Manufacturing method for die

A manufacturing method and mold technology are applied in the field of mold manufacturing to achieve the effects of promoting crystallization and suppressing the generation of flash.

Active Publication Date: 2013-04-10
POLYPLASTICS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the current situation is that there is no technology to sufficiently promote crystallization by setting the mold temperature to 100°C or lower.

Method used

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  • Manufacturing method for die
  • Manufacturing method for die
  • Manufacturing method for die

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0089] In Example 1, the following materials were used.

[0090] Crystalline resin: polyphenylene sulfide resin (PPS resin) (manufactured by Polyplastics Co., Ltd., "FORTRON 1140A64" T c2 : 225°C)

[0091] The relationship between the crystallization speed (LogK (K is the speed)) of the above-mentioned crystalline resin and the resin temperature (°C) is shown in Figure 4 . The temperature at which the crystallization rate is sufficiently fast is set to 150° C. or higher. In addition, the desired degree of crystallinity was set to 30%.

[0092] Heat insulation layer: polyimide resin (polyimide resin varnish (manufactured by Fine Chemical Japan Co., LTD.), spraying with a thermal conductivity of 0.2W / m·K, baking at 250°C for 1 hour, Then grind the polyimide side.)

[0093] T c2 Determination method: Using a differential scanning calorimeter (DSC7 manufactured by PerkinElmer), keep the thermoplastic resin at 340°C for 2 minutes in a nitrogen atmosphere, then lower the temp...

Embodiment 2

[0108] Changed insulation layer material from polyimide to silica (ceramic 1), L S = 2.5 mm or 5 mm, and in the same manner as in Example 1, the relationship between the temperature of the resin at a depth of 7 μm from the cavity surface and the retention time of the resin in the mold was derived. Table 4 shows the time during which the resin temperature was maintained at 150° C. or higher and the crystallinity on the side where the heat-shielding layer was formed under each molding condition. Among them, the molding conditions of the derived relational expressions are the mold temperature of 100°C, the heat insulation layer (ceramic 1) of 2.5mm, the mold temperature of 100°C, and the heat insulation layer (ceramic 1) of 5mm.

[0109] In addition, the specific gravity, specific heat, thermal conductivity, and thermal diffusivity of the ceramic 1 are as follows. The thermal conductivity was calculated by measuring the thermal diffusivity by the laser flash method. The specifi...

Embodiment 3

[0117] According to the above examples, it was confirmed that the degree of crystallinity can be adjusted to 30% or more by keeping the resin flowing into the mold at a temperature of 150° C. or higher for 0.1 second or longer.

[0118] In Example 3, the thermal insulation layer was changed to a porous zirconia layer (ceramic 2) sprayed with zirconia peroxide, and it was derived using Therm1 (one-dimensional thermal conductivity analysis software). In this case, the resin flowing into the mold was kept at 150°C The thickness of the insulation layer above the state 0.1 second or more. In addition, as in Example 1, the mold is assumed to be Figure 5 Die shown. That is, L M =10mm, L P =0.7mm. The specific gravity, specific heat, thermal conductivity, and thermal diffusivity of the materials constituting the mold and the resin used the values ​​shown in Table 5 below.

[0119] table 5

[0120]

[0121]Using Therm1 (one-dimensional thermal conductivity analysis software...

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Abstract

Provided is a method of manufacturing a die for the manufacture of molded products that prevents burr formation and sufficiently promotes surface crystallization, by setting die temperature at no more than Tc2-100 DEG C when molding a crystalline thermoplastic resin. The temperature at which the crystallization speed of the resin filled into the die will be sufficiently fast in the vicinity of the surface of the die so that the degree of crystallization at the surface of the molded article will fall within a determined range, and the sustain period during which the temperature is sustained at or above the temperature at which the crystallization speed of the crystalline thermoplastic resin in the die is sufficiently fast are determined on the basis of the relationship between the crystallization speed and resin temperature of the crystalline thermoplastic resin, and the die is provided with a heat insulating layer so that when the die temperature is Tc2-100 DEG C, the period during which the temperature in the vicinity of the surface of the die is not lower than the determined temperature conforms to the determined sustain period.

Description

technical field [0001] The present invention relates to a method of manufacturing a mould. Background technique [0002] Crystalline thermoplastic resins tend to be superior in physical properties such as mechanical strength compared to amorphous thermoplastic resins, and are used in a wide range of fields such as exterior panels of home appliances, exterior and interior parts of automobiles, and the like. [0003] As described above, crystalline thermoplastic resins are excellent in physical properties, but have a slow crystallization rate and a high glass transition temperature. Therefore, it is easy to locally form an uneven crystal structure. Therefore, the surface of the molded product tends to be uneven both in appearance and in structure. [0004] In order to continuously mold molded articles made of crystalline thermoplastic resins with stable quality, it is necessary to promote crystallization. In order to promote this crystallization, for example, molded article...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B29C33/02B29C45/73B29C45/78
CPCB29C45/0025B29C45/78B29C2033/023B29C2945/76618B29K2995/0041B29C33/3842B29C45/73B29C2945/7604
Inventor 高岛正人宫下贵之广田晋一
Owner POLYPLASTICS CO LTD
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