WO2023013685A1 - Case mold - Google Patents

Abstract

Provided is a case mold capable of reducing the time until the start of manufacturing of a product using a forming mold, and reducing manufacturing costs of the forming mold. Also, molding of a modelling object corresponding to 3D data which has a higher degree of freedom in manufacturing is realized. A case mold 1 is for the manufacturing of a forming mold used for molding and is a split mold composed of at least two molds. The case mold 1 is a layered molded body including a resin composition containing, for example, polylactic acid (PLA) and acrylonitrile-butadiene-styrene copolymer (ABS). The forming mold is a gypsum mold, namely, solidified gypsum.

Description

case type

The present invention relates to a case mold used for molding.

Molding such as casting is widely used as a method for manufacturing ceramics and castings. In molding, a mold is used to fill the material of the final product (hereinafter also referred to as "product"). There are various types of molds, such as sand molds made of hardened sand, molds made of processed metal, and gypsum molds made of hardened gypsum, depending on the type of material. Gypsum is suitable as a mold material because it is easy to mold, solidifies in a short period of time, and has a smooth surface.

For example, in the case of casting, gypsum molds can be used to mold objects with complex shapes and fine irregularities on the surface. Can be used for casting. In addition, in the case of molding ceramics, since gypsum molds are excellent in water absorption, they can also be used for slip casting molding in which slurry is poured into gypsum molds, and then the slurry is discharged.

Here, we will explain the conventional manufacturing method of gypsum molds for ceramics. When manufacturing a mold for ceramics, a plurality of molds (prototype, sample mold, case mold, mold) are produced in order, and finally the mold is obtained. Specifically, first, a model (prototype) of the product is produced based on the effects of shrinkage due to firing of ceramics and an image of the finished product. Next, the original mold is transferred by casting to produce a sample mold for use in the production of the case mold. The shape transferred to the sample mold is the same shape as the mold used to manufacture the final product, but when mass-producing a large number of ceramic materials or raw materials for the product in the original shape, a large number of molds are required. Therefore, a case mold is required for mass production of molds. A case mold is produced by inverting the sample mold by casting, and the mold is obtained by pouring gypsum into the case mold. Although the prototype and the case mold have the same shape partially or wholly, they differ in that the prototype is used to manufacture the sample mold and the case mold is used to manufacture the mold. The case mold is manufactured to make the same mold as the sample mold or a mold that has undergone processing in order to meet the conditions required for the mold according to the manufacturing process.

As mentioned above, the conventional mold manufacturing method requires a large number of molds from the time the mold is made to the start of manufacturing the final product, requiring a great deal of time and effort. As a result, the time and labor involved are reflected in the price of the final product, making it difficult to reduce the price in response to market demands for lower prices.

JP 2016-83664 A

As a method to reduce the time and effort required to manufacture such molds, methods such as directly manufacturing molds from 3D data using a 3D additive manufacturing method or an NC (numerical control) cutting machine. is proposed. In Patent Document 1, as the foundry sand, a coated sand obtained by coating a refractory aggregate with a water-soluble binder and gypsum powder are mixed is used, and the mixture is formed with such a mixture. A method for producing a laminated mold (mold) is described in which the solidification or hardening of a sand layer is carried out by spraying an aqueous medium.

In the case of the method described in Patent Document 1, by manufacturing the molding die by lamination molding, there is no need to manufacture a master mold, a sample mold, or a case mold, thereby shortening the time and effort required to obtain one molding die. can.

However, when mass-producing a large number of final products, a large number of molds are also required. Since manufacturing by lamination molding takes a long time for one time manufacturing, when it is necessary to manufacture a large number of molding dies, the process of manufacturing the molding dies takes a lot of time. Therefore, especially when mass-producing a large number of final products, it is required to quickly manufacture a mold and shorten the time until the start of production of the final product. In addition, since the materials used for lamination molding are also relatively expensive, lamination molding of a large number of molding dies leads to an increase in the manufacturing cost of the molding dies, that is, the product manufacturing cost.

In addition, in the case of a method of directly manufacturing a forming die using an NC cutting machine, etc., it may be difficult to manufacture a complicated structure such as a crucible shape due to restrictions on the arm shape of the NC cutting machine.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a case mold capable of shortening the time until the start of manufacturing (mass production) of a product using a molding die and reducing the manufacturing cost of the molding die. do.

