JP4922700B2 - Double-sided painting molding method of molded products with thermosetting resin - Google Patents

Description

  The present invention relates to a molding method in which painting is performed on both an inner surface and an outer surface of a molded product during compression molding of the molded product with a thermosetting resin.

  Compression molding is employed for molding a thermosetting resin molded product (for example, tableware, various containers). Compression molding is performed by putting a material resin between a heated core mold and a cavity mold and compressing the material resin by closing the core mold and the cavity mold.

To paint on both the inner and outer surfaces of a molded product produced by this compression molding, first, the molded product is compression-molded with the lower cavity mold and the upper core mold, and the core mold is opened. Then, after releasing from the molded product in the cavity mold, a foil having a pattern is put in the molded product with the inside of the molded product as a table, the core mold is re-closed, and the inner surface is painted. Next, the molded product is released from the cavity mold and turned upside down, and the inside on which the painting has been completed is fitted into the upward core mold prepared as the lower mold, and the outside is turned upside down, and there is a pattern on the outside. The core mold and the cavity mold prepared as the upper mold are closed to paint the outer surface of the molded product.
Japanese Patent No. 3398818

  In the above conventional painting molding method, the inner surface of the molded product is preceded by painting, and the molded product is turned upside down to paint the outer surface, so the cavity mold is the lower mold and the core mold is Two molding machines are required: a molding apparatus arranged as an upper mold, and a molding apparatus arranged as a core mold as an upper mold and a cavity mold as a lower mold. Also, the molded product on which the inner surface has been painted is removed from the cavity mold, and this is turned upside down and fitted to the core mold of another molding machine, which causes problems in work efficiency. In some cases, the yield also has a problem because it may be damaged during the transition.

  The present invention has been conceived to solve the above-described conventional problems, and its purpose is to provide a single cavity mold that can be opened and closed with respect to the core mold and a cavity split mold formed by a pair of split molds. It is an object of the present invention to provide a new double-sided painting method for a molded article using a thermoplastic resin that can perform painting on both the inner and outer surfaces of the molded body without inverting the compression molded body upside down.

  According to the above-mentioned object, the present invention is to mold the inner body of the molded product by compressing the material resin on the core mold by closing the core mold and the single cavity mold, and separating the inner body from the cavity mold by opening the mold. After the mold is held and held in the core mold, the cavity mold is replaced with a cavity split mold by a pair of split molds having an undercut portion on the cavity surface, and the cavity split mold and the core mold are closed to close the inner body. Forming the outer body by compressing the material resin, molding the molded body of the inner and outer two-layer molded product by the outer body and the inner body, and holding the molded body in the cavity split mold by opening the mold Then, after releasing from the core mold, putting a foil with a picture between the core mold and the molded body, painting the inner surface of the molded body by closing the core mold and the cavity split mold, and Hold the molded body in the cavity split mold by opening the mold Separating the core mold again, putting a coating material between the molded body and the core mold, then closing the core mold and the cavity split mold to coat the inner surface of the molded body, and the cavity After the split mold is opened to the side and separated from the molded body, the molded body is held in the core mold by opening the cavity split mold, and a foil with a picture is inserted between the molded body and the cavity split mold. After that, the core mold and the cavity split mold are closed with the split mold open, and after the mold is closed, the split mold is closed and painting is performed on the outer surface of the molded body.

