JP5148376B2 - Injection mold and method of manufacturing resin molded product using the same - Google Patents

Description

  TECHNICAL FIELD The present invention relates to an injection mold, and in particular, an injection mold that can be used for manufacturing a resin molded product to which a transfer layer of a transfer sheet is transferred simultaneously with injection molding, and a resin molded product using the mold. It is about the method.

  There is a resin molded product having a pattern transferred to the surface, such as a casing of a mobile phone. For example, using a molding simultaneous transfer device, this resin molded product is fed into a mold for injection molding by using a transfer layer including a design, and the transfer layer is transferred to the resin portion at the same time as injection molding. Manufactured (for example). The molding simultaneous transfer device includes an injection molding machine, an injection molding die, and a transfer sheet feeding device. The injection mold includes a fixed mold, a movable mold that forms a cavity between the fixed mold and mold clamping, and a clamp that brings the transferred transfer sheet into and out of contact with the movable mold parting surface. ing. The transfer sheet feeding device is a device that feeds a roll-shaped long transfer sheet vertically into the injection mold along the movable parting surface, and is attached to the upper part of the movable plate of the injection molding machine. The unwinding part is formed, and a winding part attached to the lower part of the movable platen.

In the production of the resin molded product, first, in a state where the mold is opened, the transfer sheet fed from the unwinding portion is aligned and brought into contact with the movable parting surface by a clamp. Next, the transfer sheet is arranged along the movable cavity surface by suction. Next, the mold is clamped and a molten resin is injected into the cavity to form a resin portion. At the same time, a transfer layer is transferred to the resin portion to mold a resin molded product. After the resin molded product is cooled and solidified, the mold is opened and the transfer sheet is released from the movable parting surface by clamping, and the resin molded product is taken out from the injection mold. In this manner, a resin molded product having a pattern transferred to the surface is manufactured.
Japanese Patent Laying-Open No. 2005-343027

  In the conventional mold for injection molding as described above and the resin molded product manufacturing method using the same, when the contact is released from the parting surface by clamping from the state where the transfer sheet is in contact with the parting surface, the transfer sheet Static electricity is generated on the movable surface and the transfer sheet that were in contact with each other. This is so-called peeling charging. At this time, the transfer sheet and the parting surface are charged with opposite polarities. If the transfer sheet is polyethylene terephthalate (PET) resin, contact is released from the movable mold made of steel, and the transfer sheet is charged to the positive electrode and the surface of the movable mold is charged to the negative electrode. Since the movable surface is charged by peeling electrification, the dust and the dust drifting in the atmosphere are easily attached to the movable cavity surface. The foil dust is a small piece of the transfer layer that is generated when the base sheet is peeled from the resin portion. Further, since the foil dust is charged on the positive electrode, it is attracted to the movable surface by the Coulomb force, and is more easily attached to the movable cavity surface. When injection molding is performed in a state where foreign matters such as foil dust, dust, and dust adhere to the cavity surface, dents that are dents are generated on the surface of the resin molded product. Since the foreign matter is not in direct contact with the resin molded product by the transfer sheet, it is not attached to the resin molded product and removed. Therefore, once the dent is generated, the same dent is continuously generated, and there is a possibility that defective products are continuously formed.

  The present invention has been made to solve the above-described problems, and reduces the generation of static electricity when releasing the contact of the transfer sheet from the parting surface and makes it difficult for foreign matter to adhere to the cavity surface. An object of the present invention is to provide a molding die and a method for producing a resin molded product using the same.

  In order to achieve the above object, the invention according to claim 1 is the manufacture of a resin molded product in which a transfer sheet having a transfer layer on a base sheet is fed into a mold and the transfer layer is transferred simultaneously with injection molding. An injection mold that can be used for a fixed mold, a movable mold that forms a cavity between the fixed mold by clamping, at least one of a fixed parting surface and a movable mold parting surface A clamp that contacts and releases the transfer sheet with respect to the provided parting surface, and a transfer sheet that contacts the transfer sheet in contact with the transfer sheet when viewed from the mold clamping direction. And an antistatic sheet that is attached to the portion and can reduce the generation of static electricity due to the contact release of the transfer sheet.

