JP5557485B2 - Integrated mold container molding method - Google Patents

Description

  The present invention relates to a method for forming an integrally molded container for storing, transporting and transporting various articles.

  As shown in FIG. 4, as an example, the mold structure used in the conventional integral mold container molding method includes a fixed mold Mf and a movable mold Mm. Only an appropriate number of resin gates Gf are formed. A cavity C for an integral mold container is formed between the fixed mold Mf and the movable mold Mm. From the resin gate Gf formed in the fixed mold Mf, the cavity C is formed in the cavity C. By injecting the molten resin, the molten resin is injected into the cavity C, and the integral mold container is formed. Fm is a movable side mounting plate, Ff is a fixed side mounting plate, and S is a spacer.

  The above-mentioned integral mold container molding method is disclosed in Patent Document 1 as an example.

JP 2005-313427 A

  As shown in the conventional integral mold container molding method described above, when the resin gate Gf is formed only on the fixed mold Mf, the molten resin is reliably transferred to the entire cavity C. In order to inject, the width W of the cavity C perpendicular to the injection direction of the molten resin is increased, or the melt flow rate MFR of the resin is increased.

  By the way, in recent years, in order to reduce the weight of the integrally molded container, it is required to reduce the thickness of the bottom part, the side wall and the like of the integrally molded container. If the thickness of the bottom part, the side wall, etc. of the integrally molded container is made thin, the problem that the molten resin is not injected into the whole cavity C occurs.

  In order to solve such a problem, as described above, the resin melt flow rate MFR is increased. However, if the resin melt flow rate MFR is increased, the impact strength by the Charpy impact test or the like is increased. Therefore, there is a problem that the impact resistance of the molded integrally molded container is lowered, and the integrally molded container is easily damaged.

  Instead of increasing the melt flow rate MFR of the resin, the injection pressure of the molten resin into the cavity C is increased. In order to increase the injection pressure, the fixed mold Mf constituting the mold structure is used. In addition, the strength and rigidity of the mold structure must be increased, for example, by increasing the thickness of the mold such as the movable mold Mm, so that there is a problem that the manufacturing cost of the mold increases.

  An object of the present invention is to solve the problems of the conventional invention described above.

In order to achieve the above-mentioned object, the present invention provides an appropriate number of resin gates in a fixed mold constituting the mold structure, and also in a side slide mold constituting the mold structure. Alternatively, the even vertical portions of the stationary mold, and disposing a resin gate of appropriate number, wherein the resin gate, and configured to inject the molten resin into the cavity, and, the resin gate, integrally mold It is arranged so as to coincide with the intersection of the horizontal rib and the vertical rib formed on the side wall of the container, and the molten resin is injected into the cavity from the resin gate.

  The molten resin can be reliably injected into the entire cavity without increasing the melt flow rate MFR of the resin. Therefore, it is possible to suppress a decrease in impact resistance of the integrally molded container due to an increase in the melt flow rate MFR of the resin. In addition, a resin having a low melt flow rate MFR, in other words, a low-cost recycled resin or the like can be used. Therefore, the price of the integrally molded container can be reduced.

  In addition, the injection pressure can be lowered, and therefore the thickness of the fixed mold, movable mold and side slide mold that make up the mold structure can be reduced, reducing the manufacturing cost of the mold. can do.

  Furthermore, the injection molding time of the integral mold container can be shortened, and therefore the injection molding work efficiency of the integral mold container can be increased.

  Furthermore, the color and hue of the molten resin injected from the resin gate disposed in the fixed mold and the color and hue of the molten resin injected from the resin gate disposed in the side slide mold Ms are displayed. Therefore, the appearance value of the integrally molded container can be increased, and the distinguishability of the integrally formed container by changing the color and hue can be increased.

  The resin gate disposed on the mold for molding the side wall of the integrally molded container is positioned so as to coincide with the intersection of the horizontal rib and the vertical rib formed on the side wall or in the vicinity of the intersection. Since it is configured to be positioned on the horizontal rib or the vertical rib, it is possible to suppress the direct influence of the injection pressure on the flat plate-like portion of the side wall, and therefore it is possible to suppress the deformation of the side wall due to the injection pressure. .

  The resin gate disposed in the mold for molding the side wall of the integrally molded container is configured to be located at a plate-like portion located near the intersection of the horizontal rib and the vertical rib formed on the side wall. Therefore, the printing area | region and seal sticking area | region formed in a side wall can be enlarged.

FIG. 1 is a vertical sectional view of a mold structure used in the integral mold container molding method of the present invention. FIG. 2 is a vertical sectional view of another embodiment of the mold structure used in the integrally molded container molding method of the present invention. FIG. 3 is a perspective view of an integrally molded container as an example molded by the integrally molded container molding method of the present invention. FIG. 4 is a vertical sectional view of a mold structure used in a conventional integral mold container molding method.

  First, an embodiment of the present invention will be described with reference to FIG.

