JP4224241B2 - Simultaneous 2-axis tenter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stretching apparatus used for film production and the like, and more particularly to a simultaneous biaxial tenter capable of varying a stretching ratio.
[0002]
[Prior art]
In order to increase the strength at the time of film production and to obtain a film having an appropriate thickness, it is customary to perform stretching. As for the stretching, there are a method of stretching in the transport direction by a roll while transporting, and a method of stretching in a direction orthogonal to the transport direction by a tenter.
Further, there is a method called a simultaneous biaxial tenter in which a special tenter is used to simultaneously stretch in the conveyance direction and the orthogonal direction. The simultaneous biaxial tenter is used at the time of film production of nylon, PET, polyolefin and the like. In such a simultaneous biaxial stretching tenter, a pantograph or a screw is usually used as a clip mechanism that fixes the film at both ends thereof and controls conveyance and stretching.
[0003]
However, since the clip mechanism in the simultaneous biaxial tenter has a complicated structure, the transverse stretch ratio of the film can be freely adjusted within the rail movement range by providing a means for changing the rail interval along which the clip mechanism follows. However, there was a problem that the longitudinal draw ratio had to be fixed.
[0004]
In order to make this longitudinal stretch ratio free, linear motor tenters have recently appeared (for example, Katsuya Ito, “Technology Trends of Flat Film Stretch Molding”, Plastic Age, P107, Aug 2000), but the cost of manufacturing equipment is increased. However, the fact is that the introduction is not progressing.
[0005]
[Problems to be solved by the invention]
The present invention was created in view of the above-described problems of the prior art, and is to provide a coaxial biaxial tenter capable of setting a plurality of longitudinal stretching ratios with a low-cost configuration.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides the following simultaneous biaxial tenter. That is, a plurality of clip mechanisms that are connected by a pantograph and grip a film have a transport mechanism that is transported along a rail to transport the film,
A simultaneous biaxial tenter having a stretching mechanism in which the film is stretched in the transverse direction due to widening of the interval between the rails, and the film is stretched in the longitudinal direction in accordance with the expansion of the pantograph, Within the range of magnification, the longitudinal stress of the film is configured to be freely changeable by configuring the stretching stress so that it can be released.
[0007]
A desired longitudinal stretching ratio and a lateral stretching ratio are obtained by setting the interval between the rails to an interval at which a desired lateral stretching ratio is obtained. With this configuration, it is possible to obtain a stretching ratio of Nozomu Tokoro.
[0008]
The stretching stress is released by releasing the clip mechanism or slitting the film.
[0009]
The clip mechanism has a gripping part for gripping the film and a chuck connected from the gripping part via a link part, and the gripping part grips the film by the gripping part by contacting the chuck opener. Is released, and the stretching stress is released. And the desired longitudinal stretch ratio can be obtained by changing the arrangement position of the chuck opener .
[0010]
Moreover, shrinkage | contraction of a film can be suppressed by pinching and conveying the film which canceled the extending | stretching stress with a pinch guider.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be specifically described below with reference to the drawings. According to the present invention, it is possible to provide a coaxial biaxial tenter that is within the design longitudinal stretch ratio range but can take a desired longitudinal stretch ratio without replacing a pantograph, a rail, or the like. In addition, as embodiment of this invention, it can change arbitrarily limited to the following.
[0012]
FIG. 1 shows a plan view of an example of a simultaneous biaxial tenter (hereinafter referred to as a tenter) according to the present invention. In this embodiment, a PET film is manufactured using a tenter having a design draw ratio of 7 × 7, and the film is produced at two draw ratios of 7 × 7 and 5 × 5. The material of the film is arbitrary, and may be nylon or polyolefin.
The unstretched film (1) enters the tenter from the direction of the arrow in the figure, and is conveyed while being gripped at both ends by the conveying mechanisms (2) and (3) arranged on the left and right of the tenter.
[0013]
FIG. 2 is a plan view for explaining the clip mechanism of the transport mechanisms (2) and (3), FIG. 3 is a front view thereof, and FIG. 4 is a side view showing a gripping / releasing state of each clip mechanism.