  If comprised in this way, the charge amount of the parting surface from which a transfer sheet and a transfer sheet will be contact-released by the contact cancellation | release of a transfer sheet will reduce.

  According to a second aspect of the present invention, in the configuration of the first aspect of the present invention, the fixed mold includes a fixed mold side insert, the movable mold includes a movable mold side insert, and the antistatic sheet is a fixed parting. On the surface, it is affixed outward from the fixed mold side insert, and on the movable parting surface, it is affixed outward from the moveable side insert.

  If comprised in this way, an antistatic sheet will be affixed on the part which a fixed mold | type and a movable mold | type do not contact at the time of mold clamping.

  According to a third aspect of the present invention, in the configuration of the first or second aspect of the present invention, the antistatic sheet is made of the same material as the base sheet.

  If comprised in this way, the electrification rate of an antistatic sheet and a base sheet will become the same.

  According to a fourth aspect of the present invention, in the configuration of the first or second aspect of the invention, when the base sheet before the antistatic sheet contacts the parting surface is positively charged, When the base sheet is made of a material that is located on the positive electrode side of the base sheet in the charging column and is charged to the negative electrode before contacting the parting surface, the negative electrode is positioned on the negative side of the base sheet in the charging column. It consists of the material to be.

  With this configuration, when the transfer sheet is released from the parting surface, the charge amount of the transfer sheet is reduced.

  A fifth aspect of the present invention is a method for producing a resin molded article using the injection mold according to any one of the first to fourth aspects, wherein the transfer sheet is injection molded with the mold open. A step of feeding the mold into the mold, a step of bringing the transferred transfer sheet into contact with the antistatic sheet by a clamp, and placing the transfer sheet along the cavity surface by suction, and clamping the mold in the arranged state, The forming process, the molten resin is injected into the formed cavity to form the resin part, and at the same time, the transfer layer is transferred to the resin part to mold the resin molded product, and the molded resin molded product is cooled. And solidifying, and a step of opening the mold and releasing the contact of the transfer sheet from the antistatic sheet with a clamp to take out the resin molded product.

  If comprised in this way, the charge amount of the parting surface from which a transfer sheet and a transfer sheet will be contact-released by the contact cancellation | release of a transfer sheet will reduce.

  As described above, according to the first aspect of the present invention, the transfer sheet and the charge amount of the parting surface from which the transfer sheet is released due to the contact release of the transfer sheet are reduced, so that foreign matter is less likely to adhere to the cavity. The occurrence of defective products such as dents can be reduced.

  In addition to the effect of the invention described in claim 1, the antistatic sheet is attached to a portion where the fixed mold and the movable mold do not contact when the mold is clamped. Contact adjustment between the side insert and the fixed type insert becomes easy.

  In addition to the effects of the invention of claim 1 or 2, the invention described in claim 3 has a simple configuration in which the antistatic sheet and the base sheet have the same charge rate, so that the generation of static electricity due to peeling charging is simple. Can be reduced.

  In addition to the effects of the invention of claim 1 or 2, the invention described in claim 4 is based on peeling charging because the charge amount of the transfer sheet decreases when the transfer sheet is released from the parting surface. Generation of static electricity can be effectively reduced.

  According to the fifth aspect of the present invention, the charge amount of the transfer sheet and the parting surface from which the transfer sheet is released from contact due to the contact release of the transfer sheet is reduced. Therefore, it is difficult for foreign matter to adhere to the cavity, and it is possible to manufacture a resin molded product in which the transfer layer is transferred simultaneously with injection molding while reducing the occurrence of defective products such as dents.

  Next, embodiments of the invention will be described with reference to the drawings.

  FIG. 1 is a side view showing a schematic configuration of a simultaneous molding and transfer apparatus to which an injection mold according to a first embodiment of the present invention is applied.

  Referring to FIG. 1, a simultaneous molding and transfer apparatus 10 includes an injection molding machine, an injection molding die 11 and a transfer sheet feeding device 12 installed in the injection molding machine. The simultaneous molding and transfer device 10 uses a transfer sheet feeding device 12 to feed a transfer sheet 55 having a transfer layer on a base sheet into an injection molding die 11 and transfers the transfer layer simultaneously with injection molding to form a resin. This is an apparatus for manufacturing the product 57.