  In FIG. 1, Mf is a fixed mold, Mm is a movable mold, and Ms is a side slide mold. Further, a cavity C for an integral mold container is formed between the fixed mold Mf, the movable mold Mm, and the side slide mold Ms. The fixed mold Mf includes the above-described mold. Similar to the structure, an appropriate number of resin gates Gf are formed. Further, similarly to the above-described known mold structure, a movable side mounting plate Fm, a fixed side mounting plate Ff, a spacer S, and the like are arranged. Since the mold structure having such a configuration is publicly known, detailed description thereof is omitted.

  In the present invention, in addition to the resin gate Gf formed on the fixed mold Mf, an appropriate number of resin gates Gs are also formed on the side slide mold Ms.

  As described above, an appropriate number of resin gates Gf are disposed in the fixed mold Mf for molding the bottom of the integral mold container, and the side slide mold for molding the side wall of the integral mold container. By arranging an appropriate number of resin gates Gs in Ms as well, molten resin can be reliably injected into the entire cavity C without increasing the melt flow rate MFR of the resin. Therefore, it is possible to suppress a decrease in impact resistance of the integrally molded container due to an increase in the melt flow rate MFR of the resin. In addition, the resin can have a low melt flow rate MFR, in other words, a low-cost recycled resin or the like. Therefore, the manufacturing cost of the integrally molded container can be reduced.

  In addition, an appropriate number of resin gates Gf are disposed in the stationary mold Mf for molding the bottom of the integrally molded container, and the side slide mold Ms for molding the side wall of the integrally molded container. By arranging an appropriate number of resin gates Gs, the injection pressure can be lowered. Therefore, the thickness of the fixed mold Mf, the movable mold Mm, and the side slide mold Ms constituting the mold structure is reduced. The manufacturing cost of the mold can be reduced.

  Further, an appropriate number of resin gates Gf are disposed in the fixed mold Mf for molding the bottom of the integrally molded container, and the side slide mold Ms for molding the side wall of the integrally molded container. By arranging an appropriate number of resin gates Gs, it is possible to shorten the injection molding time of the integrally molded container, and therefore, it is possible to increase the injection molding work efficiency of the integrally molded container.

  Furthermore, an appropriate number of resin gates Gf are disposed in the fixed mold Mf for molding the bottom of the integrally molded container, and the side slide mold Ms for molding the side wall of the integrally molded container. By disposing the resin gate Gs, the color and hue of the molten resin injected from the resin gate Gf disposed on the fixed mold Mf and the resin gate Gs disposed on the side slide mold Ms are injected. The color and hue of the molten resin can be appropriately changed. Therefore, the appearance value of the integrally molded container can be increased, and the distinguishability of the integrally molded container by changing the color and hue can be increased. Can be increased.

  FIG. 2 shows another embodiment of the present invention. In this embodiment, the side slide mold Ms in the above-described embodiment is formed integrally with the fixed mold Mf, and other configurations are the same as those in the above-described embodiment. That is, the fixed mold Mf includes a horizontal portion Mf1 and a vertical portion Mf2 standing from both ends of the horizontal portion Mf1. And the resin gate Gs arrange | positioned by the side part slide metal mold | die Ms in the Example mentioned above is arrange | positioned by the vertical part Mf2 which comprises the fixed metal mold | die Mf.

  FIG. 3 shows, as an example, an integral mold container formed by the above-described integral mold container molding method.

  The integral mold container V has a bottom portion 1, opposed long side walls 2, and opposed short side walls 3. The upper end of the integral mold container V extends outside the integral mold container V. An upper end horizontal flange 4 is formed. Further, an appropriate number of fitting portions 1b are provided on the back surface 1a of the bottom portion 1, and the fitting portion 1b includes a peripheral wall 1b1 and a cross rib 1b2 formed in the peripheral wall 1b1. Yes. Further, an appropriate number of horizontal ribs 2b and an appropriate number of vertical ribs 2c are formed on the outer surface 2a of the opposing long side walls 2. Similarly, an appropriate number of horizontal ribs 3b and an appropriate number of vertical ribs 3c are formed on the outer surface 3a of the opposing short side wall 3 as well.

  The resin gate Gf disposed on the fixed mold Mf for molding the bottom portion 1 of the integral mold container V described above is at the intersection P1 of the intersecting rib 1b2 of the fitting portion 1b formed on the back surface 1a of the bottom portion 1. Can be arranged to match. The resin gate Gf can also be arranged so as to be positioned on the flat plate-like portion 1c of the bottom portion 1. By configuring in this way, the lower end of the runner after molding does not protrude from the lower end of the intersecting rib 1b2, and accordingly, the horizontal surface of the fitting portion 1b constituting the bottom 1 of the integrally molded container V However, it is possible to prevent the flatness from being impaired, and eventually the stability of the integrally molded container V placed on the floor or the like from being impaired.

