Mold assembly

Abstract

To prevent a recessed part, which becomes a defective molding, from being formed in a thick wall portion of an intermediate molding, without prolonging a dwelling time.SOLUTION: An injection core, which is a first mold for performing injection molding to form a preform 200 as an intermediate molding, forms a protrusion 212 on an inner surface 211 in a thick wall portion of the preform 200. To perform blow molding for forming a final molding from the preform 200, when fitting the preform 200 to a blow core 1, which is a second mold, the blow core 1 crushes the protrusion 212 from the inside of the preform 200.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a mold device.

Background Art

[0002] In injection blow molding, which is a molding method that performs injection molding and blow molding in two stages, a preform, which is an intermediate molded product, is molded by injection molding, and a product such as a container is molded by blowing air into the preform and stretching it (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the preform, which is an intermediate molded product formed by injection molding, there are thick and thin portions. Since the volume shrinkage rate due to cooling differs between the thick and thin portions, recesses that cause molding defects may be formed in the thick portion where the volume shrinkage rate is high. In order to compensate for the volume shrinkage in such recesses, pressure can be applied from the cylinder side to feed the molten resin as so-called holding pressure. However, when the thick portion is located far from the gate side where the molten resin is injected, it is necessary to lengthen the holding time in order to make the holding pressure effective. As a result, the molding cycle may become long. An object of the present invention is to suppress the formation of recesses that cause molding defects in the thick portion of the intermediate molded product without lengthening the holding time.

Means for Solving the Problems

[0005] The present invention completed for such an object is characterized in that a first mold for performing injection molding for molding an intermediate molded product forms a convex portion on the inner surface of a thick portion of the wall thickness of the intermediate molded product, and when fitting the intermediate molded product to a second mold for performing blow molding for molding a final molded product from the intermediate molded product, the second mold crushes the convex portion from the inside of the intermediate molded product, and it is a mold device. Here, the second mold may be characterized in that it crushes the convex portion while sliding on the inner surface of the intermediate molded product. Further, the shape of the convex portion may be characterized in that it is at least a shape in which the convex portion is formed even if the shape of the intermediate molded product changes after the injection molding is performed. Further, the present invention is a mold device characterized in that when fitting an intermediate molded product molded by injection molding using a first mold to a second mold for performing blow molding for molding a final molded product, a part of the second mold presses a portion that is difficult to extend from the inside of the intermediate molded product. Further, a part of the second mold may be characterized in that it is disposed at a position where it can press the portion that is difficult to extend inside the intermediate molded product. Further, it has a fixed-side mold, an intermediate mold, and a movable-side mold, and performs the injection molding in a state where the fixed-side mold and the intermediate mold having an injection core as the first mold are closed, and the blow molding is performed in a state where the intermediate mold having a blow core as the second mold and the movable-side mold are closed. This may be a feature.

Effect of the Invention

[0006] According to the present invention, it is possible to suppress the formation of recesses that cause molding defects in thick portions of the wall thickness of the intermediate molded product without increasing the holding pressure time.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. <First Embodiment> (Configuration of Blowing Core) FIG. 1 is a cross-sectional view showing an example of the configuration of a blowing core 1 applied to an intermediate mold included in a mold apparatus according to the first embodiment. FIG. 1 shows a state of viewing the blowing core 1 from the top side to the bottom side in the vertical direction. For this reason, the front side of the drawing in FIG. 1 is the top side in the vertical direction, and the back side of the drawing is the bottom side in the vertical direction. FIG. 2 is a cross-sectional view showing an example of the configuration of an injection core 100 applied to an intermediate mold included in a mold apparatus according to the first embodiment.

[0009] The injection core 1 shown in Fig. 1 is one of the molds applied to the intermediate mold provided in the mold apparatus for injection blow molding. The intermediate mold to which the injection core 1 is applied is a mold disposed between a fixed mold (not shown) and a movable mold, and is a mold having a rotating frame. Injection blow molding refers to a molding method that performs injection molding (hereinafter referred to as "injection molding") and blow molding (hereinafter referred to as "blowing molding") in two steps. Injection molding is performed in a state where the fixed mold and the injection core 100 of the intermediate mold shown in Fig. 2 are closed. Also, blow molding is performed in a state where the movable mold and the intermediate mold are closed.