  The injection mold 11 is provided on a fixed mold 17, a movable mold 18 that forms a cavity 24 between the fixed mold 17 by clamping, and a parting surface 20 of the movable mold 18. On the other hand, a clamp 25 that contacts and releases the transfer sheet 55 is provided. The fixed mold 17 is fixed to the fixed platen 15 of the injection molding machine, and the movable mold 18 is fixed to the movable platen 16 of the injection molding machine. The movable mold 18 moves in the horizontal direction with respect to the fixed mold 17 by a driving means (not shown) of the injection molding machine, and mold clamping and mold opening are performed. Details of the movable mold 18 will be described later.

  The transfer sheet feeding device 12 is a device that intermittently feeds the transfer sheet 55 along the parting surface 20 of the movable mold 18 while repeatedly running and stopping from above to below. The transfer sheet feeding device 12 includes an unwinding unit 30 installed at the upper part of the movable platen 16, a winding unit 40 installed at the lower part of the movable platen 16, and a feed direction sensor 50 installed at the upper part of the movable mold 18. And a width direction sensor 51 installed at the upper and lower portions of the movable mold 18.

  The unwinding unit 30 is a device that unwinds the transfer sheet 55 into the injection mold 11. The unwinding unit 30 includes a frame 31 having side walls on both sides in the feeding direction of the transfer sheet 55, and a reel 36, a guide roller 37, and a guide roller 38 that are attached so as to span the side plates of the frame 31. Yes. The reel 36 is rotationally driven while being controlled in speed by a driving means (not shown), and a long transfer sheet 55 wound in a roll shape is set on the reel 36. The transfer sheet 55 unwound from the reel 36 is guided to the guide roller 37 and the guide roller 38 so as to be fed to a predetermined position with respect to the movable mold 18 while being applied with a predetermined tension. The guide roller 37 and the guide roller 38 rotate following the movement of the transfer sheet 55. The frame 31 is installed on the upper part of the movable platen 16 via a connecting member 32 made of a bent plate having an L shape in side view and a slide guide made up of a block 34 and a rail 35. The connecting member 32 is fixed to the movable platen 16, and the rail 35 is fixed to the upper surface of the connecting member 32. A block 34 is fixed to the lower surface of the frame 31. By sliding the block 34 with respect to the rail 35, the frame 31, that is, the unwinding portion 30 can be moved in the width direction of the transfer sheet 55 (direction passing through the paper surface).

  The winding unit 40 is a device that winds the transfer sheet 55 unwound from the unwinding unit 30 through the injection mold 11. The winding unit 40 includes a frame 41 having side walls on both sides in the feeding direction of the transfer sheet 55, and a guide roller 47, a guide roller 48, a guide roller 49, and a winding unit that are attached so as to span the side plates of the frame 41. And a roller 46. The winding roller 46 is rotationally driven while being torque controlled by a driving means (not shown), and the transfer sheet 55 sent from the unwinding portion 30 through the inside of the injection molding die 11 is wound around the winding roller 46. Taken. The transfer sheet 55 is guided to the take-up roller 46 by a guide roller 47, a guide roller 48, and a guide roller 49 while being given a predetermined tension. The guide roller 47, the guide roller 48, and the guide roller 49 are rotated following the movement of the transfer sheet 55. Similar to the frame 31, the frame 41 is installed at the lower part of the movable platen 16 via a connecting member 42 made of a bent plate having an L shape in side view and a slide guide made of a block 44 and a rail 45. . The frame 41, that is, the winding unit 40 is movable in the width direction of the transfer sheet 55. Further, the positions of the guide roller 47 and the guide roller 38 of the unwinding unit 30 determine the distance between the parting surface 20 of the movable mold 18 and the transfer sheet 55.

  The feed direction sensor 50 is a sensor that detects dot-like feed direction marks formed on the transfer sheet 55 at regular intervals according to the pattern to be transferred. When the feed direction sensor 50 detects the feed direction mark, the traveling transfer sheet 55 stops at a predetermined position so that the pattern formed on the transfer sheet 55 and the cavity surface 23 of the movable mold 18 coincide with each other. . Specifically, when the feed direction sensor 50 detects the front end of the feed direction mark, the traveling speed of the transfer sheet 55 is reduced, and when the rear end of the feed direction mark is detected, the transfer sheet 55 is stopped.