  The present invention also molds the inner body of the molded product by compressing the material resin on the core mold by closing the core mold and the cavity split mold with a pair of split molds having an undercut portion on the cavity surface, A process of holding the inner body in the cavity split mold by mold opening and releasing from the core mold, and inserting a pictured foil between the core mold and the inner body, and then the core mold and the cavity split mold The inner surface of the inner body is painted by closing the mold, the inner body is held in the cavity split mold by opening the mold, and is released again from the core mold, and a coating material is placed between the inner body and the core mold. Then, the inner surface of the inner body is coated by closing the core mold and the cavity split mold, and the cavity split mold and the core mold are opened after the split mold is opened to the side. After holding the core mold, replace the cavity split mold with a single cavity mold And molding the outer body by compressing the material resin on the inner body by closing the cavity mold and the core mold, and molding the molded body of the inner and outer two-layer molded product by the outer body and the inner body Then, put a foil with a picture between the molded body and the cavity split mold and paint the outer surface of the mold by closing the core mold and the cavity mold, and open the core mold and the cavity mold. The method includes a step of coating the outer surface of the molded body by closing the core mold and the cavity mold by putting a coating material between the molded body and the cavity mold.

  Further, according to the present invention, a plurality of vertical grooves in contact with the end sides are formed in the peripheral surface of the end portion of the core mold, and vertical ribs for stacking are formed on the inner surface of the molded body by the vertical grooves. It is.

  In the above configuration, the core mold used for compression molding of the molded body can be used as it is as the core mold in the painting process of the inner surface and the outer surface of the molded body. In addition, the molded body is released from the core mold during painting by holding the cavity split mold, so there is no misalignment between the molded body and the core mold, and damage to the molded body due to re-molding is reliably prevented. Is done. In addition, compression molding of the molded body and painting of both the inner and outer surfaces can be performed continuously by closing the cavity split mold and opening and closing the split mold, so that the work efficiency is improved and the yield is improved because almost no defective products are generated. Furthermore, in the molding of the inner / outer two-layer molded body, both the cavity mold and the cavity split mold are arranged so as to be exchangeable with respect to the core mold, one of which is used for the primary molding and the other is used for the secondary molding. Since it can be used, even an inner and outer two-layer molded product can be easily compression-molded. Moreover, the molding cost can be reduced because only one compression molding machine is required.

  In the figure, 1 is a core mold that forms the inner surface of the molded product, and 2 is a cavity mold that molds the inner or outer body of the molded body by opening and closing the mold with the core mold 1. 3 is a cavity split mold that molds the inner or outer body of the molded body by opening and closing the mold with the core mold 1, all of which can be heated to the molding temperature. The cavity split mold is a bottom mold 32 attached to the lower surface of the base 31 and a pair of split molds 33, 33 which are slidably attached to the lower surface of the base 31 and are openable on both sides of the bottom mold 32. It consists of. An annular recess 34 for forming the bottom edge of the molded body is formed on the mold surface in contact with the split mold bottom mold 32, and the recess 34 functions as an undercut portion.

  The cavity mold 2 and the cavity split mold 3 are not shown in the figure, but are arranged in parallel with the board on the core mold 1 so that the mold can be opened and closed alternately with the core mold 1 vertically mounted as a lower mold on the compression molding machine. The core mold 1 can be exchanged by lateral movement on the core mold side or the cavity mold side. Further, the mold opening of the cavity mold 1 and the cavity split mold 3 is performed so high that the material can be inserted from the side onto the core mold 1.

  The embodiment of the present invention using the cavity mold 2 and the cavity split mold 3 is illustrated in FIGS. 1A to 1C by taking compression molding of the inner and outer two-layer cup 10 shown in FIG. The molding process shown in order in each figure of L) will be described further.

  1-1 (A) to (C) First, the cavity mold 2 is positioned above the core mold 1, and a thermosetting resin (for example, melamine resin) material resin 11 a preliminarily dried when the mold is opened is used as the core mold 1. Place it under the cavity of the cavity mold 2 (A). Next, the cavity mold 2 is lowered and the core mold 1 is closed, and the material resin 11a is compressed by pressurizing the core mold 1 and the cavity mold 2 to close the cavity, and the cavity is filled, and the molds are half-heated by heating both molds. The cured inner body 12a is subjected to primary molding (B).