[0010] In injection blow molding, first, in injection molding, which is the first stage of molding, a preform 200, which is an intermediate molded product, is molded in a state where the fixed mold and the injection core 100 of the intermediate mold shown in Fig. 2 are closed. The injection-molded preform 200 rotates and moves to the position where the second-stage molding is performed while being gripped by the rotating frame. Next, in blow molding, which is the second stage of molding, high-pressure air is blown into the preform 200 in a state where the blow core 1 of the intermediate mold shown in Fig. 1 and the movable mold are closed, and the preform 200 is stretched to form the final molded product. Examples of the method of blowing air into the preform 200 in blow molding include a method of protruding a stretching rod (not shown) capable of outputting high-pressure air into the preform.

[0011] Fig. 1 shows a state where the injection-molded preform 200 is about to be fitted into the blow core 1 of the intermediate mold for blow molding. The axial direction of the preform 200 when it fits into the blow core 1 is the left-right direction in the drawing, which is the same direction as the direction in which the intermediate mold to which the blow core 1 is applied and the movable mold open and close for blow molding.

[0012] Hereinafter, the direction in which the intermediate mold to which the injection core 1 is applied and the movable mold open and close (the left - right direction of the drawing in Fig. 1), and the direction in which the intermediate mold to which the injection core 100 is applied and the fixed mold open and close (the left - right direction of the drawing in Fig. 2) are referred to as the "opening - closing direction". Further, the right side of the drawing in the opening - closing direction is referred to as the "first side", and the left side of the drawing in the opening - closing direction is referred to as the "second side". Also, the direction orthogonal to the axial direction (opening - closing direction) of the preform 200 when the preform 200 is inserted into the injection core 1 (the up - down direction of the drawing in Fig. 1), and the direction orthogonal to the axial direction (opening - closing direction) of the injection core 100 (the up - down direction of the drawing in Fig. 2) are referred to as the "radial direction". Further, the central axis (indicated by a dashed - dotted line) side in the radial direction of the preform 200 and the central axis (indicated by a dashed - dotted line) in the radial direction of the injection core 100 are referred to as the "inner side", and the opposite side is referred to as the "outer side".

[0013] As shown in Fig. 1, the preform 200 to be injection - molded has a mouth part 201, a main body part 202, and a bottom part 203. Note that the mouth part 201, the main body part 202, and the bottom part 203 in the preform 200 are parts of the shape of the continuous preform 200 and have no clear boundary. For this reason, in the present embodiment, the part on the first side in the opening - closing direction rather than the fringe 204 which is a part protruding outward in the preform 200 is defined as the mouth part 201, and the part near the end on the second side in the opening - closing direction of the preform 200 is defined as the bottom part 203. Also, the part of the preform 200 other than the mouth part 201 and the bottom part 203 is defined as the main body part 202. Note that the fringe 204 is included in the mouth part 201.

[0014] The injection core 1 has at least a convex part 11 that fits into an injection port 205 formed in the mouth part 201 of the preform 200, and a through - hole 12 through which a stretching rod (not shown) inserted into the preform 200 passes. The convex part 11 is a cylindrical convex part protruding to the second side in the opening - closing direction of the injection core 1. The outer surface 111 in the radial direction of the convex part 11 is composed of a smooth surface that slidably supports the inner surface 211 of the mouth part 201 of the preform 200, and also functions as a mold for molding at least a part of the surface 211.

[0015] On the inner surface 211 of the mouth portion 201 of the preform 200, an annular convex portion 212 formed during injection molding is formed. The convex portion 212 is a convex portion formed on the inner surface 211 in the thick portion of the wall thickness of the preform 200, and is a convex portion deliberately formed during injection molding. That is, a recess 101 is deliberately formed in the injection core 100 of FIG. 2. By filling the recess 101 with molten resin during injection molding, the convex portion 212 of FIG. 1 is formed. The reason for deliberately forming the convex portion 212 during injection molding is to suppress the formation of recesses that cause molding defects in the preform 200. The recesses that cause molding defects formed on the inner surface 211 of the preform 200 will be described with reference to FIG. 3.

[0016] FIG. 3 is a diagram showing a specific example in the case where a recess 213 that causes molding defects is formed in the preform 200, which is an intermediate molded product. In the present embodiment, a convex portion 212 (see FIG. 1) is formed in the thick portion of the wall thickness of the injection-molded preform 200. Thereby, the formation of a recess 213 that causes molding defects on the inner surface 211 of the preform 200 is suppressed. On the other hand, when the convex portion 212 is not formed on the inner surface 211 of the preform 200, as shown in FIG. 3, a recess 213 that causes molding defects may be formed on the inner surface 211 of the thick portion of the wall thickness of the preform 200. This is because the volume shrinkage rate associated with the cooling of the thick portion of the preform 200 is higher than the volume shrinkage rate associated with the cooling of the thin portion of the wall thickness.