  The width direction sensor 51 is a sensor that detects a continuous linear width direction mark formed on the side of the transfer sheet 55 in the longitudinal direction of the transfer sheet 55. A width direction mark is detected by two sensors, a width direction sensor 51 installed at the upper part of the movable mold 18 and a width direction sensor 51 installed at the lower part of the movable mold, and the inclination of the transfer sheet 55 with respect to the feeding direction is adjusted. The Specifically, with the transfer sheet 55 stopped in the feed direction by the feed direction sensor 50, the transfer sheet 55 is moved in the width direction, and the two upper and lower width direction sensors 51 are positioned at one of the width direction marks. When the side edge is detected, the moving speed of the transfer sheet 55 is reduced. When the upper and lower width direction sensors 51 detect the other end of the width direction mark, the movement of the transfer sheet 55 in the width direction is stopped. Since the movement distance of the transfer sheet 55 in the width direction is short, the movement of the transfer sheet 55 may be stopped when the upper and lower width direction sensors 51 first detect one end of the width direction mark.

  The transfer sheet 55 is unwound from the reel 36 of the unwinding section 30, guided by the guide roller 37 and the guide roller 38, and then positioned at a predetermined position by the feed direction sensor 50 and the width direction sensor 51 described above. The stopping and running are repeated along the parting surface 20 of the movable mold 18. Then, it is guided by the guide roller 47, the guide roller 48, and the guide roller 49 and is taken up by the take-up roller 46 of the take-up unit 40. Movement of the transfer sheet 55 in the width direction is performed by movement of the unwinding unit 30 and the winding unit 40.

  The transfer sheet 55 is a substrate sheet on which a transfer layer that is transferred to the resin portion 56 at the same time as injection molding is formed. The transfer layer includes a release layer that forms the outer surface of the resin molded product 57 and protects the pattern layer, a pattern layer on which the pattern, feed direction mark, and width direction mark are expressed, and adhesion between the resin portion 56 and the transfer layer There are an adhesive layer that improves the adhesion, an anchor layer that protects the pattern layer and improves the adhesion between layers. Furthermore, when improving the peelability of the transfer layer from the base sheet, a release layer is formed between the base sheet and the transfer layer.

  For the base sheet, materials such as resin sheets such as polyethylene terephthalate (PET), polypropylene (PP), and acrylic, metal foil, glassine paper, coated paper, cellophane and other cellulose-based sheets are used.

  For the release layer, an acrylic (PMMA) resin, a polyester resin, a copolymer such as a vinyl chloride-vinyl acetate copolymer resin, or the like is used. In order to increase the hardness of the release layer and improve the scratch resistance of the resin molded product 57, an ultraviolet curable resin, an electron beam curable resin, or the like is used. The release layer is printed on the substrate sheet by a gravure printing method, a screen printing method, an offset printing method, or the like.

  The pattern layer is formed of a colored ink containing a resin and a coloring material such as a pigment or a dye. Resins used as binders include polyvinyl resins, polyamide (PA) resins, polyester resins, PMMA resins, polyurethane resins, polyvinyl acetal resins, polyester urethane resins, cellulose ester resins, alkyd resins, etc. is there. The pattern layer is printed on the release layer by a gravure printing method, a screen printing method, an offset printing method, or the like. When it is desired to express metallic luster as a pattern, the pattern layer is composed of a metal thin film layer formed by a vacuum deposition method, a sputtering method, an ion plating method, a plating method or the like. The symbol layer is set entirely or partially depending on the symbol to be expressed.

  The resin portion 56 is made of a material that matches the purpose of the molded product. For example, acrylonitrile butadiene styrene (ABS), PMMA, polystyrene (PS), styrene acrylonitrile (AS), polycarbonate (PC), polyvinyl chloride (PVC), PP, PET resin and the like.

