JP2007320168A - Mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold which has superior practicality and enables production of a pulp molding with very high quality. <P>SOLUTION: The mold is used to form a molding 5 and consists of a pair of cavity mold 1 and a core mold 2 opposite to each other. A cavity insert 7 forming a cavity 6 to be charged with a material for the molding 5 and a core insert 8 are each arranged removably on the opposite faces 3 and 4 of the cavity mold 1 and the core mold 2, respectively, and insulation members 11 and 12 insulating the cavity nesting 7 and the core nesting 8 from the outside are disposed in the cavity mold 1 and the core mold 2, respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a molding die.

  In recent years, for example, disclosed in Japanese Patent Application Laid-Open No. 2002-67014 (Patent Document 1) related to the prior application of the applicant due to repeated increases in cost of plastic materials due to high oil prices and increasing interest in reducing environmental impact. There is an urgent need to improve the productivity of biodegradable pulp injection or compression molded products (paper-based three-dimensional structures obtained by injection or compression molding of pulp and starch-based materials). .

  Although it has become possible to mold any pulp injection or compression molded product by technological development so far, in terms of obtaining a high quality pulp injection or compression molded product at high cycle, It is insufficient.

  That is, at present, it is a necessary condition to increase the productivity (reducing the drying time of the material) to efficiently vaporize and remove the moisture contained in the molding material in the molding process. For example, the moisture in the material is discharged as water vapor by repeating the operation of slightly opening a gap after filling the mold and core molds.

JP 2002-67014 A

  However, by repeating the above operation and discharging moisture in the material as water vapor, it has become possible to efficiently drain moisture, but the drying time of the material is still insufficient, and further production is not possible. There is a demand for improvement in performance.

  In view of the above demands, the present inventors have found that the conventional mold structure has poor temperature control accuracy and efficiency, and it is difficult to further improve productivity only by improving molding conditions and molding machine operation. Based on knowledge, as a result of various experiments, we have found a structure that can greatly improve the heating efficiency of the mold, and completed it, and it is a mold with excellent practicality that can obtain extremely high quality pulp molded products Is to provide.

  The gist of the present invention will be described with reference to the accompanying drawings.

  A molding die for molding a molded product 5, which is composed of a pair of opposing molds 1 and a core mold 2, and the opposing surfaces 3 and 4 of the mold 1 and the core mold 2 have A cavity insert 7 and a core insert 8 that form a cavity 6 filled with a material to be the molded product 5 are detachably provided. The mold insert 1 and the core mold 2 are provided with the insert insert 7. In addition, the present invention relates to a molding die characterized in that heat insulating members 11 and 12 for heat insulating the core insert 8 and the outside are provided.

  The molding die according to claim 1, wherein the heat insulating members 11 and 12 are provided so as to cover at least the back and side surfaces of the cavity insert 7 and the core insert 8. It is concerned.

  Further, in the molding die according to any one of claims 1 and 2, the cabinet insert 7 or the core insert 8 is provided in mounting recesses 9 and 10 formed in the mold 1 or the core mold 2, The heat insulating members 11 and 12 relate to the molding die characterized in that the mounting recesses 9 and 10 are provided at the boundary with the cabinet insert 7 or the core insert 8.

  The molding die according to any one of claims 1 to 3, wherein heat insulating members 15 and 16 are provided on the back side of the mold 1 and the core die 2. It is related to.

  The molding die according to any one of claims 1 to 4, wherein the cabinet insert 7 and the core insert 8 are disposed at an inner position of the heat insulating members 11 and 12 with respect to the mold insert 7 and the core insert 8. The present invention relates to a molding die characterized in that heating sections 17 and 18 for heating 8 are provided.

  6. The molding die according to claim 5, wherein the heating portions 17 and 18 are configured by an electric heater or a flow passage through which a heating fluid flows.

  The molding die according to any one of claims 1 to 6, wherein the mold insert 7 and the core insert 8 are provided with temperature sensors 21 and 22, respectively. It is concerned.