[0017] Since high precision is required for the inner diameter of the mouth portion 201 of the preform 200, if a concave portion 213 is formed inside the mouth portion 201, the final molded product is likely to be treated as a defective product. Although there are also thick-walled portions in the main body portion 202, in the first embodiment, the purpose is to suppress the formation of the concave portion 213 inside the thick-walled portion of the mouth portion 201 where particularly high precision is required. For this reason, for example, the suppression of molding defects (for example, transfer defects described later) that may occur in the thick-walled portion of the main body portion 202 (the portion indicated by the broken line in FIG. 1) is outside the scope of the purpose of the first embodiment and is the purpose of the second embodiment described later.

[0018] FIG. 4 is a cross-sectional view showing an example of a state in which the preform 200 is fitted to the injection core 1. The preform 200 is fitted to the injection core 1 prior to the start of injection molding. Specifically, a rotating frame (not shown) fits the preform 200 to the injection core 1. FIG. 4 shows a state in which the injection port 205 of the preform 200 is fitted to the convex portion 11 of the injection core 1. The inner surface 211 of the mouth portion 201 of the preform 200 slides on the radially outer surface 111 of the convex portion 11 of the injection core 1 when the injection port 205 is fitted to the convex portion 11. At this time, the tip portion 112 of the convex portion 11 of the injection core 1 crushes the convex portion 212 (see FIG. 1) of the surface 211 of the preform 200 in accordance with the sliding of the surface 211 of the preform 200. As a result, as shown in FIG. 4, the radially inner surface 211 of the preform 200 is smoothed.

[0019] Here, if the shape and size of the recessed portion 213 (see FIG. 3) that becomes a molding defect formed in the preform 200 can be accurately predicted, at the stage where the preform 200 is injection-molded, the thickness of the wall thickness may be set so that the inner surface 211 of the preform 200 becomes smooth. However, since there are individual differences in the preforms 200 to be injection-molded, it is difficult to accurately predict the shape and size of the recessed portion 213 that can be formed in each individual preform 200. Also, as in the example of FIG. 3, the recessed portion 213 may be formed on the inner surface 211 of the thick-walled portion of the preform 200, or the recessed portion 213 may not be formed depending on the molding conditions. Further, due to some factor, an unintended convex portion may be formed on the inner surface 211 of the preform 200.

[0020] On the other hand, in the present embodiment, the injection mold is configured to always form a convex portion 212 on the inner surface 211 of the preform 200. The shape and size of the convex portion 212 to be formed on the preform 200 are not particularly limited. For example, the shape and size of the convex portion 212 are designed by predicting to some extent the shape and size of the recessed portion 213 that can be formed when the convex portion 212 is not formed on the preform 200. Then, the shape of the recessed portion 101 of the injection core 100 in FIG. 2 is designed according to the designed shape and size of the convex portion 212.

[0021] The prediction of the shape and size of the recessed portion 213 is made based on past molding results, information on prototypes, and the like. However, it is only necessary that the convex portion 212 is formed to such a size that the tip portion 112 of the convex portion 11 of the blowing core 1 can be crushed when the preform 200 is fitted to the blowing core 1. For this reason, it is not necessary to accurately predict the shape and size of the recessed portion 213 that can be formed when the convex portion 212 is not formed on the preform 200.

[0022] FIG. 5 is a diagram showing a specific example of a bottle container 400 that is a final molded product formed by blow molding. When injection molding is performed after fitting the preform 200 into the injection core 1 by the method shown in FIG. 4 above, for example, as shown in FIG. 5, a bottle container 400 as a final molded product is molded. The position 500 indicated by the broken line at the mouth portion 401 of the bottle container 400 shown in FIG. 5 indicates the position where the convex portion 212 (see FIG. 1) of the preform 200 was formed. The position 500 has become a smooth surface by being crushed by the injection core 1 (see FIG. 4).

[0023] Summarizing the above, the mold device to which the present invention is applied only needs to have the following configuration and can take various embodiments. That is, the mold device according to the first embodiment is such that an injection core 100, which is a first mold for performing injection molding for molding a preform 200 that is an intermediate molded product, forms a convex portion 212 on the inner surface 211 in the thick portion of the wall thickness of the preform 200, and when fitting the preform 200 into an injection core 1, which is a second mold, for performing blow molding for molding a final molded product from the preform 200, the injection core 1 crushes the convex portion 212 from the inside of the preform 200. The mold device is characterized by this.