  For the release layer, a melamine resin or the like is used, and for the adhesive layer, a heat-sensitive or pressure-sensitive resin suitable for the material of the resin part 56, for example, if the resin part 56 is a PMMA resin, a PMMA resin is used. A thermosetting urethane resin or the like is used for the anchor layer. The release layer, the adhesive layer, and the anchor layer are printed by a gravure printing method, a screen printing method, or the like.

  Next, details of the movable mold 18 will be described.

  FIG. 2 is a front view showing the schematic configuration of the movable type (1) shown in FIG. 1, and (2) is a cross-sectional view taken along the line II-II shown in (1).

  Referring to (1) and (2) of FIG. 2, in the movable mold 18, a movable side insert 22 having a rectangular shape in front view is embedded in the center of the parting surface 20. A cavity surface 23 having a concave shape with a rectangular shape when viewed from the front is formed. A clamp 25 is provided above and below the cavity surface 23 so as to straddle the movable side insert 22. The transfer sheet 55 is conveyed between the clamp 25 and the parting surface 20. An antistatic sheet 60 is attached to the upper and lower parting surfaces 20 of the movable side insert 22, that is, the hatched portion shown in FIG. 2 (1). In other words, the antistatic sheet 60 is affixed to a part of the parting surface 20 with which the transfer sheet 55 comes into contact with the transfer sheet 55 in contact with the parting surface 20 when viewed from the mold clamping direction. It is pasted more outward. The hatched portion shown in (1) of FIG. 2 is stepped down from the other portions, and the fixed mold 17 and the movable mold 18 are separated when the mold is clamped so as not to contact the transferred transfer sheet 55. It is a part that does not touch. Since the antistatic sheet 60 is affixed to this non-contact portion, and the surface of the antistatic sheet 60 does not protrude from the parting surface 20 of the movable mold side insert 22, The contact adjustment with the fixed side insert 21 is facilitated. When the transfer sheet feeding device 12 is installed on the fixed mold 17 side and the transfer sheet 55 is in contact with the parting surface 19 of the fixed mold 17, the antistatic sheet 60 is outward from the fixed mold side insert 21. It will be pasted.

  The material of the antistatic sheet 60 is determined according to the material of the base sheet of the transfer sheet 55. If the material of the base sheet is PET resin, the antistatic sheet 60 is made of the same kind of PET resin. Alternatively, when the base sheet material is PET resin, and the base sheet before contacting the parting surface 20 is charged to the positive electrode, the antistatic sheet 60 has a charge train on the positive electrode side from the base sheet material. Use the material that is located, for example nylon (registered trademark). Alternatively, when the base sheet material is PET resin, and the base sheet before contacting the parting surface 20 is charged to the negative electrode, the antistatic sheet 60 is placed on the negative electrode side of the base sheet material in the charging row. The material to be positioned is used, for example, Teflon (registered trademark). For example, a thickness of 38 μm or 50 μm is used. Although the antistatic sheet 60 is directly attached to the parting surface 20, the antistatic sheet 60 may be attached to a thin plate in advance to provide rigidity, and the thin plate may be attached to the parting surface 20. If comprised in this way, diversion to another metal mold | die will become easy and the attachment state of the antistatic sheet 60 can be stabilized easily.

  Next, the manufacturing method of the resin molded product 57 using the injection mold 11 will be described.

  FIG. 3 is a schematic view showing a manufacturing process of a resin molded product using the injection mold shown in FIG.

  Referring to (1) of FIG. 3, before the state shown in (1) of FIG. 3, the transfer sheet 55 is first opened in the mold open state, and the transfer sheet feeding device 12 is used to inject the injection mold 11. Sent in. The transfer sheet is arranged so that the patterns formed on the cavity surface 23 and the transfer sheet 55 match. At this time, the transfer sheet 55 is first fed at a high speed, and thereafter, the transfer sheet 55 is fed at a low speed so that the symbols match. Next, the transfer sheet 55 is brought into contact with the parting surface 20 by moving the clamp 25 toward the parting surface 20 of the movable mold 18. That is, the transfer sheet 55 is brought into contact with the antistatic sheet 60 by moving the clamp 25. Then, the transfer sheet 55 is arranged along the cavity surface 23 by suction. In the present invention, the “contact” of the transfer sheet 55 to the antistatic sheet 60 is not limited to the case where the transfer sheet 55 and the antistatic sheet 60 are actually in contact, but the actual contact. Although not included, this includes the case where the transfer sheet 55 and the antistatic sheet 60 are close to each other in the clamped state. Next, as shown in (1) of FIG. 3, the fixed mold 17 and the movable mold 18 are clamped to form the cavity 24. Next, molten resin is injected into the formed cavity 24 to form the resin portion 56, and at the same time, the transfer layer of the transfer sheet 55 is transferred to the resin portion 56 to form a resin molded product 57. Next, the molded resin molded product 57 is cooled and solidified.