The case mold of the present invention is a case mold for manufacturing a mold used for molding, and is characterized by being a laminate molding of a resin composition.
Here, "molding" means molding by filling or pressing a material such as china clay, metal, or resin into a mold, such as casting, pressure casting, and press molding.

The mold is characterized by being a gypsum mold that is a solidified gypsum.

The case mold is characterized by being a split mold consisting of at least two molds. The above split mold is useful for preventing gypsum, resin, and metal from being caught due to volumetric changes.

The case mold has a concave portion and a convex portion for alignment, and the mold manufactured using the case mold has a convex alignment portion and a concave alignment portion, and a plurality of The molding die is characterized in that the convex alignment portion of one molding die and the concave alignment portion of the other molding die are fitted and combined. The alignment portion is useful when misalignment between the molds is expected during the molding process of the material.

The case mold of the present invention is a case mold for manufacturing a mold used for molding, and since the case mold is a laminated molding of a resin composition, the steps before manufacturing the case mold are simplified. It is possible to shorten the time until the start of manufacturing the product using the molding die and reduce the manufacturing cost of the molding die. This leads to a reduction in product manufacturing cost and time. Moreover, the time required to manufacture the mold is shorter and the cost is lower than when the mold is directly manufactured by a method such as lamination molding without using a case mold.

Since the mold is a gypsum mold, which is a solidified gypsum, when the mold is manufactured by putting gypsum dissolved in water or liquid into the case mold, the gypsum will solidify in a short time, and the productivity of the mold will be improved. better than As a result, the time required to start manufacturing the product can be further shortened.

The case mold has a shape that does not leak liquid, or a shape that does not leak liquid made by combining split molds consisting of at least two molds. It can be easily demolded from. As a result, the yield in manufacturing the mold is improved, leading to a further reduction in the product manufacturing cost. Even if there is a gap between the split molds, there is no problem if the shape of the mold does not affect the production of the product.

The case mold has a concave portion and a convex portion for alignment, the mold manufactured using the case mold has a convex alignment portion and a concave alignment portion, and has a plurality of molds. Since the convex alignment part of one molding die and the concave alignment part of the other molding die are fitted and combined, multiple molding dies can be brought into close contact without gaps during product manufacturing. Easy to combine. As a result, the yield during product manufacturing is improved, leading to a further reduction in product manufacturing cost.

It is a perspective view of the case type|mold of this invention. It is an enlarged plan view of the inside of the case mold. 2 is a perspective view of the inside of the case mold shown in FIG. 1; FIG. 1 is a perspective view of a mold; FIG. 1 is a perspective view of a final product; FIG.

An embodiment of the case type of the present invention will be described using FIG. FIG. 1 is a perspective view of a case type. As shown in FIG. 1, the case mold 1 is a split mold composed of two case molds 1a and 1b. The case mold 1 is used to manufacture a mold used for molding. The case mold 1 is a laminate molded product of a resin composition, and a layered structure corresponding to the shape can be visually recognized on the surface thereof (see FIG. 2).

As mentioned above, since the case mold is a laminate molded product of a resin composition, it is possible to directly manufacture the case mold based on the three-dimensional data of the final product without producing a prototype or sample mold. simplifies the process before As a result, it is possible to shorten the time until the start of manufacturing the product using the molding die and reduce the manufacturing cost of the molding die, leading to a reduction in the product manufacturing cost. In addition, the prototype, sample mold, and mold can be molded from a laminate molded product of a resin composition based on three-dimensional data, and the shape can be confirmed.

I will explain the manufacturing method of the case type (laminated molded body). A laminate molded body can be produced by a laminate molding apparatus called a so-called 3D printer. Examples of methods for producing a laminate molded body using a laminate molding apparatus include a fused deposition modeling method (hereinafter also referred to as an "FDM method"), a stereolithography method, an inkjet method, a powder combustion method, and a powder adhesion method. methods and the like can be mentioned. As a method for manufacturing a laminated molded body, the FDM method is preferable because the equipment and materials are easy to handle and the equipment installation environment is highly flexible. The FDM method is a method in which a resin composition melted by heat is pushed out from a nozzle and stacked on a stage to form an object.

