JPH0347729A - Rigid synthetic resin sheet - Google Patents

Abstract

PURPOSE:To obtain rigid synthetic resin sheet, the physical properties of only the specified part of which shows those of nonrigid synthetic resin sheet while the physical properties of the remaining part remains those of the rigid synthetic resin, by a method wherein only the necessary part of all the rigid synthetic resin having sheet-like thickness is turned to be nonrigid. CONSTITUTION:A rigid synthetic sheet 9 is strongly held by holders 5 and 6 on a supporting plate 8 and pressing cylinders 2 and 3, which are connected to a vibration generating device. Air holes are bored on a cooling platen 4 so as to correspond to a heating body 1 in order to jet compressed cooling air. Further, under the condition that the power source of the heating body 1 is turned off, vibration is given to the sheet 7 through the cylinder 2 or 3 and the sheet 7 is cooled down with cooling air blasted from the air holes, by restoring the cylinder 3 and the holder 6 to their initial positions, one cycle completes. In the sheet thus obtained, region, which corresponds to the shape of the heating body and is softened, is formed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to stationery files, file cases, polygonal columns,
This invention relates to a hard synthetic resin sheet useful for manufacturing polygonal pyramidal partitions, bellows bodies, etc.

[Prior art]

It is not easy to bend a rigid synthetic resin sheet.
Furthermore, it is well known that if the material is forcibly bent, a whitening phenomenon will occur at the bent portion, leading to immediate breakage.

Therefore, it would be convenient if only the bending portion could be made soft, but such a technique is not yet known.

[Purpose of the invention]

An object of the present invention is to soften only the portion of a hard synthetic resin sheet that is desired to be partially softened.

〔composition〕

The inventor of the present invention first heats a portion of a hard synthetic resin sheet that is desired to be partially softened, stretches the heated portion, and then vibrates on the order of 10° to 10'Hz, cools, and restores almost simultaneously. A method for partially softening a hard synthetic resin sheet, a means for holding the hard synthetic resin sheet, a means for heating a portion of the hard synthetic resin sheet to be softened for a period of several seconds or less, and heating A method of partially softening a hard synthetic resin sheet characterized by comprising a means for stretching the stretched portion, a means for applying vibration on the order of 10' to 10'Hz to the stretched portion, and a cooling means provided corresponding to the heating means. We proposed a device for this purpose.

The present invention relates to a rigid synthetic resin sheet characterized by having a partially softened region, which can be obtained for the first time by means of this novel method and apparatus.

Hard synthetic resins include polystyrene, polyethylene,
Examples include polypropylene, hard polyvinyl chloride, polycarbonate, polyester, ABS, and the like. Sheet thickness is approximately 0°15~4+I1m, usually 0.2~1
, 2+u+.

The shape of the part you want to soften in order to heat it.

For example, a heating element having a belt-shaped smooth blade with a width of 1 to 10 mm, preferably 2 to 4 mm is heated by electrical means, and the sheet is pressed from both the upper and lower sides, or in some cases only from one side.The heating time is approximately 2 seconds. within, preferably 1
Within seconds.

A diameter of about 1.3 to 2.0 times is sufficient for stretching.

On the order of 100-10'Hz, preferably 10'-
Vibration application, cooling and restoration on the order of 10”Hz (
Return the stretched device to its original position. Actually, for example, width 2
Even if the ml+ material is stretched to 1.5 times, the width after stretching is 300 mm, so it is nothing but returning the lam to the original direction) at almost the same time.

There is no particular restriction on the means for imparting vibration to the seat, but for example, a cylinder of 10' to
All you have to do is give it a vibration of O'Hz.

Specifically, the hard synthetic resin sheet with partially softened regions of the present invention can be manufactured as follows.

As shown in FIG. 1A, the hard synthetic resin sheet 7 is placed on the support plate 8.
It is firmly held by upper holders 5 and 6 and press cylinders 2 and 3, and press cylinders 2 and 3 are connected to a vibration generator. Air holes were bored in the cooling @ 4 corresponding to the heating body 1 so that cooling compressed air could be injected.

The heating element 1 can be heated instantaneously by electrical means, and is electrically heated for about 0.2 to 0.5 seconds (1 second at most). At this time, the heating element 1 is brought into pressure contact with the sheet 7. When the electricity is turned off, the heating element 1 stretches the pair of holder 6 and press cylinder 3 in the direction of the arrow while keeping the sheet 7 lightly pressed. Note that the stretching may be performed in both left and right directions.

Next, turn off the power to heating element 1, and turn off cylinder 2 or 3.
The cycle is completed by applying vibration to the seat 7 and at the same time blowing cooling air through the air holes to cool the seat 7 while returning the cylinder 3 and the holder 6 to their original positions.

The time from stretching to the end of the process varies depending on the thickness of the sheet.
．． It is about 5 to 3 seconds, usually about 1.5 to 1.7 seconds.