In FIG. 2, each clip mechanism (10) (10) (10) (10) is connected by a pantograph (11) (12) (14), and an end (12a) of the pantograph (12) is connected to a clip mechanism bar ( 13) is fitted in the groove (13a).
[0014]
FIG. 2 shows a state in which the pantographs (11) and (12) are expanded. When the pantographs (11) and (12) are contracted, the end part (12a) slides in the groove (13a). 13), and the pantograph (14) is refracted at the connecting portion (14a) with the adjacent pantograph (14) and becomes substantially parallel to the crosspiece (13).
[0015]
A large number of clip mechanisms (10) connected by such a pantograph are very continuous to form the transport mechanisms (2) and (3) in FIG. As shown in FIGS. 3 and 4, wheels (15) and (15) are arranged on the bottom of the crosspiece (13) of the clip mechanism, and the rails (4), (4), (5) and (5) shown in FIG. Each clip mechanism (10) is transferred by rotating up.
Particularly in the vicinity of the position A in the transport mechanism (2) (3), a guide (not shown) for narrowing the interval between the protrusions (16) and (16) is laid between the rails to contract the pantograph, while in the vicinity of the position B The pantograph is expanded by a guide that widens the interval between the protrusions (16) and (16).
[0016]
Further, (a) in FIG. 4 shows a state where the gripping part (17) for fixing the film is gripped, and (a) shows a state where the film is released. The gripping portion (17) is composed of an iron disc body on both the upper surface (17a) and the lower surface (17b) and is magnetized so that the film can be firmly fixed in the gripping state.
[0017]
The upper surface (17a) is connected to the chuck (19) by the link portion (18). While the chuck is tilted in the gripping state as shown in (a), the chuck (19) is upright in the released state, and the upper surface (17a) is At the same time as it rises, it moves to the pantograph side and escapes from the magnetizing action.
As described above, the clip mechanism (10) that can be effectively held and released by inverting the chuck (19) is configured.
[0018]
In the present embodiment, the transport mechanisms (2) and (3) hold the both ends of the film (1) at the position A and transport them in accordance with the transfer of the clip mechanism (10). And, at the position B, the gap between the rails (4) (4) and the rails (5) (5) is widened, so that the film (1) is stretched in the lateral direction, while the pantographs (11) (12) (13) The film is stretched in the longitudinal direction in accordance with the expansion. This is the configuration of simultaneous biaxial stretching.
[0019]
In conventional simultaneous biaxial stretching, gripping by the clip mechanism continues to the end of the transport mechanism (corresponding to position D), and a chuck opener is provided at the end, and the film shrinks due to stress as the chuck opens. To do. The dotted line (1 ′) in FIG. 1 indicates the shape of the film in the conventional configuration.
[0020]
Thus, in the conventional simultaneous biaxial tenter, the stretch ratio of the film is fixed, and even if the transverse stretch ratio is changed by changing the rail interval, the longitudinal stretch ratio depending on the interval of the clip mechanism is changed. I wasn't able to. Therefore, in order to cope with a plurality of draw ratios, the configuration of the tenter has to be changed, and a flexible manufacturing process cannot be realized at a very high cost.
[0021]
In this invention, the tenter which can arrange | position a chuck | zipper opener (20) in arbitrary site | parts is created, and the filter of several draw ratio is manufactured.
The chuck opener (20) is made of a resin having a substantially triangular pyramid shape, and the chuck (19) is gradually brought upright by one surface of the side abutting against the pantograph side of the chuck (19), so that the gripping part (17) To cancel. The state of a in FIG. 3 shows a state in which contact with the chuck opener (20) has started, and b shows a state in which the chuck is upright and the grip is released. The state of b in FIG. 3 is the state of the clip mechanism (10) at the position C in FIG.
