JPS63213692A - Production of forming die - Google Patents

Abstract

PURPOSE:To easily obtain the title porous forming die, by growing a minute nonconductive part generated at the initial stage of electrocasting under specified conditions in a main die body to be formed on the surface of a mandrel by electrocasting, and allowing the part to penetrate the die to provide many through holes. CONSTITUTION:Many minute nonconductive parts are provided on the surface of an electrically conductive layer 8 furnished on the surface of the mandrel 5. Besides, the mandrel 5 is stopped at the initial stage of electrocasting, and an electrolyte contg. no surfactant is used. Electrocasting is carried out by using the electrolyte to grow an electrocast layer 9 on the surface of the mandrel 5, and the main die body 1 is formed. A minute part not to be electrodeposited is generated on the nonconductive part at the initial stage of electrocasting. The part not to be electrodeposited is grown with the progress of electrocasting, and allowed to penetrate the die. Many through holes 2 are formed in the die 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a method for manufacturing a porous molding die formed by electroforming.

(Prior art and problems to be solved by the invention) Conventionally,
In order to form porous molds for vacuum forming, etc., the molds are molded using a thermal spraying method to make them naturally porous.
The method used was to mix water with a synthetic resin material, form a mold, and then dehydrate it to make it porous.

However, in these methods, the holes are too small to perform vacuum suction during vacuum forming, and the holes are not penetrating and are easily clogged, making cleaning the holes difficult.

Another method used was to form molds using electroforming, which is an applied technology for plating. This electroforming method will be briefly described below.

■ First, a spray solution containing a mixture of paste sample lacquer and butyl acetate solution is sprayed onto the model to be electroformed (hereinafter referred to as the mandrel).
Gives conductivity to the mandrel.

■ Next, a pretreatment solution made by mixing hydrochloric acid and stannous chloride in pure water is applied to the mandrel with a brush, etc., to activate the surface of the mandrel and prevent the formation of pinholes. Perform processing.

■ Next, perform electroforming. The electrolytic solution used is a mixture of nickel sulfamate solution and boric acid, to which a small amount of sodium lauryl sulfate, for example, is added as a surface active additive. This sodium lauryl sulfate prevents pinholes from forming in the electroformed layer on the surface of the mandrel during electroforming.

The electroformed material and the mandrel are immersed in the electrolyte stored in the electrolyte tank, the electrolyte is circulated, and the cathode rocker is operated to move the mandrel in the electrolyte. In the meantime, a current of 0.6 A is passed for 3 to 4 hours per surface f 100 cm'' of the mandrel to electrodeposit a thin electroformed layer over the entire surface of the mandrel.

After confirming that the electroformed layer is thinly electrodeposited, the current is converted to 1 to 2 A per 100 CI112- of the mandrel area, and electroforming is continued to make the electroformed layer smooth and finished into the desired shape. , and more mandrel and 'F! The R layer is separated to form a mold body.

(2) A porous mold is completed by making a large number of small holes in the mold body formed as described above using a cone with a tip diameter of 0.3++ on or a laser beam.

However, even in the electroforming mold as described above, the work of forming a large number of small holes is not only very complicated, but also! 2. In the case of a mold having an irregular shape, there is a problem in that holes cannot be made through the mold depending on the location.

This invention was made in order to solve the above-mentioned problems, and its purpose is to facilitate vacuum suction, etc., and to make it possible to easily clean the inside of the through hole because it is less likely to be clogged. Another object of the present invention is to provide a method for manufacturing a molding die that is easy to manufacture.

Structure of the Invention (Means for Solving the Problem) In order to achieve the above-mentioned object, the present invention provides a conductive layer on the surface of the mandrel, and provides a large number of minute non-conductive parts on the surface of the conductive layer. The mold body is formed by performing electroforming on the surface of the mandrel that is in a stopped state at least in the initial stage of electroforming in an electrolytic solution that does not contain surfactant additives. A method was adopted in which minute non-electrodeposited portions were generated, and as electroforming progressed, the non-electrodeposition portions were allowed to grow and pass through to form a large number of through holes in the mold body.

That is, in conventional electroforming technology, pinholes occur irregularly and unstablely, and moreover, they appear largely on the surface, so they have been considered to be defects that must be avoided.

