JP2001018234A - Production of die for molding with stitch pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a die for molding with a stitch pattern, which is free from a problem in strength and precision, without necessitating highly experienced skill with reduced man-hour and to provide the die for molding in a short delivery date at a low cost. SOLUTION: A resist agent 5 for a seam is stuck on the faces of the die for molding. Many seams 11 are formed by etching the faces of the die exposed between the resist agent 5 for the seams by means of an etching liquid. Thereafter, a resist agent 8 for a fine line is stuck to each seam 11 and the seams 11 exposed between the resist agent 8 for the fine lines are etched by an etching liquid and thereby the fine lines are formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold having a stitch pattern on a mold surface and various types of resin molding (for example, injection molding, reaction injection molding, transfer molding, blow molding, stamping molding, rotation molding, slash molding, vacuum molding,
Pressure molding etc.) and rubber molding (eg transfer molding etc.)
The present invention relates to a method for producing a molding die used in the method.

[0002]

2. Description of the Related Art A stitch pattern includes a seam where a thread repeatedly appears at a predetermined length,
Each thread has a thread (spiral pattern generated by twisting the thread) that appears on the surface of the thread and has fine irregularities. Such a stitch pattern is effective in giving a texture close to that of real leather sewn with thread in a resin molded product such as an instrument panel of an automobile, a console box, and a steering wheel. It is preferred. Such a resin molded product needs to be molded by a molding die having a stitch pattern on a mold surface. Conventionally, this type of molding die with stitch pattern
It was mainly manufactured by the following three methods, but there were problems with each method.

(A) Electroforming method A thread is actually sewn into a master model, and a matrix is manufactured by repeating inversion with an epoxy resin or the like based on the master model, and nickel is electroformed on the matrix by electroforming. A method of manufacturing a metal mold by forming a shell by attaching the shell, demolding the shell, and providing a backing for reinforcement on the back surface of the shell. This method takes time and effort in terms of man-hours for reversal from the matrix, electrodeposition speed limits, man-hours for removing the shell, and man-hours for backing,
There is a problem that the delivery time becomes longer and the cost becomes higher. Also,
There is also a problem that the strength is weak due to the shell structure and the material of nickel.

(B) Precision casting method A method in which a thread is actually sewn into a master model, a mold is made of plaster or the like based on the master model, and a molten metal is poured into the mold to manufacture a mold. This method is liable to cause distortion and warpage due to non-uniformity during the solidification and shrinkage of the molten metal, and has a problem in accuracy. In particular, the larger the mold, the more pronounced the problem.

(C) Method of using mechanical engraving and hand-engraving together Seams are engraved by an engraving machine on the mold surface of a mold having no stitch pattern formed by various methods such as die engraving, and then each seam is engraved by hand engraving. A method of engraving the thread and adding a stitch pattern. In this method, a high degree of skill is required for processing, and in recent years, since there are very few skilled workers, there is a problem that the delivery time is long and the cost is high.

An object of the present invention is to provide a molding die with a stitch pattern which solves the above problems and has no problem in strength and accuracy.
An object of the present invention is to provide a method that can be manufactured with a small number of man-hours without requiring a high degree of skill, and that can be provided inexpensively with a short delivery time.

[0007]

In order to achieve the above object, a method of manufacturing a molding die having a stitch pattern according to the present invention comprises the steps of: adhering a seam resist to a mold surface of the molding die; After forming a large number of stitches by etching the mold surface exposed between the resist agents for use with an etching solution, a thread resist agent is attached to each of the seams, and is exposed between the thread resist agents. Forming a thread by etching the seam with an etching solution,
We took the measure.

Here, the method of attaching the resist agent to the mold surface or the seam is not particularly limited, but the following method can be exemplified. (A) Apply a photosensitive resist to the mold surface or seam,
The original stitch pattern is transferred to the resist agent by a photographic method or an indirect transfer method, and the photosensitive agent is printed. (A) A transfer sheet comprising a transparent resin film and a photocurable resist agent adhered to one surface thereof, the resist agent side of which is attached to a mold surface, and the transfer sheet is exposed from above to expose the resist agent Is cured and adhered to the mold surface, and then the transparent resin film is peeled off to leave the resist agent on the mold surface.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a molding die for injection-molding a resin molded product (for example, a steering wheel pad of an automobile) will be described with reference to the drawings. .

FIG. 1 shows the entirety of a molding die 1 manufactured, and a stitch pattern 10 is formed on a pattern forming portion of a mold surface 2. As shown in FIG. 4C, the stitch pattern 10 includes a seam 11 where a thread repeatedly appears at a predetermined length.
Each of the stitches 11 includes a thread 12 (spiral pattern generated by twisting the thread) 12 which appears on the surface of the thread, and has fine irregularities. The molding die 1 is manufactured by the following method.

(1) As shown in FIG. 1, the mold surface 2 is formed by various methods (for example, cutting, electric discharge machining, etc.) which are not limited to a specific method. As shown in FIG. 2 (a), in order to express a dent of the leather that occurs when a thread is sewn into real leather at the time of forming the mold surface 2 in a resin molded product, as shown in FIG.
Are formed in the pattern formation portion of the above.
In addition, fine waviness of leather due to the sewing (three-dimensional appearance)
As shown in FIG. 2 (b),
Are formed in the upper surface of the substrate.