  When the compression molding of the inner body 12a is finished, the cavity mold 2 is raised and the mold is opened. By this mold opening, the inner body 12 a is released from the cavity mold 2 and is held by the core mold 1. Next, the cavity mold 2 for the core mold 1 is replaced with a cavity split mold 3. This mold exchange is performed by moving laterally on the cavity mold side or laterally moving on the core mold side. The cavity split mold 3 is positioned above the core mold 1 with the split molds 33 and 33 closed by the mold exchange. Another preliminarily dried material resin 11b of melamine resin is placed on the inner body 12a on the core mold side and placed under the cavity (C).

  1-2 (D) to (F) Next, the cavity split mold 3 is lowered and the core mold 1 and the mold are closed. By closing and pressurizing the cavity split mold 3, the material resin 11b is compressed and filled into the cavity, and the outer body 12b is secondarily molded into the semi-cured inner body 12a. Thereby, both are integrated and the molded body 12 of the cup 10 shown in FIG. 2 is compression-molded (D).

  This secondary molding is finished before the inner body 12a and the outer body 12b are completely cured, and the cavity split mold 3 is immediately lifted and released from the core mold 1 with the split dies 33 and 33 closed. (The figure is omitted). At this time, since the bottom edge 12c formed by the recess 34 becomes an undercut in the mold surface, the molded body 12 is not detached from the cavity split mold 3 and is held in the cavity split mold from the core mold 1. Exit and release (E).

  When the secondary molding is completed, the painting foil 13 is put on the mold surface of the core mold 1 (E). The foil 13 is formed in a ring-shaped belt made of printing paper impregnated with melamine resin and dried. After the foil 13 is fixed to the core mold 1 so as not to be displaced by mold pressure, the cavity split mold 3 is lowered. Then, the core mold 1 is closed (F). The foil 13 is adhered to the inner surface of the molded body 12 by the pressurization after the mold is closed.

  When painting with the foil 13 is completed, the cavity split mold 3 is lifted in that state, and the molded body 12 is released from the core mold 1. The molded body 12 is detached from the core mold 1 while being held in the cavity split mold without being separated by the bottom edge 12c that is undercut (not shown). Further, the foil 13 moves to the inner body 12a and leaves the mold surface of the core mold 1.

  1-3 (G) to (I) When mold opening is completed, a transparent coating material 14a of melamine resin is placed on the core mold 1 and placed between the core mold 1 and the molded body 12 (G). Thereafter, the cavity split mold 3 is lowered together with the molded body 12 to close the core mold 1. The coating material 14a is compressed and stretched between the mold surface of the core mold 1 and the inner side surface of the molded body 12 to form a coating layer 14 that covers the inner surface of the molded body 12 together with the foil 13 (H).

  When the molding of the coating layer 14 is completed, the cavity split mold 3 is opened. This mold opening is performed by first opening the split molds 33 and 33 away from the peripheral side surface of the molded body 12 and then raising the cavity split mold 3. Due to the separation of the split dies 33, 33, the molded body 12 remains in a state of being fitted to the core die 1 without being held by the cavity split die 3. When the mold opening of the cavity split mold 3 is completed, a painting foil 15 having a pattern different from that of the foil 13 is placed outside the molded body 12 (I).

  1-4 (J) to (L) When the foil 15 is inserted, the cavity split mold 3 is lowered while the split molds 33 and 33 are opened until the bottom mold 32 contacts the bottom surface of the molded body 12 (J). Next, the split dies 33, 33 are closed and the compact 12 is pressurized from the side. By this pressurization and heating by the cavity split mold 3, the foil 15 is welded to the outer surface of the molded body 12 and painting is performed (K).

  After the painting by the foil 15 is completed, the cavity split mold 3 is lifted together with the molded body 12 while the split molds 33 and 33 are closed, and the core mold 1 is opened (L). Next, the cavity mold side is moved laterally, or the core mold side is slid, and the cavity mold 2 is shifted from the core mold 1 to the side, and the split molds 33 and 33 are opened laterally at that position, thereby dividing the cavity mold. 3, the molded body 12 is taken out. As shown in FIG. 2, the molded body 12 is taken out as a cup 10 in which different patterns 16 and 17 are painted on both the inner surface and the outer surface. Thereafter, the cavity mold 2 is positioned above the core mold 1 to prepare for the next molding step.