In contrast, in the present invention, the minute non-electrodeposited portions generated at the initial stage of electroforming are allowed to grow during the same electroforming process, and are made to penetrate through the holes, creating minute holes that can be used for vacuum suction, etc., instead of pinholes. This can be said to be a revolutionary mold manufacturing method based on a completely reversible idea.

(Function) Since the through holes are formed by growing minute non-electrodeposited portions, airflow resistance during vacuum suction, etc. is low, and the through holes are less likely to be clogged. Further, since the through holes are formed at the same time as electroforming, there is no need to perform a through hole forming step after electroforming.

In particular, since not only conductive parts but also minute non-conductive parts are formed in the conductive layer, it is difficult for the electroforming material to electrodeposit on these non-conductive parts at the initial stage of electroforming, and the minute non-electrodeposited parts This contributes to the formation of through holes on the surface of the mandrel.

Furthermore, since the electrolytic solution does not contain a surfactant additive and the mandrel is stopped in the electrolytic solution at least at the initial stage of electroforming, minute non-electrodeposited parts are likely to occur.

(First Example) Hereinafter, a first example in which the present invention is embodied in a mold for vacuum forming will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a mold body according to the present invention, which is formed by electroforming. Reference numeral 2 denotes a large number of through holes provided through the mold body 1, and as will be described later, minute non-electrodeposited portions generated at the initial stage of electroforming are covered with gold in the thickness direction during electroforming. The diameter of the mold body 1 gradually increases from the front surface to the back surface as shown in FIG. 3(b). In addition, through hole 2
Although the shape is shown as a simplified tapered shape as shown in FIG. 3(b), it goes without saying that the way it spreads varies depending on the electroforming conditions. For example, the inner surface of the through hole 2 may be uneven, or adjacent through holes 2 may be connected to each other.

The maximum diameter of this through hole 2 on the surface side of the mold body 1 is 0.
The thickness is preferably 1 to 0.5 mm. While it is necessary to increase the vacuum suction power, there are two through holes in the synthetic resin molded part.
This is to prevent any traces from remaining. Further, the number of through holes 2 is desirably 5 to 10,000 per 10 cm" of area of the mold body 1 from the viewpoint of vacuum suction force.

This mold body 1 is mounted on a vacuum forming device, and vacuum forming is performed by driving the suction pump P of the vacuum forming device to reduce the pressure on the back side of the mold body 1. During this vacuum forming, gold is sucked into the molded object W made of a synthetic resin material or the like through the numerous through holes 2 of the water body 1, and it is brought into close contact with the surface side of the mold body 1.

Next, the equipment, materials, etc. used to manufacture this mold body 1 will be explained.

3 is an electrolytic solution stored in an electrolytic solution tank A as shown in FIGS. 2(a) and (b), which is composed of 450 Q/Jl of sulfamine-strengthened nickel solution and 40 g,/i or more of boric acid. , its temperature is maintained at 37°C to 40°C. The p-toro 10 of this electrolytic solution 3 is adjusted to remain within the range of 3.8 to 4.2 by adding a nickel chloride agent as an additive.

If the pH value of the electrolytic solution 3 exceeds the above range, the cathode current efficiency during electroforming will decrease, while the pto1 value will decrease to 3.
If it does not reach 8, basic precipitates will be formed in the electrolytic solution 3, causing defects such as the electrolyzed metal becoming more likely to discolor.

Here, in the electrolytic solution 3 of this example, lauryl sulfate 1 to
Since it does not contain surfactant additives such as lithium, it does not have the effect of suppressing the formation of pinholes.

Therefore, non-conductor portions (which were conventionally the seeds of pinholes) are likely to occur in the early stages of electroforming, and the growth of through holes 2 is also promoted.

Reference numeral 4 denotes an electroformed material placed in the electrolytic solution 3, and nickel is used in this embodiment.