  Next, referring to (2) of FIG. 3, the mold is opened and the transfer layer is peeled off from the transfer sheet 55. Next, referring to FIG. 3 (3), the transfer sheet 55 is released from the parting surface 20 by moving the clamp 25 in a direction away from the parting surface 20 of the movable mold 18. That is, by releasing the clamp 25, the transfer sheet 55 is released from contact with the antistatic sheet 60. Next, the resin molded product 57 is taken out from the injection mold by a robot (not shown). In this manner, the transfer sheet 55 having the transfer layer on the base sheet is fed into the mold, and the resin molded product 57 to which the transfer layer is transferred simultaneously with the injection molding is manufactured.

  Next, changes in the potential of the transfer sheet during injection molding will be described.

  FIG. 4 is a diagram showing the relationship between the potential of the transfer sheet and time in the manufacturing process of the resin molded product using the injection mold shown in FIG. 1 (1). It is a figure at the time of adding use of a static elimination device to the (1).

  Referring to (1) of FIG. 4, the vertical axis represents the potential of the transfer sheet 55 fed into the mold, and the horizontal axis represents elapsed time. The solid data line is the case where the resin molded product 57 is manufactured using the injection mold 11 with the antistatic sheet 60 attached as shown in FIG. 2, and the broken data line indicates the injection molding. This is a case where the antistatic sheet 60 is not attached to the metal mold 11. In both the solid data line and the broken data line, the potential of the transfer sheet 55 changes in accordance with the injection molding cycle. The potential of the transfer sheet 55 was detected using an electrostatic sensor in the vicinity below the injection mold 11. The process from point A through points B, C, D and E to return to the next point A is one injection molding cycle in which one resin molded product 57 is manufactured.

  A point A to a point B are states when the clamp 25 is opened in a state where the mold is opened, and the transfer sheet 55 is released from the parting surface 20 of the movable mold 18. At the same time, the molded resin molded product 57 is taken out. Next, from point B to point C, the transfer sheet 55 is fed downward at high speed in order to place the next pattern on the cavity surface 23. Next, from point C to point D, the transfer sheet 55 is fed downward at a low speed. Next, from point D to point E, the clamp 25 is closed and the transfer sheet 55 is brought into contact with the parting surface 20 and is brought into close contact with the cavity surface 23 by suction. Next, points E to A are in a state where the mold is clamped and injection molding is performed. Although the magnitudes of the potentials are different, the operation states of the injection molding die 11 and the transfer sheet 55 with respect to the potential change for each injection molding cycle are the same for the solid data line and the dashed data line.

  Referring to the solid data line in FIG. 4 (1), at point B, that is, when the clamp 25 is opened and the transfer sheet 55 is released from the parting surface 20 of the movable die 18, the potential is increased. It changes rapidly and is the highest. From there, the potential decreases rapidly with the high speed feeding of the transfer sheet 55 from the point B to the point C, and the potential gradually decreases with the low speed feeding of the transfer sheet 55 from the point C to the point D. ing. Further, the point A returns to the original potential at the point A during the injection molding after the clamping from the point D to the point E. The broken data line in (1) of FIG. 4 also changes in the same way, although the magnitude of the potential is different. Here, when comparing the solid data line and the broken data line, the solid data line has a low point A, that is, the maximum value of the potential because the antistatic sheet 60 is used. I understand.

