JPS6114912A - Manufacturing method of molded part - Google Patents

Abstract

PURPOSE:To facilitate the mold releasing work and at the same time prevent the surface of a product from marring by a method wherein pour is pured in the cavity of a porous molding tool, cooled, solidified and applied with positive pressure of air through the through holes of the molding tool. CONSTITUTION:Pouring material M is injected in the cavity 4 of a molding tool 3 having a large number of through holes perforated in order to cool and solidify the pouring material M in the cavity 4 by means of a stationary mold 2 and a movable mold 15, both temperatures of which are normal. Next, air is flowed through an air circulating pipe 19 and through holes 18 in the direction of the stationary mold 2 in order to separate a parting part 17. Further, air is sent through an air circulating pipe 7 to an air collecting groove 6 so as to be flowed through through holes 5 to the cavity 4 in order to release the pouring material M from the mold.

Description

[Detailed description of the invention] Technical field The present invention relates to a method for manufacturing a molded article.

Conventional technology Generally, when performing injection molding or injection molding, when resin is injected into the mold, air vent holes are provided in places where air is likely to accumulate as a way to bleed out the air in the mold. Air vent holes may leave visible marks on the molded product, damaging its appearance.

Furthermore, if air removal is insufficient, air burns may occur in the molded product, and furthermore, the weld depth will increase in the welded portion, resulting in a more pronounced deterioration in appearance quality.

Furthermore, if the mold cavity has grains, it is likely to be captured by the mold with grains when the product is released from the mold, resulting in poor mold release and damaging the product surface, reducing the product value. .

OBJECTS OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and provide a method for manufacturing a molded product that is easy to perform during mold release and that causes very little damage to the surface of the product.

Structure of the invention - In order to achieve the above object, the present invention injects a heated and fluidized injection material into the cavity of a porous mold provided in a fixed mold and/or a movable mold. The process consists of a step of cooling and solidifying the injection material M, and a step of releasing the solidified injection material from the mold by applying positive air pressure through the through hole of the mold after the cooling and solidification step. .

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to the drawings.
1 shows the entire mold, and 2 is a fixed mold of the same mold 1. 3
is a porous mold embedded in the fixed mold 2, and 4 is its cavity. The mold 3ii' is formed into an uneven shape by electroforming, and is further provided with a large number of through holes 5, the details of which will be described later. Reference numeral 6 denotes an air collection groove surrounding the mold 3, which communicates with a pressure converting mechanism 8 disposed outside the mold 1 via an air distribution pipe 7. The pressure conversion mechanism 8 includes a vacuum pump 9, a pressure pump 10,
Further K consists of a switching valve 11 provided between both pumps 9 and 10.

12 is a nozzle guide hole recessed in the outer surface of the fixed type 2; 13 is a nozzle abutment portion formed by recessing the inner end of the guide hole 12 further inward; and 14 is a nozzle contact portion formed from the abutment portion 13 into the cavity. It is a runner that extends to 4.

As shown in FIG. 2, a nozzle (not shown) enters into the nozzle guide hole 12 during the molding process and comes into contact with the nozzle contact portion 13, and then synthetic resin, rubber, etc. is heated and turned into a fluid. The injection material M2 is sent to the cavity 4 via the runner 14.

Reference numeral 15 denotes a movable mold disposed opposite to the fixed mold 2, the central part of which is formed in an uneven shape corresponding to the mold 3 of the fixed mold 2, and the concave part 16 is filled with porous material. A mold release part 17 is irremovably fitted inside. In addition, the same mold release part 1
7 is formed by electroforming to have a large number of through holes 18 like the mold 3, and the air circulation vibrator 1
It is substantially surrounded by an air collection groove 20 which communicates via a pressure transducer 9 with another pressure transducer mechanism (not shown) having the same construction as the pressure transducer 8.

Note that the fixed mold 2 and the movable mold 15 are kept at room temperature during the molding process.