5 is a mandrel placed in the electrolytic solution 3 at a position facing the electroforming material 4, and is made of a synthetic resin material such as epoxy, acrylic, acrylic-butadiene-styrene copolymer, vinyl chloride, solid wax, metal, It is made of wood, ceramics, fabric, thread, etc. This mandrel 5 is a model of the mold body 1 shown in FIGS. 1 and 3(b), and is suspended from a cathode rocker 6 movably attached to the upper end of the electrolyte tank A. (b
), the cathode rocker 6 moves back and forth in the electrolyte 3 in accordance with the movement of the cathode rocker 6 in the length direction.

Note that 7 is a moving device that drives the cathode locker 6 back and forth. In addition, a power source S is provided outside the electrolyte tank A,
The electroformed material 4 is electrically connected to the anode, and the spray layer 8 of the mandrel 5 is electrically connected to the cathode.

Next, a method for manufacturing the mold body 1 will be explained in order.

(2) In order to make the mold body 1 porous, the mandrel 5 is subjected to a surface treatment process and a racking process before being immersed in the electrolytic solution 3.

First, in the surface treatment step, the surface of the mandrel 5 is polished with an abrasive such as a solvent or polishing powder to remove impurities attached to the surface and roughen the surface. The purpose of the roughening of the surface is to improve the conformability of the leading material and to increase the adhesion of the M casting film. After this, mandrel 5
is washed with water to remove the abrasive on the surface, and then dried with jet air to complete the surface treatment process.

In the racking process, a spray liquid is injected onto the desired surface of the mandrel 5 for electroforming to impart conductivity. This spray solution was prepared by mixing paste sample lacquer (RC-10 manufactured by Hideki Metal Powder Co., Ltd. was used in this example) and a butyl acetate solution in a 1:1 ratio. It is made by mixing vinyl chloride lacquer liquid in a proportion of 30% or less based on the total amount of the compounded liquid.

This spray liquid is sprayed twice until the surface of the mandrel 5 exhibits a complete metallic color, and as shown in FIG. After forming, the mandrel 5 is air-dried for about 24 hours. Since the spray liquid contains a vinyl chloride lacquer liquid, the spray layer 8 on the surface of the mandrel 5 has low conductivity, and a large number of holes 2 are likely to be formed on the surface of the mandrel 5.

From a more microscopic perspective, in the spray layer 8, not only conductive parts made of silver powder but also minute non-conductive parts are formed by the vinyl chloride lacquer scattered in the silver powder, so the II property as a whole is lowered. It is. Electroforming material is difficult to electrodeposit on the minute non-electroconductive portions formed by the vinyl chloride lacquer at the initial stage of electroforming, which will be described later, and therefore contributes greatly to the generation of minute non-electrodeposited portions.

By adjusting the degree of mixing of the vinyl chloride lacquer liquid in the spray liquid, the conductivity of the surface of the mandrel 5 can be freely set, and the size and distribution of the non-conductive parts can be changed. It is possible to change the dimensions of the mandrel 5 and to freely manage the number of through holes 2 per unit area of the mandrel 5 and the aperture ratio. Therefore, for example, the fourth
As in the mold shown in Figure (a), many through holes 2 may be formed only in a part of the mold body 1 surrounded by the two-dot chain line. As shown in FIG. 4(b), this part has an uneven part 10 for forming wrinkles and an uneven part 11 for forming threads such as stitches, so by increasing the number of through holes 2, it is possible to This uneven portion 10 is made by firmly bringing W into close contact with the mold body 1.
．． 11 can be attached to the molded object W.

Also, other insulating materials may be used in place of the vinyl chloride lacquer solution as a contaminant in the spray solution.

Note that a silver wave film may be provided on the surface of the mandrel 5 to impart conductivity before the racking step.

After the racking process is finished, the mandrel 5 is washed with water again to remove foreign matter from the surface, and the pretreatment of the mandrel 5 is completed.

(2) In this embodiment, the step of activating the surface of the mandrel 5 using a pretreatment liquid in the prior art is omitted. This is to facilitate the formation of minute non-electrodeposited portions on the surface of the mandrel 5 at the initial stage of electroforming.

(2) Subsequently, the mandrel 5 and the electroformed material 4 are immersed in the electrolytic solution 3 in the electrolytic solution tank A. At this time, the electrolytic solution 3 is in a stopped state without being circulated, and the moving device 7 of the cathode locker 6 is in an OFF state, so the mandrel 5 also does not move. This is to facilitate the generation of minute non-electrodeposited portions.

