JPS5942934A - Press mold for disc - Google Patents

Abstract

PURPOSE:To equalize the distribution of temperature of a stamper-attached section by a method in which an enclosed space where a refrigerant is confined between the stamper-attached face and the heating and cooling section of a press mold is provided, and the high heat conductivity of the refrigerant by utilizing its phase change in the enclosed space is utilized. CONSTITUTION:A flow path 5 through which a fluid for cooling or heating is flowed in provided to a press mold 1 for disc, and an enclosed space 8 is provided between the flow path 5 and a stamper-attached face 7. The enclosed space 8 is evacuated to vacuum and then confined with a refrigerant 11, e.g., water, ammonia, etc. The enclosed space 8 is of a disc form having two faces in parallel with the stamper-attached face 7 as end faces, and a large number of small grooves 11 and 12 are preferably provided on both the faces.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] This invention relates to a press mold for records, video discs, etc.

[Technical background of the invention and its problems]

Discs such as records are made by stamping a material such as vinyl chloride while being stretched under heat, and then cooled and solidified.

For this purpose, as shown in FIG. 1, a heating steam pipe 2 and a cooling water pipe 3 are connected to the press mold 1 via a valve 4, and steam and water are supplied to a flow path 5 by operating the pulp 4. They are introduced alternately and discharged from the outlet 6.

By the way, in order to manufacture discs without warpage or distortion,
From the viewpoint of stamping accuracy and residual stress, it is desirable that the disk material be heated and cooled as uniformly as possible. To avoid this, the shape and position of the flow path should be determined so that the temperature distribution on the stamper mounting surface 7 is as uniform as possible.

However, the temperature of the fluid changes in the direction of the flow path, and therefore a temperature distribution also occurs in the mold.

However, when the mold is heated, it transfers heat to the disk material that is being expanded, so a local temperature drop occurs in the area where the disk material is in contact.

For these reasons, it is extremely difficult to uniformize the temperature of the mold with high precision.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to improve the drawbacks of the conventional press molds for discs as described above, and to provide a press mold for discs that can accurately uniformize the temperature distribution on the stamper mounting surface.

[Summary of the invention]

This invention provides a sealed space filled with a refrigerant between the stamper attachment surface of a press mold for disks and the heating and cooling parts, and achieves high heat transfer ability by utilizing the phase change of the refrigerant within this sealed space. By using this, the temperature distribution on the stamper mounting surface is made uniform.

〔Effect of the invention〕

By making the temperature distribution uniform on the stamper mounting surface in this way, problems such as uneven stamping and disk warping caused by residual stress can be solved.

This effect is particularly noticeable in cases such as video discs, which require high precision.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIG. The stamper mounting surface 7 is provided with a flow path 5 through which cooling and heating fluids flow.
A closed space 8 is provided between them. The sealed space 8 is in the shape of a disk whose end surfaces are two planes parallel to the stamper mounting surface 7, and has a disk shape whose end surfaces are two planes parallel to the stamper mounting surface 7. ', -ri, the plane 9 adjacent to the stamper mounting surface 7 and the plane 10 adjacent to the cooling and heating parts? 6 are provided with narrow grooves 12.

Further, the sealed space 8 is filled with a refrigerant 11 such as water or ammonia after being evacuated. When manufacturing a disk, heating steam is first introduced into the flow path of such a mold. At this time, the liquid refrigerant 11 adhering to the plane 10 quickly evaporates, increasing the pressure of the vapor in the closed space 8. Then, rapid condensation occurs on the low-temperature plane 9, and the plane 9 is heated by the heat of condensation at this time.

Next, cooling water is introduced into the mold channel. At this time, the plane 10 is cooled and the steam in the closed space 8 condenses on this plane.
The pressure of the steam in the closed space 8 decreases. Then, the liquid held on the plane 9 evaporates, and the plane 9 is cooled by the heat of evaporation at this time.

By heating and cooling the plane 10 in this way, the plane 9
Therefore, the stamper mounting surface can be heated and cooled.

By heating and cooling the flat surface 9 in this way, the temperature of the flat surface 9, and therefore the stamper mounting surface 7, can be kept uniform with very high precision. Even if a
Heating takes place. In addition, the disk material, heating, etc. can be applied to the flat surface 9 ii! Even if temperature unevenness occurs, evaporation occurs in areas where the temperature is high and condensation is promoted in areas where the temperature is low, thereby making the temperature of the plane 9 uniform. Therefore, the disc obtained by ξ has a high jit degree without warping or the like. If 111 is provided on plane 9 or plane 10,
It is difficult for dripping to occur, and /it can be held uniformly and in large quantities with the metal plate.

The same effect can be expected even if a wire mesh is attached instead of the groove 12.

Figure 1 is a cross-sectional view schematically showing a disk press mold used in a conventional disk manufacturing method, and Figure 2 is a disk press in an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a mold.

DESCRIPTION OF SYMBOLS 1...Press mold for disk, 2...Steam pipe for heating, 3...Water supply for cooling, 4...Pulp, 5...Flow path, 6...Outlet compensation", 7.・・Stamper attachment surface・, 8
...? 1.) Closed space, 9... adjacent to the stamper mounting surface, 10... surface adjacent to the heating and cooling section, 11.
...refrigerant, 12...groove.

Claims (1)

[Scope of Claims] (In a press mold for a disk having a heating/cooling section for flowing water vapor for IJ heating or cooling water, there is a space between the heating/cooling section and the stamper mounting surface. A press mold for a disk characterized by having a sealed space in which a refrigerant is sealed. (2) The sealed space provided in the mold is a disc-shaped space having two planes parallel to the stamper mounting surface. A press mold for a disc according to claim 1, characterized in that: (3) Of the two planes parallel to the meta/par mounting surface, at least the plane closer to the stamper mounting surface has a thin A press mold for a disc according to claim 2, characterized in that a groove is provided. (4) At least a plane near the stamper mounting surface among the 2,000 planes parallel to the stamper mounting surface. A press mold for a disk as set forth in item 2 or 3 of the scope of patent nM, characterized in that a wire mesh is attached to the press mold.