When manufacturing a laminate molded body with the laminate molding apparatus described above, the apparatus cuts the target object into slices on a plane parallel to the stage and forms layers of several μm to several mm on the stage one by one from the bottom in order. To go. Therefore, a layered structure aligned in the stacking direction (vertical direction with respect to the stage) is formed on the side surface of the completed laminate molded body.

Fig. 2 shows an enlarged plan view of the inside of the case mold. As shown in FIG. 2, on the side surface of the case mold 1b, a layered structure in which fine grooves (steps) are arranged in one direction in the stacking direction (horizontal direction of the paper surface) can be visually recognized.

A layered structure is usually visible on the side of the laminate. The spacing and height of adjacent steps in the layered structure are, for example, approximately 0.01 mm to 1 mm, respectively, depending on the lamination forming apparatus. This layered structure is called a stack mark. For this reason, when a molding die is manufactured by using the laminated case mold as it is, the traces of lamination are transferred to the surface of the molding die, and the transferred lamination traces are also transferred to the product manufactured by the molding die. be. Therefore, if the interval and height of the steps are larger than a predetermined value, the appearance of the product may be affected. If you do not care about the effect of lamination traces on the appearance of the product, use the laminate as it is.

Lamination marks on the surface of the case mold can be smoothed by applying putty material, sandpaper, sandblasting, polishing with a polishing machine, chemical surface treatment, heat melting, etc. As a smoothing method, application of a putty material or the like is preferable from the viewpoint of process easiness. The putty material to be applied can be freely selected from, for example, epoxy putty, polyester putty, lacquer putty, instant adhesive putty, gypsum putty, calcium carbonate putty, acrylic paint, urethane paint, epoxy paint, and silicone paint. As the putty material, epoxy putty and polyester putty are preferable from the viewpoints of filling the steps of the layered structure, non-fluidity, adhesion, and the like.

From the viewpoint of die cutting, it is preferable that part or all of the surface of the case mold is smooth. By smoothing part or all of the surface of the case mold, the mold is less likely to be subjected to resistance when it is demolded from the case mold, and the mold can be demolded more easily. In addition, since traces of lamination are not transferred to the surface of the product, a good appearance can be obtained. The term "smooth" as used herein means a state in which the layered structure normally possessed by the laminated molded product immediately after production has disappeared to such an extent that it cannot be visually recognized. For the sake of simplification of the work, there are cases where the traces of lamination are not processed. There is also a method of omitting processing by creating fine lamination traces that cannot be confirmed to be transferred to the product when forming a layered structure.

The case type before smoothing has different arithmetic average roughness measured in the lamination direction and the direction perpendicular to it, and the surface roughness is anisotropic. On the other hand, the case type after smoothing has substantially the same arithmetic average roughness measured in the stacking direction and the direction orthogonal thereto, and the surface roughness has no anisotropy.

The size of the case mold 1 in Fig. 1 is approximately 20 cm x 20 cm x 10 cm. The size of the laminate can also be selected according to the performance of the 3D printer, including the shape of the case mold 1 . However, depending on the resin material, shrinkage may affect the dimensions, so care must be taken when designing the 3D data and setting the output conditions of the 3D printer.

A part of the case mold may include a part that is not a laminated molding of the resin composition. This portion is made of any material such as resin or metal. The portion of the laminated molding of the resin composition in the case mold is preferably 30% by volume or more, more preferably 50% by volume or more, and even more preferably 70% by volume or more, relative to the total volume. Most preferably, substantially the entire (90% by volume or more) or the entirety (100% by volume) of the case mold is a laminate molded body of the resin composition.

Case-type resin compositions include, for example, polylactic acid (PLA), acrylonitrile-butadiene-styrene copolymer (ABS), acrylonitrile-styrene-acrylate copolymer (ASA), polypropylene (PP), and polyvinyl alcohol (PVA). , polyvinyl butyral (PVB), polycarbonate (PC), silicone resin, wax, nylon resin such as polyamide (PA), acrylic resin such as polymethyl methacrylate (PMMA), urethane resin such as thermoplastic polyurethane (TPU) Resins, polyester resins such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), fluorine resins such as polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), polyethylene (PE), polystyrene (PS), Various resins such as epoxy resins (EP), phenolic resins (PF), etc. may be included. From the viewpoint of dimensional stability, the case-type resin composition preferably contains PLA as a base resin, which has a lower heat shrinkage rate than general resins and is inexpensive. Since the resin composition of the case type contains PLA, even a relatively large mold for which it is difficult to ensure dimensional stability can be manufactured with stable dimensions.

