JPH0637080B2 - Simultaneous biaxial stretching device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a simultaneous biaxial stretching device equipped with an endless link device for continuously stretching a plastic film or sheet biaxially in the longitudinal and transverse directions. Simultaneous 2 which is particularly suitable when a shrinking step is provided in the machine direction and the transverse direction after stretching.
The present invention relates to an axial stretching device.

[Conventional technology]

As a conventional simultaneous biaxial stretching device, Jitsuko Sho 45-6785
JP-A-59-67015 and JP-A-61-58723.
Has been proposed in the issue. The device disclosed in Japanese Utility Model Publication No. 45-6785 will be described with reference to FIG. 4. The sheet-like material 1 is continuously advanced in the direction of arrow A while its both ends are held by the holding device 2 of the endless link device 3. However, it is simultaneously stretched in two directions. The endless link device 3 is endlessly driven by the sprockets 7, 8 and 9, and its movement is restricted by the guide rails 4, 5 and 6 arranged on both sides of the sheet 1. B is a link pitch adjusting section, C is a sheet-shaped object gripping section in which the gripping device 2 grips both ends of the sheet-shaped object 1, and D is a sheet-shaped object 1 for stretching.
A preheating section for heating the sheet material, E a stretching section for simultaneously stretching the sheet material 1 in two directions, the F a heat treatment section for heat setting the stretched sheet material at a predetermined temperature, and G a gripping device 2.
Is a sheet-like object separating section for separating the sheet-like object 1, and L is a returning section of the endless link device 3. Link pitch adjustment section B
In order to reduce the driving power and smooth the link driving, a space ring is provided on the link shaft and the space rings are brought into contact with each other to transmit the driving force in the minimum pitch section. Also, JP-A-59-67015
For the purpose of stable running at high speed, the issue proposes that the running locus of the link device is restrained by guide rails to be endless rails.

[Problems to be Solved by the Invention]

The above-mentioned prior art does not take into consideration the behavior of simultaneous stretching and contraction in the vertical and horizontal directions after heat treatment, and there is a drawback that stable operation cannot be performed due to interference due to a difference in thermal expansion between the link device and the guide rail, and restraint. there were.

It is an object of the present invention to provide a simultaneous biaxial stretching device capable of maintaining a stable operating state for producing a sheet-like material having physical properties balanced in two directions.

[Means for Solving the Problems]

The purpose of the above is to draw a sheet-like material in two directions in the vertical and horizontal directions at the same time, and perform a heat treatment to shrink the machine in the horizontal direction and simultaneously shrink the machine in the machine direction. This is achieved by providing the necessary guide rails to the.

[Work]

The driving load is dispersed by the intermediate drive device provided in the heat treatment section, and the link initial device provided at the entrance of the contraction section allows the link device to smoothly operate the locus, so that the stretching section, the heat treatment section, the contraction section, It is possible to stabilize the pushing or pulling state of the link device in the cooling section.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. In FIG. 1, the unstretched flat film 1 is heated in the preheating section A by gripping both side edges in the gripping section K by the gripping apparatus 3 provided in the endless link device 2, and in the stretching section B in the two horizontal and vertical directions. After being simultaneously stretched and heat-treated in the heat treatment section C, the film is contracted in the contraction section D, cooled in the cooling section E, the film 1 is separated, and the film 1 is continuously advanced in the arrow direction through the section F. The endless link device 2 is guided by the guide rails 4, 5 and 6, and the sprockets 7, 8 and 9 provided at both ends and the intermediate drive device 2 are guided.
Driven by 1. The endless link forms the endless link device 2 by returning to the gripping section K through the return section G and the link pitch adjusting section J.