  The molding die according to any one of claims 1 to 7, wherein the molding die is an injection molding die A.

  The molding die according to any one of claims 1 to 7, wherein the molding die is a compression molding die B.

  The molding die according to any one of claims 1 to 9, wherein the molding die is for molding the molded product 5 using a material mainly composed of pulp and starch. It relates to a molding die.

  Since this invention was comprised as mentioned above, it becomes a shaping die excellent in practicality which can obtain a high-quality pulp molded product very efficiently.

  An embodiment of the present invention which is considered to be suitable will be briefly described with reference to the drawings showing the operation of the present invention.

  By suppressing the heat radiation from the cavity insert 7 and the core insert 8 that form the cavity 6 by the heat insulating members 11 and 12, the heating efficiency of the cavity insert 7 and the core insert 8 is improved, and for example, the cavity 6 is filled. In order to efficiently dry the molded product 5 made of the material, the temperature of the mold nesting 7 and the core nesting 8 can be maintained even if the operation of slightly opening the cavity mold 1 and the core mold 2 after filling the material is repeated. It is difficult to decrease, and even if it decreases, it returns to a predetermined set temperature in a short time.

  Therefore, it becomes easy to maintain the molded product 5 in the cavity 6 at a predetermined temperature necessary for drying the molded product 5, and a high-quality molded product that is sufficiently dried as compared with the prior art can be obtained in a short time. Can be removed from the mold, and productivity is improved accordingly.

  In addition, the present inventors produce a mold having a shape of □ 300 mm and a thickness of 1.0 mm, and heat insulating members 11 and 12 covering the back surface and the side surface of the cavity insert 7 and the core insert 8 of the mold mold 1 and the core mold 2. In addition, when experiments were performed using molds in which temperature sensors 21 and 22 for temperature control were provided in the cavity insert 7 and the core insert 8 respectively, the heating efficiency was greatly improved and the molding time of the material could be greatly reduced. Have confirmed. This experiment was confirmed with an injection mold and a compression mold having the same structure, and it was confirmed that the above results were obtained in both.

  That is, according to the present invention, the mold temperature lowered during molding can be recovered in a short time and maintained, and if the mold temperature does not decrease (in other words, the molded product taken out is completely removed). If it can be dried), it can be determined that the productivity is continuously good, and therefore, a sufficiently high quality molded product can be obtained.

  Further, for example, heating units 17 and 18 for heating the cabinet insert 7 and the core insert 8 are provided at the inner positions of the heat insulating members 11 and 12 in the cabinet insert 7 and the core insert 8. When configured as a flow passage through which a heated fluid circulates as 18, for example, a heat medium other than a general electric heater, that is, pressurized hot water, pressurized steam or heated oil can be used. (It is not necessary to purchase a dedicated electric heater each time a mold is newly created, and a flow path having a desired shape can be formed in the cavity insert 7 and the core insert 8). It ’s fine.)

  In addition, when the electric heater is used, only linear processing can be performed. When the molded product has a three-dimensional shape, the distance from the electric heater to the molded product 5 in the cavity 6 becomes non-uniform, and as a result, the mold surface (the mold insert 7). In addition, the temperature of the core insert 8) may become uneven, and unevenness and insufficient drying may occur on the surface of the molded product. However, by using a gas or liquid heating medium (heating fluid), a heat supply source (heating unit 17. Since the distance from 18) to the molded product 5 can be made uniform even if it is a three-dimensional shape, there is no temperature unevenness on the mold surface, and a high-quality molded product can be obtained. As a result, the degree of freedom in mold design is increased, which leads to a reduction in mold production costs. In addition, if even one electric heater that maintains the mold temperature is cut, insufficient drying or unfilling occurs. However, this problem can be solved by using a heating fluid.

  Therefore, the present invention is particularly useful in a mold having a structure in which a pulp-and-starch-containing material containing moisture added to impart fluidity is continuously formed stably and efficiently at a high cycle. Will be demonstrated.

  Specific embodiments of the present invention will be described with reference to the drawings.