Turn on the power supply S and set the area of the mandrel 5 to 100 cm2.
When a current of 3 A per 100 Ω is passed between the electroformed material 4 and the spray layer 8 of the mandrel 5, the electroform material 4 is electrolyzed and coated onto the spray layer 8 of the mandrel 5, and 711! Casting FI9
is formed.

At the beginning of this electroforming process, as mentioned above, one layer of spray 8
The electroforming material 4 is more likely to be electrodeposited on the conductive parts made of silver powder, but it is difficult to electrodeposit the electroforming material 4 on the minute non-conductive parts made of vinyl chloride lacquer scattered in the silver powder. A minute non-electrodeposited part is generated starting from the conductive part.

As electroforming progresses, this minute non-electrodeposited portion grows to become a through hole 2.

In particular, in this embodiment, in addition to the presence of this non-conductive part, as described above, techniques such as adjusting the composition of the electrolytic solution 3, omitting the surface activation treatment of the mandrel 5, stopping the cathode rocker 6, and adjusting the current are used. is added, the generation and growth of the above-mentioned non-[1 part] is further facilitated.

In addition, in this embodiment, the through hole 2 becomes 'Fi' as the electroforming progresses.
The cast R9 grew not only in the thickness direction but also in the radial direction, and the back side of the mold body 1 became a through hole 2 with an enlarged diameter.

After confirming that the entire desired surface of the mandrel 5 is coated with the electroformed layer 9 and that a large number of through holes 2 are formed in the electroformed layer 9, a current is applied to the mandrel 5 with a
Reduce it to about 1~2△ cni'$.

Thereafter, by circulating the electrolytic solution 3 and further operating the cathode rocker 6, the cathode current density is made uniform, so that the thickness of the electroformed layer 9 is made uniform.

(2) When the surface of the mandrel 5 is electroformed as described above, the mandrel 5 is taken out from the electrolytic solution 3 and dried. After this, the electroformed layer 9 is peeled off from the mandrel 5. In addition, since the spray layer 8 is interposed between the electroformed layer 9 and the surface of the mandrel 5, the electroformed layer 9 can be easily peeled off. The electroformed layer 9 removed from the mandrel 5 is used as the mold body 1 of the mold.

Since the through hole 2 is formed by growing minute non-electrodeposited portions, the airflow resistance during vacuum suction is low, and vacuum suction is easy to perform. Further, the through hole 2 is less likely to be clogged, and the inside of the through hole 2 can be cleaned easily. Furthermore, since the through holes 2 are formed at the same time as the electroforming, there is no need to perform the step of forming the through holes 2 after electroforming, and the mold can be manufactured easily.

In particular, since not only a conductive part but also a minute non-conductive part is formed in the spray layer 8 as a four-electroconductive layer, it is difficult for the electroforming material 4 to electrodeposit on this non-conductive part at the initial stage of electroforming. This contributes to the generation of minute non-electrodeposited portions, making it easier for through holes 2 to be formed in the electroformed layer 9 on the surface of the mandrel 5.

Furthermore, since the electrolytic solution 3 does not contain a surfactant additive and the mandrel 5 is stopped in the electrolytic solution 3 at least at the beginning of electroforming, minute non-electrodeposited parts are likely to occur, and the mandrel 5 The through holes 2 are more easily formed in the electroformed layer 9 on the surface.

Further, the diameter of the through hole 2 of this embodiment gradually increases on the back side of the mold body 1 as electroforming progresses. Therefore, the diameter of the through hole 2 is sufficiently small on the front side of the mold body 1, so that not only no trace of the through hole 2 remains on the surface of the molded product, but also the diameter is large on the back side of the mold body 1. Therefore, the airflow resistance during vacuum suction is also lowered, and the suction force is increased, which is ideal for the mold.

(Second example) Next, a second embodiment of the invention will be described.

In this example, surfactant additives such as sodium lauryl sulfate are not added to the electrolyte 3 as in the first example, but the other steps are different from the first example and are similar to normal electroforming. It is something that is done.