  When a plurality of stacking vertical ribs 18 are provided at the lower portion of the inner surface as in the cup 10 shown in FIG. 3, a plurality of vertical strips are formed on the peripheral surface of the end of the core as shown in FIG. A core mold 1 'is used in which the groove 19 is recessed to the point where it comes into contact with the end of the core. If there is an upward vertical groove 19 on the side surface of the core, a part of the material resin 11a is pressed into the vertical rib 18 when the inner body 12a is compression-molded by the cavity mold 2. Since the direction in which the vertical ribs 18 are drawn is upward, it does not become an obstacle when the molded body 12 formed by the inner body 12 a and the outer body 12 b is released from the core mold 1. For this reason, even the cup 10 having the vertical ribs 18 for stacking can be compression-molded by the steps shown in FIGS.

  5 (A) to 5 (L) exemplify the molding of the inner / outer two-layered hot water bath 101 shown in FIG. 6 and precede the compression molding and inner surface painting of the inner body 12a by the cavity split mold 3, followed by the cavity mold. The steps in the case of performing compression molding of the outer body 12b and painting of the outer surface by 2 will be described in order. As the cavity split mold 3, split molds 33, 33 in which an undercut part 35 is provided on the bottom edge of the inner body and the cavity surface are used in the form of the cup 101.

  5-1 (A) to (C) First, the cavity split mold 3 is positioned above the core mold 1 with the split molds 33 and 33 closed, and the material resin 11a of melamine resin is placed on the core mold 1 to form the cavity. Put down (A). Next, the cavity split mold 3 is lowered and the core mold 1 is closed, and the material resin 11a is compressed by pressurization of the core mold 1 and the cavity split mold 3 to fill the cavity, and both molds are heated. The inner body 12a semi-cured by the above is subjected to primary molding (B).

  When the compression molding of the inner body 12a is finished, the cavity split mold 3 is opened upward. The compression-molded inner body 12a is released from the core mold 1 and released from the core mold 1 while being held in the cavity split mold by the undercut portion 35 formed on the cavity surfaces of the split molds 33 and 33 without being detached from the cavity surface. To do. After this mold opening, the mold foil 13 formed on the annular band is fitted with the melamine resin impregnated into the mold surface of the core mold 1 and dried and is fixed to the core mold surface (C).

  5- (D) to (F) Next, the cavity split mold 3 is lowered to close the core mold 1. The foil 13 is adhered to the inner surface of the molded body 12 by the pressurization after the mold is closed (D). When painting with the foil 13 is completed, the cavity split mold 3 is lifted in that state, and the inner body 12a is released from the core mold 1. The inner body 12a is pulled out of the core mold 1 while being held in the cavity split mold again by the undercut portion 35 and released. Further, the foil 13 moves to the inner body 12a and leaves the mold surface of the core mold 1. When the mold opening is completed, a transparent coating material 14a made of melamine resin is placed on the core mold 1 and placed between the core mold 1 and the inner body 12a (E).

  Next, although not shown in the drawing, the cavity split mold 3 is lowered together with the inner body 12a to close the core mold 1 and the mold. The coating material 14a is compressed and extended between the mold surface of the core mold 1 and the inner surface of the inner body 12a, and covers the inner surface of the inner body 12a together with the foil 13, as shown in the enlarged view of FIG. The coating layer 14 becomes.

  When the molding of the coating layer 14 is completed, the cavity split mold 3 is opened. This mold opening is performed by first opening the split molds 33 and 33 and then raising the cavity split mold 3. The undercut portion 35 ′ formed on the outer surface of the inner body 12 a is released from the cavity surface by the side mold opening, and the inner body 12 a is fitted to the core mold 1 without being held away from the cavity split mold 3. It remains in the state (F).

