JPH02131920A - How to operate simultaneous biaxial stretching equipment - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the operation of a simultaneous two-sleeve stretching device equipped with an endless link device that simultaneously and continuously stretches thermoplastic resin or two axes in the length direction and width direction. Let's look at methods.

[Conventional technology]

As described in Japanese Patent Application Laid-Open No. 49-40369, the conventional equipment was designed to make the physical properties of the film uniform over the entire width of the film after stretching, and to create equipment suitable for increasing speed and increasing the width. For simplicity, Y y = also Ideally, the locus 1 should be in a straight line. If this ideal straight line is approached, when the link suddenly changes its course in the middle direction near the entrance of the stretching section, a large force will be applied to the link, which is the film gripping device, and the rail, which is the guide groove that regulates the movement of the link. Damage to the equipment may result. Therefore, in the early stages of stretching, the increase in the stretch ratio in the length direction is made larger than the stretch ratio in the middle direction, while in the later stages of stretching, the increase in the stretch ratio in the middle direction is made larger than the stretch ratio in the length direction to maintain balance. I was driving.

[Issues that Masaaki tries to solve]

In recent years, sheet-like materials have become more diverse, such as ultrathinness and special molecular orientation, and the physical properties of conventional films, especially the molecular orientation in the plane direction of the film, are becoming stricter (required). In particular, X>Y, lα
1≧0. 3. No consideration was given to the case of A (where A is the value zJt of X and Y).

An object of the present invention is to provide a method for operating a simultaneous biaxial stretching apparatus that can produce a film with high dimensional stability under stretching conditions in which the final stretch ratio X in the longitudinal direction is larger than the final stretch ratio Y in the middle direction. In particular.

[Means to solve the problem]

The above objective is ideally achieved by stretching with a linear stretching trajectory X where y = When manufacturing excellent sheet-like products, this can be achieved by controlling the longitudinal and transverse stretching ratios at predetermined stretching ratios for each ideal stretching line and operating under limited trajectory conditions. be done.

[For production]

In the early stage of stretching, by keeping the increase in the stretching ratio in the width direction to the minimum necessary and correcting the deficiency in the later stage of stretching, it is possible to suppress the load acting on the links and rails. On the other hand, from the functional point of view of the film, in order to compensate for the imbalance caused by the above, the increase in the stretching ratio in the machine direction should be as large as necessary in the early stage of stretching, contrary to the trajectory of the stretching ratio in the middle direction, and in the late stage of stretching. , it becomes possible to achieve balance by making it smaller.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to N3. In the figure, the sheet-like material I is held at both ends by the grippers 2 of the link device 3, and is simultaneously stretched vertically and horizontally in the direction of the arrow 6 in a section E. The linkage 13 is driven endlessly by the sub-routes 7.8 and 9, and its movement is regulated by guide rails 4, 5.6 arranged at both ends of the sheet. B is a link-bee-yy-adjustment section, C is a sort-like object gripping section, D is a preheating section, E is a stretching section, F is a heat treatment section, G is a sheet-like object release section, and H is a return section.

The movement of the link device i3 in the extension section, that is, the magnification locus is arbitrarily determined by the shape of the guide rails 4, 5.6. FIG. 3 shows the optimum stretching conditions when X>Y. The horizontal axis represents the length of the stretching process and corresponds to the stretching section El in FIG. That is, point 0 indicates the starting point of stretching, and point 1.0 indicates the end point of the stretch. The vertical axis represents the stretch ratio in the machine direction (M, D) and the transverse direction (T
, D) Stretching ratio.

7 in the stretching process at a low medium magnification in the longitudinal direction (λ4, D).
Until the process of 0 inch or less, stretching is carried out early above the ideal M, D fold line, that is, in the range where the low stretching ratio is increased. Stretching is performed slowly in the range below the ideal straight line in the process of crossing the line.

On the other hand, for the stretching ratio in the width direction (T, D), slow stretching is performed in the former half of the stretching process, preferably 40% or less, below the ideal straight line, and the subsequent T, D ratios are Try to conceive early within the range above the ideal curve.

According to the first embodiment, a large force is not applied to the links and rails at the initial stage of stretching, and smooth operation is possible for increasing the width and speed.

[Effect of Yumei]

According to Masaaki Moto, JL has developed an operation for producing a highly dimensionally stable film with a unique molecular orientation in a stretching process in which the final stretching ratio in the longitudinal direction is greater than the final stretching ratio in the widthwise direction. There is an effect that makes it possible.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a simultaneous biaxial stretching device according to an embodiment of the present invention, FIG. 2 is a partial plan view showing details of the relative relationship between the link device and the rail in the stretching process, and FIG. 3 is a plan view of the stretching section. FIG. 3 is an operating characteristic diagram showing a drawing magnification locus in FIG.

Claims (1)

[Claims] 1. An endless link device in which link plates of equal length are connected in a zigzag pattern, and a guide rail that has a film gripper at one end of the link device and guides the link device are provided at both ends of the film. , in a method of operating a simultaneous biaxial stretching device in which the link device is driven by a plurality of sprockets and the film is stretched simultaneously in both longitudinal and lateral directions, when the final stretching ratio in the longitudinal direction is larger than the final stretching ratio in the transverse direction, 1. A method of operating a simultaneous biaxial stretching apparatus, characterized in that the stretching ratio in the direction and the stretching ratio in the lateral direction are controlled at predetermined stretching ratios for each ideal stretching straight line. 2. Regarding the longitudinal stretching ratio, the range of 70% or less of the total stretching process with respect to the ideal stretching straight line is stretched earlier, and the stretching process exceeding this range is performed later, and at the transverse direction stretching ratio, the stretching is Claim 1, characterized in that control is performed using two stretching ratio trajectories: stretching slowly in the first half of the entire stretching process with respect to an ideal straight line, and stretching earlier in the stretching process beyond that range. How to operate a simultaneous biaxial stretching device.