JPS5887009A - Injection molding method for ceramic resin - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a ceramic resin injection molding method that does not cause blockage in passages such as spools and runners in the mold, and therefore does not cause deterioration in yield or strength of molded products. The object of the present invention is to provide a ceramic resin injection molding method that can stably produce molded products having a smooth surface.

The injection molding method for ceramic resin involves heating a ceramic resin obtained by kneading ceramic powder and synthetic resin, and molding the resin in an injection mold as shown in FIG. 1 in a state where the fluidity is divided into individual parts.

That is, the molding die 1 consists of a fixed die 2 and a movable die 3, and after the die 1 is closed, the tip of the injection molding machine 4 is connected to the frame 5 attached to the fixed die 2. If the ceramic resin is injected into the mold 1 by contacting the tip, the ceramic resin will be transferred to the spool 5. It is injected and filled into the cavity 7 through the runner 6 and pressurized. During the pressurization period, conductive holes 8, 8 for guiding the heating medium are formed on the outer periphery of the cavity 7 formed by the fixed mold 2 and the movable mold 3, respectively,
The molded article M is manufactured while being heated by conducting the heating medium.

However, unlike general synthetic resins, ceramic resins have a fast cooling and solidification rate, and solidification progresses even during the injection process. In particular, recent ceramic resins tend to have relatively poor fluidity in order to improve the strength of molded products, which further accelerates cooling and solidification of the spool 5, runner 6, etc., and prevents passage blockages. There is a risk of this happening.

Therefore, in order to prevent passage blockage as described above, if the mold 1 is heated to a temperature equivalent to that of the ceramic resin fluid during the pressurization period, passage blockage of the spool 5, runner 6, etc. can be prevented; There is a disadvantage that the time required for the completion of the pressurization period until the molded article M is cooled, solidified, and taken out is long, and the efficiency of the molding cycle is poor.

In addition, since the surface of a ceramic resin molded product is hard and difficult to polish, the conductivity formed on the outer periphery of the cavity 7 of the fixed mold 2 and the movable mold 3 that form the cavity I of the mold 1 is difficult. The temperature of the molded product M in the gap 7 is controlled by passing a heating medium through the holes 8, 8, and the molded product M is heated to a temperature suitable for the surface condition of the molded product M to form a smooth surface. However, as mentioned above, bringing the mold 1 to the same temperature as the ceramic resin fluid during the pressurization period inevitably results in a higher temperature than the mold temperature required for the molded product, and therefore the surface condition of the molded product M It is difficult to maintain the condition well.

According to the present invention, by having the structure described in the claims, it is possible to prevent clogging in the passages of susols, runners, etc. by heating the passages, and to stably produce molded products with smooth surfaces. Moreover, we were able to obtain a ceramic resin injection molding method in which the efficiency of the molding cycle was improved by cooling the passages such as the spool and runner.

FIG. 2 shows one embodiment of the present invention. Next, the present invention will be explained based on FIG. The mold 9 is composed of a fixed mold 10 and a movable mold 11, and includes a spool 12 formed in the fixed mold 10 and a runner 13 formed by the fixed mold 10 and the movable mold 11. Conductive holes 14 and 14 are formed on the outer periphery of each of the two. In the illustrated example, the spool 12 is fitted into the fixed mold 10, but the spool 12 may be formed directly on the fixed mold 10.

Both are connected to a temperature controller 15 to form a circuit 16,
Further, switching pulps 17 and 17 are attached to the IN and OUT sides of the circuit 16, respectively, so that the circuit 16 can be switched to the circuit 18. The circuit 18 also includes a cooling temperature controller 1.
9 is connected. The circuit 16 contains a heating medium (for example, oil) that can be heated to a temperature equivalent to the temperature of the ceramic resin fluid, and the circuit 18 contains a medium (such as oil) that is at about room temperature.
For example, air, etc.) can be circulated.

On the other hand, a conductive hole 21.
21 are formed, and these communicate with each other and are connected to the temperature controller 22 to form a circuit 23. In addition, it is shown in Figure 2.