  5 (G) to (I) When the mold opening of the cavity split mold 3 is completed, the cavity split mold 3 is replaced with a single cavity mold 2. Then, a material resin 11b of melamine resin is placed on the inner body 12a and is inserted between the cavity mold 2 and the inner body 12a (G). Thereafter, the cavity mold 2 is lowered and the core mold 1 is closed, the material resin 11b is compressed by pressurization by the mold closing, and the outer body 12b is secondarily formed into the inner body 12a semi-cured by heating. This secondary molding is completed before the inner body 12a and the outer body 12b are completely cured. Thereby, both are united and the molded object 12 of the cup 101 shown in FIG. 6 is compression-molded (H).

  When the compression molding of the molded body 12 is completed, the cavity mold 2 is raised and the core mold 1 is opened. The compression molded body 12 is in close contact with the core mold 1, and there is no undercut portion on the cavity surface of the cavity mold 2, so that the molded body 12 is not held by the cavity mold 2 and remains as it is. Remains in a state of being fitted to. After the mold is opened, the outer foil 12b is impregnated with melamine resin and dried with a pattern-containing printing paper, and an annular foil painting foil 15 is fitted and fixed to the outer body 12b (I).

  5 (J) to (L) After the foil is inserted, the cavity mold 2 is lowered and closed with the core mold 1, and the molded body 12 is pressed to attach the foil 15 to the outer surface of the outer body 12b (J ). When painting with the foil 15 is completed, the cavity mold 2 is raised and the mold is opened from the core mold 1. Since the molded body 12 is released from the cavity mold 2 and remains in the fitted state with the core mold 1, after the mold is opened, a transparent coating material 20a of melamine resin is placed on the outer body 12b, and the cavity mold 2 and the molded body are placed. Put between 12 (K).

  Next, although not shown in the figure, the cavity mold 2 is lowered and closed with the core mold 1. The coating material 20a is compressed and stretched between the cavity surface of the cavity mold 2 and the outer surface of the outer body 12b, and as shown in the partially enlarged view of the cup 101 in FIG. It becomes the coating layer 20 which coat | covers an outer surface. When the molding of the coating layer 20 is completed, the cavity mold 2 is opened (L). As a result of mold opening, the molded body 12 remains in the core mold 1 and is taken out from the core mold 1 as a hot water bath 101 in which different patterns 102 and 103 are painted on both the inner surface and the outer surface as shown in FIG.

  The painting molding method of the present invention is a molded product other than a cup or a cup, for example, a bowl, a bowl, a bowl, a bowl, a variety of containers, etc., as long as it can be held by the cavity split mold. Needless to say, the present invention can be applied to the compression molding. Also, depending on the structure of the molding machine, the arrangement of the molds is reversed. Conversely, the core mold is the upper mold, the cavity mold and the cavity split mold are the lower mold, and the core mold side is moved up and down, and the mold opening and closing with both The arrangement may be arbitrarily selected. Therefore, the present invention is not limited to the above embodiment.