(2) As shown by hatching in FIG. 2 (c), each of the curved concave portions 4 of the mold surface 2 is formed so as to surround the machining region 6 except for the machining region 6 having a long hole shape. The resist agent 5 is deposited by a photographic method. (3) As shown by hatching in FIG. 3A, an etching-resistant film 7 is applied to the mold surface 2 other than the seam resist agent 5 and the processing area 6. Etching resistant coating 7
There is no particular limitation as long as it can protect the mold surface 2 from the etching solution, and examples thereof include an acid-resistant coating.

(4) As shown by an arrow in FIG. 3B, an etching solution (for example, a ferric chloride solution, a cupric chloride solution, or the like) is brought into contact with the mold surface 2 so that the seam resist agent 5 A large number of seams 11 are formed by etching the mold surface 2 of the processing region 6 exposed to the seam. (5) As shown in FIGS. 3B to 3C, the seam resist 5 and the etching resistant coating 7 are removed from the mold surface 2 by a known method such as dissolution and washing.

(6) As shown in FIG. 3 (c), a strip-shaped or thin-line thread resist agent 8 is adhered to each stitch 11 by a photographic method. (7) As shown by hatching in FIG. 4A, an etching resistant film 7 (the same as above) is applied to the mold surface 2 other than the seam 11.

(8) As shown by an arrow in FIG. 4 (b), an etching solution (the same as above) is brought into contact with the mold surface 2, and the seam 11 exposed between the thread resist agents 8 is etched with the etching solution. By doing so, the thread 12 is formed. (9) As shown in FIGS. 4B to 4C, the thread resist agent 8 and the etching resistant coating 7 are removed from the mold surface 2 by a known method such as dissolution and washing.

(10) If necessary, the corners of the seam 11 and the thread 12 generated by the etching are lightly etched so as to be rounded and finished.

FIG. 5 shows a stitch pattern forming portion of a resin molded product 20 injection-molded using the molding die 1 manufactured as described above. According to the above-mentioned raised line 3,
Leather dents created when threads are sewn into real leather 2
1 is formed, and the curved concave portion 4 forms a fine waviness 22 of leather by the sewing. The stitch pattern 23 composed of the seam 24 and the thread 25 is formed by the stitch pattern 10 composed of the seam 11 and the thread 12.

According to the method of manufacturing the molding die 1 of the present embodiment, the following operational effects can be obtained. Since the stitch pattern 10 is formed on the molding die 1 formed into a desired shape by cutting, electric discharge machining, or the like, it is possible to easily cope with a design change during the production of the die 1. Further, the strength of the molding die 1 is also high. The method of forming the stitch pattern 10 is simpler than the conventional method, and can be performed with a small number of man-hours without requiring a high level of skill. Since there is no distortion or warpage due to the formation of the stitch pattern 10, the accuracy of the molding die 1 can be maintained. Since the photographic method is used to form the stitch pattern 10, the accuracy of the pitch of the seam 11 and the thread 12 is relatively good.

The present invention is not limited to the above-described embodiment, and may be embodied with appropriate modifications without departing from the spirit of the invention, for example, as described below. (1) The seam 11 is etched by a plurality of steps in which the etching width is gradually changed, so that the cross-sectional shape of the seam 11 is close to the real shape. (2) Gold used for various types of resin molding other than injection molding (eg, reaction injection molding, blow molding, stamping molding, rotation molding, slash molding, vacuum molding, pressure molding, etc.) and rubber molding (eg, transfer molding, etc.) Be embodied in a type.

[0020]

As described above, the method for manufacturing a molding die with a stitch pattern according to the present invention is configured as described above. Therefore, a molding die with a stitch pattern having no problem in strength and accuracy requires a high level of skill. The present invention has an excellent effect that it can be manufactured with a small number of man-hours and can be provided inexpensively with a short delivery time.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a molding die with a stitch pattern according to an embodiment of the present invention.

FIGS. 2A and 2B are enlarged views of a ridge formed on a mold surface of the molding die, FIG. 2A is a perspective view of the ridge, FIG. 2B is a perspective view of a curved recess formed, and FIG. () Is a perspective view when a seam resist is adhered.

3 (a) is a perspective view when an etching-resistant film is applied and formed, FIG. 3 (b) is a perspective view when a seam is formed by etching, and FIG. 3 (c) shows a seam resist agent and an etching-resistant film. It is a perspective view at the time of removing and attaching the thread resist agent.

4 (a) is a perspective view when an etching resistant film is applied and formed; FIG. 4 (b) is a perspective view when a thread is formed by etching; FIG. 4 (c) is a perspective view showing the thread resist agent and the etching resistant film. It is a perspective view at the time of removal.

FIG. 5 is an enlarged perspective view showing a stitch pattern of a resin molded product molded using the molding die.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Molding die 2 Mold surface 3 Ridge 4 Curved concave part 5 Seam resist agent 6 Processing area 7 Etching resistant coating 8 Thread resist agent 10 Stitch pattern 11 Seam 12 Thread

Claims (1)

[Claims] 1. After forming a large number of seams by attaching a seam resist to a mold surface of a molding die and etching the mold surface exposed between the seam resists with an etchant, Manufacturing a molding die with a stitch pattern, wherein a thread is formed by attaching a thread resist to each seam and etching a seam exposed between the thread resists with an etchant; Method.