Now, before describing the electroforming method for manufacturing the mold 4 of the fixed mold 2 and the mold release part 17 of the movable mold 15, a normal electroforming method will be described. Note that electroforming is herein referred to as plating in a broad sense. In addition, the mold 3 and the mold release part 11
Since they are formed by the exact same method, only the mold 3 will be explained here as an example.

Generally, the plating method involves spraying a conductivity-imparting film, such as a spray liquid formed by mixing a paste silver lacquer and a glutyl acetate solution, onto the plating material to impart conductivity to the plating material. A pretreatment liquid made by mixing hydrochloric acid and stannous chloride in pure water is applied with a brush, etc., to activate the surface of the plating material and perform pretreatment to prevent pinholes from forming. There is.

The plating solution is formed by mixing a nickel sulfamino acid solution and leg acid, and then adding a small amount of sodium lauryl sulfate as a surface active additive. This sodium lauryl sulfate prevents pinholes from forming in the plating layer on the surface of the plating material during plating D-roe.

After this, the plating material and the plating material are added to the plating solution stored in the plating solution tank. The plating material 100 is dipped between the plating materials while circulating the plating solution and operating the cathode locker, and moving the plating material in the plating solution to prevent pinholes from forming.
For CJ, a current of 0.6 A is applied for 3 to 4 hours so that a plating layer is deposited on the entire surface of the plating material.

After confirming that the plating layer has been deposited, convert the current to 1 to 2 AK per 100 cd of the plating material, continue plating to make the plating layer smooth, finish it in the desired shape, and then apply the plating material. A mold 3 is formed by separating the plated layer. Note that when the current is increased to the above value by 19, pinholes are generated on the surface of the plating material.

In the above-mentioned plating method, the generation of pinholes in the mold 3 is prevented, but in this invention, the generation of pinholes is promoted by the method described below.
(+- It is made porous by growing into through holes 5. That is, (1) Do not add surface active additives such as sodium lauryl sulfate to the plating solution.

(2) Before plating, a lacquer solution mixed with an insulating material such as vinyl chloride is sprayed onto the plating material for approximately 1 hour.
A layer of 5 μm is formed 2 to reduce the electrical conductivity of the surface of the plated material.

(3) Do not use any pre-treatment g in pre-treatment of plating materials.

(4) Do not circulate the plating solution during plating.
Furthermore, keep the cathode rocker stationary (5)
A stronger current than usual is passed during plating.

However, it is possible to form the through holes 5 in the mold 3 by at least one of these methods. Now, how to use the mold 1 configured as described above will be described below.

As shown in FIG. 2, the movable mold 15 was moved in the direction of the fixed mold 2 so that the opposing surfaces of both 2.15 were in contact with each other, and then the movable mold 15 entered the nozzle guide hole 12 of the fixed mold 2. When the injection material M is injected through the nozzle, the injection material M is sent to the cavity 4 of the mold 3 via the runner 14 of the fixed mold 2. At this time, the vacuum pump 9 of the pressure conversion mechanism 8 is operated to completely extract the air accumulated in the cavity 4 of the fixed mold 2 into the air collection groove 6 through the entire passage hole 5, and then The pressure conversion mechanism is activated to completely bleed air from the concave portion 16 of the movable mold 15 as well. Note that even if the vacuum pump 9 is not used, the air can be sufficiently vented if the cavity 4 is left open to the atmosphere. As mentioned above, since the fixed mold 2 and the movable mold 15 are kept at room temperature, the injection material is cooled and solidified within the MH cavity 4, and the injection material is cooled and solidified within the MH cavity. The shape corresponds to the .

When the injection material M is solidified, the pressure conversion mechanism on the movable mold 15 side is activated to send air to the air collection groove 20 through the air distribution pipe 19 of the movable mold 15. Then, the air flows through all the through holes 18 of the mold release part 17 in the direction of the fixed mold 2,
A portion of the injection material M that has solidified within the cavity 4 of the mold 3 acts as a positive pressure on a portion of the injection material M that has solidified.