(A)-(C) It is explanatory drawing of the formation process of the double-sided painting molding method of the molded article concerning this invention. (D)-(F) It is explanatory drawing of the formation process of the double-sided painting molding method of the molded article concerning this invention. (G)-(I) It is explanatory drawing of the formation process of the double-sided painting molding method of the molded article concerning this invention. (J)-(L) It is explanatory drawing of the shaping | molding process of the double-sided painting molding method of the molded article concerning this invention. It is a half vertical front view which expands and shows a part of cup which pictured on both inside and outside by the shaping | molding process of FIG. It is a half vertical front view of the cup which has the vertical rib for stacking in the lower part of an inner surface. It is a schematic sectional drawing of the core type | mold and cavity type | mold which can shape | mold the vertical rib for stacking. (A)-(C) It is explanatory drawing of the other shaping | molding process by the shaping | molding method concerning this invention. (D)-(F) It is explanatory drawing of the other shaping | molding process by the shaping | molding method concerning this invention. (G)-(I) It is explanatory drawing of the other shaping | molding process by the shaping | molding method concerning this invention. (J)-(L) It is explanatory drawing of the other shaping | molding process by the shaping | molding method concerning this invention. It is a half vertical front view which expands and shows a part of hot water bath which pictured on both inside and outside by the shaping | molding process of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Core type | mold 2 Cavity type | mold 3 Cavity split type | mold 10 Cup 11a Inner material resin 11b Outer material resin 12 Molded body 12a Inner body 12b Outer body 12c Bottom edge 13 Inner foil 14 Inner coating layer 15 Outer foil 16 Inner surface Pattern 17 on the outer surface 18 Vertical ribs 19 for stacking 20 Core-type vertical grooves 20 Inner coating layer 32 Bottom mold 33 Divided mold 35 Undercut portion 101 Cup 102 Inner pattern 103 Outer pattern 103

Claims (3)

By closing the core mold and the single cavity mold, the material resin on the core mold is compressed to mold the inner part of the molded product, and the inner body is released from the cavity mold by mold opening and held in the core mold. Then, replacing the cavity mold with a cavity split mold by a pair of split molds having an undercut portion on the cavity surface;
Forming the outer body by compressing the material resin on the inner body by closing the cavity split mold and the core mold, and molding the molded body of the inner and outer two-layer molded product by the outer body and the inner body; ,
The molded body is held in the cavity split mold by mold opening and released from the core mold, and a foil with a picture is inserted between the core mold and the molded body, and then the core mold and the cavity split mold are closed. Painting the inner surface of the molded body by
The molded body is held in the cavity split mold by opening the mold, released from the core mold again, and a coating material is put between the molded body and the core mold, and then the core mold and the cavity split mold are closed. And coating the inner surface of the molded body,
After opening the split mold of the cavity split mold to the side and separating it from the molded body, the molded mold is held in the core mold by opening the cavity split mold, and a foil with a picture is formed between the molded mold and the cavity split mold. After closing the mold, the core mold and the cavity split mold are closed with the split mold open, and after the mold is closed, the split mold is closed and painting is performed on the outer surface of the molded body,
A method for double-sided painting of a molded product using a thermosetting resin, characterized by comprising By closing the core mold and the cavity split mold with a pair of split molds having an undercut part on the cavity surface, the material resin on the core mold is compressed to mold the inner body of the molded product, and the inner body is molded Holding in the cavity split mold by opening and releasing from the core mold;
After putting a pictured foil between the core mold and the inner body, the inner mold is painted on the inner surface by closing the core mold and the cavity split mold, and the inner body is held in the cavity split mold by opening the mold. Holding the mold again from the core mold, placing a coating material between the inner body and the core mold, and coating the inner surface of the inner body by closing the core mold and the cavity split mold; and
Opening the cavity split mold and the core mold after opening the split mold to the side and holding the inner body in the core mold, then replacing the cavity split mold with a single cavity mold;
By molding the cavity mold and the core mold, the material resin on the inner body is compressed to mold the outer body, and the molded body of the inner and outer two-layer molded product is molded by the outer body and the inner body. Putting a pictured foil between the body and the cavity split mold and painting the outer surface of the molding by closing the core mold and the cavity mold;
Opening the core mold and the cavity mold, putting a coating material between the molded body and the cavity mold, and coating the outer surface of the molded body by closing the core mold and the cavity mold; and
A method for double-sided painting of a molded product using a thermosetting resin, characterized by comprising   3. The molding method according to claim 1 or 2, wherein a plurality of vertical grooves in contact with the end sides are formed in the peripheral surface of the end of the core mold, and vertical ribs for stacking are formed by the vertical grooves on the inner surface of the molded body. A method for double-sided painting of a molded product using a thermosetting resin, characterized by being molded into

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