[0024] Thereby, the convex portion 212 is formed on the inner surface 211 in the thick portion of the wall thickness of the preform 200 by injection molding. Then, when fitting the preform 200 into the injection core 1 for performing blow molding, the injection core 1 crushes the convex portion 212 from the inside of the preform 200. As a result, without increasing the holding pressure time, the inner surface 211 of the preform 200 can be smoothed during the conventional operation of fitting the preform 200 into the injection core 1 for performing blow molding.

[0025] Here, the injection core 1 may be characterized in that it crushes the convex portion 212 while sliding on the inner surface 211 of the preform 200. As a result, the injection core 1 crushes the convex portion 212 while sliding on the inner surface 211 of the preform 200. As a result, when fitting the preform 200 to the injection core 1 to perform injection molding, the inner surface 211 of the preform 200 can be smoothed during the conventional operation of sliding the injection core 1 on the inner surface 211 of the preform 200.

[0026] Further, the shape of the convex portion 212 may be characterized in that at least the convex portion is formed even if the shape of the preform 200 changes after injection molding (for example, even if the volume shrinks due to cooling). As a result, the shape of the convex portion 212 is designed so that at least the convex portion is formed due to the change in the shape of the preform 200 after injection molding. As a result, when fitting the preform 200 to the injection core 1, the convex portion 212 is always formed on the inner surface 211 of the thick portion of the wall thickness of the preform 200, so that the surface 211 can be smoothed.

[0027] Further, it may be characterized in that injection molding is performed in a state where the fixed mold, the intermediate mold, and the movable mold are closed, and the fixed mold and the intermediate mold having the injection core 100 as the first mold are closed, and blow molding is performed in a state where the intermediate mold having the injection core 1 as the second mold and the movable mold are closed.

[0028] As a result, in the mold apparatus, by performing injection molding in a state where the fixed mold and the intermediate mold having the injection core 100 as the first mold are closed, the convex portion 212 is formed on the inner surface 211 in the thick portion of the wall thickness of the preform 200. Then, in order to perform blow molding in a state where the intermediate mold having the injection core 1 as the second mold and the movable mold are closed, when fitting the preform 200 to the injection core 1, the injection core 1 crushes the convex portion 212 from the inside of the preform 200. As a result, without increasing the holding pressure time, the inner surface 211 of the preform 200 can be smoothed during the conventional operation of fitting the preform 200 to the injection core 1 to perform blow molding.

[0029] <Second Embodiment> FIGS. 6(A) and 6(B) are cross-sectional views showing an example of the configuration of the blowing core 2 applied to the intermediate mold included in the mold apparatus according to the second embodiment. FIGS. 6(A) and 6(B) show a state of the blowing core 2 viewed from the top side to the bottom side in the vertical direction. For this reason, the front side of the drawings in FIGS. 6(A) and 6(B) is the top side in the vertical direction, and the back side of the drawings is the bottom side in the vertical direction.

[0030] The blowing core 2 shown in FIGS. 6(A) and 6(B) is one of the molds applied to the intermediate mold included in the mold apparatus that performs injection blow molding, similar to the above-described first embodiment. Further, the intermediate mold to which the blowing core 2 is applied is a mold disposed between a fixed-side mold (not shown) and a movable-side mold 60, and is a mold having a rotating frame.

[0031] FIG. 6(A) shows a state after the injection-molded preform 200 is inserted into the blowing core 2 of the intermediate mold for blow molding. The axial direction of the preform 200 inserted into the blowing core 2 is the left-right direction in the drawing, and is the same direction as the direction in which the intermediate mold to which the blowing core 2 is applied and the movable-side mold open and close for blow molding.

[0032] The blowing core 2 has at least a convex portion 31 that fits into a blowing port 205 formed in the mouth portion 201 of the preform 200, and a through hole 32 that penetrates a stretching rod 40 inserted into the preform 200. The convex portion 31 is a cylindrical convex portion that protrudes toward the second side in the opening / closing direction of the blowing core 2. The outer surface 311 of the convex portion 31 is composed of a smooth surface that slidably supports the inner surface 211 of the mouth portion 201 of the preform 200, and also functions as a mold for molding at least a part of the surface 211. The difference between the first embodiment and the second embodiment is that the convex portion 31 of the blowing core 2 according to the second embodiment is longer toward the second side in the opening / closing direction than the convex portion 11 (see FIG. 1) of the blowing core 1 according to the first embodiment. Specifically, the convex portion 31 of the blowing core 2 has a shape that is long enough for a part thereof to be inserted into the inside of the movable-side mold 60 located on the second side in the opening / closing direction with respect to the blowing core 2.