  In addition, the resin gate Gs disposed in the vertical portion Mf2 constituting the side slide mold Ms and the fixed mold Mf for molding the long side wall 2 of the integral mold container V is formed on the long side wall 2. It is preferable to arrange so as to coincide with the intersection P2 between the horizontal rib 2b and the vertical rib 2c. Further, the resin gate Gs disposed on the side slide mold Ms for forming the short side wall 3 of the integral mold container V and the vertical part Mf2 constituting the fixed mold Mf is formed on the short side wall 3. It is preferable to arrange so as to coincide with the intersection P3 between the horizontal rib 3b and the vertical rib 3c. By configuring in this way, it is possible to suppress the direct influence of the injection pressure on thin portions such as the flat plate-like portion 2d of the long side wall 2 and the flat plate-like portion 3d of the short side wall 3, and accordingly The deformation of the long side wall 2 and the short side wall 3 due to the injection pressure can be suppressed.

By the way, when an integral mold container having a wall thickness of 2 mm or less is injection-molded, if the resin gate Gf is formed only in the fixed mold Mf as in the prior art, the melt flow rate MFR of the resin (SI unit is g / 10 min, measurement method is JISK7210, ISO1133 and test condition 230 ° C.) must be at least 45 or more, and if it is less than 45, in cavity C, There is a problem that the molten resin does not spread evenly, and the Charpy impact strength (SI unit is kJ / m ² , the measurement method is JISK7111, ISO179, and the test condition is 23 ° C.) of the integrally molded container. It becomes 5.5 or less, and the impact strength of the integrally molded container is lowered.

  In the present invention, an appropriate number of resin gates Gf are disposed in a fixed mold Mf for molding the bottom of the integral mold container, and a side slide mold for molding the side wall of the integral mold container. Even when Ms is provided with an appropriate number of resin gates Gs, the above-described melt flow rate MFR can be set to 30 or less even when an integrally molded container having a thickness of 2 mm or less is injection-molded. Therefore, the Charpy impact strength of the integrally molded container can be 7 or more.

  The resin gate Gf disposed in the fixed mold Mf for molding the bottom portion 1 of the integral mold container V is placed at the intersection P1 of the intersecting rib 1b2 of the fitting portion 1b formed on the back surface 1a of the bottom portion 1. Instead of being arranged, it can be arranged on the intersecting rib 1b2 located near the intersection P1 or on the back surface 1a of the bottom 1 located near the intersecting rib 1b2.

  Similarly, a resin gate Gs disposed on the vertical portion Mf2 constituting the side slide mold Ms and the fixed mold Mf for molding the long side wall 2 of the integral mold container V is formed on the long side wall 2. Instead of being arranged at the intersection P2 between the horizontal rib 2b and the vertical rib 2c, the horizontal rib 2b or the vertical rib 2c located near the intersection P2 or the outer surface 2a of the long side wall 2 located near the intersection P2 may be arranged. it can. As described above, when the resin gate Gs is arranged on the horizontal rib 2b or the vertical rib 2c located in the vicinity of the intersection point P2, the plate-like shape of the long side wall 2 is provided in the same manner as the resin gate Gs is arranged at the intersection point P2 described above. The direct influence of the injection pressure on the thin-walled portion such as the plate-like portion 2d can be suppressed, and therefore deformation of the long side wall 2 due to the injection pressure can be suppressed. Further, by arranging the resin gate Gs on the outer surface 2a of the long side wall 2 located in the vicinity of the intersection P2, it is possible to enlarge the printing area and the sticking area formed on the long side wall 2.

  Similarly, a resin gate Gs disposed in the vertical portion Mf2 constituting the side slide mold Ms and the fixed mold Mf for forming the short side wall 3 of the integral mold container V is formed on the short side wall 3. Instead of being arranged at the intersection P3 between the horizontal rib 3b and the vertical rib 3c, the horizontal rib 3b or the vertical rib 3c located near the intersection P3, or the outer surface 3a of the short side wall 3 located near the intersection P3 may be used. it can. As described above, when the resin gate Gs is arranged on the horizontal rib 3b or the vertical rib 3c located in the vicinity of the intersection P3, as in the case where the resin gate Gs is arranged at the intersection P3 described above, a flat plate shape of the short side wall 3 is formed. The direct influence of the injection pressure on the thin-walled portion such as the plate-like portion 3d can be suppressed, and therefore deformation of the short side wall 3 due to the injection pressure can be suppressed. Further, by arranging the resin gate Gs on the outer surface 3a of the short side wall 3 located in the vicinity of the intersection P3, it is possible to enlarge a printing area and a seal sticking area formed on the short side wall 3.

C ················ cavity Gf, Gs ·················· Resin gate Mf ······························・ ・ ・ ・ ・ Moveable mold Ms ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Side slide mold V ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Integrated mold container 1 ・ ・ ・ ・ ・・ ・ ・ ・ ・ Bottom 2 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Long side wall 3 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Short side wall

Claims (1)

An appropriate number of resin gates are arranged on the fixed mold constituting the mold structure, and also suitable for the side slide mold constituting the mold structure or the vertical part of the fixed mold. A plurality of resin gates are arranged so that molten resin is injected into the cavity from the resin gates, and the resin gates are formed with horizontal ribs and vertical ribs formed on the side walls of the integrally molded container. A method for molding an integrally molded container , wherein the molten resin is poured into the cavity from the resin gate.

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