Simultaneously with this air supply, the movable mold 15 is moved in a direction away from the fixed mold 2. Then, the through hole 1B of the mold release part 17
The mold release part 17 is separated by the injection material M due to the positive pressure of the air, as shown in FIG.
The movable mold 15 is separated from the fixed mold 2 without damaging the shape of the solidified injection material M.

After the movable mold 15 is separated, the pressurizing pump 1o of the pressure conversion mechanism 8 on the fixed mold 2 side is activated to send air to the air collection groove 6 through the air distribution pipe differential. Then, the air flows into the cavity 4 through the through hole 5 of the mold 3, and acts as a positive pressure on the injection material M within the cavity 4. Therefore, the injection material M in the cavity 4 is easily released from the mold. This mold release work is carried out by applying uniform positive pressure to the product surface of the injection material M using air acting from a large number of through holes 5 uniformly provided throughout the mold 3, so that the grain is removed. The injection material M can be released from the mold 3 with a pattern such as engraving without damaging the product surface.

Moreover, even in the right-angled portion of the mold 3 of the fixed mold 2, the injection material M is released from the mold without damaging its shape due to the positive pressure of air from the through hole 5. Then, the released injection material MK is deburred with a cutter or the like and finished as a product.

Furthermore, after injecting the resin into the mold 1, the cavity 4 of the fixed mold 2 and the concave portion 16 of the movable mold 15 are filled with the through holes 5, 1.
Air is removed uniformly from the entire surface in one pass, so
No air burn occurs.Furthermore, since this air removal is completely performed, weld marks are less noticeable and the transferability of wrinkles, wrinkle patterns, etc. is excellent.

Although not directly related to this invention, if the fixed mold 2 and the movable mold 15 are separated, a sheet material is placed over the mold 3 of the fixed mold 2, and the vacuum pipe 9ft of the pressure conversion mechanism 8 is operated. Negative pressure is applied to the sheet material through all the through holes 5 of the mold 3, so that vacuum forming can be performed.

The present invention is not limited to the above-mentioned embodiments, and for example, (1) the mold release part 17 of the movable mold 15 is omitted, (2) the fixed mold 2 and the movable mold 15f are arranged above and below, and (2) the mold 3f is arranged vertically.
, provided on the movable mold 15, etc., any changes can be made without departing from the gist of the invention.

Effects of the Invention As detailed above, the present invention provides injection material M heated and fluidized into the cavity 4 of the porous mold 3 provided in the fixed mold 2 and/or the movable mold 15 of the mold 1. Inject and
It consists of a step of cooling and solidifying the injection material My, and a step of releasing the solidified injection material M from the mold 3 by applying positive pressure with air through all the through holes 5 of the mold 3 after the cooling and solidifying step. As a result, the work at the time of demolding is easy, and the product surface is hardly damaged, which is an excellent effect.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a mold for carrying out this invention;
2 to 4 are cross-sectional views showing the steps of this invention.

Claims (1)

[Claims] 1. Fixed mold (2) and/or movable mold (15) of mold (1)
) Cavity (4) of porous mold (3)
A process of injecting the injection material (M) which has been heated into a fluid and cooling and solidifying the injection material (M), and after the cooling and solidification process, air is injected through the through hole (5) of the mold (3). The solidified injection material (M
) is released from the mold. 2. In the mold release step, air is supplied from a pressure pump (10) to an air collection groove (6) that surrounds the mold (3) and communicates with a pressure pump (10) provided outside the mold (1). send air,
The production of a molded article according to claim 1, characterized in that the air is applied by applying positive pressure to the injection material (M) through the through hole (5) of the mold (3). Method. 8. The method for manufacturing a molded article according to claim 1, wherein the mold (3) is formed by electroforming.