[0033] In the blow molding process, the main body 202 and the bottom 203 of the preform 200 are stretched by the high-pressure air output from the stretching rod 40 shown in FIG. 6(B), and the shape of the mold 60 on the movable side is transferred. Then, the bottle container 400, which is the final molded product, is molded. However, in the main body 202 of the preform 200 (see FIG. 6(A)), there is a portion (hereinafter referred to as the "difficult-to-transfer portion") 510 where it is difficult to transfer the shape of the mold during blow molding. The difficult-to-transfer portion 510 is, for example, a portion that is difficult to stretch due to a thick wall thickness. Specifically, for example, referring to FIG. 1 described above, in the portion surrounded by the broken line of the preform 200, there is a boundary portion between a portion that is approximately solidified during injection molding and a portion that is stretched as an object of blow molding while maintaining a molten state. This boundary portion corresponds to the difficult-to-transfer portion 510 shown in FIG. 6(A).

[0034] FIGS. 7(A) and (B) are enlarged views of the difficult-to-transfer portion 510 shown in FIG. 6(A) described above. FIG. 7(A) shows an enlarged view of the difficult-to-transfer portion 510 when injection molding is performed by the blow core 2 according to the second embodiment. FIG. 7(B) shows, as a comparison target, an enlarged view of the difficult-to-transfer portion 510 when injection molding is performed by the blow core 1 according to the first embodiment described above. Note that the difficult-to-transfer portion 510 shown in FIG. 7(B) is the portion with a thick wall thickness of the preform 200 indicated by the broken lines in FIGS. 1 and 4 described above.

[0035] As shown in FIGS. 7(A) and 7(B), the convex portion 31 of the injection core 2 according to the second embodiment is longer toward the second side in the opening / closing direction than the convex portion 11 of the injection core 1 according to the first embodiment. For this reason, as shown in FIG. 7(A), the convex portion 31 of the injection core 2 is pushed in along the movable die 60 where the transfer-difficult portion 510 is located on the outer side in the radial direction. As a result, transfer defects, which are molding defects, are suppressed. On the other hand, as shown in FIG. 7(B), the length of the convex portion 11 of the injection core 1 toward the second side in the opening / closing direction is not long enough to push the transfer-difficult portion 510 located on the outer side in the radial direction toward the movable die 60, and thus transfer defects occur in the transfer-difficult portion 510.

[0036] That is, the mold device according to the second embodiment of the present invention presses the tip portion 312 of the convex portion 31, which is a part of the injection core 2, against the transfer-difficult portion 510, which is a difficult-to-stretch portion, from the inside of the preform 200 when fitting the preform 200, which is an intermediate molded product molded by injection molding using the injection core 100 as the first mold, into the injection core 2, which is the second mold for performing injection molding to form the final molded product.

[0037] Thereby, when fitting the preform 200 into the injection core 2 from the preform 200, which is an intermediate molded product molded by the injection core 100, the tip portion 312 of the convex portion 31, which is a part of the injection core 2, presses the transfer-difficult portion 510, which is a difficult-to-stretch portion, from the inside of the preform 200. As a result, since the transfer-difficult portion 510 is pushed toward the movable die 60, transfer becomes easier and transfer defects are suppressed.

[0038] Here, the tip portion 312 of the convex portion 31, which is a part of the injection core 2, may be arranged at a position (for example, a position inserted into the movable die 60) where the transfer-difficult portion 510 can be pressed inside the preform 200. As a result, the tip 312 of the convex portion 31, which is a part of the blowing core 2 that presses the transfer-difficult portion 510, is disposed at a position where it can press the transfer-difficult portion 510 inside the preform 200. As a result, since the transfer-difficult portion 510 is pushed toward the movable mold 60 on the movable side, it becomes easier to transfer, and transfer defects are suppressed.

[0039] Further, it may be characterized in that injection molding is performed in a state where a fixed mold, a movable mold 60, and an intermediate mold are closed, and the fixed mold and the intermediate mold having an injection core 100 as a first mold are closed, and blow molding is performed in a state where the movable mold 60 and the intermediate mold having a blowing core 2 as a second mold are closed.