  The present embodiment is a molding die for molding a molded product 5, and the molding die is composed of a pair of opposed molds 1 and a core mold 2, and the opposite surfaces 3 of the mold 1 and the core mold 2. 4 is provided with a cavity insert 7 and a core insert 8 which form a cavity 6 filled with a material to be the molded product 5, and are detachably attached to the cavity mold 1 and the core mold 2. Insulating members 11 and 12 for insulating the cabinet insert 7 and the core insert 8 from the outside are provided.

  Each part will be specifically described.

  As a material for obtaining the molded product 5, pulp fiber: 60 wt%, starch (water-soluble binder): 30 wt%, PVA: 10 wt% added with water to have a water content of 40 wt%. It has been adopted. In addition, instead of starch, gelatinized starch may be employed. In this case, for example, moisture is added to pulp fiber: 60 wt%, gelatinized starch: 30 wt%, PVA: 10 wt% to obtain a moisture content of 40 wt%. Prepare as follows.

  The material thus prepared is heated to a temperature of about 90 ° C., filled in the cavity 6 of the injection mold A held at about 180 ° C., and molded into a molded product 5.

  As shown in FIG. 1, the injection mold A is composed of a mold 1 and a core 2. In this embodiment, an appropriate drive mechanism (not shown) such as a piston mechanism that causes the mold 1 to be fixed to the mold 1 and the core 2 to move the core 2 to and away from the mold 1 is provided. The movable mold 2 is set. In the figure, reference numeral 23 denotes a mold fixing part to which the mold 1 is fixed, and 24 denotes a core fixing part to which the core mold 2 is fixed (the back of the core fixing part 24 (molding machine movable platen) A drive mechanism is provided.).

  A cavity insert 7 and a core insert 8 forming a cavity 6 are detachably provided in the mounting recesses 9 and 10 formed in the mold 1 and the core mold 2, respectively. A cavity 6 is formed between the cavity insert 7 and the core insert 8 by bringing the opposing contact surfaces (parting surfaces 25 and 26) of the cavity insert 7 and the core insert 8 into close contact with each other.

  The cavity mold 1 and the core mold 2 include a rear surface 27 and side surfaces standing on the periphery of the bottom surface portion 27 so as to cover the rear surface and side surfaces of the cavity insert 7 and the core insert 8 except for the parting surfaces 25 and 26. Box-shaped heat insulating members 11 and 12 each having a portion 28 are provided.

  In this embodiment, the heat insulating members 11 and 12 are provided in the mounting recesses 9 and 10 in which the cabinet insert 7 and the core insert 8 are provided, and the mold insert 7 or the core insert 8 is provided on the heat insulating members 11 and 12. ing. The height of the side surface portion 28 of the heat insulating members 11 and 12 does not protrude from the mounting recesses 9 and 10, specifically, the opposing surfaces 3 and 4 of the mold mold 1 and the core mold 2, the mold insert 7 and the core insert. It is set to be exactly the same height as the 8 parting surfaces 25 and 26. Further, the width and depth of the back surface portion 28 of the heat insulating members 11 and 12 are set to be the same for the heat insulating member 11 provided in the mold 1 and the heat insulating member 12 provided in the core die 2.

  That is, in this embodiment, when the mold insert 7 and the core insert 8 are brought into close contact with each other (the parting surfaces 25 and 26), the heat insulating members 11 and 12 are brought into close contact with each other (the side portions of the heat insulating members 11 and 12). 28 edges are in close contact with each other), and the entire cavity insert 7 and core insert 8 can be concealed. Therefore, the heat retaining properties of the cavity insert 7 and the core insert 8 are greatly improved, and the temperature required for molding (for drying the material) can be maintained well.