It takes at most 4 seconds, usually 1.7 seconds, from when the sheet 7 is firmly held by the cylinders 2 and 3 and the holders 5 and 6 to the end of the process.
~2.2 seconds.

Cylinder 3 due to vibration applied from cylinder 2 or 3
Everything resonates, but the degree of resonance is extremely subtle and cannot be confirmed with the naked eye.

In the sheet thus obtained, a softened region is formed corresponding to the shape of the heating body. The softened region 7' is the second region when the heating element is applied from one side of the sheet.
When the heating element is applied to the sheet from both sides, the state shown in part (a) of Figure A is obtained, and the state shown in part (b) of Figure 2B is obtained. The state shown in FIG. 2(B) is more advantageous than the state shown in FIG. 2(A) when this portion is to be bent many times at an angle of 90° or more.

The softened regions include (1) a region corresponding to the VI line when the sheet is folded to form a hollow polygon, and (2) a region corresponding to the twill line when the sheet is folded to form a box. (3) an area corresponding to the twill line when the sheet is folded to form a polygonal pyramid; (4) an area corresponding to the twill line of the partition when the sheet is folded to form the partition inside the box. , (5) a region corresponding to the bent part of the file, and (6) a region corresponding to the twill line of the bellows body. If you attach the lid, it becomes a container), (2)
The sheet of (3) has a box shape, the sheet of (3) has a polygonal pyramid, and the sheet of (4)
The sheet in (5) is for the partition, the sheet (5) is for the file, (
The sheets of 6) can be used to manufacture bellows bodies respectively. Further, the sheet of the present invention can be effectively used as a foldable mount. The one in Figure 3 is the softened region 7'
If a hard synthetic resin sheet having the above-mentioned shape is bonded with the adhesive portion or welded portion 9 on top of the left end, it will become a hollow rectangular prism, and if a lid is attached to it from above and below, it will become a container. In the case shown in FIG. 4, the bent portion 7' of a simple box is made into a softened region. In FIG. 5, a bent portion 7' for forming a square pyramid is made into a softened region.

In FIG. 6, the bent portion 7' is made into a softened region when used as a bellows body or a partition. When this is used as a partition, it is used in the form of a sectional view shown in FIG. 8(A). FIG. 8(B) is an enlarged view of portion E in FIG. 8(A). The one shown in FIG. 7 can be used as a foldable mount, and the folded portion 7' is the softened area.

Incidentally, Table 1 shows the repeated bending/opening/closing test of the hard polyvinyl chloride sheet (type shown in FIG. 2 (B)) softened according to the present invention.

Table 1 Note 1) Test method: One side of the opening/closing sheet is fixed to a stand, and the other side is connected to a switch with an opening/closing speed of 10 times/minute and a bending angle of 180° to examine changes in the appearance of the opening/closing part.

2) O mark: No abnormality Δ mark: Whitening occurred × mark: Fracture [Effect] The present invention softens only the necessary parts of a hard synthetic resin having a sheet-like thickness, so it is a hard synthetic resin. However, it is a completely new type of hard synthetic resin sheet that exhibits the physical properties of a soft synthetic resin only in specific parts.

By using the partially softened rigid synthetic resin sheet of the present invention, boxes, packaging materials, files (
It is possible to manufacture various articles with bent parts such as stationery very easily.

Further, the softened portion can be easily cut with household scissors, making processing convenient.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention, in which A shows a heating process, B shows a stretching process, and C shows a vibration and cooling restoration process. Figures 2 (A) and (B) are partially enlarged views of the softened area, and Figures 3 to 7 are for explaining how to set up the softened area and how to use the sheet. Top view of the sheet, No. 8
Figure (A) is a sectional view when the sheet of Figure 6 is used as a partition, and (B) is an enlarged view of portion E thereof. 1... Heating body 2, 3... Cylinder 4...
・Cooling plates 5, 6...Holder 7...Synthetic resin sheet 7'...Softened area 8...Support plate 9...Gluing portion or welding portion Applicant Ryu Mizoguchi (Outside, 1 person) Figure 2 Figure 5 Figure 6 Figure Door diagram Figure 7 Figure 8 (B)

Claims (1)

[Claims] 1. A hard synthetic resin sheet characterized by having a partially softened region. 2. A partially softened hard synthetic resin sheet, characterized in that the region corresponding to the twill lines when the sheet is bent to form a hollow polygonal prism is softened. 3. A partially softened hard synthetic resin sheet, characterized in that the region corresponding to the twill lines when the sheet is bent to form a box is softened. 4. A partially softened hard synthetic resin sheet, characterized in that the region corresponding to the twill lines when the sheet is bent to form a polygonal pyramid is softened. 5. A partially softened hard synthetic resin sheet, characterized in that the region corresponding to the twill lines of the partition when the sheet is bent to form the partition inside the box is softened. 6. A partially softened hard synthetic resin sheet, characterized in that a region corresponding to the bent portion of the file is softened. 7. A partially softened hard synthetic resin sheet, characterized in that a region corresponding to the twill lines of the bellows body is softened.