  Referring to (2) of FIG. 4, (2) of FIG. 4 shows a change in potential of the transfer sheet 55 when air ions are supplied to the atmosphere in the mold of the injection mold 11 by a static eliminator. ing. The solid data line is the case where the resin molded product 57 is manufactured using the injection mold 11 with the antistatic sheet 60 attached as shown in FIG. 2, and the broken data line indicates the injection molding. This is a case where the antistatic sheet 60 is not attached to the metal mold 11. When comparing the solid data line and the broken data line, the point B, that is, the highest potential value is almost the same size, but the solid data line has a lower point A and the lowest potential value. Thus, the potential in the state of the point E immediately before that is also low. In addition, when comparing the solid line data in FIG. 4 (1) and the solid line data in FIG. 4 (2), the potential decreases as a whole, and the change range from the lowest value to the highest value of the potential is also shown. You can see that it is getting smaller. Specifically, the highest potential value is about 3.5 kV lower from about 9.5 kV to about 6 kV, and the lowest potential value is about 2.2 kV lower from about 4 kV to about 1.8 kV.

  From the above, in the manufacturing method of the resin molded product 57 using the injection mold 11 configured as described above, the transfer sheet 55 and the parting surface from which the transfer sheet 55 is released from contact due to the contact release of the transfer sheet 55. The amount of charge of 20 is reduced. Therefore, the phenomenon that foreign matter is attracted by the Coulomb force and the foreign matter adheres to the cavity surface 23 is less likely to occur, and the occurrence of defective products such as dents generated on the surface of the resin molded product 57 is reduced and injection is performed. A resin molded product 57 in which the transfer layer is transferred simultaneously with molding can be produced. If air ions are supplied to the atmosphere in the mold of the injection mold 11 using a static eliminator, the charge amount of the transfer sheet 55 can be further reduced.

  If the antistatic sheet 60 is made of the same material as that of the base sheet, the charge rates of the antistatic sheet 60 and the base sheet are the same. Therefore, the generation of static electricity due to peeling charging when the transfer sheet 55 is released from the parting surface 20 can be reduced with a simple configuration.

  When the base sheet before contacting the parting surface 20 is charged to the positive electrode in the antistatic sheet 60, a material located on the positive electrode side of the base sheet in the charging train is used. In the case where the base sheet before contacting the cutting surface 20 is charged to the negative electrode, the transfer sheet 55 can be contacted from the parting surface 20 by using a material positioned on the negative electrode side of the base sheet in the charging train. At the time of release, the polarity charged normally by the peeling charge and the polarity charged on the transfer sheet 55 become opposite and repel each other, so the charge amount of the transfer sheet 55 is positively reduced. Therefore, generation of static electricity due to peeling charging can be effectively reduced.

  FIG. 5 is a front view (1) showing a schematic configuration of a movable mold of an injection mold according to the second embodiment of the present invention, and (2) is shown by (1). It is sectional drawing of a VV line. FIG. 3 is a diagram corresponding to FIG. 2 of the first embodiment. Since the basic configuration is the same as that of the injection mold 11 according to the first embodiment, different points will be described.

  Referring to FIG. 5, in the first embodiment, the antistatic sheet 60 is stuck outward from the movable mold side insert 22, but the injection mold 61 according to the second embodiment. Then, the antistatic sheet 70 is affixed including the movable side nest 22 part excluding the cavity surface 23. In other words, the antistatic sheet 70 is affixed to the entire surface of the parting surface 20 with which the transfer sheet 55 contacts, except for the cavity surface 23, where the transfer sheet 55 overlaps with the contacted transfer sheet 55 as viewed from the mold clamping direction. . With this configuration, the transfer sheet 55 and the movable parting surface 20 are not in contact with each other, and the antistatic sheet 70 is in contact with each other. Therefore, it is possible to effectively reduce the amount of static electricity due to peeling charging when the transfer sheet 55 is released from the parting surface 20.

  In each of the above embodiments, the transfer sheet feeding device is installed on the movable mold side and the transfer sheet is contacted and released from the movable mold side. However, the transfer sheet is contacted and released from the parting surface. If the antistatic sheet is attached, the transfer sheet feeding device may be installed on the fixed mold side, and the transfer sheet may be contacted and released from the fixed mold side. May be installed, and separate transfer sheets may be contacted and released from both sides.