[0022]
This tenter having a design draw ratio of 7 × 7 is adjusted so as to shrink to a design ratio after passing the position D in the conventional configuration. However, according to this configuration, since the gripping can be finished at an arbitrary position in the transport mechanism (2) (3), for example, when a stretch ratio of 5 × 5 is desired, for example, a clip mechanism ( 10) is released and the desired 5 × 5 stretch is obtained by shrinkage due to stress.
[0023]
Similarly, according to this configuration, it is possible to realize an arbitrary stretch ratio by simply changing the position where the chuck opener (20) is disposed.
Note that the chuck opener (20) is arranged based on the desired longitudinal stretching ratio, and the distance between the rails (4) (4) and (5) (5) is adjusted in order to obtain the desired lateral stretching ratio. Therefore, the change of the rail interval can be easily handled by moving the transport mechanisms (2) and (3).
[0024]
The arrangement position of the chuck opener (20) may be configured so that it can be selected for each longitudinal stretching ratio in consideration of shrinkage stress in advance according to the material of the film. That is, at a stretching ratio of 3 to 10 times suitable for using the tenter in the present invention, when using PET, a chuck opener position to obtain a stretching ratio of 3 times, a position of 4 times,... It can be specified in advance and can be configured to realize a desired draw ratio immediately.
[0025]
In the above embodiment, the clip mechanism (10) is used as the fixing device, and the stretching stress is released by releasing the grip. However, in the present invention, the stretching stress is not necessarily released by the presence or absence of fixing by the fixing device. It can also be released by slitting the film.
In the case of slitting the film, a member that prevents propagation, such as a roller, may be disposed immediately before the cutter so that the slit does not propagate upstream of the conveyance.
[0026]
Furthermore, in this invention, the shrinkage | contraction inhibitor (30) shown in FIG. 5 can be arrange | positioned, and a more exact draw ratio can also be implement | achieved.
The shrinkage suppressor (30) includes a pinch guider (31) composed of two rollers for sandwiching the film, a support base (32) for pivotally supporting the pinch guider (31), and a support base (32) by screw feed. It is comprised from the transfer part (33) moved substantially parallel to a conveyance direction, and the guide rail (34) holding a support stand (32) at the time of transfer.
[0027]
The guide rail (34) is fixed to the angle (21) provided on the transport mechanism (2) with a pin (22), and as shown in FIG. Install.
A plurality of pairs of pin guiders (31) are arranged at positions facing the conveying mechanism (2) side and the (3) side at appropriate intervals with the screw of the transfer section (33).
[0028]
The two rollers of the pinch guider (31) press each other, and the film (1) is sandwiched therebetween. Since the film (1) is being conveyed, the shrinkage in the width direction of the film (1) is suppressed while the roller rotates.
At this time, the pinch guider (31) is tilted so that the open end side is on the upstream side in the transport direction of the film (1), thereby acting in the direction in which the film (1) is stretched, and more effectively suppressing shrinkage.
[0029]
Here, the guide rail (34) can be appropriately set in the present invention, but it is desirable that the guide rail (34) has an inclination of approximately 5 degrees to 20 degrees inward from the film conveyance direction, and at a smaller angle than this, If the angle cannot be followed by the contraction, and the angle is larger than that, the contraction is too large.
[0030]
The arrangement interval between the pinch guider (31) and the support base (32) can also be set as appropriate depending on the characteristics of the material, temperature, etc. Generally, it is preferable to provide the interval between about 50 cm to 100 cm from the time when the grip is released. .
More preferably, it is arranged at an interval of about 50 cm in the vicinity of the release point, and at an interval of about 100 cm in the vicinity of the end of the transport mechanism. This is because the shrinkage of the film is intense near the release point and a lot of support is required, but the shrinkage is suppressed near the end, and the main purpose is to transport the film stably. is there.
In particular, since the pinch guider acts to stretch the film, it tends to cause distortion, and an unnecessary arrangement is not preferable.
[0031]
The tenter in the present invention has the above-described configuration, and a specific operation example is shown below.
For example, when it is desired to stretch at a stretch ratio of 5 × 5, first stretch is performed at the design ratio (in this case, 7 × 7), and a pass line is performed.