[0040] As a result, when the preform 200 is fitted from the inside of the preform 200 to the blowing core 2 of the intermediate mold from the preform 200, which is an intermediate molded product formed by the injection core 100 of the intermediate mold, the tip 312 of the convex portion 31, which is a part of the blowing core 2, presses the transfer-difficult portion 510, which is a portion difficult to extend from the inside of the preform 200. As a result, since the transfer-difficult portion 510 is pushed toward the movable mold 60 on the movable side, it becomes easier to transfer, and transfer defects are suppressed.

[0041] <Comparison of Embodiments> The blowing core 2 applied to the intermediate mold included in the mold apparatus according to the second embodiment has basically the same configuration as the blowing core 1 applied to the intermediate mold included in the mold apparatus according to the above-described first embodiment. However, the length of the portion of the convex portion 31 of the blowing core 2 toward the second side in the opening / closing direction of the portion that can be inserted into the preform 200 is longer than the length of the portion of the convex portion 11 of the blowing core 1 toward the second side in the opening / closing direction of the portion that can be inserted into the preform 200. For this reason, when the preform 200 is fitted to the convex portion 31 of the blowing core 2, the convex portion 31 is deeply inserted into the preform 200, so that the tip 312 on the second side in the opening / closing direction of the convex portion 31 can push the transfer-difficult portion 510 of the preform 200 outward in the radial direction. As a result, it is possible to suppress the occurrence of transfer defects in the transfer-difficult portion 510 in the second embodiment as compared with the first embodiment.

[0042] <Others> As described above, the embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments. Also, the effects of the present invention are not limited to those described in the above embodiments. For example, the configurations of the injection core 1 shown in FIGS. 1 and 4, the injection core 100 shown in FIG. 2, and the injection core 2 shown in FIGS. 6(A) and 6(B) are merely examples for achieving the object of the present invention and are not particularly limited.

[0043] Also, in the above-described embodiments, the final molded product is the bottle container 400. However, the final molded product does not have to be a bottle container. Any molded product formed by injection blow molding may be used.

[0044] Furthermore, the final molded product does not have to be a molded product formed by injection blow molding. As long as molding is performed using different molds for molding the intermediate molded product and the final molded product, for example, a molded product formed by so-called two-color molding in which different resins or materials are combined and integrated, or a molded product formed by so-called insert molding in which insert parts such as metal screws and terminals are previously placed in a mold and molten resin is injected around them for integral molding may be the final molded product.

Description of Reference Numerals

[0045] 1, 2... injection core, 11, 31... convex portion, 12, 32... through hole, 40... extension rod, 60... movable mold, 100... injection core, 200... preform, 201... mouth portion, 202... main body portion, 203... bottom portion, 204... fringe, 205... injection port, 212... convex portion, 400... bottle container, 510... difficult-to-transfer portion

Claims

1. A first mold for performing injection molding to mold an intermediate molded product forms a convex portion on the inner surface of a thick portion of the wall thickness of the intermediate molded product, and when the intermediate molded product is fitted into a second mold to perform blow molding for molding the final molded product from the intermediate molded product, the second mold crushes the convex portion from the inside of the intermediate molded product. A mold apparatus characterized by this. Mold apparatus.

2. The second mold is characterized by crushing the convex portion while sliding on the inner surface of the intermediate molded product. The mold apparatus according to claim 1.

3. The shape of the convex portion is characterized in that even if the shape of the intermediate molded product changes after the injection molding is performed, at least the shape in which the convex portion is formed is maintained. The mold apparatus according to claim 1.

4. When fitting an intermediate molded product molded by injection molding with a first mold into a second mold for performing blow molding for molding a final molded product, a part of the second mold presses a portion that is difficult to extend from the inside of the intermediate molded product. A mold apparatus characterized by this. Mold apparatus.

5. A part of the second mold is arranged at a position inside the intermediate molded product where the portion that is difficult to extend can be pressed. The mold apparatus according to claim 4.

6. Having a fixed-side mold, an intermediate mold, and a movable-side mold, Performing the injection molding with the fixed-side mold and the intermediate mold having an injection core as the first mold in a mold-closed state, Performing the blow molding with the intermediate mold having a blow core as the second mold and the movable-side mold in a mold-closed state. The mold apparatus according to claim 1 or 4.

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