In addition, the case-type resin composition includes fillers such as graphite, carbon black, graphene, carbon nanotubes, carbon fibers, glass fibers, cellulose nanofibers, cellulose nanocrystals, metal fine particles, metal oxide fine particles, and gypsum powder. can include The case-type resin composition preferably contains gypsum powder, which has a relatively small volume expansion coefficient and is inexpensive, from the viewpoints of strength, dimensional stability, cost, etc., in consideration of compatibility with the mold. By including gypsum powder in the resin composition of the case mold, even relatively large molds for which it is not easy to ensure dimensional stability can be manufactured with stable dimensions, and the price of the case mold can be reduced, resulting in improved quality of the final product. It leads to price reduction.

The case mold may be a split mold consisting of at least two molds, or may consist of only one mold. Since the case mold is a laminate molded body of a resin composition, it is easier to split than a gypsum mold, which may break if split. When the case mold is a split mold consisting of at least two molds, even if there is a difference in the volume expansion rate between the case mold and the molding die, the molding die may not come off from the case mold (biting) or may be caught. You can avoid damage. For example, in a combination of a case mold made of resin and a gypsum mold, it is possible to prevent the gypsum mold from becoming stuck in the case mold (biting) or being caught and damaged. In addition, since the case mold is a split mold, when manufacturing the mold using the case mold, the split mold can be designed in consideration of the release angle of the mold. It can be easily demolded. Furthermore, since the case mold is a laminate molded body of a resin composition, the case mold is appropriately deformed and no excessive force is applied to the mold. As a result, chipping and scratching during die cutting are less likely to occur, thereby improving the yield in manufacturing the mold.

The structure of the case type will be explained using FIG. 3 is a perspective view of the inside of the case mold shown in FIG. 1. FIG. This case mold is a case mold for forming a left-right symmetric mold in order to save the number of case molds to be manufactured. By making two molds from the case mold of FIG. 1, the four lateral faces of the mold of FIG. 5 are formed. As shown in FIG. 3, the case mold 1a has a concave portion 2 for alignment with the case mold 1b that is combined facing each other, and the case mold 1b has a convex portion 3 for alignment with the case mold 1a. have. Further, the case mold 1a has a protruding portion 4 for forming a recessed alignment portion in the molding die, which is used for alignment when assembling a plurality of molding dies to be described later. The case mold 1b has projections 5 and 6 and a recess 7 for forming a convex alignment portion and a concave alignment portion in the molding die. The shapes of the concave portions 2, the convex portions 3, the projecting portions 4, 5 and 6, and the concave portions 7 are not limited to linear or non-linear and can be any shape. For example, a gypsum mold or a resin mold can be produced by pouring gypsum or a resin composition into the case mold, which is a close combination of the case mold 1a and the case mold 1b.

　The molding die manufactured with the case mold shown in Figures 1 to 3 will be explained using Figure 4. 4(a) and 4(b) are perspective views of the mold. As shown in FIGS. 4(a) and 4(b), the mold 8 manufactured using the two case molds described above has a convex alignment portion 9 and concave alignment portions 10 and 11. have.

FIG. 4(c) is a plan view of the state in which two molding dies are combined. As shown in FIG. 4C, of the two molds 8a and 8b, one mold 8a has a convex alignment portion 9a and a concave alignment portion 10a, and the other mold 8b has a concave alignment portion. By fitting and combining the alignment portion 10b and the convex alignment portion 9b, it is possible to easily assemble a plurality of molding dies in close contact without gaps when manufacturing a product. When the mold is a split mold, the number of molds is not limited to two, and a plurality of molds may be combined. The concave alignment portion 11 can be used in combination with another mold (not shown).

The material of the mold to be manufactured using the case mold of the present invention is free from, for example, materials such as gypsum, resin, resin composition, metal, etc., which solidify from a liquid or slurry due to the passage of time, chemical reaction, or change in state. can be selected to As the material for the mold, gypsum is preferable from the viewpoint of productivity and molding accuracy. By using gypsum as the material for the mold, the gypsum solidifies in a short period of time during the production of the mold, so that the productivity of the mold is excellent. When a resin or a resin composition is used as the material of the molding die, thermoplastic resin, thermosetting resin, photo-setting resin, and moisture-setting resin can be included.

