JPH01159223A - Molding device for optical disk - Google Patents

Abstract

PURPOSE:To improve accuracy and productivity and prevent deformation, by a method wherein the width of an air blow-off slit is made variable to a mold release surface side at the time of release of a disklike information medium from a mold. CONSTITUTION:At the time of taking-out of a product, the molded product is pressed and released with an ejecting surface 62 which is obtained by widening an area of a tapered part 61 of a sleeve 6 by ejecting the runner ejecting sleeve 6. However, in this instance, a width of a slit becomes wide through a movement of the sleeve 6, air or gas is pressed in through an air blow-off slit S, which is blown off strongly and mold release can be performed easily and accurately. In other words, the title device can be constituted so that the width of the slit becomes narrower at the time of filling of raw material resin and wider at the time of blowing-off of the air or the gas. As an ejected area for only a part of the ejecting sleeve 6 having the tapered part 61 is wide, deformation, warp angle and deflection due to unbalance at the time of ejection of a molded product are controlled to the utmost and it becomes possible to mass-produce a product whose accuracy is high and quality is favorable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a molding apparatus for optical discs, etc., for injection molding disc-shaped media such as optical discs and magneto-optical discs.

[Conventional technology]

In general, information disks such as optical disks or magneto-optical disks used as information recording carriers are molded products that are injection-molded in a disk mold, and conventionally in this type of molding equipment, when the product is taken out, the mold is released. When ejecting the molded product, air and gas are blown out from the air and gas blowing slit S formed between the stamper holder b and the sleeve C in the movable mold a, as shown in Fig. 3. Accordingly, the product M is released from the stamper.

[Problem that the invention seeks to solve]

However, since the air and gas blowing slit S in this conventional molding device is located on the product surface, the width of the blowing slit S must be made small to prevent mold release. It is not possible to blow uniformly and strongly, leading to poor mold release, and serious defects such as uneven birefringence and shape deformation.Moreover, when the molded substrate is made of polycarbonate resin, it is exposed to high temperatures of approximately 120°C. The molded product has to be taken out, and the quality tends to deteriorate further due to deformation due to unbalance when the molded product is ejected, that is, distortion or warpage of unevenness on the substrate part.
If this runout or warpage was large, the laser would be unable to follow the track, resulting in product defects and problems in terms of processing accuracy and reliability.

The present invention aims to accurately eliminate these conventional drawbacks, and it is possible to mold disk-shaped media with high accuracy without causing flashing, improve productivity, prevent deformation during mold release, and improve reliability and quality. The object of the present invention is to provide a molding apparatus for optical discs, etc., which has a simple configuration and is inexpensive, which can greatly increase the performance.

[Means for solving problems]

The present invention provides a fixed mold and a movable mold for molding a disk-shaped information medium, which are disposed opposite to each other, and which is interposed between the two molds, and a ring member for molding the outer peripheral portion of the disk is fitted into a tapered portion. It is provided with a stamper holder consisting of an outer stamper holder 4 and an inner stamper holder 5 for fixing the stamper 10 on the movable mold 2, and the inner stamper holder 5 A molded product release ejecting sleeve 6 is disposed inside the molded product, and a gate cut bunch 9 and a runner ejecting pin 7 are disposed inside the sleeve 6.
In the molding device, the width of the air blowing slit is set to the side of the mold release surface when releasing the mold. This is a molding device for optical discs, etc., characterized in that the molding device is variable in relation to

〔Example〕

Embodiments of the present invention will be described with reference to FIGS. 1 and 2. A fixed mold 1 and a movable mold 2 for molding a disk-shaped information medium
A ring member 3 and an outer stamper are disposed facing each other and are interposed between both molds 1 and 2 to mold the outer circumference of the disk.
It consists of an outer stamper presser 4 and an inner stamper presser 5 for fixing the sleeve 6, gate cut bunch 9 and stamper 10 to the movable mold 2. A stamper holder is attached to the fixed side mold 1, and a sprue bushing 8 and a ring member 3 are attached to the fixed side mold 1.
In the molding apparatus, a molded product release ejecting sleeve 6 is disposed inside the inner stamper presser 5, and a gate cut bunch 9 and a runner ejecting pin 7 are slidably provided in the sleeve 6. In the molding device in which a slit S for blowing air for mold release is formed between the inner stamper presser 5 and the protruding sleeve 6, the width of the slit S for blowing out air can be varied with respect to the mold release surface side at the time of mold release. That is, the tapered portion 6. has a large diameter expanding toward the protrusion side of the sleeve 6. and the tapered portion 6. This is a molding device for optical discs, etc., in which an air blowing slit S is formed along the outer circumferential surface of the mold to allow air to flow out.

In this case, the protruding sleeve 6 is slidably fitted into the gate cut punch 9 and is made of a hollow cylindrical body having a protruding surface 6t at one end and an air pressing surface 63 at the other end. Also, as the inner stamper presser 5, the tapered portion 6 of the sleeve 6 is used. The sleeve 6 is provided with a tapered recess 5 into which the sleeve 6 can be fitted, and the outer circumferential surface of the tapered portion 61 and the inner circumferential surface of the conical recess 51 form an air blowout three/)S. However, it is preferable that the protruding surface 6□ is provided on the surface of the inner stamper presser 5 or at a position protruding from it when the inner stamper presser holder 5 is in its retracted position.