Next, the chuck opener (20) is operated, both ends of the film (1) that has come out are pinched by the pinch guider (31), and the transfer unit (33) is operated, whereby the pinch guider (31) is placed in the tenter. Transfer sequentially.
[0032]
When the pinch guider (31) is transferred in this way, the shrinkage of the film is suppressed, so that the inclination of the guide rail (34) is adjusted according to the suppression amount.
Through the above steps, a desired 5 × 5 film is unloaded from the end portions of the transport mechanisms (2) and (3).
[0033]
The pinch guider is used as a fixing device, and the conveyance / stretching of the film is governed by gripping / releasing the pinch guider, but the present invention is not limited to the above, and the position of the fixing device in the tenter can be fixed with a configuration capable of fixing the film. Any configuration that can change the draw ratio by changing is included in the present invention. The structure of the fixing device can be arbitrarily changed.
[0034]
【The invention's effect】
The simultaneous biaxial tenter of the present invention is provided with the above-described configuration, thereby realizing a variable stretch ratio, which was difficult with the conventional simultaneous biaxial tenter.
That is, a desired longitudinal stretching ratio can be obtained within the design longitudinal stretching ratio range by changing the stretching stress release position and without performing expensive changes such as replacement of a pantograph or rail. This contributes to cost reduction of the manufacturing system, and various films can be manufactured quickly.
[0035]
In particular, the configuration for changing the position of the fixing device for applying / releasing the stretching stress can be realized by using the existing fixing device, so that the cost can be reduced and the introduction is extremely easy.
[0036]
Moreover, by providing a shrinkage suppressor in the present invention, the unstable shrinkage of the film is suppressed, contributing to accurate film production. A highly accurate film leads to high added value of the product, and can improve the production efficiency.
[Brief description of the drawings]
FIG. 1 is a plan view of a simultaneous biaxial tenter according to the present invention.
FIG. 2 is a plan view illustrating a clip mechanism.
FIG. 3 is a front view of the same.
FIG. 4 is a side view showing a gripping / releasing state of each clip mechanism.
FIG. 5 is a perspective explanatory view of a shrinkage suppressor.
[Explanation of symbols]
Position of clip mechanism b Position of clip mechanism 10 Clip mechanism 12 Pantograph 13 Cross section 14 Pantograph 14a Same as above, Connection section 15 Wheel 20 Chuck releaser 21 Angle 22 Screw 31 Pinch guider 32 Support base 33 Transfer section 34 Guide rail

Claims (7)

A plurality of clip mechanisms that are connected by a pantograph and grip a film have a transport mechanism that is transported along a rail to transport the film,
Due to the wide spacing between the rails, the film is stretched in the transverse direction,
In accordance with the expansion of the pantograph, a simultaneous biaxial tenter having a stretching mechanism in which the film is stretched in the longitudinal direction,
By configuring the stretching stress to be freely releasable within the design longitudinal stretching ratio range ,
A simultaneous biaxial tenter characterized in that the longitudinal stretch ratio of the film can be freely changed .   The simultaneous biaxial tenter according to claim 1, wherein a desired longitudinal draw ratio and a transverse draw ratio are obtained by setting the interval between the rails to an interval at which a desired transverse draw ratio is obtained.   The simultaneous biaxial tenter according to claim 1 or 2, wherein the stretching stress is released by releasing the gripping of the clip mechanism.   The simultaneous biaxial tenter according to claim 1 or 2, wherein the stretching stress is released by a slit of the film. The clip mechanism has a grip part for gripping the film, and a chuck connected from the grip part via a link part,
4. The simultaneous biaxial tenter according to claim 3, wherein when the chuck comes into contact with the chuck opener, the gripping of the film by the gripping part is released and the stretching stress is released.   6. The simultaneous biaxial tenter according to claim 5, wherein a desired longitudinal stretching ratio is obtained by changing a position where the chuck opener is disposed.   The simultaneous biaxial tenter according to any one of claims 1 to 6, wherein the film is released from the stretching stress and is conveyed by pinching with a pinch guider to suppress shrinkage of the film.

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