  In addition, heat insulating members (heat insulating plates) 15 and 16 are continuously provided on the back side of the heat insulating members 11 and 12 in the mold 1 and the core die 2. That is, the heat insulating plates 15 and 16 are continuously provided on the opposite surfaces 13 and 14 side of the opposing surfaces 3 and 4 where the mounting recesses 9 and 10 are provided as the mold 1 and the core die 2. Specifically, the heat insulating plates 15 and 16 are provided on the upper surface of the cavity mold fixing portion 23 to which the cavity mold 1 is fixed and the lower surface of the core mold fixing portion 24 to which the core mold 2 is fixed. In other words, in this embodiment, the heat insulating plate 15 is provided on the opposite surface 13 of the mold 1 via the mold fixing portion 23, and the heat insulating plate 16 is fixed on the opposite surface 14 of the core die 2 with the core mold. It is provided via the part 24 (and an interposition member 35 described later). Therefore, the heat radiation from the cabinet mold 1 and the core mold 2 as well as the cabinet insert 7 and the core insert 8 is suppressed by the heat insulating plates 15 and 16.

  In this embodiment, the heat insulating plates 15 and 16 are provided on the upper surface of the cavity mold fixing portion 23 and the lower surface of the core mold fixing portion 24, but between the cavity mold 1 and the cavity mold fixing portion 23, the core mold 2 and the postscript interposed member 35, or between the core mold fixing portion 24, the postscript ejector plate 33, and the postscript interposed member 35, and the like.

  Further, heating units 17 and 18 for heating the cabinet insert 7 and the core insert 8 are provided at the inner positions of the heat insulating members 11 and 12 as the mold insert 7 and the core insert 8. Specifically, a flow passage through which a heating fluid such as pressurized hot water, pressurized steam, or heated oil circulates is employed as the heating units 17 and 18. The flow passages are formed in the cavity insert 7 and the core insert 8, respectively.

  Therefore, the cavity insert 7 and the core insert 8 can be heated more quickly and uniformly with good responsiveness, and the heat insulating action by the heat insulating members 11 and 12 is extremely excellent in heating efficiency.

  Furthermore, unlike an electric heater with restrictions on bending or the like, the path of the heating fluid can be set relatively freely, and in particular, the flow path and the molded product 5 are provided at the same interval as much as possible at any location. Further, by making the flow passages in accordance with the shape of the molded product, uniform heating without any unevenness is possible. Further, since the flow passage can be formed relatively freely, the mold design can be performed more freely.

  Further, the cavity insert 7 and the core insert 8 are provided with temperature sensors 21 and 22 (thermocouples and the like), respectively. Therefore, the temperature of each of the cabinet insert 7 and the core insert 8 can be measured more accurately. In addition, as described above, the cavity insert 7 and the core insert 8 are quickly and uniformly heated by the heat insulating members 11 and 12 and the heating parts 17 and 18, so that a highly reliable temperature measurement is possible. Temperature control using the temperature measurement result can also be performed with good responsiveness by being directly heated by the flow path, and overshooting and undershooting hardly occur, and extremely efficient heating is possible.

  The mold 1 is provided with a gate 29 for introducing a material for obtaining the molded product 5 into the cavity 6, and the gate 29 is connected to the nozzle 30. The nozzle 30 is connected to a material supply unit 31 in which the material is stored. The material stored in the material supply unit 31 is stirred by a screw and pushed out from the nozzle 30 into the cavity 6 by a piston mechanism or the like. .

  The core mold 2 is provided with an extruding pin 32 that protrudes and retracts after the molded product 5 is formed and then the back surface of the molded product is extruded to release the molded product from the core mold 2. In the figure, reference numeral 33 denotes an ejector plate in which an extruding pin 32 is connected via a connecting portion 34 and moves up and down by a piston mechanism or the like, and 35 denotes the ejector provided between the core die 2 and the core die fixing portion 24. It is an interposition member for forming a movable space of the plate 33.

  Further, the wall surfaces of the cavity mold 1 and the core mold 2 are subjected to a roughening process such as embossing, so that an appropriate flow resistance is generated in the filling direction of the molded product 5. Therefore, the material filled in the cavity 6 is uniformly filled.