In this case, the generation of pinholes on the surface of the mandrel 5 is promoted only by the modification of the electrolytic solution 3.
The incidence of through holes 2 is extremely low compared to the case of the example.

this? [In contrast to the R method, if vinyl chloride lacquer is mixed into the spray liquid in the pretreatment of the mandrel 5 to form the spray 1fI8, the rate of occurrence of the through holes 2 can be increased slightly.

Furthermore, (1) In the pretreatment of the mandrel 5, no pretreatment liquid is used.

(2) During electroforming, the electrolytic solution 3 is not circulated, and the cathode rocker 6 is also kept in a stopped state.

(3) Applying a stronger current than usual during electroforming.

By appropriately combining the following steps, the mold body 1
The number of through holes 2 can be managed.

By the way, in the above-mentioned embodiment, as shown in FIG.
A spray liquid prepared by pre-mixing a vinyl chloride lacquer liquid with paste trial lacquer is sprayed onto the mandrel 5, and minute non-conductive parts are formed by the vinyl chloride lacquer scattered in this spray layer 8, as shown in Fig. 6. As shown, after spraying the paste test lacquer on the surface of the mandrel 5, a further vinyl chloride lacquer can be sprayed and interspersed on the spray layer 8, and the non-conductive portions can be formed by the vinyl chloride lacquer. Of course, spray one layer 8
It is also possible to form the non-conductive portion by other methods, such as by making a recess in the surface.

Furthermore, the mold of the present invention can be used not only in vacuum forming methods, but also in blow molding methods, injection molding methods, rim urethane molding methods, and the like.

Note that this invention is not limited to the above-described embodiments, and for example, other metals that can be electrolyzed with positive ions may be used instead of nickel as the electroforming material 4, as long as they do not deviate from the spirit of the invention. Any changes are possible.

Effects of the Invention As detailed above, this invention penetrates a mold body formed by electroforming by growing minute non-electrodeposited portions generated at the initial stage of electroforming. By providing a large number of through holes, it is easy to perform vacuum suction, etc., and the through holes are less likely to be clogged, making it easy to crush the inside of the through holes, and furthermore, it is easy to manufacture molds. It has this excellent effect.

In particular, since not only conductive parts but also minute non-conductive parts are formed in the conductive layer, it is difficult for the electroforming material to electrodeposit on these non-conductive parts at the initial stage of electroforming, and the minute non-electrodeposited parts Moreover, because the electrolyte does not contain surfactant additives and the mandrel is stopped in the electrolyte at least at the beginning of electroforming, minute non-electrodeposited parts are likely to occur, and the mandrel Through holes are more likely to be formed on the surface.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the mold according to the present example, not showing the state in which it is used;
FIG. 2(a) is a schematic diagram showing an electroforming method for manufacturing a mold, FIG. 2(b) is a plan view of FIG. 2(a), and FIG.
a) is a cross-sectional view showing the state of electroforming on the mandrel;
Figure (b) is a partially broken enlarged sectional view of the mold, Figure 4 (a) is a plan view showing another example of the mold, and Figure 4 (b) is Figure 4 (a).
FIG. 5 is a partially enlarged sectional view showing a method for forming a non-conductive part in this embodiment, and FIG. 6 is a partially enlarged sectional view showing another example of a method for forming a non-conductive part in this embodiment. It is. Mold body 1, through hole 2, electrolyte 3, mandrel 5, spray layer 8 (conductive layer). Patent Applicant: Konan Special Industry Co., Ltd. Agent: Patent Attorney On 1) Bo Xun Figure 18 (b) Figure 4 (a) Figure 4 (b)

Claims (1)

[Claims] 1. A conductive layer (8) is provided on the surface of the mandrel (5), and a large number of minute non-conductive parts are provided on the surface of the conductive layer (8), and does not contain a surfactant additive. Mandrel (5) kept in a stopped state at least at the initial stage of electroforming in electrolyte (3)
The mold body (1) is formed by performing electroforming on the surface of the mold body (1), and a minute non-electrodeposited part is generated in the non-conductive part at the beginning of the electroforming, and as the electroforming progresses, the mold body (1) is formed. A method for manufacturing a molding die, characterized in that a large number of through holes (2) are formed in a mold body (1) by growing a fitting portion to penetrate the mold body.