Therefore, during molding, after the movable mold 2 is moved and fitted to the fixed mold 1, the mold is clamped by applying pressure, and then vacuum is applied to the cavities in both molds 1.2 before material is supplied. After suction, the raw material is supplied, the material is injected with a slurry, and molded while maintaining pressure (Fig. 2 (A)). After cooling, the gate cut punch 9 is moved to cut out the sprue runner, and the mold is opened to form the product. The tapered portion 6. of the sleeve 6 can be removed by protruding the runner protrusion sleeve 6 (FIG. 2(B)). The molded product is pressed and released by the protruding surface 68 with a larger area, but at this time, the inside of the slit becomes wider due to the movement of the sleeve 6.
Air or gas is press-fitted from the air blowing slit S and is blown out strongly, making it possible to easily and accurately release the mold (second
In other words, the inside of the slit can be narrowed when filling the raw material resin, and the inside of the slit can be made wide when air or gas is blown out.

Further, the protruding sleeve 6 has a tapered portion 6. Because the protrusion area is large in certain parts, the molded product may become unbalanced when ejected, resulting in deformation and warpage angle.

This makes it possible to mass-produce products with high precision and good quality, with vibrations suppressed as much as possible.

In addition, the protruding surface 6 of the protruding sleeve 6! may be aligned with the surface of the inner stamper presser 50 at the alignment position, or the protruding sleeve 6 with the tapered portion 61 may be fitted into the gate cut punch 9 so as to be actuated by air drive during demolding. It is installed inside the stamper holder 5, is slidably provided in the cylinder chamber 15 formed in the movable mold 2, and is designed to be operated by fluid pressure pressurized from the air or gas supply path 16. has been done.

[Effects of the Invention] - The present invention provides a molding device in which a slit is formed between the inner stamper holder and the protruding sleeve to blow out air for releasing the mold when releasing the disk-shaped information medium from the mold. By changing the pressure to the mold release surface side during mold release, it is possible to strengthen the blowing of air or gas, and the molded product can be released from the mold well.There is no deformation of the shape, and there is no problem with unbalanced ejection of the molded product. It is possible to produce with good processing accuracy without causing any bad phenomena such as deformation, angle, runout, etc., and it is possible to significantly improve quality and reliability.
Since the inside of the slit can be kept narrow during filling of raw materials, there are no occurrences of flashing, there is no risk of defects or deterioration that have an adverse effect on the disk, and there are advantages such as easy handling of the molding operation and extremely high productivity.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 2A is a longitudinal sectional view of an embodiment of the present invention. B and C are diagrams illustrating the operation of the stamper holder in a used state, and FIG. 3 is a diagram illustrating the operation of a conventional stamper holder. l...Fixed side mold, 2...Movable side mold, 3...Ring member, 4...Outer stamper holder, 5...Inner stamper holder, 5 straight...Conical shape Recessed portion, 6... Projection sleeve, 61... Tapered portion, 7... Projection pin, 8... Spoop foucher, 9... Gate cut punch, 10... Stamper 115... Cylinder chamber, 16...Air supply path, S...Air blowing slit. Patent Applicant: Minoru Yakushi, Patent Attorney, TDC Co., Ltd.

Claims (4)

[Claims] (1) A fixed side mold (1) and a movable side mold (2) for molding a disk-shaped information medium are arranged facing each other, and both molds (1) are arranged facing each other.
)(2) A ring member (3) which is interposed between them and forms the outer periphery of the disk is fitted thereinto for fixing the stamper (10) to the movable mold (2). A stamper holder is provided with an outer stamper holder (4) and an inner stamper holder (5), and a molded product release protruding sleeve (6) is disposed inside the inner stamper holder (5). ) is slidably provided with a gate cut punch (9) and a runner ejection pin (7), and an air blowing slit (S) for mold release is provided between the inner stamper holder (5) and the ejection sleeve (6). ), wherein the width of the slit for blowing out the air is varied with respect to the mold release surface side at the time of mold release. (2) The protruding sleeve (6) is provided with a tapered portion (6_1) having a large diameter on the end surface on the side of the molded product,
2. The molding device according to claim 1, wherein an air blowing slit (S) is formed along the outer circumferential surface of the tapered portion (6_1) to cause air to flow out. (3) The protruding sleeve (6) is slidably fitted into the gate cut punch (9) and is made of a hollow cylindrical body with an air pressing surface (6_3) at the other end. A molding apparatus according to claim 1 or 2. (4) The inner stamper presser (5) fits into the conical recess (6_1) of the sleeve (6).
5_1), in which an air blowing slit (S) is formed by the outer circumferential surface of the tapered portion (6_1) and the inner circumferential surface of the conical recess (5_1).
The molding device according to any one of items 1 to 3.