In FIG. 2, the mold 9 is closed, and an injection molding machine (not shown) is brought into contact with the tip of the spool 12 to inject a ceramic resin fluid. In this case, the switching valve 17.17
A mold opening signal S is sent to close the circuit 16, and the heating medium whose temperature has been adjusted by the temperature controller 15 is conducted to the conductive holes 14, 14. Since the temperature controller 15 heats the heating medium to the same temperature as the fluid of the ceramic resin, the ceramic resin flowing inside the stool 12 and the runner 13 flows smoothly into the cavity 20 without being cooled and solidified. is filled with a predetermined amount and pressurized.

On the other hand, the molded product M in the cavity 20 is heated by the temperature controller 22 so that the molded product M has an appropriate surface humidity, and a heat medium is passed through the through holes 21 and 21 to maintain the molded product M at a predetermined surface temperature. Heat it so that

As mentioned above, since cooling and solidification does not occur in the spool 12 and runner 13, the set pressure of the injection molding machine can be sufficiently propagated to the molded product M, and therefore the molded product M can be sufficiently pressurized and filled. The molded product M can be molded with a smooth surface because almost no internal defects occur and the surface temperature can be maintained at a temperature suitable for the molded product M. In the illustrated example, heating is performed using a heating medium, but a heater such as an electric heater may be used, or both may be used in combination.

Next, the switching valves 1γ and 17 are switched by sending a signal S' for the end of pressurization to the switching valves 17 and 17, and the circuit 16 is opened and the circuit 18 is closed.
A cooling humidity controller 19 attached to the mold 8 conducts a medium at about room temperature to the conduction holes 14, 14, so that the ceramic resin in the stool 12 and the runner 13 is rapidly cooled and solidified, and the mold 9 is opened. Thereafter, the molded product M can be taken out by protruding the outer bunch 24 and the jet pin 25.

That is, by conducting a low-temperature phase heat medium into the conduction holes 14, 14, the ceramic resin in the spool 12 and the runner 13 is rapidly cooled and solidified, so that the molded product M
The extraction time can be shortened.

After taking out the molded product M and completing the molding process as described above, the mold opening signal S is sent to the switching valve 17.17 again to switch the switching valve 17.17 to open the circuit 18, close the circuit 16, and After heating the pool 12 and runner 13 to a temperature equivalent to that of the ceramic resin fluid and closing the mold 9, the ceramic resin fluid is injected into the mold 9 in the same manner as described above to continuously form a molded product. can be manufactured.

As described above, the present invention prevents the flow of ceramic resin by heating the passages of the stool and part of the runner of a mold for molding ceramic resin to a temperature equivalent to that of the fluid of the ceramic resin. The predetermined amount of the body can be sufficiently filled into the cavity, and the set pressure of the injection molding machine can be sufficiently propagated to the raw ceramic resin in the cavity, thereby preventing internal cracks due to insufficient filling of the molded product, insufficient pressurization, etc. 2) It is possible to heat the molded product to the temperature necessary to form a surface condition that does not reduce its strength, and the passages of the stools, runners, etc. can be rapidly cooled after the pressurization is completed, so the time required to take out the molded product is almost unchanged compared to conventional methods. Therefore, the efficiency of the molding cycle does not decrease.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional mold, and FIG. 2 is a mold circuit configuration diagram for explaining the present invention in detail. 9: Mold, 10: Fixed mold, 11: Movable mold, 12 Nisnor, 13: Runner, 14, 21: Conduction hole, 15,
19, 22: Temperature controller, 16.18.23: Circuit, 1
7: Switching pulp, 20: Gabity, 24: Outer bunch, 25: Z pin. (11) 48-

Claims (1)

[Claims] Spools and runners for ceramic resin molding molds
A ceramic resin injection molding method characterized in that the outer periphery of the passage such as - is appropriately heated or cooled by a heating and cooling system separate from the heating member on the outer periphery of the cavity of the mold.