  From the above, the cavity inserts 7 and the core inserts 8 provided in the mold 1 and the core mold 2 held at about 180 ° C. are brought into close contact with each other and the cavity 6 is filled with a material of about 90 ° C. In addition to vaporizing moisture in the material contained in the molded product 5, the core mold 2 is slightly moved to intermittently form a gap of about 0.02 to 0.5 mm between the parting surfaces 25 and 26. By drying and solidifying the material so that water vapor generated in the cavity 6 is released from the gap, a molded product 5 having pulp as a main material can be obtained.

  In the present embodiment, the example in which the present invention is applied to the injection mold A has been described. However, the same applies to the case where the present invention is applied to the compression mold B. This compression mold B does not require the gate, nozzle, material supply portion, etc. used in the injection mold A and can be realized at a lower cost. Moreover, it is good also as a structure which shape | molds not only the material which has a pulp and starch as a main component but another material.

  Since the present embodiment is configured as described above, heat dissipation of the cavity insert 7 and the core insert 8 is suppressed by suppressing heat radiation from the cavity insert 7 and the core insert 8 forming the cavity 6 by the heat insulating members 11 and 12. For example, in order to dry the molded product 5 filled in the cavity 6 efficiently, the mold mold 1 and the core mold 2 are filled with the material and the operation of slightly opening the gap is repeated. The temperature of the nesting 7 and the core nesting 8 is unlikely to decrease, and even if it decreases, it returns to a predetermined set temperature in a short time.

  Therefore, it becomes easy to maintain the molded product 5 in the cavity 6 at a predetermined temperature necessary for drying the molded product material 5, and it is possible to obtain a high-quality molded product by drying more reliably. Needless to say, the molded product 5 can be taken out from the mold in a short time as compared with the prior art, and the productivity is improved accordingly.

  Therefore, in this example, it is possible to stably and efficiently form a material mainly composed of pulp and starch containing moisture added to impart fluidity in a high cycle, and extremely efficiently It is an injection mold that is extremely practical and capable of obtaining a quality pulp molded product.

It is a schematic explanatory sectional drawing of a present Example. It is general | schematic explanatory sectional drawing of another example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cavity type 2 Core type 3/4 Opposite surface 5 Molded product 6 Cavity 7 Cavity nesting 8 Core nesting 9/10 Mounting recess
11 ・ 12 Heat insulation material
15.16 Heat insulation material (heat insulation plate)
17 ・ 18 Heating section
21 ・ 22 Temperature sensor

Claims (10)

  A molding die for molding a molded product, the molding die comprising a pair of opposed molds and a core mold, and the opposing surfaces of the molds and the core mold are filled with the material to be the molded product A cavity insert and a core insert that form a cavity to be formed are detachably provided, and the cavity mold and the core mold are provided with heat insulating members that insulate the cavity insert and the core insert from the outside, respectively. A molding die characterized by being made.   The molding die according to claim 1, wherein the heat insulating member is provided so as to cover at least a back surface and a side surface of the cabinet insert and the core insert.   The molding die according to any one of claims 1 and 2, wherein the cabinet insert or core insert is provided in a mounting recess formed in the cabinet mold or core mold, and the heat insulating member is the mounting recess. A molding die, which is provided at a boundary with the mold nesting or the core nesting.   The molding die according to any one of claims 1 to 3, wherein a heat insulating member is provided on the back side of the mold and the core die.   5. The molding die according to claim 1, wherein a heating unit that heats the mold nest and the core nest is provided at an inner position of the heat insulating member by using the mold nest and the core nest. A molding die characterized by   6. The molding die according to claim 5, wherein the heating portion is configured by an electric heater or a flow passage through which a heating fluid flows.   The molding die according to any one of claims 1 to 6, wherein a temperature sensor is provided in each of the cabinet insert and the core insert.   The molding die according to any one of claims 1 to 7, wherein the molding die is an injection molding die.   The molding die according to any one of claims 1 to 7, wherein the molding die is a compression molding die. The molding die according to any one of claims 1 to 9, wherein the molding die is for molding a molded product using a material mainly composed of pulp and starch. .

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