film 8 in the forward direction X1 is appropriately adjusted, and the dancer roller 45A rises to a predetermined position.

The tension measuring unit 45 only needs to measure the balance between the force pulling the film 8 in the forward direction X1 at the entrance 14 and the tension applied to the film 8, so the position of the dancer roller 45A can be variously modified in addition to the tension applying mechanism 40E shown in FIG. 12. However, as shown in FIG. 12, it is preferable that the dancer roller 45A is disposed at a position farther from the entrance 14 (in other words, from the stretching processing unit 11 in FIG. 2) than the guide roller 42A. This allows the area occupied by the tension applying mechanism 40E to be reduced.

Also, as shown in FIG. 12, when the fulcrum 45C is fixed to the side wall of the housing 47, the radius of rotation of the support plate 45B increases by increasing the distance between the dancer roller 45A and the side wall of the housing 47, so that the movable distance of the dancer roller 45A in the Z direction can be increased. On the other hand, the size of the housing 47 can be reduced by reducing the distance of the guide roller 42A from the side wall of the housing 47. Therefore, as shown in FIG. 12, it is preferable that the dancer roller 45A is disposed farther from the entrance portion 14 (in other words, from the stretching processing portion 11 in FIG. 2) than the guide roller 42A.

In addition, the driving roller 41 is positioned higher than the guide roller 42A, with the installation surface FL of the stretching device 5 as the reference surface. The guide roller 42C is positioned lower than the driving roller 41 and the guide roller 42A. The dancer roller 45A is positioned lower than the guide roller 42C. As described above, the dancer roller 45A measures the tension by using its own weight. As shown in FIG. 13 as a modified example of the tension applying mechanism 40F, by adding the guide rollers 42E and 42F, it is also possible to realize a structure in which the dancer roller 45A is positioned higher than the guide roller 42C. However, as can be seen by comparing FIG. 12 with FIG. 13, when the dancer roller 45A is positioned lower than the guide roller 42C, the structure of the tension applying mechanism 40E can be simplified.

Also, as shown in FIG. 12, the guide roller 42C is disposed at a position farther from the entrance section 14 (in other words, from the stretching processing section 11 in FIG. 2) than the dancer roller 45A. Although not shown, as a modified example of the tension applying mechanism 40E, the dancer roller 45A may be disposed at a position farther from the entrance section 14 (in other words, from the stretching processing section 11 in FIG. 2) than the guide roller 42C. However, in this case, the contact area between the film 8 and the guide roller 42C is smaller than in the example shown in FIG. 12. Therefore, from the viewpoint of increasing the contact area between the guide roller 42C that applies resistance to the film 8 and the film 8, it is preferable that the guide roller 42C is disposed at a position farther from the entrance section 14 (in other words, from the stretching processing section 11 in FIG. 2) than the dancer roller 45A, as shown in FIG. 12.

Note that FIG. 12 shows a representative modified version of FIG. 7. However, as a modified version of tension applying mechanism 40B shown in FIG. 9 or tension applying mechanism 40D shown in FIG. 11, a tension measuring unit 45 and control unit 46 shown in FIG. 12 may be added. Tension applying mechanism 40F shown in FIG. 13 is a modified version of tension applying mechanism 40C shown in FIG. 10.

The invention made by the inventor has been specifically described above based on the embodiment and examples, but it goes without saying that the present invention is not limited to the above embodiment or examples, and various modifications are possible without departing from the gist of the invention.

For example, the above-mentioned stretching device 5 is particularly effective when used to stretch membranes that contain oil, such as battery separators, but it can also be used to stretch membranes that do not contain oil.

1 Thin film manufacturing system 2 Kneading extrusion device (twin-screw kneading extrusion device)
2A Raw material supply section 3 T-die 4 Raw material cooling device 4A Guide roller (roller)
5 Stretching device (simultaneous biaxial stretching device)
6 Take-up device 7 Winding device 8 Film 8b Back surface 8f Front surface 8F Contraction force 8T Tension 10A, 10B Link device 11 Stretching processing section 12 Heat processing section 13A, 13B Rail 14 Inlet section (inlet side)
15 Exit part (exit side)
16 Cover 16s Side 20 Link 21 Clip 21A Spring 21B Grip portion 22 Upper stage side link plate 23 Lower stage side link plate 24, 25 Rail holder 26, 27 Shaft 28 Pin 29 Engagement portion 31, 32, 33 Sprocket 40A, 40B, 40C, 40D, 40E, 40F, 40Z Tension imparting mechanism portion 41 Drive roller (roller)
42, 42A, 42B, 42C, 42D, 42E, 42F Guide rollers (rollers)
43 Nip roller (roller)
44 Motor 45 Tension measuring unit 45A Dancer roller (roller)
45B Support plate 45C Support point 45D Sensor 46 Control unit 47 Housing FL Installation surface X1 Forward direction X2 Reverse direction θ1 Angle

Claims (21)

