JPS61199942A - Ruled line machining method - Google Patents

Abstract

(57) [Summary] 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 a ruled line processing method in which ruled lines are formed in advance along fold lines when a plastic sheet is folded to make a case or the like.

(Prior art) Conventionally, in order to provide ruled lines on a plastic sheet, the general method is to press the plastic sheet between a ruling blade and a receiving material. In order to heat and soften the portion, a) a method of heating the crease blade, b) a method of high-frequency heating of the sheet,
C) A method using a ruled edge roll and a heated lower roll (Japanese Patent Application Laid-open No. 59-29136) has been used.

(Problems to be Solved by the Invention) However, in the above-mentioned conventional crease processing method, the method of heating the crease blade (a) tends to cause deformation of the crease blade due to thermal expansion, and the crease depth etc. It is difficult to adjust the rate, and the method (b) of high-frequency heating takes time for one shot, resulting in poor production efficiency, and the method (C) of using rolls tends to cause stress in the flow direction of the sheet. Furthermore, it is difficult to adjust the depth, width, etc. of the ruled lines, as pressure is likely to be insufficient in areas where a plurality of ruled lines are gathered.

(Means for Solving the Problems) The present invention is characterized in that a plastic sheet is compressed between a ruled blade and a heated receiving plate, which are arranged so that the cutting edges are on substantially the same plane. In forming the ruled line, the ruled line processing method is characterized in that the ruled line blade is kept at a lower temperature than the receiving plate.

Embodiments of the present invention will be described in detail below with reference to the drawings.

Fig. 1 is a side sectional view showing an example of an apparatus for carrying out the method of the present invention, Fig. 2 is a perspective view of a plastic sheet that has been subjected to creasing and is beaten into a predetermined shape, and Fig. 3 is an enlarged view of the creasing blade. FIG. 4 is an enlarged sectional view of ruled lines.

The creasing blade 2 is arranged on the formwork 1 so that its cutting edges are aligned on substantially the same plane, so that the plastic sheet 4 can be evenly compressed between it and the receiving plate 3. The scoring blade 2 is kept at a lower temperature than the receiving plate 3, preferably below the softening temperature of the sheet to be processed. For this purpose, the scoring blade 2 may be heated and cooled without being heated, but it may be heated or cooled at a low temperature in order to keep the processing conditions constant.

The receiving plate 3 is heated by a cartridge heater 31 or the like so that the plastic sheet 4 can be heated and softened.
By keeping the creasing blade 2 at a lower temperature than the receiving plate 3, expansion and deformation of the creasing blade 2 is small, and it can be softened sufficiently over a relatively wide range.

In order to press the plastic sheet 4, for example, as shown in FIG.
A method can be adopted in which the material is lowered and compressed. In this case, the temperature of the scoring blade 2 must be set below the softening temperature of the plastic sheet 4 to prevent the plastic sheet 4 from softening and deforming before being pressed. However, it is needless to say that the invention is not limited to the example shown in FIG. 1 as long as measures are taken to prevent the plastic sheet 4 from coming into contact with the receiving plate 3 before being compressed.

The cross-sectional shape of the ruled blade 2 is preferably such that the cutting edge 21 has a flat central part and rounded corners, as shown in FIG. 3, or a semicircular shape (not shown). Also,
The width W (n+m) of the ruled blade 2 varies slightly depending on the thickness t (nm) of the plastic sheet 4 and the material, but in the case of hard polyvinyl chloride, it is 1.3≦W/l≦3.0. It is preferable to set the width W so that

The heating temperature of the receiving plate 3 needs to be determined experimentally, taking into account the material, thickness, pressing time of the plastic sheet 4, width, length, number of ruled blades 2, etc.

The ruled lines 41 obtained by the present invention have grooves 42 on the receiving plate side and grooves 43 on the ruling blade side on both sides of the plastic sheet 4, respectively, as shown in FIG. 4. However, when the receiving plate temperature is high, the grooves on the receiving plate side 42 becomes deep, and when it is low, the groove 43 on the ruled line blade side becomes deep.

If necessary, a large number of horizontal grooves may be provided on the cutting edge of the ruled line blade 2, and the plate 3 may be embossed or processed with fluorine resin. Alternatively, the position of the receiving plate 3 corresponding to the ruled edge 2 may be made high so that the plastic sheet does not touch other parts of the receiving plate. Next, to give an example of processing conditions, the plastic sheet 4 is
, hard polyvinyl chloride sheet of thickness Q, 3 mm)
(The softening temperature specified in JISK6734 is 55 degrees Celsius), when the temperature of the receiving plate 3 is 150 to 180 degrees Celsius, the crease blade 2 is not actively heated, and the clamping time is 0.5 seconds, the creases 41 The thickness of the plastic sheet 4 is 20 to 60
% bendability and dimensional accuracy were formed.

(Effects of the Invention) As described above, according to the method of the present invention, the sheet is softened by the receiving plate 3 without heating the creasing blade to a high temperature, so there is no deformation of the blade, and The uneven processing temperature caused by uneven contact between the crease blade and the plastic sheet, which was seen in the past, is also eliminated. Furthermore, since the plastic sheet is processed without tension using a flat device, the depth and width of the ruled lines will not be inaccurate. Therefore, ruled lines with excellent bendability can be formed on the plastic sheet with high precision and efficiency.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a side cross-sectional view showing an example of an apparatus for carrying out the method of the present invention, FIG. 2 is a perspective view of a plastic sheet that has been subjected to ruled lines and is beaten into a predetermined shape; FIG. 3 is an enlarged sectional view of the ruled line blade, and FIG. 4 is an enlarged sectional view of the ruled line.

Claims (1)

[Claims] When forming creases on a plastic sheet by compressing the plastic sheet between a crease blade and a heated receiving plate, which are arranged so that the cutting edges are on substantially the same plane, the crease blade is heated to a temperature lower than that of the receiving plate. A method for processing ruled lines that is characterized by preserving the lines.