  In each of the above embodiments, the antistatic sheet is set to be larger than the width of the transfer sheet. However, the antistatic sheet is pasted to a portion overlapping the transfer sheet as viewed from the mold clamping direction. If so, the antistatic sheet may be smaller than the width of the transfer sheet. Alternatively, an antistatic sheet may be partially attached such that it is attached only above the insert and not attached below the insert. The predetermined area is such a magnitude that the charge amount of the peeling charge on the parting surface with which the transfer sheet and the transfer sheet come into contact changes depending on the presence or absence of the antistatic sheet.

  Further, in each of the above embodiments, the transfer sheet is sent in the vertical direction, but the transfer sheet may be sent in other directions such as the horizontal direction as long as it is along the parting surface.

  Furthermore, in each of the above embodiments, a one-color molding machine using one type of resin is used. However, if a resin molded product to which a transfer layer is transferred simultaneously with injection molding can be manufactured, A multicolor molding machine such as a two-material molding machine using various types of resins may be used.

1 is a side view showing a schematic configuration of a simultaneous molding and transfer apparatus to which an injection mold according to a first embodiment of the present invention is applied. (1) is a front view showing a schematic configuration of the movable type shown in FIG. 1, and (2) is a sectional view taken along line II-II shown in (1). It is the schematic which showed the manufacturing process of the resin molded product using the metal mold | die for injection molding shown in FIG. (1) is a diagram showing the relationship between the potential of the transfer sheet and time in the manufacturing process of the resin molded product using the injection mold shown in FIG. 1, and (2) is the (1) It is a figure at the time of adding use of a static eliminator. (1) is a front view showing a schematic configuration of a movable mold of an injection mold according to the second embodiment of the present invention, and (2) is a VV line shown in (1). FIG.

Explanation of symbols

11, 61 Injection mold 17 Fixed mold 18 Movable mold 19, 20 Parting surface 21 Fixed mold side insert 22 Mobile mold side insert 23 Cavity surface 24 Cavity 25 Clamp 55 Transfer sheet 57 Resin molded product 60, 70 Charging Prevention sheet

Claims (5)

A transfer sheet having a transfer layer on a base sheet is fed into a mold, and at the same time as injection molding, an injection mold that can be used for manufacturing a resin molded product to which the transfer layer is transferred,
Fixed type,
A movable mold that forms a cavity with the fixed mold by mold clamping;
A clamp that is provided on at least one of the fixed parting surface and the movable parting surface, and makes the transfer sheet contact and release contact with the provided parting surface;
An antistatic sheet that is affixed to a part of the parting surface that contacts the transfer sheet that overlaps the transfer sheet in contact with the parting surface when viewed from the mold clamping direction, and that can reduce the generation of static electricity due to the contact release of the transfer sheet; A mold for injection molding. The fixed mold includes a fixed mold side nest;
The movable type includes a movable type side insert,
The antistatic sheet is affixed outward from the fixed mold side insert on the fixed parting surface, and the movable side insert on the movable parting surface. The injection mold according to claim 1, which is further affixed outward.   The injection mold according to claim 1 or 2, wherein the antistatic sheet is made of the same material as the base sheet.   When the base sheet before contacting the parting surface is charged to the positive electrode, the antistatic sheet is made of a material positioned on the positive electrode side of the base sheet in the charging train. The injection mold according to claim 1 or 2, wherein when the base sheet before contact is charged to the negative electrode, the base sheet is made of a material positioned on the negative electrode side of the base sheet. A method for producing a resin molded product using the injection mold according to any one of claims 1 to 4,
With the mold open, the step of feeding the transfer sheet into the injection mold,
A step of bringing the transferred transfer sheet into contact with the antistatic sheet by the clamp and arranging the transfer sheet along the cavity surface by suction; and
Clamping the mold in the arranged state to form the cavity;
Injecting molten resin into the formed cavity to form a resin part, and simultaneously transferring a transfer layer to the resin part to mold a resin molded product,
Cooling and solidifying the molded resin molded product;
And a step of releasing the contact of the transfer sheet from the antistatic sheet by the clamp and taking out the resin molded product.

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