JPH07119065B2 - Curling method for hard vinyl chloride resin sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is a roll or the like made of a long sheet, and a hard vinyl chloride resin sheet having curl can be continuously and easily corrected. Regarding curl correction method.

(Prior art and its problems) A flat sheet made of a hard vinyl chloride resin sheet is used for punching to produce flat plates of various shapes, for example, a circular top plate provided on the top of a capacitor. ing.

In such a punching process, when a sheet (roll) obtained by winding a long sheet is unwound and supplied to a punching device, the curl of the sheet due to curling tends to increase as the winding diameter of the roll decreases. is there. As a means for reducing such curl, there is a method of increasing the outer diameter of the winding core, but depending on the material of the sheet and the storage condition, the curl cannot be completely eliminated.

Another method is to use a flat cut sheet instead of a roll sheet, but it is inefficient in work and the product is partially cut at the edge of the cut sheet. There was a problem that the product in that part was lost.

(Means for Solving the Problems) The present invention has found a method for easily correcting a curl even on a curled sheet, and the gist is to continuously A hard vinyl chloride resin sheet that runs as it is immersed in warm water heated above the Crushberg flexible temperature of the sheet, removes water and cools, and at the same time, pulls it while applying tension evenly to the sheet. A curl straightening method for a hard vinyl chloride resin sheet characterized by the above.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic sectional view showing an example of an apparatus used in the method of the present invention.

The sheet 1 unwound from the roll 11 wound on the winding core is the first
The vehicle is continuously driven by the seat path shown in the figure. First, the sheet is nipped by the brake rolls 2, then immersed in the warm water 8 in the warm water tank 7, and passes between the straightening roll groups 3. The number and arrangement of the straightening rolls can be appropriately determined, but as shown in FIG. 1, it is preferable to arrange the straightening rolls so that they are bent at least once in the direction opposite to the direction of the curl, because the curl straightening effect is large.

The temperature of the hot water in the hot water tank must be equal to or higher than the Crashberg flexible temperature of Sheet 1 (according to JIS K-6734), and if it is lower than this temperature, the curl straightening effect of the sheet does not occur. Further, when the hot water temperature approaches the boiling point, the amount of hot water that volatilizes increases, so it is necessary to appropriately collect the volatilized hot water.

The dipped sheet emerges from the hot water surface, and the water adhering to the sheet surface is removed by the water draining roll 4 such as a rubber roll. Then, the sheet is naturally dried between the draining roll 4 and the guide rolls 5 provided after the draining roll 4, and forcedly cooled and dried by hot air or cold air. The sheet after cooling and drying is transferred to the next step by the take-up roll 6.

In the present invention, at least during cooling, it is necessary to pull the sheet while uniformly applying tension to the sheet, and tension can be applied by providing a speed difference between the draining roll 4 and the pulling roll. By applying such a tension, a sheet stretching effect is produced, and the curl can be corrected.

Further, the tension may be applied from the sheet in the hot water tank, and in this case, a speed difference may be provided between the brake roll 2 and the take-up roll 6.

(Example) Hard vinyl chloride sheet (sheet thickness 0.3 mm, sheet width 70 m
m, Crashberg flexible temperature, 60 ° C) core (outer diameter 100
mm) and was stored at room temperature of 20 to 35 ° C. for 1 month. The curl was corrected using the above-mentioned scroll sheet and the apparatus shown in FIG.

Temperature of hot water: 75 ℃ Sheet length in hot water: 1m Tension between brake roll 2 and take-up roll 6; 1Kg / sheet width Roll for straightening 3; 2 take-up speed; 10m / min Take-off conditions above As a result of curl straightening, a completely flat sheet was obtained on the outer peripheral portion and the unwinding portion side of the roll, and there was no shrinkage of the width of the sheet, dimensional change, abnormal appearance, etc. On the other hand, in the case where the roll is stored as it is without performing the curl correction, the curl on the core side is remarkable and there is a problem in punching.

(Effects of the Invention) According to the method of the present invention, by using warm water of a specific temperature, it is possible to uniformly heat the sheet unlike warm air and correct the curl accurately, and to adhere to the sheet. This has the advantage that dust and the like can be easily removed.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of an apparatus used in the present invention. 1 ... Hard vinyl chloride sheet 2 ... Brake roll, 3 ... Straightening roll 6 ... Take-up roll, 8 ... Hot water

Claims (1)

[Claims] 1. A continuously running hard vinyl chloride resin sheet is dipped in warm water heated to a temperature higher than the crushberg softening temperature of the sheet to remove water and cool, and at least during cooling, tension is applied to the sheet. A curl straightening method for a hard vinyl chloride resin sheet, which is characterized in that it is uniformly added and collected.