The final product manufactured with the case type shown in Fig. 4 will be explained using Fig. 5. FIG. 5 is a perspective view of ceramics and resin moldings, which are examples of final products. As shown in FIG. 5, the final product 12 has a plate shape. The final product 12 is manufactured by filling potter's clay or resin in a space formed by combining the case mold shown in FIG. be done.

Although FIG. 4 shows a mold with a simple structure as an example, by combining a plurality of molds with more complicated shapes, final products with various structures can be manufactured. The material of the final product manufactured using the molding die can be freely selected from, for example, metal, gypsum, ceramics, resin composition, elastomer, and the like. As for the material of the mold, a combination of materials that are easy to separate and easy to demold may be selected in consideration of physical properties such as volume expansion coefficient, surface energy and surface roughness of the material of the final product. As for the material of the case mold, considering the volume expansion coefficient, surface energy, surface roughness, etc. of the mold material, a combination of materials that are easy to separate and easy to demold may be selected. For example, the material of the mold is preferably a material that has a lower surface energy than the final product, and the material of the case mold is preferably a material that has a lower surface energy than the surface of the mold.

An example of the manufacturing procedure of the case type of the present invention will be explained. The case mold is manufactured by laminate-molding PLA filaments with an FDM-type laminate molding machine ANYCUBIC MEGA X (manufactured by ANYCUBIC JP). The case mold is a split mold consisting of two molds, and when combined, the maximum size is about 30 cm on all sides. The case type is manufactured with a thickness of about 2 cm so as not to be affected by the warping of the ends. After laminate molding, the case mold is separated from the stage of the laminate molding apparatus.

An example of the procedure for manufacturing a mold using the above case mold will be explained. Two case molds with a smoothed layered structure are positioned and combined so that the concave portion of one case mold and the convex portion of the other case mold are aligned, and fixed using a rubber band or the like. A gypsum mold can be obtained by pouring gypsum from the opening of the fixed case mold and allowing it to stand still for a predetermined time.

An example of the manufacturing procedure for ceramic products using the multiple molds manufactured by the above procedure will be explained. The plurality of molds each have a convex alignment portion and a concave alignment portion. Among the plurality of molds, the convex alignment portion of one mold and the concave alignment portion of the other mold are fitted, and the convex alignment portions of all the molds and the concave alignment portions are fitted. It is fixed so that the alignment parts are combined with each other. Combine with other molds as needed. Sludge or resin, which is fluid clay (potter's clay), is cast into the combined molding die to mold the product.

The case mold of the present invention can shorten the time until the start of manufacturing the product using the molding die and reduce the manufacturing cost of the molding die, so that the product manufacturing cost can be reduced. It can be suitably used for molding.

1, 1a, 1b Case mold 2 Recess 3 Protrusion 4, 5, 6 Protrusion 7 Recess 8, 8a, 8b Mold 9, 9a, 9b Protrusion alignment part 10, 10a, 10b, 11 Concave position Joint part 12 Final product

Claims (8)

A case mold for manufacturing a mold used for molding,
A case mold, wherein the case mold is a laminate molding of a resin composition. The case mold according to claim 1, wherein the mold is a gypsum mold that is a solidified gypsum. The case mold according to claim 1, wherein the case mold is a split mold consisting of at least two molds. The case mold has a concave portion and a convex portion for alignment,
A mold manufactured using the case mold has a convex alignment portion and a concave alignment portion,
3. The plurality of molds are combined by fitting the convex alignment portion of one of the molds with the concave alignment portion of the other mold. Stated case type. A case mold for manufacturing a mold used for molding,
The case mold is a laminate formed entirely or substantially entirely of a resin composition, and is a split mold composed of at least two or more molds,
A case mold, wherein the mold is a gypsum mold that is a solidified gypsum. The case mold according to claim 5, wherein the gypsum mold is a gypsum mold for ceramics used for molding ceramics. The case type according to claim 1, wherein the resin composition is a resin composition containing polylactic acid (PLA) as a base resin. The case mold according to claim 1, wherein part or all of the surface of the case mold is a surface smoothed with a putty material.

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