2 and 3 show details of the endless link device 2. Both ends of the pair of outer links 12 and 13 of equal length and the pair of inner links 14 and 15 are connected to each other in a folded shape by link shafts 16a and 16b, and the link shaft 16b is driven by being meshed with the sprocket described above. , Bearing rollers 17 and 18 provided at the lower ends of the link shafts 16a and 16b
Roll along the grooves formed by the guide rails 4, 6 and 4, 5, respectively. 19 is an endless link device 2
Is a roller chain that regulates the maximum pitch of the bearings, and 20 is a space ring attached to the upper portions of the bearing rollers 17 and 18. FIG. 2 shows a state in which each part of the link device 2 is completely opened, and the grip pitch P of the film 1 is given by Pmax. At this time, the dimension H between the link shafts is Hmin.
In this state, the bearing rollers 17, 18 are constrained to Hmin by the guide rails 4, 5, 6 and the roller chain 19 is pulled by the sprockets 7, 8, 9 in an unconstrained state. FIG. 3 shows bearing rollers 17 and 18
Shows a state in which the distance Hi between the link shafts 16a and 16b is increased by being restrained by the guide rails 4, 6 and 4, 5, and the roller chain 19 is folded in a folding shape, and the pitch of the gripping device 3 is Pi. Thus, the change in the grip pitch of the grip device 3 of the endless link device 2 by restraining the bearing rollers 17 and 18 by the guide rails 4, 5 and 6 is a basic structure for stretching the sheet-like material. . Grip pitch P in grip section K
Is defined as Pmin (H = Hmax), Pmin is a state in which adjacent space rings 20 are in contact with each other, and the sprocket 8
Is driven by pushing the space ring 20.
After traveling in the preheating section A, in the extension section B, the guide rails 4, 5, 6 regulate the guide rails 4, 5 and 6 so that the endless link device 2 gradually travels while opening from the state of Hmax to Hmin at the end of the extension section B and the grip pitch P. Varies from Pmin to Pmax. As a result, the film 1 is in the flow direction (longitudinal direction).
Since the guide rails 4, 5 and 6 are set to gradually open in the direction perpendicular to the flow direction of the film 1 at the same time when the film 1 is drawn, the film 1 is also drawn in the perpendicular direction (transverse direction) at the same time. It In the heat treatment section C, it is driven by the intermediate drive device 21 in a state where the longitudinal and transverse simultaneous stretching is completed. The intermediate drive device 21 drives the link shaft 16b in the traveling direction with the roller chain 19 fully opened. In the contraction section D, the film holding pitch P is reduced by only a few percent due to the regulation of the guide rails 4, 5 and 6 again, and the film is contracted in the longitudinal direction. Since the film 1 is also set to be gradually closed, the film 1 is contracted in the lateral direction at the same time. However, as shown in FIG. Since it is mechanically difficult to bend the roller chain 19 to a folding scale as shown in FIG. 3 only with the restraint of 6, the roller chain initial folding device 22 is installed at the initial position of the contraction section D. Roller chain initial folding device 22
Is to apply an acting force to the center pin portion in a direction perpendicular to the roller chain 19, and if only an initial trigger for the folding scale is given, then the guide rails 4, 5 and 6 are only restrained to a predetermined gripping pitch. Can be contracted up to.

In the sections A, B, C, D, E, F, the endless link device 2 is pushed by the sprocket 8 and finally pulled by the sprocket 9, but the position where the pushing force of the pulling force changes is the sprocket. 8 and 9, the intermediate drive device 21, the positional relationship between the roller chain initial folding device 22 and the number of link devices between them, the change points X ₁ , X ₂ , X ₃ are respectively X ₁ is a stretching section. The upstream side of B is adjusted to 0 to 1 / 5B, preferably 1 / 10B, X ₂ is adjusted between the intermediate drive device 21 and the roller chain initial folding device 22, that is, the position of C ₂ , and X ₃ is the roller chain. It is adjusted to the exit side of the initial folding device, that is, the position of D ₂ . In the return section G, the endless link device 2 is pushed in by the sprocket 9 and pulled by the sprocket 7, but the change point Y between the pushing force and the pulling force is 0 to 1/10 G on the sprocket 9 side in the return section G. Preferably 1
Adjust to / 50G. In the link pitch adjustment section, the endless link device 2 is pushed in by the sprocket 7 and pulled by the sprocket 8 while rapidly reducing the link pitch P, but a change point Z between the pushing force and the pulling force.
Is the sprocket 7 side 1 of the link pitch adjustment section J
It is adjusted to / 3 to 2 / 3J, preferably 3 / 5J.

〔The invention's effect〕

According to the present invention, a roller chain initial folding device is provided,
By adjusting the minute size of the regulation of the endless link device and the guide rail, not only the mechanical running state but also the stable running of the film can be performed.

[Brief description of drawings]

FIG. 1 is a plan view of a film simultaneous biaxial stretching device according to an embodiment of the present invention, FIGS. 2 and 3 are detailed plan views of the endless link device, and FIG. 4 is a conventional simultaneous biaxial stretching device. It is a top view. 1 ... Film, 2 ... Endless link device, 3 ... Grip device, 4, 5, 6 ... Guide rail, 7, 8, 9 ... Sprocket, 21 ... Intermediate drive device, 22 ... Roller chain initial stage Folding device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsu Noma Yamato Prefecture Shimomatsu City HigashiToyoi 794 Address Higashi Toyoi Co., Ltd. Hitachi Ltd. Kasado Factory Examiner Hisanao Tanaka

Claims (1)

[Claims] 1. A thermoplastic flat film is stretched while moving, so that a preheating section, a stretching section, a heat treatment section, a shrinking section, a cooling section and a separating section are formed in order from the inlet side to the outlet side of the flat film. As described above, a pair of guide rails provided in a substantially divergent shape in the advancing direction of the flat film, and a plurality of guide rails provided for each guide rail and connected to each other in a folded shape by a roller chain are provided. A pair of loop-shaped endless link devices each having an equal length link, a plurality of gripping devices connected to each endless link device and gripping the side edge of the flat film, an inlet side of the flat film, and A drive sprocket, which is provided on the outlet side and moves each endless link device along each guide rail, and during the heat treatment section. And a pair of intermediate drive devices for moving the endless link devices, respectively, and a pair of roller chain initial folding devices provided at the beginning of the contraction section for providing initial cues for bending the roller chain. And a simultaneous biaxial stretching device.