A stretching apparatus, comprising:
a stretching treatment section for stretching the oil-containing resin film;
a tension applying mechanism that applies tension to the resin film and supplies the resin film to the stretching processing unit;
Where:
The tension applying mechanism includes:
a first roller, a second roller and a third roller for transporting the resin film and supplying it to the stretching processing section;
the resin film is transported in a first direction from the first roller to the second roller and in a second direction from the second roller to the third roller;
the first direction is a forward direction from the tension applying mechanism toward the stretching processing unit,
The second direction is a reverse direction that is opposite to the forward direction . the tension applying mechanism has a nip roller facing the second roller,
The stretching device according to claim 1 , wherein a portion of the oil is removed by contacting the resin film with the second roller and the nip roller. The tension applying mechanism includes:
a tension measuring unit that measures the tension applied to the resin film;
The stretching apparatus according to claim 1 , further comprising a control unit that controls a driving force for transporting the resin film based on a measurement result by the tension measuring unit. The tension applying mechanism further includes a fourth roller and a dancer roller,
the resin film is transported in a third direction from the third roller toward the dancer roller and in a fourth direction from the dancer roller toward the fourth roller,
the third direction and the fourth direction are different directions,
the third and fourth directions are different from the first and second directions, respectively;
The stretching apparatus according to claim 3 , wherein the tension measuring unit measures the tension of the resin film between the third roller and the dancer roller and between the fourth roller and the dancer roller. The stretching device according to claim 1, wherein the third roller is positioned at a height different from that of the second roller and is located farther from the stretching processing section than the second roller. the tension applying mechanism has a nip roller facing the second roller,
the resin film has one surface and another surface opposite to the one surface,
The stretching device according to claim 1 , wherein the one surface of the resin film contacts the second roller, and the other surface of the resin film contacts each of the third roller and the nip roller. The tension applying mechanism includes:
a fourth roller provided for adjusting a height of the resin film supplied to the stretching processing section, the fourth roller being brought into contact with the resin film after the third roller and the resin film have come into contact with each other;
a dancer roller that comes into contact with the resin film and is movable in a height direction of the tension applying mechanism in response to the tension of the resin film;
a support plate for supporting the dancer rollers in a state capable of moving in accordance with the movement of the dancer rollers;
and
the tension measuring unit has a sensor for detecting a direction of movement and an amount of movement of the dancer roller,
The stretching apparatus according to claim 3 , wherein the dancer rollers are disposed at a position farther from the stretching processing section than the fourth roller. the second roller is disposed at a higher position than the fourth roller,
the third roller is disposed at a lower position than the first roller and the second roller,
The drawing apparatus according to claim 7 , wherein the dancer roller is disposed at a lower position than the third roller. The stretching device according to claim 8, wherein the third roller is disposed at a position farther from the stretching processing section than the dancer roller. The stretching device according to claim 2, wherein the surface of the nip roller is covered with a polymer resin film. The tension applying mechanism includes:
a fourth roller that comes into contact with the resin film after the third roller comes into contact with the resin film; and
a fifth roller that contacts the resin film before the first roller;
having
The stretching apparatus according to claim 1 , wherein the fifth roller is disposed at a lower position than each of the first and fourth rollers. A stretching apparatus, comprising:
a stretching treatment section for stretching the oil-containing resin film;
a tension applying mechanism that applies tension to the resin film and supplies the resin film to the stretching processing unit;
Where:
The tension applying mechanism includes:
a first roller, a second roller and a third roller for transporting the resin film and supplying it to the stretching processing section;
the resin film is transported in a first direction from the first roller to the second roller and in a second direction from the second roller to the third roller;
the first direction and the second direction are different directions,
The third roller is located at a height different from that of the second roller and is disposed at a position farther from the stretching processing section than the second roller. the tension applying mechanism has a nip roller facing the second roller,
The stretching apparatus according to claim 12 , wherein a portion of the oil is removed by contacting the resin film with the second roller and the nip roller. The tension applying mechanism includes:
a tension measuring unit that measures the tension applied to the resin film;
The stretching apparatus according to claim 12 , further comprising a control unit that controls a driving force for transporting the resin film based on a measurement result by the tension measuring unit. The tension applying mechanism further includes a fourth roller and a dancer roller,
the resin film is transported in a third direction from the third roller toward the dancer roller and in a fourth direction from the dancer roller toward the fourth roller,
the third direction and the fourth direction are different directions,
the third and fourth directions are different from the first and second directions, respectively;
The stretching apparatus according to claim 14 , wherein the tension measuring unit measures the tension of the resin film between the third roller and the dancer roller and between the fourth roller and the dancer roller. the tension applying mechanism has a nip roller facing the second roller,
the resin film has one surface and another surface opposite to the one surface,
The stretching device according to claim 12 , wherein the one surface of the resin film contacts the second roller, and the other surface of the resin film contacts each of the third roller and the nip roller. The tension applying mechanism includes:
a fourth roller provided for adjusting a height of the resin film supplied to the stretching processing section, the fourth roller being brought into contact with the resin film after the third roller and the resin film have come into contact with each other;
a dancer roller that comes into contact with the resin film and is movable in a height direction of the tension applying mechanism in response to the tension of the resin film;
a support plate for supporting the dancer rollers in a state capable of moving in accordance with the movement of the dancer rollers;
and
the tension measuring unit has a sensor for detecting a direction of movement and an amount of movement of the dancer roller,
The stretching apparatus according to claim 14, wherein the dancer roller is disposed at a position farther from the stretching processing section than the fourth roller. the second roller is disposed at a higher position than the fourth roller,
the third roller is disposed at a lower position than the first roller and the second roller,
18. The drawing apparatus according to claim 17, wherein the dancer roller is disposed at a lower position than the third roller. The stretching device according to claim 8, wherein the third roller is disposed at a position farther from the stretching processing section than the dancer roller. The stretching device according to claim 13, wherein the surface of the nip roller is covered with a polymer resin film. The tension applying mechanism includes:
a fourth roller that comes into contact with the resin film after the third roller comes into contact with the resin film; and
a fifth roller that contacts the resin film before the first roller;
having
The drawing apparatus according to claim 12, wherein the fifth roller is disposed at a lower position than each of the first and fourth rollers.

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