JPS5839864Y2 - mold for molding - Google Patents

Description

[Detailed Description of the Invention] The present invention provides an effective structure for a molding die used for molding polymer products such as plastic molding, tire molding, or shell molding.

Molded products made from thermosetting synthetic resins are made by filling a mold with resin pellets and pressurizing them under heating conditions, but depending on the specific temperature conditions, these molded products may form so-called cavities or have hot water leaks. Not only does this result in molding defects such as insufficient molding, but also distortion and deformation of the product taken out of the mold often occur due to uneven internal residual stress during molding.

The present invention provides a mold that can improve the quality of such molded products, improve yield, and shorten molding time. In the embodiment shown in FIG. 1, 1 is an upper mold;
2 is a lower mold, 3 is a coating layer of far-infrared emitting ceramics sprayed on the molding surface of the upper mold, and 4 is a coating layer of far-infrared rays-emitting ceramics sprayed on the molding surface of the lower mold.

It is known that infrared rays are emitted by applying heat to ceramics, but the present invention uses ceramics that emit far infrared rays, such as 85% ZrO2 or Sin, as the main component, on the molding surface of the molding mold 1°2. , as a mineralizing agent MnO2
The coating layers 3 and 4 were thermally sprayed and fired by adding 1.5% of Pe203 and 2.5% of Pe203, and the remainder was clay as a plasticizer.

The thickness of this coating layer may be appropriately set from several 10 microns to several millimeters depending on the size, shape, etc. of the mold.

In addition to the above-mentioned ceramic materials, known far-infrared emitting ceramics can be used.

In this way, when hot molding is performed using a mold coated with far-infrared emitting ceramic, far-infrared rays proportional to the fourth power of the temperature are emitted from the inner surface of the mold due to the special heat of the molding, and this far-infrared rays It penetrates into the inside of the material, increasing the heating rate by 30 to 50%, making the heat distribution even, and making each part of the molding material homogeneous by far-infrared molecular vibration, eliminating air bubbles and filling even the smallest details. It is possible to obtain a good molded product with no unevenness of stress.

In particular, since various polymeric materials have a large absorption of far infrared rays of 3 to 15 microns, it is advantageous to use the mold of the present invention in plastic molding, and molded products without distortion or deformation can be obtained.

In addition, similar benefits can be achieved in rubber tire molding, reducing molding time and improving wear resistance.

Note that the mold surface formed by spraying ceramics is somewhat rougher than the polished metal surface, and therefore the molding surface can be made smooth by coating the ceramics spraying surface with tetrafluoroethylene resin.

Figure 2 shows the test results of rubber (SBR) vulcanized using the mold of the present invention and a conventional mold without coating treatment. The dotted line shows the mold without coating, curve A shows the tensile strength, curve B shows the hardness, and curve C shows the elongation.The vulcanization time to obtain a product with a hardness of H358 can be reduced by about 30%. , it is possible to obtain products with almost no difference in strength and elongation in a short time.

In this way, the molded product of the mold is coated with far-infrared emitting ceramics by thermal spraying, etc., so the far-infrared rays emitted from this coating layer due to the heat of the molding heat the molding material quickly and reduce the temperature. In addition to uniform distribution, it is possible to perform homogeneous and dense molding by applying molecular vibrations, enabling precise molding, obtaining high-quality molded products without bubbles or distortion, and improving the quality of molded products. and has the effect of improving yield.

[Brief explanation of the drawing]

FIG. 1 is a sectional side view showing an embodiment of the present invention, and FIG. 2 is a characteristic curve diagram of a molded product using the mold of the present invention and a conventional mold. 1 is an upper mold, 2 is a lower mold, and 3 and 4 are far-infrared emitting ceramic coating layers.

Claims (1)

[Claims for Utility Model Registration] 1. A molding die characterized in that a coating layer of far-infrared emitting ceramic is provided on the molding surface. 2. The molding die according to claim 1, which is provided with a coating layer made of zirconia-based ceramics. 3. The molding die according to claim 1 or 2, wherein a coating of tetrafluoroethylene resin is provided on the far-infrared emitting ceramic coating layer.